Two missense mutations identified in venous thrombosis patients impair the inhibitory function of the protein Z dependent protease inhibitor

2012 ◽  
Vol 107 (05) ◽  
pp. 854-863 ◽  
Author(s):  
Nigel P. Birch ◽  
Peter J. Browett ◽  
Paul B. Coughlin ◽  
Anita J. Horvath ◽  
Neil S. Van de Water ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Venous Thrombosis ◽  
Nonsense Mutation ◽  
Healthy Controls ◽  
Missense Mutations ◽  
Wild Type ◽  
Protein Z ◽  
Inhibitory Function

SummaryProtein Z-dependent protease inhibitor (ZPI) is a plasma inhibitor of factor (F)Xa and FXIa. In an earlier study, five mutations were identified within the ZPI gene of venous thrombosis patients and healthy controls. Two of these were nonsense mutations and three were missense mutations in important regions of the protein. Here we report that two of these latter three mutations, F145L and Q384R, impair the inhibitory function of ZPI in vitro. Recombinant wild-type and mutant proteins were prepared; stability in response to thermal challenge was similar. Inhibition of FXa in the presence of the cofactor protein Z was reduced 68-fold by the Q384R mutant; inhibition of FXIa by the F145L mutant was reduced two- to three-fold compared to the wild-type ZPI. An analysis of all five ZPI mutations was undertaken in a cohort of venous thrombosis patients (n=550) compared to healthy controls (n=600). Overall, there was a modest increase in incidence of these mutations in the thrombosis group (odds ratio 2.0, 1.05–3.7, p=0.044). However, in contrast to W324X (nonsense mutation), the Q384R missense mutation and R88X nonsense mutation were evenly distributed in patients and controls; F145L was rare. The final mutation (S143Y) was also rare and did not significantly alter ZPI function in laboratory studies. The F145L and particularly the Q384R mutation impaired the function of the coagulation inhibitor ZPI; however, there was no convincing association between these mutations and venous thrombosis risk. The functional role for ZPI in vivo has yet to be clarified.

scholarly journals Mesenchymal stem cells express serine protease inhibitor to evade the host immune response

Blood ◽  
2011 ◽  
Vol 117 (4) ◽  
pp. 1176-1183 ◽  
Author(s):  
Najib El Haddad ◽  
Dean Heathcote ◽  
Robert Moore ◽  
Sunmi Yang ◽  
Jamil Azzi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
T Cell ◽  
Protease Inhibitor ◽  
Serine Protease ◽  
Serine Protease Inhibitor ◽  
Cytotoxic T Cell ◽  
Wild Type

Abstract Clinical trials using mesenchymal stem cells (MSCs) have been initiated worldwide. An improved understanding of the mechanisms by which allogeneic MSCs evade host immune responses is paramount to regulating their survival after administration. This study has focused on the novel role of serine protease inhibitor (SPI) in the escape of MSCs from host immunosurveillance through the inhibition of granzyme B (GrB). Our data indicate bone marrow–derived murine MSCs express SPI6 constitutively. MSCs from mice deficient for SPI6 (SPI6−/−) exhibited a 4-fold higher death rate by primed allogeneic cytotoxic T cells than did wild-type MSCs. A GrB inhibitor rescued SPI6−/− MSCs from cytotoxic T-cell killing. Transduction of wild-type MSCs with MigR1-SPI6 also protected MSCs from cytotoxic T cell–mediated death in vitro. In addition, SPI6−/− MSCs displayed a shorter lifespan than wild-type MSCs when injected into an allogeneic host. We conclude that SPI6 protects MSCs from GrB-mediated killing and plays a pivotal role in their survival in vivo. Our data could serve as a basis for future SPI-based strategies to regulate the survival and function of MSCs after administration and to enhance the efficacy of MSC-based therapy for diseases.

scholarly journals APR-246 Reveals a Therapeutic Potential Via Triggering Different Cell Death Mechanisms in Diffuse Large B Cell Lymphoma

