Peptide OM-LV20 promotes arteriogenesis induced by femoral artery ligature via the miR-29b-3p/VEGFA axis.

BACKGROUND AND AIMS: Therapeutic arteriogenesis is a promising direction for the treatment of ischemic disease caused by atherosclerosis. However, pharmacological or biological approaches to stimulate functional collateral vessels are not yet available. Identifying new drug targets to promote and explore the underlying mechanisms for therapeutic arteriogenesis is necessary. METHODS: Peptide OM-LV20 (20 ng/kg) was administered for 7 consecutive days on rat hindlimb ischemia model, collateral vessel growth was assessed by H&E staining, liquid latex perfusion, and specific immunofluorescence. In vitro, we detected the effect of OM-LV20 on human umbilical vein endothelial cells (HUVEC) proliferation and migration. After transfection, we performed quantitative real-time polymerase chain reaction, in situ-hybridization and dual luciferase reporters to assessed effective miRNAs and target genes. The proteins related to downstream signaling pathways were detected by Western blot. RESULTS: OM-LV20 significantly increased visible collateral vessels and endothelial nitric oxide synthase (eNOS), together with enhanced inflammation cytokine and monocytes/macrophage infiltration in collateral vessels. In vitro, we defined a novel microRNA (miR-29b-3p), and its inhibition enhanced proliferation and migration of HUVEC, as well as the expression of vascular endothelial growth factor A (VEGFA). OM-LV20 also promoted migration and proliferation of HUVEC, and VEGFA expression was mediated via inhibition of miR-29b-3p. Furthermore, OM-LV20 influenced the protein levels of VEGFR2 and phosphatidylinositol3-kinase (PI3K)/AKT and eNOS in vitro and invivo. CONCLUSIONS: Our data indicated that OM-LV20 enhanced arteriogenesis via the miR-29b-3p/VEGFA/VEGFR2-PI3K/AKT/eNOS axis, and highlighte the application potential of exogenous peptide molecular probes through miRNA, which could promote effective therapeutic arteriogenesis in ischemic conditions.

Betaine prevents cognitive dysfunction by suppressing hippocampal microglial activation in chronic social isolated male mice.

Chronic social isolation (SI) stress, which became more prevalent during the COVID-19 pandemic, contributes to abnormal behavior, including mood changes and cognitive impairment. Known as a functional nutrient, betaine has potent antioxidant and anti-inflammatory properties in vivo. However, whether betaine can alleviate the abnormal behavior induced by chronic SI in mice remains unknown. In this study, we investigated the efficacy of betaine in the treatment of behavioral changes and its underlying mechanism. Three-week-old male mice were randomly housed for 8 weeks in either group housing (GH) or SI. The animals were divided into normal saline-treated GH, normal saline-treated SI, and betaine-treated SI groups in the sixth week. The cognitive and depression-like behavior was determined in the eighth week. We found that long-term betaine administration improved cognitive behavior in SI mice but failed to prevent depression-like behavior. Moreover, long-term betaine administration inhibited hippocampal microglia over-activation and polarized microglia toward the M2 phenotype, which effectively inhibited the expression of inflammatory factors in SI mice. Finally, the protective effect of betaine treatment in SI mice might not be due to altered activity of the hypothalamic-pituitary-adrenal axis. Collectively, our findings reveal that betaine can improve SI-induced cognitive impairment, thus providing an alternative natural source for the prevention of memory loss caused by SI or loneliness.

Prognostic value of pretreatment systemic immune-inflammation index in Chinese esophageal squamous cell carcinoma patients receiving radical radiotherapy: A meta-analysis.

BACKGROUND: The association between pretreatment systemic immune-inflammation index (SII) and long-term survival among Chinese esophageal squamous cell carcinoma (ESCC) patients who received radical radiotherapy remains unclear. The aim of this study was to identify the prognostic role of pretreatment SII in Chinese ESCC patients receiving radical radiotherapy based on current evidence. METHODS: The PubMed, EMBASE, Web of Science and CNKI databases were searched up to March 18, 2023. Primary and secondary outcomes were overall survival (OS) and progression-free survival (PFS), respectively. The hazard ratios (HRs) with corresponding 95% confidence intervals (CIs) were combined to assess the predictive role of pretreatment SII for long-term survival of Chinese ESCC patients receiving radiotherapy. All statistical analyses were conducted by STATA 15.0 software. RESULTS: A total of 8 eligibility studies involving 2101 cases were included in this meta-analysis. The pooled results demonstrated that elevated pretreatment SII was significantly related to worse OS (HR = 1.59, 95% CI: 1.24-2.02, P < .001) and PFS (HR = 1.33, 95% CI: 1.13-1.57, P < .001). Besides, subgroup based on TNM stage showed similar results. CONCLUSION: Pretreatment SII could serve as a novel prognostic factor in Chinese ESCC patients receiving definitive radiotherapy and patients with an elevated SII may experience poorer survival.

Inflammatory Cytokines Changed in Patients With Depression Before and After Repetitive Transcranial Magnetic Stimulation Treatment.

