Mitofusin2 (MFN2) Preserves Mitochondrial Integrity and Function in Megakaryocytes and Platelets

Abstract Genome wide association studies (GWAS) have associated mitochondria related loci with platelet numbers, function, and CVD. However, causality has not been established for many of these variants, and their mechanism and functional consequences are unknown. One such variant, MFN2 eQTL rs1474868 (T/T), has been associated with reduced platelet counts and reduced expression (5 fold) of MFN2 RNA in platelets. We show here that the MFN2 T/T variant corresponds with significantly reduced MFN2 protein in platelets. This difference contributes to a significant correlation between MFN2 RNA levels and mitochondrial load and potential in platelets. MFN2 RNA is also reduced by T/T in human cord blood derived megakaryocytes resulting in unfused mitochondria and impaired megakaryopoiesis. Using platelet/megakaryocyte specific Mfn2-/- (Mfn2 KO) mice, we show that Mfn2 impacts platelet numbers, activation and function by regulating mitochondrial energetics. Platelets without Mfn2 had reduced mitochondrial membrane potential and significantly reduced platelet lifespan (P<0.01) that was attributed to an increased rate of phosphatidylserine (PS) flipping (P=0.01). Increased RNA expression with conversely reduced protein expression of Ndufb8 (P<0.01), an index nuclear encoded complex I subunit that is stable only in a fully assembled complex I, suggested a defect in complex I assembly in Mfn2 KO platelets. Furthermore, complex I activity was reduced in Mfn2 KO platelets compared to WT platelets (P<0.01). Both basal and thrombin triggered mitochondrial oxygen consumption rate as assessed by Seahorse analyzer was significantly reduced in Mfn2 KO platelets (1.28 pmol/min/µg protein) compared to WT control platelets (3.06 pmol/min/µg protein). Platelet activation was subtly, yet significantly, decreased in Mfn2 KO platelets compared to WT platelets as assessed by surface expression of activated integrin alpha2b/beta3 and P-selectin. In addition, Mfn2 KO platelets had impaired Ca 2+ signaling, ROS generation, and procoagulant platelet formation (PS +ve platelets), and formed fewer platelet-neutrophil aggregates (PNAs) compared to WT platelets (P=0.01). Consistent with this, we observed significantly prolonged bleeding times in Mfn2 KO mice compared to their WT control littermates (P=0.001). Finally, mice with loss of platelet Mfn2 exhibited a modest reduction in ischemic stroke infarct size after cerebral ischemia-reperfusion that was statistically significant (P<0.01). Taken together these results suggest that MFN2 preserves mitochondrial functions necessary for platelet survival and activity, and that loss of MFN2 leads to accelerated platelet death, dysfunction, and altered hemostasis and thrombosis. Disclosures Rondina: Novartis: Research Funding; Platelet Biogenesis: Membership on an entity's Board of Directors or advisory committees; Acticor Biotech: Membership on an entity's Board of Directors or advisory committees; Platelet Transcriptomics: Patents & Royalties.

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Electron leak from NDUFA13 within mitochondrial complex I attenuates ischemia-reperfusion injury via dimerized STAT3

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1704723114 ◽

2017 ◽

Vol 114 (45) ◽

pp. 11908-11913 ◽

Cited By ~ 14

Author(s):

Hengxun Hu ◽

Jinliang Nan ◽

Yong Sun ◽

Dan Zhu ◽

Changchen Xiao ◽

...

Keyword(s):

Molecular Structure ◽

Oxygen Consumption ◽

Complex I ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Ros Generation ◽

Cell Protection ◽

Causative Relationship ◽

R Process ◽

And Function

The causative relationship between specific mitochondrial molecular structure and reactive oxygen species (ROS) generation has attracted much attention. NDUFA13 is a newly identified accessory subunit of mitochondria complex I with a unique molecular structure and a location that is very close to the subunits of complex I of low electrochemical potentials. It has been reported that down-regulated NDUFA13 rendered tumor cells more resistant to apoptosis. Thus, this molecule might provide an ideal opportunity for us to investigate the profile of ROS generation and its role in cell protection against apoptosis. In the present study, we generated cardiac-specific tamoxifen-inducible NDUFA13 knockout mice and demonstrated that cardiac-specific heterozygous knockout (cHet) mice exhibited normal cardiac morphology and function in the basal state but were more resistant to apoptosis when exposed to ischemia-reperfusion (I/R) injury. cHet mice showed a preserved capacity of oxygen consumption rate by complex I and II, which can match the oxygen consumption driven by electron donors ofN,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD)+ascorbate. Interestingly, at basal state, cHet mice exhibited a higher H2O2level in the cytosol, but not in the mitochondria. Importantly, increased H2O2served as a second messenger and led to the STAT3 dimerization and, hence, activation of antiapoptotic signaling, which eventually significantly suppressed the superoxide burst and decreased the infarct size during the I/R process in cHet mice.