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3521-3521
Author(s):  
Yuheng Hong ◽  
Tianyuan Ren ◽  
Xiaoxuan Wang ◽  
Kai Fu ◽  
Xianhuo Wang ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Missense Mutations ◽  
Wild Type ◽  
Tp53 Mutations ◽  
Large B Cell Lymphoma ◽  
Large B Cell

Abstract Background: Diffuse large B cell lymphoma (DLBCL) is the most common lymphoid malignancy and is characterized by its pronounced genetic and clinical heterogeneity. Although the first-line therapy (R-CHOP) improves the curability of patients with DLBCL, nearly 40% remainder ultimately undergo relapsed or refractory disease. Emerging evidence has shown that TP53 mutations correlate with the recurrence and progression of DLBCL. APR-246, also known as PRIMA-1MET, can reactivate the trans-activation of TP53 mutants by facilitating their DNA binding to target genes, making it a promising therapeutic compound for mutated TP53 carcinomas. Although APR-246 in combination with other chemicals has been applied in clinical trials for non-Hodgkin lymphoma (NHL), the efficacy and the underlying molecular mechanisms of APR-246 on DLBCL remain unclear. The arms are to investigate the TP53 mutations and the correlation of mutated TP53 with the prognosis. Furthermore, we evaluated the effect of APR-246 on DLBCL in vitro and in vivo. Methods: Multiple datasets, including the Gene Expression Omnibus (GEO) and cBioPortal, were searched for available data for DLBCL. For evaluation of APR-246 effect on DLBCL in vitro, ten DLBCL cell lines harbouring different and representative molecular properties, especially distinct TP53 mutation status, were tested. To validate the therapeutic effect of APR-246 in vivo, NSG mice were injected subcutaneously with the DLBCL cells with TP53 mutations to establish a xenograft animal model, and then these mice received the APR-246 administration. The cell viability of DLBCL was measured post addition of APR-246. Pharmaceutical inhibition of different cell death pathways was applied to elucidate the mechanisms by which APR-246 functions. Results: Total 2204 patients with DLBCL were evaluated, of which nearly 15% contained TP53 mutations. The missense mutation of TP53 was up to 76% and mutations occurring in the DNA binding domain (DBD) was about 90%. Patients with TP53 mutations had poor OS (p=0.0118). Further, we found that patients with TP53 mutations in GCB and UNC subtypes exhibited inferior OS (p=0.043; p=0.049, respectively), but no in ABC subtype. Notably, TP53 single mutations located in the DBD (exon 5-8) led to an unfavorable survival (p=0.0263), while patients carrying TP53 multiple mutations and single mutations in other domains exhibited no difference in survival time than those with wild-type TP53. APR-246 induced the cell death in a dose dependent manner for all DLBCL cell lines. DLBCL cells with TP53 missense mutations in the DBD were the most sensitive to APR-246 than those with intact or other types of mutated TP53. APR-246 mediated the cell death via p53-dependent ferritinophagy for DLBCL cells with TP53 missense mutations in the DBD. In addition, APR-246 also induced the ferroptosis for other DLBCL cells harbouring wild type TP53 and other forms of TP53 mutations. Conclusions: Nearly 15% of patients with DLBCL harbouring TP53 mutations had inferior prognosis than those with wild-type TP53. Patients with TP53 single mutations occurred in the DBD (exon 5-8) showed poorer prognosis than those with TP53 multiple mutations and single mutations in other domains. APR-246 induced the cell death of DLBCL through different mechanisms, depend on different forms of TP53 mutations, which provided an evidence for clinical application of APR-246 in the treatment of DLBCL. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

scholarly journals A link between increased transforming activity of lymphoma-derived MYC mutant alleles, their defective regulation by p107, and altered phosphorylation of the c-Myc transactivation domain.

