Role of microRNAs in the process of metformin treating multiple diseases

Metformin as the first-line treatment for type 2 diabetes mellitus has been discovered to exert beneficial effects on many diseases for nearly ten years, but its specific mechanism is still unclear. As a new class of gene expression regulators with pleiotropic properties, microRNAs (miRNAs) participate in multiple physiological processes such as cell differentiation, proliferation, survival, and metabolism, which drive them to play a regulatory role in the occurrence, development and even treatment of various diseases. A substantial body of research has found the relationship between metformin and miRNAs, in which metformin can alter the expression profiles of miRNAs in multiple disease states and on the other hand the signal pathways involving miRNAs may contribute to the pharmacological actions of metformin. This review summarizes the effects of metformin on miRNAs and their relationship in different diseases (like tumor, metabolic diseases, etc.), which should be of a great help for our better understanding of the mechanism of metformin for treating multiple diseases.

Recent Advances in the Endogenous Brain Renin-Angiotensin System and Drugs Acting on It

The RAS (renin-angiotensin system) is the part of the endocrine system that plays a prime role in the control of essential hypertension. Since the discovery of brain RAS in the seventies, continuous efforts have been put by the scientific committee to explore it more. The brain has shown the presence of various components of brain RAS such as angiotensinogen (AGT), converting enzymes, angiotensin (Ang), and specific receptors (ATR). AGT acts as the precursor molecule for Ang peptides—I, II, III, and IV—while the enzymes such as prorenin, ACE, and aminopeptidases A and N synthesize it. AT1, AT2, AT4, and mitochondrial assembly receptor (MasR) are found to be plentiful in the brain. The brain RAS system exhibits pleiotropic properties such as neuroprotection and cognition along with regulation of blood pressure, CVS homeostasis, thirst and salt appetite, stress, depression, alcohol addiction, and pain modulation. The molecules acting through RAS predominantly ARBs and ACEI are found to be effective in various ongoing and completed clinical trials related to cognition, memory, Alzheimer’s disease (AD), and pain. The review summarizes the recent advances in the brain RAS system highlighting its significance in pathophysiology and treatment of the central nervous system-related disorders.

The Role of Tumor Associated Macrophages (TAMs) in Cancer Progression, Chemoresistance, Angiogenesis and Metastasis - Current Status

: Tumor associated macrophages (TAMs), located in the tumor microenvironment (TME), play a significant role in cancer cell survival and progression. TAMs have been involved in producing immuno-suppressive TME in the tumor by generating inflammatory mediators, growth factors, cytokines, chemokines, etc. TAMs can influence the angiogenesis, metastatic behavior of tumor cells (TCs) and cause multidrug resistance. TAMs within the TME can enhance cancer cell metastasis and are stromal and perivascular. The angiogenesis is promoted at the hypoxia, and the avascular zones of TME. Differentiation states of TAMs are considered ‘plastic’ as they exhibit temporal expression of one or several phenotypes depending on local cues. Emerging cancer research depicted the epigenetic regulation of macrophage polarization (both M1s, M2s) and their potential implications to develop pharmacologic modulators and microRNAs to act as molecular switches and even to serve as targeted therapies to inhibit tumor growth. In the present article, the role of TAMs in tumor progression, angiogenesis and metastasis was discussed. In addition, key signaling cascades regulated by TAMs, which have a role in chemoresistance, were also discussed. Currently, novel pleiotropic properties of various anticancer phytomedicines are gaining importance as they assist in overcoming TAMs-induced chemoresistance. Moreover, these phytomedicines are being tested as ‘adjunct therapeutics’ along with chemotherapeutic agents, anti-angiogenic molecules, anti-metastatic compounds, and other immune-checkpoint blockers against tumor metastasis/angiogenesis. Hence, a brief note on natural products targeting TAMs was provided. In summary, this review would benefit pharmacologists and medical professionals to develop therapies to target TAMs using multi-OMICs approaches, including genomics, epigenomics, transcriptomics, and proteomics.