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Exome Sequencing in Venous Thromboembolic Disease Identifies Excess Mutation Burden in PROS1, PROC, SERPINC1 and STAB2

Blood ◽

10.1182/blood.v128.22.3794.3794 ◽

2016 ◽

Vol 128 (22) ◽

pp. 3794-3794 ◽

Cited By ~ 4

Author(s):

Karl C. Desch ◽

Ayse Bilge Ozel ◽

Matt Halvorsen ◽

Paula M. Jacobi ◽

Marine Germain ◽

...

Keyword(s):

Exome Sequencing ◽

Board Of Directors ◽

Association Studies ◽

Coagulation Factor ◽

The United States ◽

European Ancestry ◽

P Value ◽

Genome Wide Association Studies ◽

Common Variants ◽

Advisory Committees

Abstract Deep vein thrombosis and pulmonary embolism, collectively referred to as venous thromboembolism (VTE), are the third leading cause of cardiovascular death in the United States. Genetic factors account for 50-60% of VTE risk and a recent meta-analysis of genome-wide association studies confirmed that common variants in F5, ABO, and seven other loci are associated with VTE. Rare mutations in the anticoagulant genes PROC, PROS1 and SERPINC1 have been linked to VTE in family studies. In order to identify new genetic variants altering the risk for VTE, we performed whole exome sequencing (WES) in 373 unrelated individuals of European ancestry with unprovoked VTE and compared results to a previously sequenced control cohort of 5784 unrelated Europeans. To avoid variant calling bias, only SNVs from exons with >10X coverage and less than 5% difference in coverage between cases and controls were included, removing 11,813 of 188,689 intervals. We used an emerging framework for a "collapsing" analysis on genes, defining qualifying variants on the basis of annotation and minor allele frequency <0.05%, and assumed a dominant model of inheritance. Tests were performed via a Fisher's exact test for a total of 11,585 CCDS genes. Strikingly, ranked by p-value, the top 4 genes were PROS1 (P= 2.01E-09, OR 11.8), STAB2 (P=2.70E-7, OR 3.37), PROC (P=3.24E-05, OR 11.0) and SERPINC1 (P=1.10E-04, OR 8.5). We detected 29 qualifying variants in 373 cases and 106 qualifying variants in 5784 controls in STAB2. This gene encodes Stabilin-2, which is a transmembrane glycoprotein scavenger receptor. Common variants at ABO are associated with VTE and are also known to regulate von Willebrand Factor (VWF) and coagulation Factor VIII (F8) plasma levels. Common variants in STAB2 are also associated with VWF/F8 levels in a large GWAS and with VTE risk in a smaller candidate gene study, suggesting that haploinsufficiency for Stabilin-2 may increase VTE risk through elevated levels of VWF/F8. Although replication and functional testing of these findings is warranted, this study demonstrates the utility of collapsing analyses using WES data to identify multiple loci harboring an excess of rare variants in individuals with a common complex disease trait. Disclosures Ginsburg: Shire: Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties: recombinant VWF and recombinant ADAMTS13; Portola Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees.

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P0536HYPOTHERMIA DURING RENAL ISCHEMIA-REPERFUSION IN MICE: A PROTECTIVE EFFECT ON RENAL AND MITOCHONDRIAL FUNCTIONS

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfaa142.p0536 ◽

2020 ◽

Vol 35 (Supplement_3) ◽

Author(s):

Maxime Schleef ◽

Delphine Baetz ◽

Bruno Pillot ◽

Christelle Leon ◽

Noelle Gallo-Bona ◽

...

Keyword(s):

