scholarly journals The Pathogenesis of COVID-19 Myocardial Injury: An Immunohistochemical Study of Postmortem Biopsies

2021 ◽  
Vol 12 ◽  
Author(s):  
Camila Hartmann ◽  
Anna Flavia Ribeiro dos Santos Miggiolaro ◽  
Jarbas da Silva Motta ◽  
Lucas Baena Carstens ◽  
Caroline Busatta Vaz De Paula ◽  
...  
Keyword(s):  
Myocardial Injury ◽  
Histological Analysis ◽  
Immunohistochemical Study ◽  
Myocardial Dysfunction ◽  
Blue Staining ◽  
Control Group ◽  
Caspase 9 ◽  
Interstitial Edema ◽  
Caspase 1 ◽  
Tnf Α

RationaleMyocardial injury associates significantly and independently with mortality in COVID-19 patients. However, the pathogenesis of myocardial injury in COVID-19 remains unclear, and cardiac involvement by SARS-CoV-2 presents a major challenge worldwide.ObjectiveThis histological and immunohistochemical study sought to clarify the pathogenesis and propose a mechanism with pathways involved in COVID-19 myocardial injury.Methods and ResultsPostmortem minimally invasive autopsies were performed in six patients who died from COVID-19, and the myocardium samples were compared to a control group (n=11). Histological analysis was performed using hematoxylin-eosin and toluidine blue staining. Immunohistochemical (IHC) staining was performed using monoclonal antibodies against targets: caspase-1, caspase-9, gasdermin-d, ICAM-1, IL-1β, IL-4, IL-6, CD163, TNF-α, TGF-β, MMP-9, type 1 and type 3 collagen. The samples were also assessed for apoptotic cells by TUNEL. Histological analysis showed severe pericardiocyte interstitial edema and higher mast cells counts per high-power field in all COVID-19 myocardium samples. The IHC analysis showed increased expression of caspase-1, ICAM-1, IL-1β, IL-6, MMP-9, TNF-α, and other markers in the hearts of COVID-19 patients. Expression of caspase-9 did not differ from the controls, while gasdermin-d expression was less. The TUNEL assay was positive in all the COVID-19 samples supporting endothelial apoptosis.ConclusionsThe pathogenesis of COVID-19 myocardial injury does not seem to relate to primary myocardiocyte involvement but to local inflammation with associated interstitial edema. We found heightened TGF-β and interstitial collagen expression in COVID-affected hearts, a potential harbinger of chronic myocardial fibrosis. These results suggest a need for continued clinical surveillance of patients for myocardial dysfunction and arrythmias after recovery from the acute phase of COVID-19.

scholarly journals The Pathogenisis of COVID-19 Myocardial Injury: an Immunohistochemical Study of Postmortem Biopsies 

2020 ◽  
Author(s):  
Camila Hartmann ◽  
Anna Flavia dos Santos Miggiolaro ◽  
Jarbas da Silva Motta Junior ◽  
Lucas Baena Carstens ◽  
Caroline Busatta Vaz De Paula ◽  
...  
Keyword(s):  
Myocardial Injury ◽  
Immunohistochemical Study ◽  
Tunel Assay ◽  
Blue Staining ◽  
Histopathological Analysis ◽  
Interstitial Edema ◽  
Caspase 1 ◽  
Tnf Α ◽  
Type 3

