Abstract 285: Osteopontin Deficiency Ameliorates Heart Failure with Preserved Ejection Fraction Pathology by Upregulating Mitochondrial 2-Oxoglutarate Dehydrogenase Like Enzyme

2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Keyvan Yousefi ◽  
Wen Ding ◽  
Lina A Shehadeh

HFpEF is an increasingly prevalent syndrome associated with impaired myocardial energetics, for which no etiologic therapy is available. Osteopontin (OPN) is a matricellular protein that is upregulated in the circulation of HFpEF patients, and reported to induce mitochondrial stress in rodent cardiomyocytes. Here we evaluate the role of circulating OPN in regulating myocardial function in the nephrotic Col4a3 -/- mouse model of HFpEF. We performed extensive cardiac, biochemical and mitochondrial analyses of the Col4a3 -/- mouse and found a striking HFpEF phenotype. We showed OPN levels were elevated in Col4a3 -/- mice (FC=2.1, n=6; p<.01). Col4a3 -/- mice were hypertensive, had diastolic dysfunction, myocyte hypertrophy and interstitial fibrosis - all of which were ameliorated in Col4a3 -/- OPN -/- mice (n=5-20; p<.05). Col4a3 -/- hearts had dysmorphic mitochondria (EM), lowered antioxidant capacity as a 50% reduction in GSH/GSSG ratio (n=6; p<.05) and lower protein levels of mitochondrial respiratory complexes I, II and IV (p<.05). Flux assay in adult cardiomyocytes showed that maximal respiration was reduced in Col4a3 -/- hearts (575.84±37.6 vs 322.34±25.48 pmol/min in WT, n=9; p<.0001). Microarray data (validated by mitochondrial blot) implicated OGDHL as decreased in Col4a3 -/- hearts but increased in double knockout Col4a3 -/- OPN -/- hearts compared to WT (n=3; p<.05). OGDH activity was also lower in Col4a3 -/- hearts (17.1±7.3 vs 2.5±1.1 mU/mg in WT; n=6; p<.05). In Col4a3 -/- mice, heart-specific AAV9-mediated overexpression of OGDHL, similar to global OPN KO, improved survival by ~50-100% (p<.0001). Isovolumetric relaxation time, a marker of diastolic dysfunction, which is prolonged in Col4a3 -/- mice (26.17 vs 15.30±1 ms, n=26; p<.001) was decreased in Col4a3 -/- OPN -/- mice (18.1±1 ms, n=37; p<.01) as well as in AAV9-cTnT-OGDHL-treated Col4a3 -/- mice (16.7±2.5 ms, n=8; p<.05). In conclusion, we present a new mouse model for HFpEF in which diastolic function and lifespan can be improved by genetic deletion of OPN or cardiac OGDHL gene therapy. Our results elucidate for the first time the pivotal roles of circulating OPN and cardiac OGDHL in HFpEF pathophysiology and present two related potential therapeutic targets for HFpEF.

2015 ◽  
Vol 13 (02) ◽  
pp. 1550002
Author(s):  
Mohammad-Hadi Foroughmand-Araabi ◽  
Bahram Goliaei ◽  
Kasra Alishahi ◽  
Mehdi Sadeghi ◽  
Sama Goliaei

Although it is known that synonymous codons are not chosen randomly, the role of the codon usage in gene regulation is not clearly understood, yet. Researchers have investigated the relation between the codon usage and various properties, such as gene regulation, translation rate, translation efficiency, mRNA stability, splicing, and protein domains. Recently, a universal codon usage based mechanism for gene regulation is proposed. We studied the role of protein sequence patterns on the codons usage by related genes. Considering a subsequence of a protein that matches to a pattern or motif, we showed that, parts of the genes, which are translated to this subsequence, use specific ratios of synonymous codons. Also, we built a multinomial logistic regression statistical model for codon usage, which considers the effect of patterns on codon usage. This model justifies the observed codon usage preference better than the classic organism dependent codon usage. Our results showed that the codon usage plays a role in controlling protein levels, for genes that participate in a specific biological function. This is the first time that this phenomenon is reported.