Renal Function ◽

Complex I ◽

Mild Hypothermia ◽

Ischemia Reperfusion ◽

Renal Ischemia ◽

Serum Urea ◽

Mitochondrial Stress ◽

Urea Level ◽

Mitochondrial Functions ◽

Significant Difference

Abstract Background and Aims Renal ischemia reperfusion (RIR) can induce mitochondrial stress triggering cell death and eventually leading to acute kidney injury (AKI). It has been suggested that mild hypothermia could be protective in RIR without clear underlying mechanisms. We aimed to show that mild hypothermia (34°C) during RIR protects renal mitochondrial function and prevents AKI. Method Male C57BL6 mice were assigned to 4 groups: normothermic ischemic (RIR-37°C) group (n=14) and hypothermic ischemic (RIR-34°C) group (n=14) with body temperature maintained at respectively 37°C or 34°C during 20 minutes of renal ischemia by bilateral renal clamping under general anesthesia; normothermic sham (Sham-37°C) group (n=10) and hypothermic sham (Sham-34°C) group (n=10) with only anesthesia and laparotomy at 37°C or 34°C respectively. Renal function (serum urea concentration) and isolated renal mitochondria function (capacity of mitochondria to retain calcium i.e. calcic retention capacity (CRC), and oxidative phosphorylation capacity of electron transport chain complexes (complex I, II and IV)) were assessed 2 hours and 24 hours after reperfusion. All animal procedures were approved by local Ethics Committee. Data are presented as median with IQR. Results All the parameters monitored were not modified by the temperature in the sham groups, and there was no mortality in those 2 groups. Mortality was 33% in the RIR-37°C group and 11% in the RIR-34°C group 24 hours after reperfusion (p=0.58). Renal ischemia was responsible for a significant increase of serum urea level 2 hours after reperfusion at 37°C [18.7 (17.3–19.0) mmol/L] compared to sham groups (p=0.02), whereas no significant increase was observed in the RIR-34°C group. After 24 hours of reperfusion serum urea level was improved in the RIR-34°C group [22.7 (11.5–42.0) mmol/L] compared to RIR-37°C [60.8 (58.0–69.7) mmol/L, p=0.001]. CRC was not modified by RIR after 2 hours of reperfusion in both groups. CRC was preserved 24 hours after reperfusion in the RIR-34°C group [260 (210–320) nmol Ca2+/mg protein] with no difference compared to Sham-37°C [320 (280–360) nmol Ca2+/mg protein p=0.18] whereas CRC was significantly decreased in the RIR-37°C group compared to Sham-37°C [120 (0–130) vs 320 (280–360) nmol Ca2+/mg protein p=0.004). Complexes I, II and IV were lowered after 2 hours of reperfusion in the RIR-37°C group (p<0.05), and complexes II and IV activities remained altered 24 hours after reperfusion, compared to Sham-37°C (p=0.009 and p=0.02 respectively). In the RIR-34°C group, complexes I, II and IV activities were preserved 2 hours after reperfusion but complex I activity decreased 24 hours after reperfusion. We found significant difference between complexes II and IV activities between IRI-34°C and RIR-37°C. Conclusion Mild hypothermia (34°C) during RIR significantly protected renal mitochondrial respiration and mitochondrial stress, associated with a preserved renal function after 2 hours of reperfusion and an improved renal function 24 hours after reperfusion compared to normothermic mice (37°C).

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Evaluation of Health Related Questionnaire Among Mycosis Fungoides and Lymphomatoid Papulosis

Blood ◽

10.1182/blood.v126.23.5603.5603 ◽

2015 ◽

Vol 126 (23) ◽

pp. 5603-5603 ◽

Cited By ~ 1

Author(s):

Rakhshandra Talpur ◽

Iris Wieser ◽

Casey Wang ◽

Lyons Genevieve ◽

Madeleine Duvic

Keyword(s):