1995 ◽  
Vol 15 (8) ◽  
pp. 4031-4042 ◽  
Author(s):  
A T Hoang ◽  
B Lutterbach ◽  
B C Lewis ◽  
T Yano ◽  
T Y Chou ◽  
...  
Keyword(s):  
Transcriptional Activation ◽  
Cyclin A ◽  
Missense Mutations ◽  
Regulatory Domain ◽  
Wild Type ◽  
Transcriptional Regulatory ◽  
Transforming Activity ◽  
Type C

The c-Myc protein is a transcription factor with an N-terminal transcriptional regulatory domain and C-terminal oligomerization and DNA-binding motifs. Previous studies have demonstrated that p107, a protein related to the retinoblastoma protein, binds to the c-Myc transcriptional activation domain and suppresses its activity. We sought to characterize the transforming activity and transcriptional properties of lymphoma-derived mutant MYC alleles. Alleles encoding c-Myc proteins with missense mutations in the transcriptional regulatory domain were more potent than wild-type c-Myc in transforming rodent fibroblasts. Although the mutant c-Myc proteins retained their binding to p107 in in vitro and in vivo assays, p107 failed to suppress their transcriptional activation activities. Many of the lymphoma-derived MYC alleles contain missense mutations that result in substitution for the threonine at codon 58 or affect sequences flanking this amino acid. We observed that in vivo phosphorylation of Thr-58 was absent in a lymphoma cell line with a mutant MYC allele containing a missense mutation flanking codon 58. Our in vitro studies suggest that phosphorylation of Thr-58 in wild-type c-Myc was dependent on cyclin A and required prior phosphorylation of Ser-62 by a p107-cyclin A-CDK complex. In contrast, Thr-58 remained unphosphorylated in two representative mutant c-Myc transactivation domains in vitro. Our studies suggest that missense mutations in MYC may be selected for during lymphomagenesis, because the mutant MYC proteins have altered functional interactions with p107 protein complexes and fail to be phosphorylated at Thr-58.

scholarly journals Zebrafish mafbb Mutants Display Osteoclast Over-Activation and Bone Deformity Resembling Osteolysis in MCTO Patients

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 480
Author(s):  
Yujie Han ◽  
Weihao Shao ◽  
Dan Zhong ◽  
Cui Ma ◽  
Xiaona Wei ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Cell Differentiation ◽  
Bone Development ◽  
Myeloid Differentiation ◽  
Missense Mutations ◽  
Wild Type ◽  
Bone Deformity ◽  
Tarsal Bones

Multicentric carpotarsal osteolysis (MCTO) is a rare skeletal dysplasia with osteolysis at the carpal and tarsal bones. Heterozygous missense mutations in the transcription factor MAFB are found in patients with MCTO. MAFB is reported to negatively regulate osteoclastogenesis in vitro. However, the in vivo function of MAFB and its relation to MCTO remains unknown. In this study, we generated zebrafish MAFB homolog mafbb mutant utilizing CRISPR/Cas9 technology. Mafbb deficient zebrafish demonstrated enhanced osteoclast cell differentiation and abnormal cartilage and bone development resembling MCTO patients. It is known that osteoclasts are hematopoietic cells derived from macrophages. Loss of mafbb caused selective expansion of definitive macrophages and myeloid cells, supporting that mafbb restricts myeloid differentiation in vivo. We also demonstrate that MAFB MCTO mutations failed to rescue the defective osteoclastogenesis in mafbb−/− embryos, but did not affect osteoclast cells in wild type embryos. The mechanism of MCTO mutations is likely haploinsufficiency. Zebrafish mafbb mutant provides a useful model to study the function of MAFB in osteoclastogenesis and the related MCTO disease.

scholarly journals A tropane-based ibogaine analog rescues folding-deficient SERT and DAT

2020 ◽  
Author(s):  
Shreyas Bhat ◽  
Daryl A. Guthrie ◽  
Ameya Kasture ◽  
Ali El-Kasaby ◽  
Jianjing Cao ◽  
...  
Keyword(s):  
Protein Folding ◽  
Active Metabolite ◽  
Protein Misfolding ◽  
Ring System ◽  
Missense Mutations ◽  
Wild Type ◽  
Structural Requirements ◽  
Underlying Mechanisms