2018 ◽  
Vol 36 (2) ◽  
pp. 110-116 ◽  
Author(s):  
Liang-Ta Yen ◽  
Yu-Chan Hsu ◽  
Jaung-Geng Lin ◽  
Ching-Liang Hsieh ◽  
Yi-Wen Lin

Background The mechanisms underlying fibromyalgia (FM) pain are not understood. The US Food and Drug Administration has recommended three drugs for treating FM—namely, pregabalin, duloxetine and milnacipran; however, these medications are associated with severe side effects. Objective To create a mouse model of FM pain using dual injections of acidic saline to cause mechanical hyperalgesia and test whether ASIC3, Nav1.7 and Nav1.8 are involved in this process and whether electroacupuncture (EA) can reverse these phenomena. Methods The FM model was established by injecting acidic saline twice into 40 ICR mice. The mice were assigned to subgroups (n=8 each) treated with different EA frequencies (2, 15 and 50 Hz). ASIC3, Nav1.7 and Nav1.8 expression levels were measured by Western blotting and immunohistochemistry. Results Significant mechanical hyperalgesia was induced on day 8 in FM mice, which was reversed by 2, 15 and 50 Hz EA. ASIC3, Nav1.7 and Nav1.8 protein levels increased significantly in both the dorsal root ganglion and in the spinal cord of FM model mice. These changes were further attenuated by 2, 15 and 50 Hz EA. Conclusion Reduced nociceptive ASIC3, Nav1.7 and Nav1.8 proteins are involved in the preventive effects of EA against FM, and this series of molecules may represent targets for FM treatment.


2019 ◽  
Vol 20 (20) ◽  
pp. 5151 ◽  
Author(s):  
Norante ◽  
Peggion ◽  
Rossi ◽  
Martorana ◽  
De Mario ◽  
...  

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the selective death of motor neurons (MNs), probably by a combination of cell- and non-cell-autonomous processes. The past decades have brought many important insights into the role of astrocytes in nervous system function and disease, including the implication in ALS pathogenesis possibly through the impairment of Ca2+-dependent astrocyte-MN cross-talk. In this respect, it has been recently proposed that altered astrocytic store-operated Ca2+ entry (SOCE) may underlie aberrant gliotransmitter release and astrocyte-mediated neurotoxicity in ALS. These observations prompted us to a thorough investigation of SOCE in primary astrocytes from the spinal cord of the SOD1(G93A) ALS mouse model in comparison with the SOD1(WT)-expressing controls. To this purpose, we employed, for the first time in the field, genetically-encoded Ca2+ indicators, allowing the direct assessment of Ca2+ fluctuations in different cell domains. We found increased SOCE, associated with decreased expression of the sarco-endoplasmic reticulum Ca2+-ATPase and lower ER resting Ca2+ concentration in SOD1(G93A) astrocytes compared to control cells. Such findings add novel insights into the involvement of astrocytes in ALS MN damage.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1114-1114
Author(s):  
Mickaël Martin ◽  
Anne Marie Knapp ◽  
Dana Ghergus ◽  
Fabien Delmotte ◽  
Laurent Vallat ◽  
...  