Quality Of Life ◽

Board Of Directors ◽

Mycosis Fungoides ◽

Research Funding ◽

Brentuximab Vedotin ◽

Function Score ◽

Advisory Committees ◽

Significant Difference ◽

And Function

Abstract INTRODUCTION AND OBJECTIVES: Mycosis Fungoides (MF) andlymphomatoid papulosis (LyP) are relatively rare and itchy skin disorders. The cosmetic disfigurement and severe pruritus dramatically affects the patient's quality of life. The focus is to examine the validity and reliability of the skindex-29, M.D. Anderson symptom inventory (MDASI) and itch-related quality of life (IQOL) questionnaire in 62 patients in a phase II trial of Brentuximab Vedotin. MATERIALS AND METHODS: Patients completed survey questionnaires related to symptoms and quality-of-life several times over the course of Brentuximab Vedotin. We compared patients' baseline scores to their end-of-study (EOS) scores. Patients were grouped by diagnosis into Mycosis Fungoides and Lymphomatoid papulosis group. Questionnaires included skindex-29, focusing on the skin conditions the patient was bothered the most. (MDASI) for patients with cancer and following the symptoms of cancer and the itchy quality of life (I-QoL) questionnaire was developed to measure the symptoms associated with cancer therapeutic agents and their effect on daily activities. Scoring for the Skindex-29, M. D. Anderson Symptom Inventory (MDASI) and the Quality of Life (QOL) survey were done according to the questionnaire specific scoring guide. Responses were compared between 2 groups using the Wilcoxon rank-sum test. RESULTS Questionnaires from 62 patients (23 LyP and 39 MF) were studied at baseline and end of study. Patients were 33 males and 29 females with median age of 60 years (range: 27-86 years). The median overall survival (OS) was significant P = 0.041, when comparing patients with MF to LyP. The median survival time for patients from time of diagnosis with MF was 14.66 years and LyP was not reached. There was no significant difference in progression free survival (PFS) between MF and LyP. The median number of Brentuximab Vedotin cycles was 7 (1-19). Skindex-29 scales, showed change in emotion scale and function scale from baseline to EOS, both groups had a decrease, patients with LyP had a larger decrease in emotion score (P = 0.069) and function score (P =0.096) over the course of the study. There was no difference in the symptom scale from baseline to EOS. The patients with LyP had a larger decrease in function score from baseline to EOS. When comparing patients with MF to those with LyP for MDASI, there is no evidence of a difference, from baseline to EOS, in either symptom severity or symptom interference in daily life. In the IQOL when comparing the LyP patients' QOL responses from baseline to EOS, did not show significant difference. Table 1. Change in Skindex-29 scales, by group Skindex Scale MF LYP p-value Change from baseline to end-of-study: N Median Min Max N Median Min Max Emotion 35 -10 -65 35 20 -22.50 -61.94 12.5 0.0698 Symptoms 35 -7.14 -46.43 42.86 20 -10.71 -53.57 28.57 0.4782 Function 35 -2.08 -50.38 27.08 20 -16.29 -44.70 14.58 0.0962 Table 2. Change in MDASI scales, by Diagnosis MDASI Scale Item MF LYP p-value Change from baseline to end-of-study: N Median Mean Std. Dev Range N Median Mean Std. Dev Range Severity 35 0.23 0.18 1.96 (-5.85, 3.15) 21 0.38 0.46 1.61 (-1.69, 5.0) 0.9595 Interference 35 0.17 0.06 3.07 (-9.17, 5.17) 19 0.0 0.11 1.59 (-3.0, 4.67) 0.6764 CONCLUSIONS A significant improvement in emotions and functional part of skindex-29 was observed when comparing patients with MF to patients with LyP. While both groups had a decrease, the patients with LyP had a larger decrease in emotion and function score over the course of the study. Disclosures Duvic: Celgene: Membership on an entity's Board of Directors or advisory committees; Rhizen Pharma: Research Funding; Allos (spectrum): Research Funding; Therakos: Research Funding, Speakers Bureau; Soligenics: Research Funding; Huya Bioscience Int'l: Consultancy; Spatz Foundation: Research Funding; MiRagen Therapeutics: Consultancy; Eisai: Research Funding; Seattle Genetics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncoceutics: Research Funding; Array Biopharma: Consultancy; Cell Medica Ltd: Consultancy; Tetralogics SHAPE: Research Funding; Innate Pharma: Research Funding; Kyowa Hakko Kirin, Co: Membership on an entity's Board of Directors or advisory committees, Research Funding.

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Understanding PITX2-dependent Atrial Fibrillation Mechanisms through Computational Models

10.20944/preprints202106.0541.v1 ◽

2021 ◽

Author(s):

Jieyun Bai ◽

Yaosheng Lu ◽

Yijie Zhu ◽

Huijin Wang ◽

Dechun Yin ◽

...

Keyword(s):

Atrial Fibrillation ◽

Computational Models ◽

Association Studies ◽

Basic Research ◽

Genome Wide Association Studies ◽

Gene Coding ◽

Patient Health ◽

Quantitative Understanding ◽

Whole Heart ◽

And Function

Atrial fibrillation (AF) is a common arrhythmia. Better prevention and treatment of AF are needed to reduce AF-associated morbidity and mortality. Several major mechanisms cause AF in patients, including a genetic predisposition to develop AF. Genome-wide association studies have identified genetic variants associated with AF populations, with the strongest hits clustering on chromosome 4q25, close to the gene coding for the homeobox transcription PITX2. Because of the inherent complexity of the human heart, experimental and basic research on PITX2-dependent AF is not sufficient for understanding atrial functional proprieties. Linking PITX2 to ion channels, cells, tissues, atria and the whole heart, computational models are necessary for achieving a quantitative understanding of atrial structure and function in PITX2-dependent AF. Computational approaches are used to capture all that we know about PITX2-dependent AF and to develop improved therapies. In the present review, we discuss advances in atrial modelling and focus on the mechanistic links between PITX2 and AF. Challenges in applying models for improving patient health are described, as well as a summary of future perspectives.