AbstractMissense mutations that give rise to protein misfolding are rare, but collectively, defective protein folding diseases are consequential. Folding deficiencies are amenable to pharmacological correction (pharmacochaperoning), but the underlying mechanisms remain enigmatic. Ibogaine and its active metabolite noribogaine correct folding defects in the dopamine transporter (DAT), but they rescue only a very limited number of folding-deficient DAT mutants, which give rise to infantile Parkinsonism and dystonia. Herein, a series of analogs was generated by reconfiguring the complex ibogaine ring system and exploring the structural requirements for binding to wild type transporters, and for rescuing two equivalent synthetic folding-deficient mutants, SERT-PG601,602AA and DAT-PG584,585AA. The most active tropane-based analog (9b) was also an effective pharmacochaperone in vivo, in Drosophila harboring DAT-PG584,585AA and rescued six out of 13 disease-associated human DAT mutants in vitro. Hence, a novel lead pharmacochaperone has been identified that demonstrates medication development potential for patients harboring DAT mutants.

Significance of distinct specifically enriched missense TP53 mutations in prostate cancer.

2020 ◽  
Vol 38 (6_suppl) ◽  
pp. 377-377
Author(s):  
Irina Vasilevskaya ◽  
Jennifer McCann ◽  
Christopher McNair ◽  
Neermala Poudel Neupane ◽  
Peter Gallagher ◽  
...  
Keyword(s):  
Gene Expression ◽  
Prostate Cancer ◽  
Missense Mutations ◽  
Wild Type ◽  
Gain Of Function ◽  
Expression Arrays ◽  
Mutational Status ◽  
Underlying Mechanisms

377 Background: The most common TP53 alterations are missense mutations occurring in the DNA binding domain. The majority of missense p53 mutants (mut-p53) demonstrate oncogenic gain-of-function (GOF) abilities, irrespective of wild-type p53 presence, and thus contribute to a more aggressive disease. In prostate cancer (PCa), characterized by comparatively low overall mutational burden, TP53 is frequently mutated in both primary and advanced disease. Despite significant progress made in the field, detailed mechanisms of GOF in PCa remain undefined due to differing features of p53 mutants. Methods: Analysis of available datasets was performed to assess TP53 mutational status in PCa patient samples and its correlation with the clinical outcome. Using hormone therapy sensitive and CRPC cells, a panel of cell lines was generated to model the two most frequently occurring mutations in the presence or absence of wild-type TP53, as occurs clinically. CHIP-seq, gene expression arrays, and in vitro and in vivo biological assays were performed to interrogate the significance of mut-p53 in PCa. Results: In PCa, missense mutations are significantly associated with decreased progression-free and overall survival. In PCa patient samples these mutations most commonly occur at the R273 residue, demonstrating specific enrichment when compared to other cancers, with R273C alteration being the most frequent. Using our cell panel, CHIP-seq data revealed an expansion of the p53 cistrome upon expression of R273C and R273H mutants in a manner distinct from p53 stabilization in the presence of wt-p53. Moreover, analysis of the TP53 missense mutant-sensitive transcriptomes demonstrated differential gene expression between these mutants, related to the expression of wild-type TP53 in those cells. Finally, R273C and R273H p53 mutants elicited context dependent effects on canonical p53 functions, thereby modulating distinct downstream biological outcomes. Conclusions: These data expand our knowledge of the underlying mechanisms by which distinct gain-of-function p53 mutants affect prostate cancer, and can lead to identification of novel therapeutic targets to improve clinical outcomes in PCa patients harboring these mutations.