Abstract Abnormal expression of the tyrosine kinase ZAP-70 by tumoral B cells in chronic lymphocytic leukemia (CLL) is associated with bad prognosis, related to B cell receptor (BCR) hypersignalling, clonal expansion and autoimmune cytopenia (AIC) occurrence, these latter being mostly induced by polyclonal IgG from the residual non tumoral B cells. We previously shown that ZAP-70 is expressed by these non tumoral B cells in CLL, positively associated with its expression in CLL B cells and with AIC occurrence (Ghergus et al. Poster ASH 2017). Here, we show for the first time a potential role of ZAP-70 expression in tolerance breakdown in CLL and in an original knock in mouse model overexpressing ZAP-70 conditionally in B cells. First, to assess a potential molecular link between ZAP-70+ CLL and non tumoral B cells, an analysis of their BCR repertoire has performed on FACS-sorting CD19+CD5-IgM-IgD- (non tumoral) and CD19+CD5+IgM-IgD- (tumoral) single B cells from blood samples of CLL patients with AIC. ZAP-70 positivity was screened by RT-PCR, and variable regions of heavy (IGVH) and light (IGVK/VL) immunoglobulin genes amplified by RT-PCR on ZAP-70+ cells. To date, analysis of 24 BCR sequences from 7 patients showed that non tumoral ZAP-70+ B cells were polyclonal, without stereotypy, using different V(D)J and CDR3 in comparison with those of the corresponding CLL B cells. IGVH of non tumoral ZAP-70+ B were mostly mutated, of replacement type, suggesting antigenic contact, contrary to CLL B cells. To determine potential autoreactivity of the non-tumoral ZAP-70+ B cells, IGVH and corresponding IGVK/VL were amplified for production of recombinant antibodies (rAb). To date, among 17 rAB from 7 different patients, 2/13 (15.4%) have an antinuclear autoreactivity on HEp-2 cells and 4/17 (23.5%) were polyreactive on ELISA (DNA, lipopolysaccharide, insulin), compared respectively to 6% and 4,3% of control B cells (Wardemann et al., Science 2003). Production of 7 additional rAb and tests for anti-erythrocytes and anti-platelets reactivity are in process. To study functional consequences of early ZAP-70 expression in B cells in vivo, we generated a knock in Zap-70+/Mb1-Cre+mouse model (KI ZAP), to induce conditional expression of ZAP-70 in the B cell compartment from the proB stage, with KI Zap-70+/Mb1-Cre-mice as controls (CTRL). The ZAP-70 mRNAs levels in B cells from KI ZAP mice were on average 20 times higher than that in CTRL B cells. Up to 20 months-old, KI ZAP mice did not develop signs of lymphoproliferation. KI ZAP mice had hypo-IgG since 16 weeks-old (p<0.001) together with hypo-IgM from 14 months-old (p<0.01). Immunophenotyping revealed a reduction in mature naive, mature switched as well as in germinal center B cells (p<0.001, p=0.002 and p<0.01 respectively) and a trend for plasma cells (p=0.07). Microarrays showed enrichment in circulating IgG and IgM autoantibodies against various antigens in KI ZAP mice. These mice had reduced apoptosis rates of proB (p<0.01), preB (p=0.02), and immatures B cells (p=0.03), together with enrichment in marginal zone (p=0.01), trend for transitional T2/T3, and reduction in B1a cells (p<0.01). After immunization by ovalbumin + Freund's adjuvant, a reduced production of specific IgG and IgM was observed (p=0.01 and p=0.03 respectively) with a trend in decreased number of antibody-secreting cells (p=0.07). KI ZAP B cells shown increased spontaneous activation and proliferation levels holding after BCR stimulation (p<0.01), as well as an increased intracellular calcic flow (p<0.001). Preliminary data suggested a reduced SYK phosphorylation after BCR stimulation in KI ZAP B cells. Our findings highlight for the first time that non tumoral B cells ZAP-70+ are distinct from CLL cells at cellular level, but probably enriched in autoreactive cells. Moreover, we shown that early ZAP-70 expression in normal B cells in vivois associated with autoimmune characteristics, together with partial block in B cells peripheral maturation, and a conversely early increased activation and proliferation status. ZAP-70 could interfere early with SYK leading to an altered BCR signaling responsible for defect in normal B maturation promoting emergence of autoreactive B cells. Mechanistic role of ZAP-70 in BCR signaling has to be further analyzed but our data open new opportunities involving ZAP-70 in the understanding of B cell development and physiopathology of tolerance breakdown. Disclosures No relevant conflicts of interest to declare.