Abstract Rationale: Myocardial injury is significantly and independently associated with mortality in COVID-19 patients. However, the pathogenesis of myocardial injury in COVID-19 is still not clear, and cardiac involvement by SARS-CoV-2 remains a major challenge worldwide. Objective: This histopathological and immunohistochemical study seeks to clarify the pathogenesis and propose a mechanism with pathways involved in COVID-19 myocardial injury. Methods and Results: Postmortem minimally invasive autopsies were performed in six patients who died from COVID-19, and the myocardium samples were compared to a control patient. Histopathological analysis was performed using hematoxylin-eosin and toluidine blue staining. Immunohistochemical (IHC) staining was performed using monoclonal antibodies against the following targets: caspase-1, ICAM-1, TNF-α, IL-4, IL-6, CD163, TGF-β, MMP-9, type 1 and type 3 collagen. The samples were also subjected to a TUNEL assay to detect potential apoptosis. The histopathological analysis showed severe pericellular interstitial edema surrounding each of the cardiomyocytes and higher mast cells count by high-power field in all COVID-19 myocardium samples. The IHC analysis showed increased expression of caspase-1, ICAM-1, IL-4, IL-6, CD163, MMP-9 and type 3 collagen in the COVID-19 patients compared to the control. No difference from the control was observed in expression of TNF-α, TGF-β and type 1 collagen. The TUNEL assay was positive in all the COVID-19 samples confirming the presence of endothelial apoptosis. Conclusions: The pathogenesis of COVID-19 myocardial injury seems to be related with pyroptosis leading to endothelial cell injury and disfunction. The subsequent inflammation with associated interstitial edema could explain the myocardial disfunction and arrythmias in these patients. Our findings also show that COVID-19 myocardial injury may cause myocardial fibrosis in the long term. These patients should be monitored for myocardial dysfunction and arrythmias after the acute phase of COVID-19.

scholarly journals Myocardial Injury in Post Mortem Biopsies of Patients with COVID-19

2020 ◽  
Author(s):  
Camila Hartmann ◽  
Anna Flavia dos Santos Miggiolaro ◽  
Jarbas da Silva Motta Junior ◽  
Lucas Baena Carstens ◽  
Caroline Busatta Vaz De Paula ◽  
...  
Keyword(s):  
Myocardial Injury ◽  
Histopathological Analysis ◽  
Interstitial Edema ◽  
Th2 Response ◽  
Caspase 1 ◽  
Tnf Α ◽  
Pathogenesis Related ◽  
Type 3

Abstract Background: Myocardial injury is significantly and independently associated with mortality in COVID-19 patients. However, the pathogenesis of myocardial injury in COVID-19 is still not clear, and cardiac involvement by SARS-CoV-2 remains a major challenge worldwide.Aim: This histopathological and immunohistochemical study seeks to clarify the pathogenesis of myocardial injury in COVID-19.Methods: Postmortem minimally invasive autopsies were performed in two patients who died from COVID-19, and the myocardium samples were compared to a control patient. Immunohistochemistry (IHC) staining was performed using monoclonal antibodies against the following targets: caspase-1, ICAM-1, TNF-α, IL-4, IL-6, CD163, TGF-β, MMP-9, type 1 and type 3 collagen.Results: The histopathological analysis showed severe pericellular interstitial edema surrounding each of the cardiomyocytes. The IHC analysis showed increased expression of caspase-1, ICAM-1, IL-4, IL-6, CD163, MMP-9 and type 3 collagen in the COVID-19 patients compared to the control. On the other hand, no difference from the control was observed in expression of TNF-α, TGF-β and type 1 collagen. Conclusion: Our findings point to a pathogenesis related with pyroptosis leading to endothelial disfunction. The subsequent inflammation with associated interstitial edema could explain the myocardial disfunction and arrythmias in COVID-19 patients. The presence of Th2 response, MMP-9 and type-3 collagen suggests progression to myocardial fibrosis in the long term.

TGF-β1 attenuates myocardial ischemia-reperfusion injury via inhibition of upregulation of MMP-1

2003 ◽  
Vol 284 (5) ◽  
pp. H1612-H1617 ◽  
Author(s):  
Hongjiang Chen ◽  
Dayuan Li ◽  
Tom Saldeen ◽  
Jawahar L. Mehta
Keyword(s):  
Myocardial Ischemia ◽  
Myocardial Injury ◽  
Ischemia Reperfusion ◽  
Myocardial Necrosis ◽  
Left Ventricular ◽  
Blue Staining ◽  
Control Group ◽  
Dependent Manner ◽  
Arterial Blood ◽  
Group I

