Histamine-2 receptor antagonist famotidine modulates cardiac stem cell characteristics in hypertensive heart disease

In search of elixir: Pharmacological agents against stem cell senescence

Stem cell senescence causes different complications. In addition to the aging phenomenon, stem cell senescence has been investigated in various concepts such as cancer, adverse drug effects, and as a limiting factor in cell therapy. This manuscript examines protective medicines and supplements which are capable of hindering stem cell senescence. We searched the databases such as EMBASE, PubMed, and Web of Science with the keywords “stem cell,” “progenitor cell,” “satellite,” “senescence” and excluded the keywords “cancer,” “tumor,” “malignancy” and “carcinoma” until June 2020. Among these results, we chose 47 relevant studies. Our investigation indicates that most of these studies examined endothelial progenitor cells, hematopoietic stem cells, mesenchymal stem cells, adipose-derived stem cells, and a few others were about less-discussed types of stem cells such as cardiac stem cells, myeloblasts, and induced pluripotent stem cells. From another aspect, 17β-Estradiol, melatonin, metformin, rapamycin, coenzyme Q10, N-acetyl cysteine, and vitamin C were the most studied agents, while the main protective mechanism was through telomerase activity enhancement or oxidative damage ablation.

Although many of these studies are in vitro, they are still worthwhile. Stem cell senescence in the in vitro expansion stage is an essential concern in clinical procedures of cell therapy. Moreover, in vitro studies are the first step for further in vivo and clinical studies. It is noteworthy to mention the fact that these protective agents have been used in the clinical setting for various purposes for a long time. Given that, we only need to examine their systemic anti-senescence effects and effective dosages.

Multi-organ damage by covid-19: congestive (cardio-pulmonary) heart failure, and blood-heart barrier leakage

Corona virus disease-19 (covid-19) is caused by a coronavirus that is also known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and is generally characterized by fever, respiratory inflammation, and multi-organ failure in susceptible hosts. One of the first things during inflammation is the response by acute phase proteins coupled with coagulation. The angiotensinogen (a substrate for hypertension) is one such acute phase protein and goes on to explain an association of covid-19 with that of angiotensin-converting enzyme-2 (ACE2, a metallopeptidase). Therefore, it is advisable to administer, and test the efficacy of specific blocker(s) of angiotensinogen such as siRNAs or antibodies to covid-19 subjects. Covid-19 activates neutrophils, macrophages, but decreases T-helper cells activity. The metalloproteinases promote the activation of these inflammatory immune cells, therefore; we surmise that doxycycline (a metalloproteinase inhibitor, and a safer antibiotic) would benefit the covid-19 subjects. Along these lines, an anti-acid has also been suggested for mitigation of the covid-19 complications. Interestingly, there are three primary vegetables (celery, carrot, and long-squash) which are alkaline in their pH-range as compared to many others. Hence, treatment with fresh juice (without any preservative) from these vegies or the antioxidants derived from purple carrot and cabbage together with appropriate anti-coagulants may also help prevent or lessen the detrimental effects of the covid-19 pathological outcomes. These suggested remedies might be included in the list of putative interventions that are currently being investigated towards mitigating the multi-organ damage by Covid-19 during the ongoing pandemic.

The Cardiac Injury Immune Response as a Target for Regenerative and Cellular Therapies

PURPOSE

Despite modern reperfusion and pharmacologic therapies, myocardial infarction (MI) remains a leading cause of morbidity and mortality worldwide. Therefore, the development of further therapeutics affecting post-MI recovery poses significant benefits. This review focuses on the post-MI immune response and immunomodulatory therapeutics that could improve the wound-healing response.

METHODS

This narrative review used OVID versions of MEDLINE and EMBASE searching for clinical therapeutics targeting the immune system during MI. Preclinical models and clinical trials were included. Additional studies were sourced from the reference lists of relevant articles and other personal files.

FINDINGS

After MI, cardiomyocytes are starved of oxygen and undergo cell death via coagulative necrosis. This process activates the immune system and a multifaceted wound-healing response, comprising a number of complex and overlapping phases. Overactivation or persistence of one or more of these phases can have potentially lethal implications. This review describes the immune response post-MI and any adverse events that can occur during these different phases. Second, we describe immunomodulatory therapies that attempt to target these immune cell aberrations by mitigating or diminishing their effects on the wound-healing response. Also discussed are adult stem/progenitor cell therapies, exosomes, and regulatory T cells, and their immunomodulatory effects in the post-MI setting.

IMPLICATIONS

An updated understanding into the importance of various inflammatory cell phenotypes, coupled with new technologies, may hold promise for a new era of immunomodulatory therapeutics. The implications of such therapies could dramatically improve patients' quality of life post-MI and reduce the incidence of progressive heart failure.