Short-term ex-vivo exposure to hydrogen sulfide enhances murine hematopoietic stem and progenitor cell migration, homing, and proliferation

From cell to organ: Exploring the toxicological correlation of organophosphorus compounds in living system

Malathion is an organophosphate compound widely used as an insecticide in the agriculture sector and is toxic to humans and other mammals. Although several studies have been conducted at different levels in different animal models. But there is no work has been conducted on the toxicological correlation from cellular to behavioral level in surviving species model. Addressing this gap through further research is essential for a comprehensive understanding of malathion's impact on biological systems, facilitating better risk assessment and management strategies. Current research systemically evaluated the effects of malathion on the central nervous system and peripheral immune cells using immunological techniques in the BALB/c mice models. For this, animals were placed inside an inhalation chamber containing malathion (dose of 89.5 mg/ml/m3) for a specific exposure time. The group exposed for 6 minutes has shown a significant change in plasma-neurotransmitter (serotonin, dopamine) levels and decreased expression of Tyrosine hydroxylase in striatum and SNPC region of brain. The depolarized mitochondria and increased level of cleaved caspase-3 level and mature neurons in DG, CA1 and CA3 were also observed in the brain. Peripheral blood analysis illustrated a decrease in total leukocyte count and an increased level of early apoptosis at the same time point. From neurobehavioral results a significant locomotor hyperactivity, restlessness, and risk-taking behavior was observed. Taken together, results from the current study indicate that exposure to malathion at prolonged time durations induces neuronal and immune cell toxicity, and its toxicity may be mediated via changes in neurotransmitter levels and metabolite concentrations.

Targeting the redox system for cardiovascular regeneration in aging

Cardiovascular aging presents a formidable challenge, as the aging process can lead to reduced cardiac function and heightened susceptibility to cardiovascular diseases. Consequently, there is an escalating, unmet medical need for innovative and effective cardiovascular regeneration strategies aimed at restoring and rejuvenating aging cardiovascular tissues. Altered redox homeostasis and the accumulation of oxidative damage play a pivotal role in detrimental changes to stem cell function and cellular senescence, hampering regenerative capacity in aged cardiovascular system. A mounting body of evidence underscores the significance of targeting redox machinery to restore stem cell self-renewal and enhance their differentiation potential into youthful cardiovascular lineages. Hence, the redox machinery holds promise as a target for optimizing cardiovascular regenerative therapies. In this context, we delve into the current understanding of redox homeostasis in regulating stem cell function and reprogramming processes that impact the regenerative potential of the cardiovascular system. Furthermore, we offer insights into the recent translational and clinical implications of redox-targeting compounds aimed at enhancing current regenerative therapies for aging cardiovascular tissues.

Emerging roles of cystathionine β-synthase in various forms of cancer

The expression of the reverse transsulfuration enzyme cystathionine-β-synthase (CBS) is markedly increased in many forms of cancer, including colorectal, ovarian, lung, breast and kidney, while in other cancers (liver cancer and glioma) it becomes downregulated. According to the clinical database data in high-CBS-expressor cancers (e.g. colon or ovarian cancer), high CBS expression typically predicts lower survival, while in the low-CBS-expressor cancers (e.g. liver cancer), low CBS expression is associated with lower survival. In the high-CBS expressing tumor cells, CBS, and its product hydrogen sulfide (H₂S) serves as a bioenergetic, proliferative, cytoprotective and stemness factor; it also supports angiogenesis and epithelial-to-mesenchymal transition in the cancer microenvironment. The current article reviews the various tumor-cell-supporting roles of the CBS/H₂S axis in high-CBS expressor cancers and overviews the anticancer effects of CBS silencing and pharmacological CBS inhibition in various cancer models in vitro and in vivo; it also outlines potential approaches for biomarker identification, to support future targeted cancer therapies based on pharmacological CBS inhibition.

Physiological roles of hydrogen sulfide in mammalian cells, tissues and organs

H2S belongs to the class of molecules known as gasotransmitters, which also includes nitric oxide (NO) and carbon monoxide (CO). Three enzymes are recognized as endogenous sources of H2S in various cells and tissues: cystathionine g-lyase (CSE), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST). The current article reviews the regulation of these enzymes as well as the pathways of their enzymatic and non-enzymatic degradation and elimination. The multiple interactions of H2S with other labile endogenous molecules (e.g. NO) and reactive oxygen species are also outlined. The various biological targets and signaling pathways are discussed, with special reference to H2S and oxidative posttranscriptional modification of proteins, the effect of H2S on channels and intracellular second messenger pathways, the regulation of gene transcription and translation and the regulation of cellular bioenergetics and metabolism. The pharmacological and molecular tools currently available to study H2S physiology are also reviewed, including their utility and limitations. In subsequent sections, the role of H2S in the regulation of various physiological and cellular functions is reviewed. The physiological role of H2S in various cell types and organ systems are overviewed. Finally, the role of H2S in the regulation of various organ functions is discussed as well as the characteristic bell-shaped biphasic effects of H2S. In addition, key pathophysiological aspects, debated areas, and future research and translational areas are identified A wide array of significant roles of H2S in the physiological regulation of all organ functions emerges from this review.