Ischemia-reperfusion (I/R) is thought to upregulate the expression and activity of matrix metalloproteinases (MMPs), which regulate myocardial and vascular remodeling. Previous studies have shown that transforming growth factor-β1 (TGF-β1) can attenuate myocardial injury induced by I/R. TGF-β1 is also reported to suppress the release of MMPs. To study the modulation of MMP-1 by TGF-β1 in I/R myocardium, Sprague-Dawley rats were given saline and subjected to 1 h of myocardial ischemia [total left coronary artery (LCA) ligation] followed by 1 h of reperfusion ( n = 9). Parallel groups of rats were pretreated with recombinant TGF-β1(rTGF-β1, 1 mg/rat, n = 9) before reperfusion or exposure to sham I/R (control group). I/R caused myocardial necrosis and dysfunction, indicated by decreased first derivative of left ventricular pressure, mean arterial blood pressure, and heart rate (all P < 0.01 vs. sham-operated control group). Simultaneously, I/R upregulated MMP-1 ( P < 0.01). Treatment of rats with rTGF-β1 reduced the extent of myocardial necrosis and dysfunction despite I/R (all P < 0.01). rTGF-β1 treatment also inhibited the upregulation of MMP-1 in the I/R myocardium ( P < 0.05). To determine the direct effect of MMP-1 on the myocardium, isolated adult rat myocytes were treated with active MMP-1, which caused injury and death of cultured myocytes, measured as lactate dehydrogenase release and trypan blue staining, in a dose- and time-dependent manner ( P < 0.05). Pretreatment with PD-166793, a specific MMP inhibitor, attenuated myocardial injury and death induced by active MMP-1. The present study for the first time shows that MMP-1 can directly cause myocyte injury or death and that attenuation of myocardial I/R injury by TGF-β1 may, at least partly, be mediated by the inhibition of upregulation of MMP-1.

scholarly journals Berberine Reduces Renal Cell Pyroptosis in Golden Hamsters with Diabetic Nephropathy through the Nrf2-NLRP3-Caspase-1-GSDMD Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Baozhu Ding ◽  
Songyan Geng ◽  
Xiaojie Hou ◽  
Xuelian Ma ◽  
Huazhou Xu ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Blood Lipids ◽  
Kidney Tissue ◽  
Inflammatory Factors ◽  
Control Group ◽  
Model Group ◽  
Golden Hamsters ◽  
Caspase 1 ◽  
Tnf Α ◽  
Nrf2 Expression

Objective. To observe the effect of berberine (BBR) on kidney cell pyroptosis in golden hamsters with diabetic nephropathy (DN) and to explore the molecular mechanism of its renal protection. Methods. Fifty clean-grade male golden hamsters were randomly divided into a control group (10) and a model building group (40). The DN model was established by high-sugar and high-fat feeding and injection of a small amount of STZ. After successful establishment of the model, they were randomly divided into a model group, western medicine group, and berberine high- and low-dose groups. The western medicine group was given irbesartan 13.5 mg/kg, and the berberine high- and low-dose groups were given BBR 200 mg/kg and 100 mg/kg, respectively, for 8 consecutive weeks. An automatic biochemical analyser was used to measure blood glucose, blood lipids, kidney function, MDA, and other indicators; radioimmunoassay was used to assess serum insulin; enzyme-linked immunosorbent assay (ELISA) was used to quantify IL-1β, IL-6, IL-18, TNF-α; HE, PAS, and Masson staining were used to observe kidney pathological tissue morphology; western blot and real-time fluorescent quantitative PCR were used to assess protein and mRNA expression of molecules, such as Nrf2, NLRP3, Caspase-1, and GSDMD; and TUNEL staining was used to detect DNA damage. SPSS statistical software was used for the data analysis. Results. The kidney tissues of golden hamsters in the control group were normal; Nrf2 was highly expressed, serum MDA level was low, NLRP3 expression in kidney tissue was not obvious, Caspase-1 and GSDMD were weakly expressed, and only a few TUNEL-positive cells were observed. Compared with the control group, the golden hamsters in the model group had obvious renal pathological damage; blood glucose, blood lipids, renal function-related indexes, insulin, and inflammatory factors IL-1β, IL-6, IL-18, and TNF-α were increased ( P < 0.05 ); NLRP3, Caspase-1, and GSDMD expression was increased; Nrf2 expression was decreased; MDA level was increased ( P < 0.05 ); and the number of TUNEL-positive cells was increased. Compared with the model group, the pathological morphology of the kidney tissue of golden hamsters in the three treatment groups was significantly improved; blood glucose, blood lipids, renal function, and the expression of inflammatory factors IL-1β and IL-6 were reduced ( P < 0.05 ); NLRP3, Caspase-1, GSDMD, and other molecular proteins and mRNA expression were decreased; Nrf2 expression was increased; MDA level was decreased ( P < 0.05 ); and the number of TUNEL-positive cells was decreased. Conclusion. DN golden hamster kidney NLRP3-Caspase-1-GSDMD signalling was enhanced. BBR can reduce oxidative stress damage by regulating antioxidative Nrf2 and then regulating NLRP3-Caspase-1-GSDMD signalling to inhibit pyroptosis, antagonizing DN inflammation-induced damage.