Studies have found that repetitive transcranial magnetic stimulation rTMS can produce antidepressant effects by affecting inflammatory cytokines in patients with depression, which plays a key role in the therapeutic mechanism of antidepressants. This study aimed to explore the changes in inflammatory cytokine levels in patients with depression after 4 weeks of rTMS treatment to determine the possible antidepressant mechanism of rTMS. This prospective, double-blind, pseudo-stimulus-controlled study was conducted, and a total of 57 patients with depression and 30 healthy controls were recruited. Patients were randomly divided into the active rTMS (n = 29) and sham rTMS groups (n = 28). The Hamilton Depression Scale was used to evaluate depressive symptoms and their severity. The serum levels of seven inflammatory cytokines were measured using enzyme-linked immunosorbent assay. Inflammatory cytokines include high-sensitivity C-reactive protein (CRP-hc); tumor necrosis factor (TNF-α); interferon (IFN-γ); interleukin-2 (IL-2); interleukin-4 (IL-4); interleukin-6 (IL-6); and interleukin-8 (IL-8). At baseline, TNF-α (F = 36.699, p < 0.001), IFN-γ (F = 8.907, p < 0.001), IL-4 (F = 66.256, p < 0.001), and IL-2 (F = 9.162, p < 0.001) levels in the depression group were significantly different from those of healthy controls. In the self-control analysis of the active rTMS group, the levels of IL-2 and CRP-hc increased significantly after 2 and 12 weeks of treatment. In the sham-rTMS group, IFN-γ increased after 2 and 12 weeks of treatment. Our results revealed that the changes in inflammatory cytokines after rTMS treatment showed different patterns compared to the sham group, suggesting that the antidepressant effect of rTMS may be related to changes in inflammatory cytokines.

A new peptide originated from amphibian skin alleviates the ultraviolet B-induced skin photodamage.

Although amphibian-derived bioactive peptides have attracted increasing attention for their potential use in the treatment of photodamage, research is still in its infancy. In this study, we obtained a new antioxidant peptide, named OA-GI13 (GIWAPWPPRAGLC), from the skin of the odorous frog Odorrana andersonii and determined its effects on ultraviolet B (UVB)-induced skin photodamage as well as its possible molecular mechanisms. Results showed that OA-GI13 directly scavenged free radicals, maintained the viability of hydrogen peroxide-challenged keratinocytes, promoted the release of superoxide dismutase, catalase, and glutathione, and reduced the level of lactate dehydrogenase. Furthermore, topical application of OA-GI13 in mice alleviated dorsal skin erythema and edema and protected the skin against UVB irradiation by increasing antioxidant levels and decreasing peroxide, malondialdehyde, and 8-hydroxydeoxyguanosine levels. OA-GI13 also alleviated oxidative stress injury in vivo and in vitro, possibly by inhibiting p38 protein phosphorylation. Our study confirmed the anti-photodamage effects of this novel amphibian-derived peptide, thus providing a new molecule for the development of drugs and topical agents for the treatment of skin photodamage.

A novel amphibian-derived peptide alleviated ultraviolet B-induced photodamage in mice.

Although the application potential of amphibian skin-derived active peptides in alleviating ultraviolet B (UVB)-induced damage has attracted increasing attention, research remains in its infancy. In this study, a new peptide (OM-GL15, GLLSGHYGRASPVAC) was identified from the skin of the green odorous frog (Odorrana margaretae). Results showed that OM-GL15 scavenged free radicals (2,2'-diazo-bis-3-ethylbenzothiazoline-6-sulfonic acid and 1,1-diphenyl-2-trinitrophenylhydrazine) and reduced Fe3+ to Fe2+. Moreover, topical administration of OM-GL15 significantly alleviated UVB-induced skin photodamage in mice. Exploration of the underlying mechanisms further showed that OM-GL15 exerted antioxidant potency. Specifically, the peptide reduced the levels of lipid peroxidation and malondialdehyde and protected epidermal cells from UVB-induced apoptosis by inhibiting DNA damage via down-regulation of p53, caspase-3, caspase-9, and Bax and up-regulation of Bcl-2. Our results highlight the potential application of amphibian skin-derived peptides in protection against UVB-induced photodamage and provide a novel peptide candidate for the development of anti-photodamage agents.

Effect and Molecular Mechanisms of Collateral Vessel Growth Mediated by Activation of Transient Receptor Potential Vanilloid Type 1.