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Exome Array Analyses Identify Low-Frequency Germline Variants Associated with Increased Risk of AML in a HLA-Matched Unrelated Donor Blood and Marrow Transplant Population

Blood ◽

10.1182/blood.v128.22.42.42 ◽

2016 ◽

Vol 128 (22) ◽

pp. 42-42

Author(s):

Alyssa I. Clay ◽

Theresa Hahn ◽

Qianqian Zhu ◽

Li Yan ◽

Leah Preus ◽

...

Keyword(s):

Board Of Directors ◽

Research Funding ◽

De Novo ◽

Association Studies ◽

Low Frequency ◽

Hematologic Malignancies ◽

Unrelated Donor ◽

Advisory Committees ◽

De Novo Aml ◽

Normal Cytogenetics

Abstract Both genome wide association studies (GWAS) of common variation and exome wide association studies (EXWAS) of rare variation have successfully identified disease susceptibility variants for a variety of diseases. One GWAS of inherited susceptibility to Acute Myeloid Leukemia (AML) has been conducted, but no EXWAS have been performed to measure risk of AML attributable to low-frequency constitutional genetic variation. We performed the first EXWAS of risk of AML as a nested case-control study in the DISCOVeRY-BMT (Determining the Influence of Susceptibility Conveying Variants Related to one-Year mortality after BMT) cohorts. The DISCOVeRY-BMT parent study examined transplant-related mortality in leukemia patients undergoing unrelated donor allogeneic BMT. To identify low frequency variants and genes contributing to increased susceptibility to AML we used genotype data from the Illumina HumanExome BeadChip typed in the DISCOVeRY-BMT cohorts; the HumanExome BeadChip contains 242,901 variants, which are mainly protein-coding variants. The optimal sequence kernel association test (SKAT-O) was used to analyze gene-level associations with risk of AML. These gene-based tests evaluate the cumulative effects of multiple single gene variants on risk of AML. Analyses were performed in all European American AML cases and two subtypes: 1) de novo AML, 2) de novo AML with normal cytogenetics. Models were adjusted for age at transplant and principal components to control for population stratification. For gene-based tests at least 2 variants with minor allele frequency (MAF) ≤ 5%, were required to be present in the gene. This yielded a total of 13,687 genes tested, and a Bonferroni corrected significance level of P<3.65 x 10-6. Association tests were performed in 1,189 AML cases reported to CIBMTR 2000-08 (Cohort 1) and 327 AML cases reported to CIBMTR from 2009-11 (Cohort 2). Controls in Cohorts 1 (n=1,986) and 2 (n= 515) were 10/10 HLA-matched unrelated donors who passed a comprehensive medical exam and deemed healthy. We used metaSKAT to combine Cohorts 1 and 2 and obtain p-values of association with AML. We present the results of gene-level tests significant in both cohorts. The likely pathogenicity of these variants was determined in silico using SIFT, PolyPhen and MutationTaster. Patient characteristics are in Table 1. DNMT3A, on chromosome 2, was associated in the gene-based test with risk of AML (Pmeta=1.70x10-9, Table 2). Three missense variants at MAF <1% comprise both overall AML and de novo AML gene-based association: exm177559 (Asn->Ser), exm177507 (Arg->His), and exm177543 (Arg->Trp). Normal cytogenetics de novo AML gene-based assocations consisted of only 2 of these variants: exm177559 and exm177507 (Table 2). While prevalence of exm177507 is <1% for all AML cases, in de novo AML with normal cytogenetics the MAF was higher at 3%. The other 2 variants had a MAF<1% irrespective of subtype. Somatically, DNMT3A is most frequently mutated in hematologic malignancies, with >30% of de novo AML cases with a normal karyotype and >10% of MDS patients having DNMT3A mutations. Although these are germline gene associations all three of the variants found have been reported somatically in hematologic malignancies. In 200 AML cases from The Cancer Genome Atlas (TCGA) p.R882H (represented as exm177507 on the exome chip) was a frequent somatic mutation (25%). Exm177543 (p.R635W) and exm177559 (p.N501S) are reported in the Catalogue of Somatic Mutations in Cancer (COSMIC) as somatic mutations involved in hematopoietic and lymphoid tissue in both cell lines and humans. Exm177507 and exm177543 show evidence of pathogenicity in all three in silico tools, while exm177559 was reported as deleterious and disease causing by Sift and MutationTaster, respectively. Our results show that multiple potentially pathogenic missense germline variants in DNMT3A comprise the gene-based association with AML, specifically de novo AML with normal cytogenetics. Given the functional nature of these variants it is possible germline risk stratification could be informative in determining AML risk, and subsequently development of AML harboring DNMT3A mutations. Confirmation of these findings in additional cohorts could have implications for individualized risk screening, prediction and prognosis. Additional cytogenetic subgroup analyses, including treatment-related AML, are underway. Disclosures Hahn: Novartis: Equity Ownership; NIH: Research Funding. McCarthy:Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Onyx: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; The Binding Site: Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Honoraria, Membership on an entity's Board of Directors or advisory committees; Gamida Cell: Honoraria, Membership on an entity's Board of Directors or advisory committees. Sucheston-Campbell:NIH/NCI: Research Funding.