Nicorandil reduces myocardial injury and improves cardiac function in valve replacement surgery.

2019 ◽  
Vol 1 (4) ◽  
pp. 120-126
Author(s):  
Wael Elfeky ◽  
Mohamed Aboelnasr ◽  
Ayman Sallam ◽  
Wael Haseeb ◽  
Dalia R El-Afify
Keyword(s):  
Valve Replacement ◽  
Myocardial Protection ◽  
Myocardial Injury ◽  
Troponin I ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Control Group ◽  
Replacement Surgery ◽  
Tnf Α ◽  
Valve Replacement Surgery

Background: Myocardial injury during cardiac surgery is associated with increased morbidity and mortality, and proper myocardial protection improves surgical outcomes. We aimed to study the role of preoperative nicorandil in myocardial protection during valve replacement surgery. Methods: The study included 40 patients who were randomized into two groups: control group, and nicorandil group. Preoperative, intraoperative, and postoperative data were collected. Creatine kinase- MB (CK-MB), troponin I, malondialdehyde (MDA), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were measured 24-hours before surgery then 4, 12 and 48 hours after aortic cross-clamp removal. Results: Nicorandil significantly decreased MDA (p=0.005 and 0.036), TNF-α (p< 0.001), IL-6 (p<0.001 and 0.003) 4 and 12 hours following the removal of aortic clamp compared to the control group. Additionally, It significantly reduced CK-MB (p< 0.0001 and 0.0002) and troponin-I (p= 0.0002 and < 0.0001) 4 and 12 hours after the removal of the aortic clamp, respectively. However, there was no significant difference in MDA, TNF-α, IL-6, CK-MB, and troponin-I levels between the nicorandil and the control group after 48 hours following the removal of aortic clamping (p= 0.084; 0.64; 0.12; 0.12; 0.75; respectively). Conclusions: Nicorandil reduced myocardial injury significantly in valve replacement surgery. Nicorandil decreased CK-MB and troponin I and improved postoperative left ventricular ejection fraction.

scholarly journals Development, Optimization and Evaluation of 2-Methoxy-Estradiol Loaded Nanocarrier for Prostate Cancer

2021 ◽  
Vol 12 ◽  
Author(s):  
Nabil A. Alhakamy ◽  
Osama A. Ahmed ◽  
Usama A. Fahmy ◽  
Hani Z. Asfour ◽  
Adel F. Alghaith ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Statistical Design ◽  
Entrapment Efficiency ◽  
Fold Increase ◽  
Glycol Succinate ◽  
Control Group ◽  
Caspase 9 ◽  
Tnf Α ◽  
M Phase

