Deficiency of Procollagen C-Proteinase Enhancer 1 in Mice has No Major Impact on Cardiac Collagen and Function Under Basal Conditions

Single-cell transcriptome reveals effects of semaglutide on non-cardiomyocytes of obese mice

Non-cardiomyocytes (nonCMs) play an important part in cardiac fibrosis pathophysiology, but the underlying molecular pathways are unknown. Semaglutide has cardioprotective properties, but it is still unclear whether it helps with cardiac fibrosis and what the processes are. The goal of this study is to use single cell transcriptomics approaches to investigate the molecular mechanism of semaglutide's cardioprotective action in obese mice. We found 15 non-CMs, with fibroblasts making up the majority of them. We found eight DEGs that altered significantly following semaglutide treatment by screening for differentially expressed genes (DEGs). DEGs were shown to have biological activities primarily related to extracellular matrix and collagen synthesis and distribution, with Serpinh1 and Pcolce expression being the most dramatically altered. Serpinh1 and Pcolce were mostly found in fibroblasts, which play a key role in the fibrosis of the heart. Furthermore, we discovered that semaglutide lowered cardiac collagen content and alleviated obesity-induced ventricular wall hypertrophy. As a result, our findings show that Serpinh1 and Pcolce, which are expressed by fibroblasts, may play a role in the development of obese cardiac fibrosis. By reducing Serpinh1 and Pcolce expression and delaying cardiac fibrosis, semaglutide may have a cardioprotective effect.

Hypoxia Alters the Proteome Profile and Enhances the Angiogenic Potential of Dental Pulp Stem Cell-Derived Exosomes

Dental pulp stem cells (DPSCs) and their exosomes (Exos) are effective treatments for regenerative medicine. Hypoxia was confirmed to improve the angiogenic potential of stem cells. However, the angiogenic effect and mechanism of hypoxia-preconditioned DPSC-Exos are poorly understood. We isolated exosomes from DPSCs under normoxia (Nor-Exos) and hypoxia (Hypo-Exos) and added them to human umbilical vein endothelial cells (HUVECs). HUVEC proliferation, migration and angiogenic capacity were assessed by CCK-8, transwell, tube formation assays, qRT-PCR and Western blot. iTRAQ-based proteomics and bioinformatic analysis were performed to investigate proteome profile differences between Nor-Exos and Hypo-Exos. Western blot, immunofluorescence and immunohistochemistry were used to detect the expression of lysyl oxidase-like 2 (LOXL2) in vitro and in vivo. Finally, we silenced LOXL2 in HUVECs and rescued tube formation with Hypo-Exos. Hypo-Exos enhanced HUVEC proliferation, migration and tube formation in vitro superior to Nor-Exos. The proteomics analysis identified 79 proteins with significantly different expression in Hypo-Exos, among which LOXL2 was verified as being upregulated in hypoxia-preconditioned DPSCs, Hypo-Exos, and inflamed dental pulp. Hypo-Exos partially rescued the inhibitory influence of LOXL2 silence on HUVEC tube formation. In conclusion, hypoxia enhanced the angiogenic potential of DPSCs-Exos and partially altered their proteome profile. LOXL2 is likely involved in Hypo-Exos mediated angiogenesis.

Procollagen C-Proteinase Enhancer-1 (PCPE-1) deficiency in mice reduces liver fibrosis but not NASH progression

Background and aims

Nonalcoholic Steatohepatitis (NASH) is a major cause of end-stage liver diseases such as cirrhosis and hepatocellular carcinoma resulting ultimately in increased liver-related mortality. Fibrosis is the main driver of mortality in NASH. Procollagen C-Proteinase Enhancer-1 (PCPE-1) plays a key role in procollagen maturation and collagen fibril formation. To assess its role in liver fibrosis and NASH progression, knock-out mice were evaluated in a dietary NASH model.

Methods

Global constitutive Pcolce^-/- and WT male mice were fed with a Choline Deficient Amino acid defined High Fat Diet (CDA HFD) for 8 weeks. Liver triglycerides, steatosis, inflammation and fibrosis were assessed at histological, biochemical and gene expression levels. In addition, human liver samples from control and NASH patients were used to evaluate the expression of PCPE-1 at both mRNA and protein levels.

Results

Pcolce gene deficiency prevented diet-induced liver enlargement but not liver dysfunction. Furthermore, liver triglycerides, steatosis and inflammation were not modified in Pcolce^-/- male mice compared to WT under CDA HFD. However, a significant decrease in liver fibrosis was observed in Pcolce^-/- mice compared to WT under NASH diet, associated with a decrease in total and insoluble collagen content without any significant modifications in the expression of genes involved in fibrosis and extracellular matrix remodeling. Finally, PCPE-1 protein expression was increased in cirrhotic liver samples from both NASH and Hepatitis C patients.

Conclusions

Pcolce deficiency limits fibrosis but not NASH progression in CDA HFD fed mice.