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Geriatric Impairments and Low Muscle Mass Are Associated with Treatment Discontinuation and Overall Survival in Newly Diagnosed Non-Transplant Eligible Multiple Myeloma Patients (nte-NDMM) Treated with Dose-Adjusted Melphalan-Prednisone-Bortezomib (MPV) — Results of the Dutch HOVON 123 Study

Blood ◽

10.1182/blood-2018-99-116920 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1889-1889 ◽

Cited By ~ 3

Author(s):

Claudia A.M. Stege ◽

Kazem Nasserinejad ◽

Mark-David Levin ◽

Saskia K. Klein ◽

Esther de Waal ◽

...

Keyword(s):

Skeletal Muscle ◽

Board Of Directors ◽

Muscle Mass ◽

Muscle Function ◽

Research Funding ◽

Prediction Models ◽

Advisory Committees ◽

Frail Patients ◽

Unfit Patients ◽

And Function

Abstract Introduction There is a high rate of treatment discontinuation (TD) in elderly patients with nte-NDMM, that negatively impacts overall survival (OS). In order to prevent TD identification of unfit and frail patients is a prerequisite, either to withhold or adapt treatment. Although the IMWG frailty score (IMWG-FS) identifies frail patients with higher TD and inferior OS there is a need for refinement. Therefore, we prospectively evaluated the feasibility of a dose-adjusted Melphalan-Prednisone-Bortezomib (MPV) regimen in nte-NDMM patients ≥75 years of age. In addition, we investigated the prognostic value of a geriatric assessment (GA) and muscle mass and function for TD and OS. This is a preliminary analysis of 220/240 included patients. A final update, including multivariable prediction models, of 240 patients will be available at the ASH meeting. Methods Patients were treated with 9 cycles of MPV: M 6 mg/m2, day 1-4; P 30 mg/m2, day 1-4; and V 1.3 mg/m2 day 1,8,15 and 22 of a 35-day cycle. Functional, cognitive, mental health, nutritional status and comorbidities were assessed at baseline (Table 1). Muscle mass and function were determined by CT scan and hand grip strength (HGS) and gait speed (GS), respectively. Presarcopenia was defined as low skeletal muscle mass (Skeletal Muscle Index (SMI) cm/m2) only, sarcopenia when additionally low muscle function (HGS or GS) was present, and severe sarcopenia when all 3 parameters were abnormal. Cut offs for muscle mass parameters were defined by sex-specific p5 and p10 values reported in the literature and a Bayesian statistical change point model. Associations between TD or OS and aforementioned factors were assessed via univariable regression models. Multivariable prediction models will be developed using variable selection procedures. Results 218/220 patients were eligible for frailty analysis; 61% frail, 28% unfit and 3% fit patients (7% unknown), according to IMWG-FS. Median follow-up was 22 months (inter quartile range (IQR) 15-32). TD within 9 cycles of MPV was 44%, being significantly higher in frail as compared to unfit patients (51% vs 29%, hazard ratio (HR) 2.52, 95% confidence interval (CI) 1.32-4.80, p=0.005, Fig. 1A). Overall response rate and median progression free survival were 74% and 17 months (IQR 12-22 months), both unaffected by frailty. Median OS was 45 months. Frail patients had a significant inferior OS as compared to unfit patients (median 31 versus 45 months, HR 2.13, 95% CI 1.21-3.76, p=0.009) (Fig. 1b). Frail patients were older, had significantly more comorbidities, lower physical function (both self-reported [EORTC QoL questionnaire and (i)ADL] and by physical examination [GS and HGS]), worse cognitive function, and more depression and malnutrition as compared to unfit patients (Table 1). Low muscle mass was detected in 13-22% of frail (depending on cut off) versus 5% of unfit patients. Sarcopenia was detected in 13-18% of frail (depending on cut off) and 5% of unfit patients. These data indicate that there are biological differences between unfit and frail patients. Subsequently, we investigated which GA and sarcopenia characteristics were associated with TD and OS. For TD, all IMWG-FS parameters but ADL, WHO ISS 3, muscle mass, depression and risk for malnutrition were associated (table 2). For OS all IMWG-FS parameters, WHO ISS 3, cytogenetic risk, muscle mass, depression, (risk of) malnutrition and cognitive function were associated (table 2). Interestingly, although there was a strong association between muscle mass as determined by CT-scan and both TD and OS, muscle function tests (HGS and GS) were not. Neither were sarcopenia definitions incorporating muscle function. Remarkably, self-reported physical functioning revealed from the QLQ-C30 was associated with TD and OS. Conclusion We here confirm the predictive value of the IMWG-FS for TD and OS. Importantly, we provided a biological background of frailty by showing more geriatric impairments and loss of muscle mass in frail versus unfit patients. In addition to known predictive factors for OS; IMWG-FS, ISS and cytogenetics, we found that GA and low muscle mass, but not muscle function, were associated with clinical outcome. We are currently developing a novel predictive scoring system for TD and OS incorporating these novel parameters, with the aim to refine currently available prediction models for identification of elderly patients who will benefit from therapy. Disclosures Levin: Celgene: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Minnema:Servier: Consultancy; Amgen: Consultancy; Takeda: Consultancy; Celgene: Consultancy, Research Funding; Janssen: Consultancy. van de Donk:Janssen Pharmceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Research Funding; Novartis: Research Funding; Bristol-Myers Squibb: Research Funding; Celgene: Research Funding. Sonneveld:Karyopharm: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; BMS: Honoraria, Research Funding. Zweegman:Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene Corp.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding.

