Velvet antler polypeptide is able to induce differentiation of neural stem cells towards neurons in vitro

Velvet antler polypeptide (VAP) protects against cerebral ischemic injury through NF-κB signaling pathway in vitro

OBJECTIVE

Velvet antler polypeptide (VAP) has been shown to play important roles in the immune and nervous systems. The purpose of this study was to investigate the protective effects of VAP on cerebral ischemic injury with the involvement of NF-κB signaling pathway in vitro.

MATERIALS AND METHODS

PC-12 cells stimulated by oxygen-glucose deprivation/reperfusion (OGD/R) was used to mimic cerebral ischemic injury in vitro. The levels of ROS, SOD, and intracellular concentrations of Ca2+ were measured by the relevant kits. Meanwhile, the expressions of inflammatory cytokines (IL-6, IL-1β, and TNF-α) were determined by ELISA kit assay. In addition, MTT, EdU, and flow cytometry assays were used to measure the cell proliferation and apoptosis. Besides which, the related proteins of NF-κB signaling pathway were measured by western blotting assay.

RESULTS

VAP alleviated cerebral ischemic injury by reducing OGD/R-induced oxidative stress, inflammation, and apoptosis in PC-12 cells in a time dependent manner. Mechanistically, VAP inhibited the levels of p-p65 and p-IkB-α in a time dependent manner, which was induced by OGD/R operation. Moreover, NF-κB agonist diprovocim overturned the suppression effects of VAP on OGD/R-induced oxidative stress, inflammation, and apoptosis in PC-12 cells.

CONCLUSIONS

The results demonstrate that VAP may alleviate cerebral ischemic injury by suppressing the activation of NF-κB signaling pathway.

Bridging neurotrophic factors and bioactive peptides to Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disorder. As the demographic shifting towards an aging population, AD has emerged as a prominent public health concern. The pathogenesis of AD is complex, and there are no effective treatment methods for AD until now. In recent years, neurotrophic factors and bioactive peptides including brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), irisin, melatonin, have been discovered to exert neuroprotective functions for AD. Bioactive peptides can be divided into two categories based on their sources: endogenous and exogenous. This review briefly elaborates on the pathogenesis of AD and analyzes the regulatory effects of endogenous and exogenous peptides on the pathogenesis of AD, thereby providing new therapeutic targets for AD and a theoretical basis for the application of bioactive peptides as adjunctive therapies for AD.

Well-known polypeptides of deer antler velvet with key actives: modern pharmacological advances

Deer antler velvet, with kidney tonifying, promoting the production of essence and blood, strengthening tendons and bones, not only has a thousand-year medicinal history but also its modern pharmacology mainly focuses on its active polypeptides on motor, nerve, and immune systems. The purpose of this report is to fill the gap in the comprehensive, systematic, and detailed review of polypeptides during the recent 30 years (1992-2023). The research method was to review 53 pharmacological articles from the Public Medicine, Web of science, ACS, and Science Direct database sources by searching the keywords "pilose antler," "deer velvet," "Pilose Antler Peptide (PAP) and Velvet Antler Polypeptide (VAP)." The results showed that deer antler polypeptides (DAPs), by regulating EGF, EGFR, MAPK, P38, ERK, NF-κB, Wnt, PI3K, Akt, MMP, AMPK, Stir1, NLRP3, HO-1, Nrf, Rho, TLR, TGF-β, Smad, Ang II, etc., revealed their effects on seven system-related diseases and their mechanisms, including osteoarthritis, intervertebral disc degeneration, osteoporosis, Alzheimer's, Parkinson's, triple-negative breast cancer, liver injury, liver fibrosis, cardiovascular disease, acute lung injury, and late-onset hypogonadism. In conclusion, DAPs have good effects on motor and other system-related diseases, but the secondary and tertiary structures of DAPs (0.5-1800 KDa) need to be further elucidated, and the structure-activity relationship study is still unavailable and needs to be covered. It is expected that this review may provide the necessary literature support for further research. The activities and mechanisms of polypeptides from the past 30 years (1992-2023) are summarized covering seven systems, related diseases, and its regulatory genes and proteins.