The therapeutic efficacy of antineoplastic agents possessing a selective target to the nucleus of the cancer cells could be enhanced through novel formulation approaches. Thus, toward the improvement of the anticancer potential of 2-methoxy estradiol (2 ME) on prostate cancer, the drug was entrapped into the hydrophobic micelles core formulated with Phospholipon 90G and d-α-tocopheryl polyethylene glycol succinate (TPGS). Optimization of the formulation was done by Box-Behnken statistical design using Statgraphics software to standardize percentages of TPGS and phospholipid to obtain the smallest particle size. The optimized formulation was found to be spherical with nanometer size of 152 ± 5.2 nm, and low PDI (0.234). The entrapment efficiency of the micelles was 88.67 ± 3.21% with &gt;93% release of 2 ME within 24 h. There was a 16-fold increase in apoptosis and an 8-fold increase in necrosis of the PC-3 cells when incubated with 2 ME micellar delivery compared to control cells (2.8 ± 0.2%). This increased apoptosis was further correlated with increased BAX expression (11.6 ± 0.7) and decreased BCL-2 expression (0.29 ± 0.05) in 2 ME micelles treated cells when compared to the control group. Further, loss of mitochondrial membrane potential (∼50-fold) by the drug-loaded micelles and free drug compared to control cells was found to be due to the generation of ROS. Findings on cell cycle analysis revealed the significant arrest of the G2-M phase of the PC-3 cells when incubated with the optimized formulation. Simultaneously, a significantly increased number of cells in pre-G1 revealed the maximum apoptotic potential of the drug when delivered via micellar formulation. Finally, upregulation of caspase-9, p53, and NO, with downregulation of TNF-α, NF-κβ, and inflammatory mediators of the PC-3 cells established the superiority of the micellar approach against prostate cancer. In summary, the acquired results highlighted the potentiality of the 2 ME-micellar delivery tool for controlling the growth of prostate cancer cells for improved efficacy.

The Absence of Toxicity in Intraperitoneal Iron Dextran Administration: A Functional and Histological Analysis

1998 ◽  
Vol 18 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Roberto F.S. Pecoits-Filho ◽  
Zbylut J. Twardowski ◽  
Yong-Lim Kim ◽  
Ramesh Khanna ◽  
Harold Moore ◽  
...  
Keyword(s):  
Prussian Blue ◽  
Peritoneal Cavity ◽  
Dose Group ◽  
Histological Analysis ◽  
Study Groups ◽  
Blue Staining ◽  
Control Group ◽  
High Dose ◽  
Iron Dextran ◽  
Group D

Objective To determine the influence of iron dextran intraperitoneal administration on the function and histology of the peritoneum in rats undergoing chronic peritoneal dialysis. Design Prospective, randomized experimental study. Materials Fifty-four Sprague-Dawley rats were divided into five groups: 3 study groups -high dose group (H), n = 12; intermediate dose (M), n = 12; and low dose group (L), n = 12 a dialysis control group (D), n = 12; and a tissue control (C), n = 7. Interventions The study groups were given Dianeal containing iron dextran in a concentration of 0.5,0.25, and 0.125 mg/L (groups H, M, and L respectively). Group D was given standard Dianeal. Group C was never dialyzed. Main Outcome Measures A 2-hour peritoneal equilibrium test (PET) was performed on the eighth day, at 3 months, and at 6 months. After the final PET, the animals were sacrificed and the peritoneal membrane was evaluated by gross inspection and light microscopy (silver, prussian blue, and trichrome staining). Results Peritoneal transport of small solutes followed the same pattern in all groups, increasing over time. The peritonitis index was similar in the groups. No iron deposits or morphologic differences were seen in the gross inspection of the peritoneal cavity. No peritoneal iron deposition was detected in the histological analysis with prussian blue staining. No differences were noted in the light microscopic analysis of the mesothelial cell layer (silver staining), nor did the morphometric analysis of the submesothelial space show any differences in thickness between the groups. Conclusion These findings suggest the absence of toxic effects of iron dextran on the peritoneal cavity of rats in the concentrat ions studied. Further studies should be performed to evaluate the effectiveness of these dosages delivered intraperitoneally to maintain iron homeostasis.