The Role of High-Density Lipoprotein in COVID-19

The current Coronavirus disease 2019 (COVID-19) pandemic has become a global challenge. Managing a large number of acutely ill patients in a short time, whilst reducing the fatality rate and dealing with complications, brings unique difficulties. The most striking pathophysiological features of patients with severe COVID-19 are dysregulated immune responses and abnormal coagulation function, which can result in multiple-organ failure and death. Normally metabolized high-density lipoprotein (HDL) performs several functions, including reverse cholesterol transport, direct binding to lipopolysaccharide (LPS) to neutralize LPS activity, regulation of inflammatory response, anti-thrombotic effects, antioxidant, and anti-apoptotic properties. Clinical data shows that significantly decreased HDL levels in patients with COVID-19 are correlated with both disease severity and mortality. However, the role of HDL in COVID-19 and its specific mechanism remain unclear. In this analysis, we review current evidence mainly in the following areas: firstly, the pathophysiological characteristics of COVID-19, secondly, the pleiotropic properties of HDL, thirdly, the changes and clinical significance of HDL in COVID-19, and fourthly the prospect of HDL-targeting therapy in COVID-19 to clarify the role of HDL in the pathogenesis of COVID-19 and discuss the potential of HDL therapy in COVID-19.

Thymic Stromal Lymphopoietin in Cutaneous Immune-Mediated Diseases

Thymic stromal lymphopoietin (TSLP) was initially demonstrated to be critical in regulating inflammatory responses among various allergic disorders (such as atopic dermatitis, food allergy, and asthma). Although two isoforms (short form and long form) of TSLP have been demonstrated in human tissues, the long form of TSLP (lfTSLP) is strongly implicated in the pathogenesis of allergies and cutaneous immune-mediated diseases. The immunomodulatory activity of lfTSLP varies widely, driving T helper (Th) cells polarizing Th2 and Th17 immune responses and inducing itch. Moreover, lfTSLP is closely associated with skin fibrosis, epidermal hyperplasia, angiogenesis, and homeostatic tolerogenic regulations. This review highlights significant progress from experimental and clinical studies on lfTSLP in cutaneous immune-mediated diseases (atopic dermatitis, psoriasis, bullous pemphigoid, systemic sclerosis, chronic spontaneous urticaria, Behçet’s disease, vitiligo, rosacea, systemic lupus erythematosus, and alopecia areata). We also offer original insights into the pleiotropic properties of the cytokine TSLP in various pathophysiological conditions, with significant clinical implications of TSLP-targeted therapies for immune-mediated skin diseases in the future.

Statins in COVID-19 Therapy

Inhibitors of 3-hydroxy-3methylgultaryl-coenzyme A reductase (statins) are one of the main groups of drugs used in preventing and treating cardiovascular diseases worldwide. They are widely available, cheap, and well-tolerated. Based on statins’ pleiotropic properties, including improvement of endothelial dysfunction, antioxidant properties, atherosclerotic plaque stabilization, and inhibition of inflammatory responses, it can be hypothesized that the use of statins, at least as an adjuvant in antiviral therapy, may be justified. All these effects might be especially beneficial in patients with COVID-19, suffering from endothelial dysfunction, microvascular and macrovascular thrombosis, and cytokine storm. Here, we review the recent data regarding the pathophysiology of SARS-CoV-2 activity in host cells, proposed COVID-19 therapy, the pleiotropic activity of statins, and statins in clinical trials in respiratory infections. According to the guidelines of the European and American Cardiac Societies, in patients with cardiovascular disease or high cardiovascular risk with concomitant COVID-19 it is recommended to continue statin treatment. However, the initiation of statin therapy de novo in COVID-19 treatment should only be done as part of a clinical trial.

