Effect of alprostadil on myocardial fibrosis in rats with diabetes mellitus via TGF-β1/Smad signaling pathway

1α,25-Dihydroxyvitamin D3 Promotes Angiogenesis After Cerebral Ischemia Injury in Rats by Upregulating the TGF-β/Smad2/3 Signaling Pathway

Stroke is a disease with high morbidity, disability and mortality, which seriously endangers the life span and quality of life of people worldwide. Angiogenesis and neuroprotection are the key to the functional recovery of penumbra function after acute cerebral infarction. In this study, we used the middle cerebral artery occlusion (MCAO) model to investigate the effects of 1α,25-dihydroxyvitamin D3 (1,25-D3) on transforming growth factor-β (TGF-β)/Smad2/3 signaling pathway. Cerebral infarct volume was measured by TTC staining. A laser speckle flow imaging system was used to measure cerebral blood flow (CBF) around the ischemic cortex of the infarction, followed by platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) and isolectin-B4 (IB4) immunofluorescence. The expression of vitamin D receptor (VDR), TGF-β, Smad2/3, p-Smad2, p-Smad3, and vascular endothelial growth factor (VEGF) was analyzed by western blot and RT-qPCR. Results showed that compared with the sham group, the cerebral infarction volume was significantly increased while the CBF was reduced remarkably in the MCAO group. 1,25-D3 reduced cerebral infarction volume, increased the recovery of CBF and expressions of VDR, TGF-β, p-Smad2, p-Smad3, and VEGF, significantly increased IB4⁺ tip cells and CD31⁺ vascular length in the peri-infarct area compared with the DMSO group. The VDR antagonist pyridoxal-5-phosphate (P5P) partially reversed the neuroprotective effects of 1,25-D3 described above. In summary, 1,25-D3 plays a neuroprotective role in stroke by activating VDR and promoting the activation of TGF-β, which in turn up-regulates the TGF-β/Smad2/3 signaling pathway, increases the release of VEGF and thus promotes angiogenesis, suggesting that this signaling pathway may be an effective target for ischemic stroke treatment. 1,25-D3 is considered to be a neuroprotective agent and is expected to be an effective drug for the treatment of ischemic stroke and related diseases.

Huiyang Shengji Extract Improve Chronic Nonhealing Cutaneous through the TGF-β1/Smad3 Signaling Pathway

Chronic nonhealing cutaneous wounds are a thorny problem in the field of surgery because of their prolonged and unhealed characteristics. Huiyang Shengji extract (HSE) is an extract of traditional Chinese medicine prescription for treating chronic wounds. This study aims to investigate the regulation of M1 macrophages on fibroblast proliferation and secretion and the intervention mechanism of Huiyang Shengji extract. We found that the effects of HSFs stimulated with paracrine factors from M1 macrophages were as follows: the proliferation of HSFs was reduced, the expression of MKI-67 was downregulated, and the content and gene expression of the inflammation factors and fibroblast MMPs were increased, while the content and gene expression of TIMP-1 are decreased, the content of human fibroblasts secreting type I collagen (COL1A1) and type III collagen (COL3A1) was decreased, and the TGF-β1/Smad3 signaling pathway was inhibited. Interestingly, HSE inhibited these effects of M1 macrophages on human fibroblasts after the intervention, and the inhibitory effect was related to the concentration. In conclusion, M1 macrophages caused changes in HSFs and secretion, while HSE has a specific regulatory effect on the proliferation and secretion of fibroblasts caused by M1 macrophages.

Activation of the cardiac non-neuronal cholinergic system prevents the development of diabetes-associated cardiovascular complications

BACKGROUND

Acetylcholine (ACh) plays a crucial role in the function of the heart. Recent evidence suggests that cardiomyocytes possess a non-neuronal cholinergic system (NNCS) that comprises of choline acetyltransferase (ChAT), choline transporter 1 (CHT1), vesicular acetylcholine transporter (VAChT), acetylcholinesterase (AChE) and type-2 muscarinic ACh receptors (M2AChR) to synthesize, release, degrade ACh as well as for ACh to transduce a signal. NNCS is linked to cardiac cell survival, angiogenesis and glucose metabolism. Impairment of these functions are hallmarks of diabetic heart disease (DHD). The role of the NNCS in DHD is unknown. The aim of this study was to examine the effect of diabetes on cardiac NNCS and determine if activation of cardiac NNCS is beneficial to the diabetic heart.

METHODS

Ventricular samples from type-2 diabetic humans and db/db mice were used to measure the expression pattern of NNCS components (ChAT, CHT1, VAChT, AChE and M2AChR) and glucose transporter-4 (GLUT-4) by western blot analysis. To determine the function of the cardiac NNCS in the diabetic heart, a db/db mouse model with cardiac-specific overexpression of ChAT gene was generated (db/db-ChAT-tg). Animals were followed up serially and samples collected at different time points for molecular and histological analysis of cardiac NNCS components and prosurvival and proangiogenic signaling pathways.

RESULTS

Immunoblot analysis revealed alterations in the components of cardiac NNCS and GLUT-4 in the type-2 diabetic human and db/db mouse hearts. Interestingly, the dysregulation of cardiac NNCS was followed by the downregulation of GLUT-4 in the db/db mouse heart. Db/db-ChAT-tg mice exhibited preserved cardiac and vascular function in comparison to db/db mice. The improved function was associated with increased cardiac ACh and glucose content, sustained angiogenesis and reduced fibrosis. These beneficial effects were associated with upregulation of the PI3K/Akt/HIF1α signaling pathway, and increased expression of its downstream targets-GLUT-4 and VEGF-A.

CONCLUSION

We provide the first evidence for dysregulation of the cardiac NNCS in DHD. Increased cardiac ACh is beneficial and a potential new therapeutic strategy to prevent or delay the development of DHD.