scholarly journals IMMU-36. HIGH AFFINITY CHIMERIC ANTIGEN RECEPTOR WITH CROSS-REACTIVITY TO CLINICALLY-RELEVANT EGFR MUTATED PROTEINS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii112-ii112
Author(s):  
Radhika Thokala ◽  
Zev Binder ◽  
Yibo Yin ◽  
Michael Milone ◽  
Donald M O’Rourke
Keyword(s):  
T Cells ◽  
Tumor Cells ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Fetal Brain ◽  
Missense Mutations ◽  
Wild Type ◽  
Car T

Abstract Tumor heterogeneity is one of the key reasons for therapeutic failure in Glioblastoma (GBM). Our chimeric antigen receptor (CAR) T cell clinical trial (NCT02209376) against Epidermal growth factor receptor (EGFR) variant III (EGFRvIII) demonstrated successful trafficking of T cells across the blood brain barrier into GBM active tumor sites. However, CART cell infiltration was associated with a selective loss of EGFRvIII+ tumor cells and upregulation of immunosuppressive molecules. Post-CAR T treated tumor specimens showed continued presence of EGFR amplification and oncogenic EGFR extracellular domain (ECD) missense mutations. To study this further We generated two structurally different CARs by fusing the scFv of mAb806 to 4-1BB and Killer immunoglobulin like receptor (KIR) co-stimulatory domains. Both 4-1BB and KIR based EGFR806 CAR T cells specifically lysed tumor cells and secreted cytokines when co-cultured with U87-MG (expressing low levels of EGFR) and U87-MG EGFR (U87-MG transduced with EGFR wild type for amplified background) cell lines and engineered to ectopically express targeted EGFR-ECD missense mutations and EGFRvIII. Unlike EGFR-specific cetuximab based CAR, EGFR-806CART cells did not kill EGFR wild type expressing fetal brain primary astrocytes and keratinocytes in vitro. We further evaluated the in vivo efficacy of 806-CARs and EGFRvIII CART currently in clinic in NSG mice. While EGFRvIII CART cells cleared EGFRvIII+ tumors alone 806 CART cells controlled EGFRvIII, amplified EGFR and EGFRR108K-mutant bearing tumors. KIR-CAR treated tumors are GVHD free and enhanced survival compared to 4-1BB based CARs. The broad specificity of EGFR806 CART cells to amplified EGFR and its mutant variants gives us the potential to clear various forms of EGFR. The enhanced anti-tumor efficacy by KIR based CAR in vivo setting provides us with additional therapeutic options.

scholarly journals Arabidopsis Disulfide Reductase, Trx-h2, Functions as an RNA Chaperone under Cold Stress

2021 ◽  
Vol 11 (15) ◽  
pp. 6865
Author(s):  
Eun Seon Lee ◽  
Joung Hun Park ◽  
Seong Dong Wi ◽  
Ho Byoung Chae ◽  
Seol Ki Paeng ◽  
...  
Keyword(s):  
Cold Stress ◽  
Wild Type ◽  
Rna Chaperone ◽  
E Coli ◽  
Cold Sensitive ◽  
Thioredoxin H ◽  
Functional Rnas

The thioredoxin-h (Trx-h) family of Arabidopsis thaliana comprises cytosolic disulfide reductases. However, the physiological function of Trx-h2, which contains an additional 19 amino acids at its N-terminus, remains unclear. In this study, we investigated the molecular function of Trx-h2 both in vitro and in vivo and found that Arabidopsis Trx-h2 overexpression (Trx-h2OE) lines showed significantly longer roots than wild-type plants under cold stress. Therefore, we further investigated the role of Trx-h2 under cold stress. Our results revealed that Trx-h2 functions as an RNA chaperone by melting misfolded and non-functional RNAs, and by facilitating their correct folding into active forms with native conformation. We showed that Trx-h2 binds to and efficiently melts nucleic acids (ssDNA, dsDNA, and RNA), and facilitates the export of mRNAs from the nucleus to the cytoplasm under cold stress. Moreover, overexpression of Trx-h2 increased the survival rate of the cold-sensitive E. coli BX04 cells under low temperature. Thus, our data show that Trx-h2 performs function as an RNA chaperone under cold stress, thus increasing plant cold tolerance.

