AKAP9 supports spermatogenesis through its effects on microtubule and actin cytoskeletons in the rat testis

Blood-testis barrier: a review on regulators in maintaining cell junction integrity between Sertoli cells

The blood-testis barrier (BTB) is formed adjacent to the seminiferous basement membrane. It is a distinct ultrastructure, partitioning testicular seminiferous epithelium into apical (adluminal) and basal compartments. It plays a vital role in developing and maturing spermatocytes into spermatozoa via reorganizing its structure. This enables the transportation of preleptotene spermatocytes across the BTB, from basal to adluminal compartments in the seminiferous tubules. Several bioactive peptides and biomolecules secreted by testicular cells regulate the BTB function and support spermatogenesis. These peptides activate various downstream signaling proteins and can also be the target themself, which could improve the diffusion of drugs across the BTB. The gap junction (GJ) and its coexisting junctions at the BTB maintain the immunological barrier integrity and can be the "gateway" during spermatocyte transition. These junctions are the possible route for toxicant entry, causing male reproductive dysfunction. Herein, we summarize the detailed mechanism of all the regulators playing an essential role in the maintenance of the BTB, which will help researchers to understand and find targets for drug delivery inside the testis.

Increased m6A-RNA methylation and FTO suppression is associated with myocardial inflammation and dysfunction during endotoxemia in mice

Endotoxemia triggers life-threatening immune and cardiovascular response that leads to tissue damage, multi-organ failure, and death. The understanding of underlying molecular mechanisms is still evolving. N6-methyladenosine (m6A)-RNA modification plays key regulatory role in numerous biological processes. However, it remains unclear whether endotoxemia alters RNA methylation in the myocardium. In the current study, we investigated the effect of lipopolysaccharide (LPS)-induced endotoxemia on m6A-RNA methylation and its implications on myocardial inflammation and left ventricular (LV) function. Following LPS administration, mice showed increases in m6A-RNA methylation in the myocardium with a corresponding decrease in the expression of fat mass and obesity-associated protein (FTO, an m6A eraser/demethylase). The changes were associated with a significant increase in expression of myocardial inflammatory cytokine genes, such as IL-6, TNF-α, IL-1β, and reduced LV function. Moreover, rat cardiomyoblasts (H9c2) exposed to LPS showed similar changes (with increase in m6A-RNA methylation and inflammatory cytokine genes, whereas downregulation of FTO). Furthermore, methylated RNA immunoprecipitation assay showed hypermethylation and increase in the expression of IL-6 and TNF-α genes in LPS-treated H9c2 cells as compared to untreated cells. Interestingly, FTO knockdown in cardiomyocytes mimicked the above effects. Taken together, these data suggest that endotoxemia-induced m6A methylation might play a critical role in expression of cardiac proinflammatory cytokines, and modulation of m6A methylation might limit myocardial inflammation and dysfunction during endotoxemia.