Expression of ADAMTS-1 mRNA in myocardium of viral heart disease mice and its clinical significance

hKLK alleviates myocardial fibrosis in mice with viral myocarditis

Myocardial fibrosis is the most serious complication of viral myocarditis (VMC). This study aimed to investigate the therapeutic benefits and underlying mechanisms of lentivirus-mediated human tissue kallikrein gene transfer in myocardial fibrosis in VMC mice. We established VMC mouse model via intraperitoneal injection with Coxsackie B3 virus. The effect was then assessed after treatment with vehicle, the empty lentiviral vectors (EZ.null), and the vectors expressing hKLK1 (EZ.hKLK1) via tail vein injection for 30 days, respectively. The results showed that administering EZ.hKLK1 successfully induced hKLK1 overexpression in mouse heart. Compared with EZ.null treatment, EZ.hKLK1 administration significantly reduced the heart/weight ratio, improved cardiac function, and ameliorated myocardial inflammation in VMC mice, suggesting that hKLK1 overexpression alleviates VMC in mice. EZ.hKLK1 administration also significantly abrogated the increased myocardial collagen content, type I/III collagen ratio, TGF-β1 mRNA and protein expression in VMC mice, suggesting that hKLK1 overexpression reduces collagen accumulation and blunts TGF-β1 signaling in the hearts of VMC mice. In conclusion, our results suggest that hKLK1 alleviates myocardial fibrosis in VMC mice, possibly by downregulating TGF-β1 expression.

Yixin Granules Reduce Myocardial Inflammation and Fibrosis in Rats with Heart Failure by Inhibiting the Expression of ADAMTS8

Yixin granules are medications modified from a Chinese prescription (Sheng Xian Tang) that has been used to alleviate shortness of breath. ADAM metallopeptidase with thrombospondin type 1 motif 8 (ADAMTS8) is upregulated in the myocardium of patients with dilated cardiomyopathy. Its high expression is associated with tumor necrosis factor (TNF) -α and myocardial fibrosis. This study aimed to explore the effect of Yixin granules on heart failure (HF) in rats and whether this effect is correlated with ADAMTS8 to provide new ideas for the treatment of HF.HF rat models were established by ligation of the left anterior descending coronary artery. Model rats were injected with adeno-associated virus vectors for the overexpression of ADAMTS8 and/or treated with Yixin granules for 4 weeks. Hematoxylin-eosin and Masson staining were used to detect myocardial injury and fibrosis, respectively. Reverse transcription polymerase chain reaction, western blotting, and/or enzyme-linked immunosorbent assay were used to detect the expression of ADAMTS8, TNF-α, interleukin (IL) -1β, IL-6, collagen I, collagen III, and α-smooth muscle actin in myocardium. The myocardial infarction area of rats was measured using 2,3,5-triphenyltetrazolium chloride staining.ADAMTS8 was upregulated in the myocardium of HF rats. Yixin granule treatment improved left ventricular contractility and reduced ADAMTS8 expression, myocardial injury, inflammation, and fibrosis in HF rats. ADAMTS8 overexpression aggravated myocardial injury, inflammation, and fibrosis. Moreover, ADAMTS8 overexpression counteracted the cardioprotective effects of Yixin granules.Yixin granules may reduce myocardial inflammation and fibrosis in HF rats by inhibiting the expression of ADAMTS8.

Dynamic resistance exercise increases skeletal muscle-derived FSTL1 inducing cardiac angiogenesis via DIP2A-Smad2/3 in rats following myocardial infarction

PURPOSE

The aim of this study was to investigate the potential of dynamic resistance exercise to generate skeletal muscle-derived follistatin like-1 (FSTL1), which may induce cardioprotection in rats following myocardial infarction (MI) by inducing angiogenesis.

METHODS

Male, adult Sprague-Dawley rats were randomly divided into 5 groups (n = 12 in each group): sham group (S), sedentary MI group (MI), MI + resistance exercise group (MR), MI + adeno-associated virus (AAV)-FSTL1 injection group (MA), and MI + AAV-FSTL1 injection + resistance exercise group (MAR). The AAV-FSTL1 vector was prepared by molecular biology methods and injected into the anterior tibialis muscle. The MI model was established by ligation of the left anterior descending coronary artery. Rats in the MR and MAR groups underwent 4 weeks of dynamic resistance exercise training using a weighted climbing-up ladder. Heart function was evaluated by hemodynamic measures. Collagen volume fraction of myocardium was observed and analyzed by Masson's staining. Human umbilical vein vessel endothelial cells culture and recombinant human FSTL1 protein or transforming growth factor-β receptor 1 (TGFβR1) inhibitor treatment were used to elucidate the molecular signaling mechanism of FSTL1. Angiogenesis, cell proliferation, and disco interacting protein 2 homolog A (DIP2A) location were observed by immunofluorescence staining. The expression of FSTL1, DIP2A, and the activation of signaling pathways were detected by Western blotting. Angiogenesis of endothelial cells was observed by tubule experiment. One-way analysis of variance and Student's t test were used for statistical analysis.