scholarly journals The Selective NLRP3-inflammasome inhibitor MCC950 Mitigates Post-resuscitation Myocardial Dysfunction and Improves Survival in a Rat Model of Cardiac Arrest and Resuscitation

2022 ◽  
Author(s):  
Guanghui Zheng ◽  
Fenglian He ◽  
Jing Xu ◽  
Juntao Hu ◽  
Weiwei Ge ◽  
...  
Keyword(s):  
Rat Model ◽  
Nlrp3 Inflammasome ◽  
Myocardial Function ◽  
Troponin I ◽  
Myocardial Dysfunction ◽  
Survival Duration ◽  
Control Group ◽  
Sprague Dawley ◽  
Sublingual Microcirculation ◽  
Caspase 1

Abstract Purpose To investigate the effects of the selective NLRP3 inflammasome inhibitor MCC950 on post-resuscitation myocardial function and survival in a rat model of cardiopulmonary resuscitation (CPR). Methods Thirty-six Sprague Dawley rats were randomized into three groups: (1) MCC950, (2) control, and (3) sham. Each group consisted of a 6 h non-survival subgroup (n = 6) and a 48 h survival subgroup (n = 6). Ventricular fibrillation (VF) was induced and untreated for 6 min. CPR was initiated and continued for 8 min. Resuscitation was attempted with a 4 J defibrillation. MCC950 (10 mg/kg) or vehicle was administered via intraperitoneal injection immediately after the return of spontaneous circulation (ROSC). Myocardial function and sublingual microcirculation were measured after ROSC in the non-survival subgroups. Plasma levels of interleukin Iβ (IL-1β) and cardiac troponin I (cTnI) were measured at baseline and 6 h in the non-survival subgroups. Heart tissue was harvested to measure the NLRP3 inflammasome constituents, including NLRP3, apoptosis-associated speck-like protein (ASC), Caspase-1, and IL-1β. Survival duration and neurologic deficit score (NDS) were recorded and evaluated among survival groups. Results Post-resuscitation myocardial function and sublingual microcirculation were improved in MCC950 compared with control (p < 0.05). IL-1β and cTnI were decreased in MCC950 compared to control (p < 0.01). The MCC950 treated groups showed significantly reduced ASC, caspase-1, and IL-1β compared with the control group (p < 0.05). Survival at 48 h after ROSC was greater in MCC950 (p < 0.05) with improved NDS (p < 0.05). Conclusion Administration of MCC950 following ROSC mitigates post-resuscitation myocardial dysfunction and improves survival.

scholarly journals Exosomes from adipose mesenchymal stem cells overexpressing Stanniocalcin-1 promote reendothelialization after carotid endarterium mechanical injury

2021 ◽  
Author(s):  
Kun Liu ◽  
Huihua Shi ◽  
Zhiyou Peng ◽  
Xiaoyu Wu ◽  
Weimin Li ◽  
...  
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Nlrp3 Inflammasome ◽  
Mechanical Injury ◽  
Molecular Probe ◽  
Blue Staining ◽  
Control Group ◽  
Lateral Migration ◽  
Post Injury ◽  
Caspase 1