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NADPH Oxidase Activation and Endothelial Nitric Oxide Synthase Uncoupling Contribute to Endothelial Dysfunction in Antiphospholipid Syndrome

Blood ◽

10.1182/blood.v126.23.4639.4639 ◽

2015 ◽

Vol 126 (23) ◽

pp. 4639-4639

Author(s):

Meifang Wu ◽

Suman Kundu ◽

Keith R. McCrae

Keyword(s):

Endothelial Cells ◽

Endothelial Dysfunction ◽

Nadph Oxidase ◽

Board Of Directors ◽

Conditioned Medium ◽

Antiphospholipid Syndrome ◽

Ros Generation ◽

Advisory Committees ◽

Nitrative Stress ◽

Enos Uncoupling

Abstract Introduction: Antiphospholipid syndrome (APS) is characterized by thrombosis and/or recurrent fetal loss in the presence of persistently elevated antiphospholipid antibodies (APLA). The majority of pathologic APLA are directed against β2-glycoprotein I (β2GPI). APLA cause endothelial dysfunction, though the underlying mechanisms have not been clearly delineated. Methods: Endothelial cells (EC) were incubated with β2GPI and either control antibodies or anti-β2GPI antibodies affinity-purified from sera of patients with APS, in the absence or presence of diapocynin, an NADPH oxidase (NOX) inhibitor, or siRNA against NOX1, NOX2, or NOX4. Generation of reactive oxygen species (ROS) in EC and conditioned medium were measured using fluorescent dyes (CM-H2DCFDA and CellROX Deep Red) or chemiluminescent substrate. NOX1, NOX2, NOX4, 3-nitrotyrosine, and thioredoxin reductase 1 (TrxR1) expression were analyzed by western blot. eNOS monomer and dimer were detected using cold (4°C) SDS-PAGE and immunoblot. Immunoprecipitation of TrxR1 was performed using protein A/G agarose. EC activation was assessed by measuring expression of E-selectin. Results: Incubation of EC with β2GPI and anti-β2GPI antibodies stimulated ROS generation in EC, as well as the release of ROS into conditioned medium. Expression of NOX2, but not NOX1 or NOX4, was significantly increased in EC exposed to anti-β2GPI antibodies, but not control IgG. Preteatment of endothelial cells with diapocynin, a NOX inhibitor, or siRNA against NOX2 and NOX4, but not NOX1, inhibited endothelial cell activation by anti-β2GPI antibodies. Furthermore, anti-β2GPI antibody-treated EC generated more peroxynitrite, as determined by 3-nitrotyrosine expression. Treatment of EC with anti-β2GPI antibodies increased eNOS monomer/dimer ratio, suggesting eNOS uncoupling. Compared to control human IgG, the TrxR1 immunoprecipitate from EC treated with β2GPI and anti-β2GPI antibodies contained more 3-nitrotyrosine level, suggesting TrxR1 tyrosine residue modification by nitration and possible loss of function. Conclusions: β2GPI and anti-β2GPI antibodies stimulate ROS generation in EC, with release into the conditioned medium. The impairment of EC activation by diapocynin, NOX2 siRNA, or NOX4 siRNA suggests that NOX mediate EC activation by anti-β2GPI antibodies. Anti-β2GPI antibodies induce nitrative stress in EC, which might be explained by eNOS uncoupling induced by these antibodies. The nitration of TrxR1, an enzyme that prevents eNOS uncoupling, may result in the inactivation of TrxR1 and contribute to eNOS uncoupling. Taken together, these studies provide preliminary evidence of the contribution of NOX activation and eNOS uncoupling in mediating oxidative and nitrative stress and induction of EC dysfunction by APLA. Disclosures McCrae: Janssen: Membership on an entity's Board of Directors or advisory committees; Syntimmune: Consultancy; Momenta: Consultancy; Halozyme: Membership on an entity's Board of Directors or advisory committees.

