Emerging roles of protein O-GlcNAcylation in cardiovascular diseases: Insights and novel therapeutic targets

Cardiovascular diseases (CVDs) are the leading cause of death globally. While the major focus of pharmacological and non-pharmacological interventions has been on targeting disease pathophysiology and limiting predisposing factors, our understanding of the cellular and molecular mechanisms underlying the pathogenesis of CVDs remains incomplete. One mechanism that has recently emerged is protein O-GlcNAcylation. This is a dynamic, site-specific reversible post-translational modification of serine and threonine residues on target proteins and is controlled by two enzymes: O-linked β-N-acetylglucosamine transferase (OGT) and O-linked β-N-acetylglucosaminidase (OGA). Protein O-GlcNAcylation alters the cellular functions of these target proteins which play vital roles in pathways that modulate vascular homeostasis and cardiac function. Through this review, we aim to give insights on the role of protein O-GlcNAcylation in cardiovascular diseases and identify potential therapeutic targets in this pathway for development of more effective medicines to improve patient outcomes.

Advances in molecular mechanisms of drugs affecting abnormal glycosylation and metastasis of breast cancer

Breast cancer remains the leading cause of cancer-related death among women worldwide, and its incidence is also increasing. High recurrence rate and metastasis rate are the key causes of poor prognosis and death. It is suggested that abnormal glycosylation plays an important role in the growth, invasion, metastasis and resistance to therapy of breast cancer cells. Meanwhile, it can be used as the biomarkers for the early detection and prognosis of breast cancer and the potential attractive targets for drug treatment. However, only a few attentions have been paid to the molecular mechanism of abnormal glycosylation in the epithelial-mesenchymal transition (EMT) of breast cancer cells and the related intervention of drugs. This manuscript thus investigated the relationship between abnormal glycosylation, the EMT, and breast cancer metastasis. Then, the process of abnormal glycosylation, the classification and their molecular regulatory mechanisms of breast cancer were analyzed in detail. Last, potential drugs are introduced in different categories, which are expected to reverse or intervene the abnormal glycosylation of breast cancer. This review is conducive to an in-depth understanding of the metastasis and drug resistance of breast cancer cells, which will provide new ideas for the clinical regulation of glycosylation and related drug treatments in breast cancer.

Gut microbiota in phytopharmacology: A comprehensive overview of concepts, reciprocal interactions, biotransformations and mode of actions

The dynamic and delicate interactions amongst intestinal microbiota, metabolome and metabolism dictates human health and disease. In recent years, our understanding of gut microbial regulation of intestinal immunometabolic and redox homeostasis have evolved mainly out of in vivo studies associated with high-fat feeding induced metabolic diseases. Techniques utilizing fecal transplantation and germ-free mice have been instrumental in reproducibly demonstrating how the gut microbiota affects disease pathogenesis. However, the pillars of modern drug discovery i.e. evidence-based pharmacological studies critically lack focus on intestinal microflora. This is primarily due to targeted in vitro molecular-approaches at cellular-level that largely overlook the etiology of disease pathogenesis from the physiological perspective. Thus, this review aims to provide a comprehensive understanding of the key notions of intestinal microbiota and dysbiosis, and highlight the microbiota-phytochemical bidirectional interactions that affects bioavailability and bioactivity of parent phytochemicals and their metabolites. Potentially by focusing on the three major aspects of gut microbiota i.e. microbial abundance, diversity, and functions, I will discuss phytochemical-microbiota reciprocal interactions, biotransformation of phytochemicals and plant-derived drugs, and pre-clinical and clinical efficacies of herbal medicine on dysbiosis. Additionally, in relation to phytochemical pharmacology, I will briefly discuss the role of dietary-patterns associated with changes in microbial profiles and review pharmacological study models considering possible microbial effects. This review therefore, emphasize on the timely and critically needed evidence-based phytochemical studies focusing on gut microbiota and will provide newer insights for future pre-clinical and clinical phytopharmacological interventions.

Experimental diabetes induced by alloxan and streptozotocin: The current state of the art

Diabetes mellitus is a chronic metabolic disorder with a high prevalence worldwide. Animal models of diabetes represent an important tool in diabetes investigation that helps us to avoid unnecessary and ethically challenging studies in human subjects, as well as to obtain a comprehensive scientific viewpoint of this disease. Although there are several methods through which diabetes can be induced, chemical methods of alloxan- and streptozotocin-induced diabetes represent the most important and highly preferable experimental models for this pathological condition. Therefore, the aim of this article was to review the current knowledge related to quoted models of diabetes, including to this point available information about mechanism of action, particular time- and dose-dependent protocols, frequent problems, as well as major limitations linked to laboratory application of alloxan and sterptozotocin in inducing diabetes. Given that diabetes is known to be closely associated with serious health consequences it is of fundamental importance that current animal models for induction of diabetes should be continuously upgraded in order to improve overall prevention, diagnosis and treatment of this pathological condition.

Arnebin-1 promotes the angiogenesis of human umbilical vein endothelial cells and accelerates the wound healing process in diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Zicao is a traditional wound healing herbal medicine that has been used for several hundred years in China. A survey of the published literatures revealed that arnebin-1, one of the naphthoquinone derivatives, played the most important role in wound healing property of this plant. However, whether arnebin-1 affects angiogenesis in vitro and has an effect on wound healing process in diabetic rats remains enigmatic. To investigate the effect of arnebin-1 with or without VEGF on proliferation, migration and tube formation of HUVECs in vitro and the effect of its topical application in the form of ointment on wound healing in a cutaneous punch wound model of alloxan-induced diabetic rats in vivo.

MATERIALS AND METHODS

The pro-angiogenic functions of arnebin-1 on HUVECs including proliferation, migration and angiogenesis were evaluated through MTT assay, wound healing assay, transwell assay and tube formation assay in vitro. Male Sprague-Dawley rats were injected intraperitoneally with alloxan to induce type І diabetic rats. Three wounds were created in each rat on the dorsal surface, and then divided to be basement treated, arnebin-1 ointment treated and untreated group correspondingly. The indicators including wound closure rate and histological evaluation were investigated on day 4 and 7 post-wounding.

RESULTS

Without VEGF, arnebin-1 did not affect the proliferation of HUVECs significantly, but had a positive effect on cell migration and tube formation. However, in the presence of minimal VEGF, Arnebin-1 could increase the proliferation, enhance the migration and promote the tube formation of HUVECs significantly. The wound closure rate was increased significantly in arnebin-1 treated group compared to that of untreated and basement treated groups in diabetic rats, and the histological evaluation also showed well organized dermal layer, reduced number of macrophages, increased number of fibroblasts, remarkable degree of neovascularization and epithelization in arnebin-1 treated group.

CONCLUSION

These findings suggest that arnebin-1 has a pro-angiogenic effect, and a synergetic effect with VEGF promotes the wound healing process in diabetic rats.