Multiomics Strategy Reveals the Mechanism of Action and Ameliorating Effect of Deer Velvet Antler Water Extracts on DSS-Induced Colitis

Velvet antler is a precious traditional Chinese medicine used for thousands of years. This study investigated the anti-colitis effects of water extracts of Formosan sambar deer (SVAE) and red deer (RVAE) to identify the possible mechanisms and the bioactive compounds using a dextran sulfate sodium (DSS)-induced colitis mouse model. The mechanism of action and the ameliorating effects of SVAE and RVAE on DSS-induced colitis were evaluated using a mouse model. Ultra-high performance liquid chromatography-mass/mass and gas chromatography-mass/mass were applied to identify the bioactive components of the SVAE and RVAE water extracts. The results revealed that both high-dose SVAE and RVAE could ameliorate the symptoms of colitis due to reduced systemic inflammatory responses, enhanced intestinal barrier integrity by restoration of tight junction proteins, and improved gut dysbiosis. The potentially bioactive components of SVAE and RVAE were identified as small molecules (<3 kDa). Further identification by untargeted metabolomics analysis suggested that l-carnitine, hypoxanthine, adrenic acid, creatinine, gamma-aminobutyric-lysine, oleic acid, glycine, poly-γ-glutamic acid, and eicosapentaenoic acid in VAWEs might be involved in ameliorating the symptoms of colitis. This study provided evidence for the potential usage of SVAE and RVAE as anti-colitis agents.

Velvet antler polypeptide combined with calcium phosphate coating to protect peripheral nerve cells from oxidative stress

Functionalizing biomaterial substrates with biological signals shows promise in regulating cell behaviors through mimicking cellular microenvironment. Calcium phosphate (CaP) coating is an excellent carrier for immobilizing biological molecules due to its non-toxicity, good biocompatibility, biodegradability, and favorable affinity to plenty of molecules. In this study, we reported the adhesion, the viability and proliferation behaviors after oxidative stress injury of Schwann cells RSC96 on CaP immobilized with the Velvet Antler Peptide (VAP) isolated from velvet antler through coprecipitation process in modified Dulbecco's phosphate-buffered saline (DPBS) containing VAP. This approach provided well retention of functional molecules up to 28 days, and supported the adhesion and proliferation of RSC96 after oxidative stress injury without cytotoxicity. The simple and reproducible method of coprecipitation suggests that CaP is an ideal carrier to functionalize materials with biological molecules for peripheral nerve repair-related applications.

Velvet antler polypeptide-loaded polyvinyl alcohol-sodium alginate hydrogels promote the differentiation of neural progenitor cells in 3D towards oligodendrocytes in vitro

Three-dimensional (3D) culture of neural progenitor cells (NPCs) in hydrogels represents a powerful means for recapitulating neurodevelopment, disease modelling and drug discovery. However, the differentiation of NPCs to oligodendrocytes in 3D scaffolds remains a great challenge. In this study, polyvinyl alcohol (PVA) - sodium alginate (SA) composite hydrogels intended for NPC culture in 3D were fabricated by ionic crosslinking between SA and calcium ions. It was demonstrated that adding PVA to the composite hydrogels resulted in increases in pore size and swelling rate and decreases in elastic moduli as the PVA proportion was enhanced. In addition, the composite hydrogels were biocompatible with mouse NPCs and improved the proliferation of the encapsulated NPCs compared with SA hydrogels. Moreover, when velvet antler polypeptides (VAPs), which were capable of facilitating the differentiation of NPCs to oligodendrocyte fate in 2D, were loaded into PVA-SA hydrogels, NPCs differentiated into neurons, astrocytes and oligodendrocytes, with the presence of VAPs promoting oligodendrogenesis in a dose-dependant manner. The present composite hydrogels provide a suitable scaffold for the construction of neural tissue engineering and neurological disease modelling.