RESULTS

Resistance exercise stimulated the secretion of skeletal muscle FSTL1, which promoted myocardial angiogenesis, inhibited pathological remodeling, and protected cardiac function in MI rats. Exercise facilitated skeletal muscle FSTL1 to play a role in protecting the heart. Exogenous FSTL1 promoted the human umbilical vein vessel endothelial cells proliferation and up-regulated the expression of DIP2A, while TGFβR1 inhibitor intervention down-regulated the phosphorylation level of Smad2/3 and the expression of vascular endothelial growth factor-A, which was not conducive to angiogenesis. FSTL1 bound to the receptor, DIP2A, to regulate angiogenesis mainly through the Smad2/3 signaling pathway. FSTL1-DIP2A directly activated Smad2/3 and was not affected by TGFβR1.

CONCLUSION

Dynamic resistance exercise stimulates the expression of skeletal muscle-derived FSTL1, which could supplement the insufficiency of cardiac FSTL1 and promote cardiac rehabilitation through the DIP2A-Smad2/3 signaling pathway in MI rats.

Network analysis of Down syndrome and SARS-CoV-2 identifies risk and protective factors for COVID-19

SARS-CoV-2 infection has spread uncontrollably worldwide while it remains unknown how vulnerable populations, such as Down syndrome (DS) individuals are affected by the COVID-19 pandemic. Individuals with DS have more risk of infections with respiratory complications and present signs of auto-inflammation. They also present with multiple comorbidities that are associated with poorer COVID-19 prognosis in the general population. All this might place DS individuals at higher risk of SARS-CoV-2 infection or poorer clinical outcomes. In order to get insight into the interplay between DS genes and SARS-cov2 infection and pathogenesis we identified the genes associated with the molecular pathways involved in COVID-19 and the host proteins interacting with viral proteins from SARS-CoV-2. We then analyzed the overlaps of these genes with HSA21 genes, HSA21 interactors and other genes consistently differentially expressed in DS (using public transcriptomic datasets) and created a DS-SARS-CoV-2 network. We detected COVID-19 protective and risk factors among HSA21 genes and interactors and/or DS deregulated genes that might affect the susceptibility of individuals with DS both at the infection stage and in the progression to acute respiratory distress syndrome. Our analysis suggests that at the infection stage DS individuals might be more susceptible to infection due to triplication of TMPRSS2, that primes the viral S protein for entry in the host cells. However, as the anti-viral interferon I signaling is also upregulated in DS, this might increase the initial anti-viral response, inhibiting viral genome release, viral replication and viral assembly. In the second pro-inflammatory immunopathogenic phase of the infection, the prognosis for DS patients might worsen due to upregulation of inflammatory genes that might favor the typical cytokine storm of COVID-19. We also detected strong downregulation of the NLRP3 gene, critical for maintenance of homeostasis against pathogenic infections, possibly leading to bacterial infection complications.

Roles of Biomarkers in Myocardial Fibrosis

Myocardial fibrosis is observed in various cardiovascular diseases and plays a key role in the impairment of cardiac function. Endomyocardial biopsy, as the gold standard for the diagnosis of myocardial fibrosis, has limitations in terms of clinical application. Therefore, biomarkers have been recommended for noninvasive assessment of myocardial fibrosis. This review discusses the role of biomarkers in myocardial fibrosis from the perspective of collagen.

ADAMTS12 acts as a cancer promoter in colorectal cancer via activating the Wnt/β-catenin signaling pathway in vitro

Background

ADAMTS12, a member of the ADAMTS family, is reported to be associated with the clinic outcome of colorectal cancer (CRC) patients. However, the functions and precise mechanism in CRC progression have yet to be fully understood.

Methods

By analyzing The Cancer Genome Atlas (TCGA) database, we examined the mRNA level of ADAMTS12 and assessed the prognostic value of ADAMTS12 in CRC patients using a tissue microarray containing 41 CRC patient samples. Cell Counting Kit-8 (CCK-8), colony formation, and transwell assays were used to quantify the impact of ADAMTS12 on cell proliferation and migration in ADAMTS12-overexpressing and ADAMTS12-deficient cell lines. The signaling pathways that ADAMTS12 mediated were identified by dual-luciferase reporter assays, and confirmed by western blotting and quantitative teal-time polymerase chain reaction (qRT-PCR).

Results

The ADAMTS12 mRNA level was upregulated in CRC tissues, and CRC patients with a high level of ADAMTS12 showed worse prognosis when compared with the patients with a low level of ADAMTS12. In vitro functional assays demonstrated that overexpression of ADAMTS12 significantly boosted cell proliferation and migration while ADAMTS12 deficiency remarkably impaired both tumor cell behaviors. Mechanical studies further verified that ADAMTS12 overexpression enhanced the transcriptional activity of β-catenin in the Wnt/β-catenin signaling pathway. In the ADAMTS12-deficient context, the downstream gene expression of myc and cyclin D1 was significantly reduced compared with that in wild-type cancer cells.

Conclusions

ADAMTS12 fulfills the tumor-promotor role by activating Wnt/β-catenin signaling pathway in colon cells and may represent a new option in CRC target treatment.