Abstract Stanniocalcin-1 (STC-1) is a secreted glycoprotein that participates in the regulation of inflammation, apoptosis, and necrosis. We investigated the reendothelialization effect of exosomes from adipose stem cells (ADSC) overexpressing STC-1 on injured carotid endarterium. ADSCs were transfected with lentivirus vectors containing pre-STC-1. PHK-26 as molecular probe was used to track the exosomes engulfed by mice arterial endothelial cells (MAEC). The role of STC-1-ADSC-Exosome (S-ADSC-Exo) in MAECs was verified through scratch test and tube forming. Expressions of STC-1 and NLRP3 inflammasome were detected by western blot and quantitative reverse transcription polymerase chain reaction. Reendothelialization effect was inhibited by the antagonist of siRNA targeting STC-1. Carotid endarterium mechanical injury was induced by insertion with a guidewire into the common carotid artery lumen. Carotid arteries were harvested for histological examination, immunofluorescence staining, and Evan’s blue staining. Transfection of STC-1 significantly enhanced STC-1 levels in ADSCs, their exosomes, and MAECs. Compared with the control group and the ADSC-Exo group, STC-1 enriched exosomes markedly inhibited the expressions of NLRP3, Caspase-1, and IL-1β in MAECs, exhibited good lateral migration capacity, and promoted angiogenesis. Administration of siRNA targeting STC-1 completely abolished down-regulation of NLRP3, Caspase-1, and IL-1β by STC-1 and inhibited effects of S-ADSC-Exo on lateral migration and angiogenesis. In vivo administration of S-ADSC-Exo had reendothelialization effect on post-injury carotid endarterium as evidenced by thinner arterial wall, low-expressed NLRP3 inflammasome, and more living endothelial cells. The reendothelialization effect of exosomes from ADSCs on post-injury carotid endarterium can be enhanced by genetic modification to contain elevated STC-1.

scholarly journals GSDMD Mediates LPS-Induced Septic Myocardial Dysfunction by Regulating ROS-dependent NLRP3 Inflammasome Activation

2021 ◽  
Vol 9 ◽  
Author(s):  
Shanshan Dai ◽  
Bozhi Ye ◽  
Lingfeng Zhong ◽  
Yanghao Chen ◽  
Guangliang Hong ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Myocardial Injury ◽  
Troponin I ◽  
Myocardial Dysfunction ◽  
Underlying Mechanism ◽  
Heart Tissue ◽  
Receptor Protein ◽  
Inflammasome Activation ◽  
Mrna Levels ◽  
Tnf Α

Myocardial dysfunction is a serious consequence of sepsis and contributes to high mortality. Currently, the molecular mechanism of myocardial dysfunction induced by sepsis remains unclear. In the present study, we investigated the role of gasdermin D (GSDMD) in cardiac dysfunction in septic mice and the underlying mechanism. C57BL/6 wild-type (WT) mice and age-matched Gsdmd-knockout (Gsdmd-/-) mice were intraperitoneally injected with lipopolysaccharide (LPS) (10 mg/kg) to mimic sepsis. The results showed that GSDMD-NT, the functional fragment of GSDMD, was upregulated in the heart tissue of septic WT mice induced by LPS, which was accompanied by decreased cardiac function and myocardial injury, as shown by decreased ejection fraction (EF) and fractional shortening (FS) and increased cardiac troponin I (cTnI), creatine kinase isoenzymes MB (CK-MB), and lactate dehydrogenase (LDH). Gsdmd-/- mice exhibited protection against LPS-induced myocardial dysfunction and had a higher survival rate. Gsdmd deficiency attenuated LPS-induced myocardial injury and cell death. Gsdmd deficiency prevented LPS-induced the increase of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in serum, as well as IL-1β and TNF-α mRNA levels in myocardium. In addition, LPS-mediated inflammatory cell infiltration into the myocardium was ameliorated and activation of NF-κB signaling pathway and the NOD-like receptor protein 3 (NLPR3) inflammasome were suppressed in Gsdmd-/- mice. Further research showed that in the myocardium of LPS-induced septic mice, GSDMD-NT enrichment in mitochondria led to mitochondrial dysfunction and reactive oxygen species (ROS) overproduction, which further regulated the activation of the NLRP3 inflammasome. In summary, our data suggest that GSDMD plays a vital role in the pathophysiology of LPS-induced myocardial dysfunction and may be a crucial target for the prevention and treatment of sepsis-induced myocardial dysfunction.

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