scholarly journals Neuroprotective Potential of a Small Molecule RET Agonist in Cultured Dopamine Neurons and Hemiparkinsonian Rats

2021 ◽  
pp. 1-24
Author(s):  
Juho-Matti Renko ◽  
Arun Kumar Mahato ◽  
Tanel Visnapuu ◽  
Konsta Valkonen ◽  
Mati Karelson ◽  
...  
Keyword(s):  
Mapk Signaling ◽  
Dopamine Neurons ◽  
Dopamine Depletion ◽  
Wild Type ◽  
Disease Modifying Therapy ◽  
Immortalized Cells ◽  
Midbrain Dopamine ◽  
6 Hydroxydopamine

Background: Parkinson’s disease (PD) is a progressive neurological disorder where loss of dopamine neurons in the substantia nigra and dopamine depletion in the striatum cause characteristic motor symptoms. Currently, no treatment is able to halt the progression of PD. Glial cell line-derived neurotrophic factor (GDNF) rescues degenerating dopamine neurons both in vitro and in animal models of PD. When tested in PD patients, however, the outcomes from intracranial GDNF infusion paradigms have been inconclusive, mainly due to poor pharmacokinetic properties. Objective: We have developed drug-like small molecules, named BT compounds that activate signaling through GDNF’s receptor, the transmembrane receptor tyrosine kinase RET, both in vitro and in vivo and are able to penetrate through the blood-brain barrier. Here we evaluated the properties of BT44, a second generation RET agonist, in immortalized cells, dopamine neurons and rat 6-hydroxydopamine model of PD. Methods: We used biochemical, immunohistochemical and behavioral methods to evaluate the effects of BT44 on dopamine system in vitro and in vivo. Results: BT44 selectively activated RET and intracellular pro-survival AKT and MAPK signaling pathways in immortalized cells. In primary midbrain dopamine neurons cultured in serum-deprived conditions, BT44 promoted the survival of the neurons derived from wild-type, but not from RET knockout mice. BT44 also protected cultured wild-type dopamine neurons from MPP +-induced toxicity. In a rat 6-hydroxydopamine model of PD, BT44 reduced motor imbalance and could have protected dopaminergic fibers in the striatum. Conclusion: BT44 holds potential for further development into a novel, possibly disease-modifying therapy for PD.

scholarly journals The double-stranded DNA-binding proteins TEBP-1 and TEBP-2 form a telomeric complex with POT-1

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sabrina Dietz ◽  
Miguel Vasconcelos Almeida ◽  
Emily Nischwitz ◽  
Jan Schreier ◽  
Nikenza Viceconte ◽  
...  
Keyword(s):  
Quantitative Proteomics ◽  
Wild Type ◽  
C Elegans ◽  
Double Stranded Dna ◽  
Telomere Sequence ◽  
Proteomics Approach ◽  
Telomeric Protein ◽  
Regulate Telomere Length

AbstractTelomeres are bound by dedicated proteins, which protect them from DNA damage and regulate telomere length homeostasis. In the nematode Caenorhabditis elegans, a comprehensive understanding of the proteins interacting with the telomere sequence is lacking. Here, we harnessed a quantitative proteomics approach to identify TEBP-1 and TEBP-2, two paralogs expressed in the germline and embryogenesis that associate to telomeres in vitro and in vivo. tebp-1 and tebp-2 mutants display strikingly distinct phenotypes: tebp-1 mutants have longer telomeres than wild-type animals, while tebp-2 mutants display shorter telomeres and a Mortal Germline. Notably, tebp-1;tebp-2 double mutant animals have synthetic sterility, with germlines showing signs of severe mitotic and meiotic arrest. Furthermore, we show that POT-1 forms a telomeric complex with TEBP-1 and TEBP-2, which bridges TEBP-1/-2 with POT-2/MRT-1. These results provide insights into the composition and organization of a telomeric protein complex in C. elegans.

Sign in / Sign up

Export Citation Format

Share Document