The Burning Necessity for Establishing National Guidelines - Side Effects of Lipid Lowering Drugs and Difficulty of using High Intensity Statins in Pakistani Population

Lipid lowering strategy has been widely used in both the primary as well as the secondary prevention of atherosclerotic cardiovascular disease, particularly in managing patients who are either diagnosed with ischemic heart disease or stroke or face great susceptibility to developing these complications as a result of risk factors like diabetes, hypertension, sedentary lifestyle and so on [1,2]. The mechanism of action of Statins is by inhibition of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase which is the rate-limiting step in cholesterol synthesis [3]. Statins hence have a great impact on the lipid metabolism and play a vital role in prevention of atherosclerotic complications [4]. They reduce LDL-C, Total cholesterol, and Triglyceride levels; slightly increase HDL-C levels [5]; and are also thought to have anti-inflammatory and other plaque stabilization effects, referred to as their pleiotropic properties [6].

Standardized bergamot polyphenolic fraction – a comprehensive dietary supplement with pleiotropic properties compared to other selected natural lipid-lowering substances available on the market

Bergamot juice has a particularly high content and a unique composition of flavonoids. It is particularly rich in flavanones and flavones. Standardized bergamot polyphenolic fraction has the same polyphenol profile as in the juice, but flavonoids are over 200 times more concentrated. Many data show its brilliant performance in hyperlipidaemia and moderate hyperglycemia. In addition, compared to other dietary supplements available on the market, it has beneficial pleiotropic properties.

Myricetin as a Promising Molecule for the Treatment of Post-Ischemic Brain Neurodegeneration

The available drug therapy for post-ischemic neurodegeneration of the brain is symptomatic. This review provides an evaluation of possible dietary therapy for post-ischemic neurodegeneration with myricetin. The purpose of this review was to provide a comprehensive overview of what scientists have done regarding the benefits of myricetin in post-ischemic neurodegeneration. The data in this article contribute to a better understanding of the potential benefits of myricetin in the treatment of post-ischemic brain neurodegeneration, and inform physicians, scientists and patients, as well as their caregivers, about treatment options. Due to the pleiotropic properties of myricetin, including anti-amyloid, anti-phosphorylation of tau protein, anti-inflammatory, anti-oxidant and autophagous, as well as increasing acetylcholine, myricetin is a promising candidate for treatment after ischemia brain neurodegeneration with full-blown dementia. In this way, it may gain interest as a potential substance for the prophylaxis of the development of post-ischemic brain neurodegeneration. It is a safe substance, commercially available, inexpensive and registered as a pro-health product in the US and Europe. Taken together, the evidence available in the review on the therapeutic potential of myricetin provides helpful insight into the potential clinical utility of myricetin in treating neurodegenerative disorders with full-blown dementia. Therefore, myricetin may be a promising complementary agent in the future against the development of post-ischemic brain neurodegeneration. Indeed, there is a scientific rationale for the use of myricetin in the prevention and treatment of brain neurodegeneration caused by ischemia.

SARS-CoV-2 Infection: A Role for S1P/S1P Receptor Signaling in the Nervous System?

The recent coronavirus disease (COVID-19) is still spreading worldwide. The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the virus responsible for COVID-19, binds to its receptor angiotensin-converting enzyme 2 (ACE2), and replicates within the cells of the nasal cavity, then spreads along the airway tracts, causing mild clinical manifestations, and, in a majority of patients, a persisting loss of smell. In some individuals, SARS-CoV-2 reaches and infects several organs, including the lung, leading to severe pulmonary disease. SARS-CoV-2 induces neurological symptoms, likely contributing to morbidity and mortality through unknown mechanisms. Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid with pleiotropic properties and functions in many tissues, including the nervous system. S1P regulates neurogenesis and inflammation and it is implicated in multiple sclerosis (MS). Notably, Fingolimod (FTY720), a modulator of S1P receptors, has been approved for the treatment of MS and is being tested for COVID-19. Here, we discuss the putative role of S1P on viral infection and in the modulation of inflammation and survival in the stem cell niche of the olfactory epithelium. This could help to design therapeutic strategies based on S1P-mediated signaling to limit or overcome the host–virus interaction, virus propagation and the pathogenesis and complications involving the nervous system.