2022 ◽  
Vol 44 (1) ◽  
pp. 336-349
Author(s):  
Marta Broniarczyk-Czarniak ◽  
Janusz Szemraj ◽  
Janusz Śmigielski ◽  
Piotr Gałecki

Schizophrenia is a serious and chronic mental illness, the symptoms of which usually appear for the first time in late adolescence or early adulthood. To date, much research has been conducted on the etiology of schizophrenia; however, it is still not fully understood. Oxytocin and vasopressin as neuromodulators that regulate social and emotional behavior are promising candidates for determining the vulnerability to schizophrenia. The aim of this study was to evaluate the expression of OXT, OXTR, AVP, and AVPR1a genes at the mRNA and protein levels in patients with schizophrenia. Due to the neurodegenerative nature of schizophrenia, the study group was divided into two subgroups, namely, G1 with a diagnosis that was made between 10 and 15 years after the onset of the illness, and G2 with a diagnosis made up to two years after the onset of the illness. Moreover, the relationship between the examined genes and the severity of schizophrenia symptoms, assessed using PANSS (Positive and Negative Syndrome Scale) and CDSS scales (Clinical Depression Scale for Schizophrenia) was evaluated. The analysis of the expression of the studied genes at the mRNA and protein levels showed statistically significant differences in the expression of all the investigated genes. OXT and AVPR1a gene expression at both the mRNA and protein levels were significantly lower in the schizophrenia group, and OXTR and AVP gene expression at both the mRNA and protein levels was higher in the schizophrenia subjects than in the controls. Furthermore, a significant correlation of OXT gene expression at the mRNA and protein levels with the severity of depressive symptoms in schizophrenia as assessed by CDSS was found.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Devin W McBride ◽  
Ari Dienel ◽  
Remya A Veettil ◽  
Kanako Matsumura ◽  
Peeyush Kumar T. ◽  
...  

Rationale: Microthrombosis has been suggested as a major factor contributing to delayed neurological deterioration in patients after subarachnoid hemorrhage (SAH). However, experimental studies on the role of microthrombi in delayed deficits after SAH has not been investigated. Our hypothesis is that, following SAH, mice which develop delayed neurological deficits have a greater number of microthrombi than mice which do not develop delayed neurological deficits. Methods: SAH was induced in adult male and female C57BL/6 mice via endovascular perforation. Mice were randomly assigned into sham (n=6/sex) or SAH groups (n=22-24/sex). Neurobehavior was performed on days 1-3, 5, and 7 post-SAH using a composite neuroscore. Animals were sacrificed on the day of delayed deficits or 7 days post-SAH. Microthrombi count and vessel diameters (for vasospasm) were measured using H&E stained brain slices. All outcomes were performed and all data were analyzed by a blinded investigator. Results: Seventeen percent (4/24) of male mice and thirty-six percent (8/22) of female mice developed delayed deficits on days 3-5 post-SAH (Figures 1A and 1B). Those mice which developed delayed deficits had significantly more microthrombi in their brains than mice which did not develop delayed deficits; vasospasm did not correlate with delayed deficits. Additionally, female SAH mice develop delayed deficits at a higher frequency than males (Figure 1C). Conclusions: This work shows for the first time delayed deficits in a SAH mouse model. Further, microthrombi correlated with delayed deficits, whereas no correlation was between delayed deficits and vasospasm. The data within this study suggests that preventing microthrombi may improve functional recovery and reduce the risk of delayed deficits.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Peidong Han ◽  
Xiaoyang Zhou ◽  
Wen Zhao ◽  
Guoli Chen ◽  
Shan Chen ◽  
...  