Information on the function of transient receptor potential vanilloid 1 (TRPV1) in arteriogenesis is limited. We aimed to verify whether TRPV1 is involved in collateral vessel growth in rat hind limbs and elucidate the possible subcellular action mechanisms. Adult Sprague Dawley rats were chosen to establish the hind limb ischemic model and treatment with capsaicin. Angiographies were performed, and tissue was isolated for immunohistochemistry. In vitro, rat aortic endothelial cells (RAECs) were treated with capsaicin and antagonist capsazepine. The RAEC proliferation was determined, and the protein and mRNA levels of Ca2+-dependent transcription factors were assessed. In vivo, the collateral vessels exhibited positive outward remodeling characterized by enhanced inflammatory cell/macrophage accumulation in the adventitia and activated cell proliferation in all layers of the vascular wall and elevated endothelial NO synthetase expression in the rats with hind limb ligation. In RAECs, TRPV1 activation-induced Ca2+-dependent transcriptional factors, nuclear factor of activated T cells 1, calsenilin and myocyte enhancer factor 2C increase, and augmented RAEC proliferation could be a subcellular mechanism for TRPV1 in endothelial cells and ultimately contribute to collateral vessel growth. TRPV1, a novel candidate, positively regulates arteriogenesis, meriting further studies to unravel the potential therapeutic target leading to improved collateral vessel growth for treating ischemic diseases.

Potential skin protective effects after UVB irradiation afforded by an antioxidant peptide from Odorrana andersonii.

With increasing demand, the development of new natural antioxidants has become a primary direction of scientific research. We previously identified a short gene-encoded peptide (OA-VI12) from Odorrana andersonii frog skin secretions that exerted direct scavenging capacity against free radicals, suggesting a possible function in protecting skin against photodamage caused by their high-altitude habitat. In the current research, we examined the effects of OA-VI12 on both UVB-irradiation and hydrogen peroxide-induced oxidative stress models established with human immortalized keratinocytes. In addition, we identified the differentially expressed genes (DEGs) in the oxidative stress and OA-VI12 groups and further performed transcriptome as well as functional and pathway enrichment analyses. Results showed that OA-VI12 protected cell viability, promoted the release of catalase, and decreased the levels of lactate dehydrogenase and reactive oxygen species. Moreover, the peptide promoted the production of superoxide dismutase and glutathione, alleviated epidermis and dermis thickness, and decreased the production of light spots and collagen fibers in skin from the photo-injured mouse model. Kyoto Encyclopedia of Genes and Genomes analysis showed mitogen-activated protein kinase (MAPK) to be the most abundant signaling pathway. Gene Ontology (GO) analysis indicated that the top 55 significantly enriched GO terms mainly involved cellular processes, parts, and binding. These results revealed the beneficial role of the small molecule gene-encoding antioxidant peptide (OA-VI12) and its potential application as a protective agent against photodamage.

A short peptide potentially promotes the healing of skin wound.

Skin wound, a common form of skin damage in daily life, remains a serious challenge in clinical treatment. Bioactive peptides with high efficiency have been considered as potential therapeutic candidates for wound healing. In this report, a novel short linear peptide, with mature peptide sequence of 'GLLSGINAEWPC' and no obvious similarity with other known bioactive peptides, was identified by genomic method from the skin of odorous frog, Odorrana andersonii Our results suggested that OA-GL12 (OA: abbreviation of species (O. andersonii), GL: two initial amino acids, 12: peptide length) obviously accelerated the scratch-healing of keratinocytes and human fibroblasts in a time- and concentration-dependent manner. Meanwhile, OA-GL12 showed significant effect in promoting the wound healing on the full-thickness skin wound model. Inflammatory assay results demonstrated that OA-GL12 induced the secretion of tumor necrosis factor (TNF) and transforming growth factor ß1 (TGF-ß1) on murine macrophage cell line (RAW264.7), which might explain the powerful accelerating capacity of wound healing. Moreover, results also indicated that epidermal growth factor receptor (EGFR) was involved in the mechanisms underlying the scratch-healing promoting activity of OA-GL12. In addition, OA-GL12 showed obvious free radical scavenging activity. Results supported that OA-GL12 did not exert risk in acute toxicity, hemolytic activity, and direct antibacterial activity. The remarkable effect of OA-GL12 on promoting wound healing verified in this research made it potential to be a novel template for the development of wound healing-promoting agents.

Collateral vessel growth induced by femoral artery ligature is impaired by denervation.

Innervation plays an important role in development and remodeling of blood vessels. However, very little is known whether innervation is involved in arteriogenesis. In the present study, we tested the hypothesis that innervation may contribute to the process of arteriogenesis induced by ligature of femoral artery in rat/rabbit hind limb with or without denervation. We found that: (1) angiography showed more collateral vessels in the ligature side than that in ligature plus denervation side; (2) collateral vessels in denervation side was characterized by an inward remodeling; (3) in both collateral vessels (CVs) from only femoral ligature side as well as the ligature plus denervation side, ICAM-1 and VCAM-1 expression was up-regulated but increased VCAM-1 was more evident in the adventitia of collateral vessels of only femoral ligature side; (4) 7 days after surgery, in CVs from the femoral ligature side only, numerous macrophages (RAM11 positive cells) and high cell proliferation ratio (ki67 positive cells) were detected, but they were less in the denervation side. In conclusion, our data demonstrate for the first time that neural regulation is one of the factors that contributes to collateral vessel growth in rat/rabbit hind limb ischemic model by showing collateral vessel growth induced by femoral artery ligature is impaired by denervation.