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Candidate Genes for Age at Menarche Are Associated With Uterine Leiomyoma

Frontiers in Genetics ◽

10.3389/fgene.2020.512940 ◽

2021 ◽

Vol 11 ◽

Author(s):

Irina Ponomarenko ◽

Evgeny Reshetnikov ◽

Alexey Polonikov ◽

Irina Verzilina ◽

Inna Sorokina ◽

...

Keyword(s):

Candidate Genes ◽

Uterine Leiomyoma ◽

Association Studies ◽

Pubertal Development ◽

Reproductive Organs ◽

Age At Menarche ◽

Genome Wide Association Studies ◽

Induced Abortions ◽

Trait Locus ◽

And Function

Age at menarche (AAM) is an important marker of the pubertal development and function of the hypothalamic–pituitary–ovarian system. It was reported as a possible factor for a risk of uterine leiomyoma (UL). However, while more than 350 loci for AAM have been determined by genome-wide association studies (GWASs) to date, no studies of these loci for their association with UL have been conducted so far. In this study, we analyzed 52 candidate loci for AAM for possible association with UL in a sample of 569 patients and 981 controls. The results of the study suggested that 23 out of the 52 studied polymorphisms had association with UL. Locus rs7759938 LIN28B was individually associated with the disease according to the dominant model. Twenty loci were associated with UL within 11 most significant models of intergenic interactions. Nine loci involved in 16 most significant models of interactions between single-nucleotide polymorphism (SNP), induced abortions, and chronic endometritis were associated with UL. Among the 23 loci associated with UL, 16 manifested association also with either AAM (7 SNPs) or height and/or body mass index (BMI) (13 SNPs). The above 23 SNPs and 514 SNPs linked to them have non-synonymous, regulatory, and expression quantitative trait locus (eQTL) significance for 35 genes, which play roles in the pathways related to development of the female reproductive organs and hormone-mediated signaling [false discovery rate (FDR) ≤ 0.05]. This is the first study reporting associations of candidate genes for AAM with UL.

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Genome-wide association studies of brain structure and function in the UK Biobank

10.1101/178806 ◽

2017 ◽

Cited By ~ 9

Author(s):

Lloyd T. Elliott ◽

Kevin Sharp ◽

Fidel Alfaro-Almagro ◽

Sinan Shi ◽

Karla Miller ◽

...

Keyword(s):

Brain Imaging ◽

Brain Structure ◽

Association Studies ◽

Structure And Function ◽

Genome Wide Association ◽

Genome Wide Association Studies ◽

Uk Biobank ◽

Genome Wide ◽

Brain Structure And Function ◽

And Function

SummaryThe genetic basis of brain structure and function is largely unknown. We carried out genome-wide association studies of 3,144 distinct functional and structural brain imaging derived phenotypes in UK Biobank (discovery dataset 8,428 subjects). We show that many of these phenotypes are heritable. We identify 148 clusters of SNP-imaging associations with lead SNPs that replicate at p<0.05, when we would expect 21 to replicate by chance. Notable significant and interpretable associations include: iron transport and storage genes, related to changes in T2* in subcortical regions; extracellular matrix and the epidermal growth factor genes, associated with white matter micro-structure and lesion volume; genes regulating mid-line axon guidance development associated with pontine crossing tract organisation; and overall 17 genes involved in development, pathway signalling and plasticity. Our results provide new insight into the genetic architecture of the brain with relevance to complex neurological and psychiatric disorders, as well as brain development and aging. The full set of results is available on the interactive Oxford Brain Imaging Genetics (BIG) web browser.

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