Junctin (JCN) and triadin (TRD) share similar structures and they both function to anchor calsequestrin (CSQ) to the ryanodine receptor (RyR) in the sarcoplasmic reticulum (SR) quaternary Ca-release complex. In failing human hearts, JCN and TRD protein levels are markedly decreased, implicating alterations in SR Ca-cycling and contractility. To address the role of combined JCN and TRD down-regulation in cardiac function, we generated and characterized a murine model deficient in both JCN and TRD. The double-knockout (DKO) mice presented lower body weight, poor fertility, and an apparent cardiac hypertrophy. In addition, deficiency of both JCN/TRD was associated with decreased peak Ca transient amplitude (34%), prolonged transient decay time (48%) and reduced caffeine-induced SR Ca-release. This depressed contractility was also confirmed at the intact organ (Langendorff perfusion) and whole animal (by echocardiography and catheterization) levels. Furthermore, examination of the properties of Ca sparks, which are informative of ryanodine receptor (RyR) gating , revealed increased frequency in the DKO myocytes, which indicated a larger opening probability of RyR. These findings suggest that the combined JCN/TRD-deficiency is associated with leaky RyR and depressed cardiac Ca-cycling, which may contribute to the progression of heart failure. This research has received full or partial funding support from the American Heart Association, AHA National Center. Table 1. Hemodynamic parameters from echocardiography and catheterization


2021 ◽  
Vol 25 (5) ◽  
pp. 445-455
Author(s):  
Naohiro Takahashi ◽  
Hiroaki Kikuchi ◽  
Ayaka Usui ◽  
Taisuke Furusho ◽  
Takuya Fujimaru ◽  
...  

Abstract Background Lipid-metabolizing enzymes and their metabolites affect inflammation and fibrosis, but their roles in chronic kidney disease (CKD) have not been completely understood. Methods To clarify their role in CKD, we measured the mRNA levels of major lipid-metabolizing enzymes in 5/6 nephrectomized (Nx) kidneys of C57BL/6 J mice. Mediator lipidomics was performed to reveal lipid profiles of CKD kidneys. Results In 5/6 Nx kidneys, both mRNA and protein levels of Alox15 were higher when compared with those in sham kidneys. With respect to in situ hybridization, the mRNA level of Alox15 was higher in renal tubules of 5/6 Nx kidneys. To examine the role of Alox15 in CKD pathogenesis, we performed 5/6 Nx on Alox15−/− mice. Alox15−/− CKD mice exhibited better renal functions than wild-type mice. Interstitial fibrosis was also inhibited in Alox15−/− CKD mice. Mediator lipidomics revealed that Alox15−/− CKD mouse kidneys had significantly higher levels of PGD2 than the control. To investigate the effects of PGD2 on renal fibrosis, we administered PGD2 to TGF-β1-stimulated NRK-52E cells and HK-2 cells, which lead to a dose-dependent suppression of type I collagen and αSMA in both cell lines. Conclusion Increased PGD2 in Alox15−/− CKD mouse kidneys could inhibit fibrosis, thereby resulting in CKD improvement. Thus, Alox15 inhibition and PGD2 administration may be novel therapeutic targets for CKD.


2020 ◽  
Vol 21 (19) ◽  
pp. 7176
Author(s):  
Ayman M. Ibrahim ◽  
Mohamed Roshdy ◽  
Sara Elshorbagy ◽  
Mohammed Hosny ◽  
Sarah Halawa ◽  
...  

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart muscle disease, with a prevalence of at least 1 in 500 in the general population. The disease is pleiotropic and is characterized by an increased stiffness of the myocardium, partly due to changes in the extracellular matrix (ECM), with elevated levels of interstitial fibrosis. Myocardial fibrosis is linked to impaired diastolic function and possibly phenotypic heterogeneity of HCM. The ECM consists of a very large number of proteins, which actively interact with each other as well as with myocardial cells. The role of other multiple components of the ECM in HCM has not been defined. Fibulin-2 is a glycoprotein component of the ECM, which plays an important role during embryogenesis of the heart; however, its role in adult myocardium has not been adequately studied. We here describe, for the first time, abnormal expression of fibulin-2 in the myocardium in patients with HCM as compared to normal controls. This abnormal expression was localized in the cytoplasm of myocardial cells and in the interstitial fibroblasts. In addition, fibulin-2 levels, measured by ELISA, were significantly elevated in the serum of patients with HCM as compared to normal controls.


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