Taku Miyasho

While ultraviolet C (UVC) radiation has beneficial applications, it can also pose risks to living organisms. Nevertheless, a detailed assessment of UVC radiation’s effects on mammalian male reproductive physiology, including the underlying mechanisms and potential protective strategies, has not yet been accomplished. This study aimed to examine the critical roles of oxidative stress, autophagy, reproductive hormonal axis, and microRNAs in UVC-induced reproductive challenges in male rats. Semen, biochemical, molecular, and in silico analyses revealed significant dysregulation of testicular steroidogenesis, impaired spermatogenesis, deteriorated sperm quality, and altered reproductive hormonal profiles, which ultimately lead to a decline in fertility in male rats exposed to UVC radiation. Our data indicated that the suppression of autophagy, stimulation of gonadotropin-inhibiting hormone (GnIH), and alteration of microRNAs serve as key mediators of UVC-induced stress effects in mammalian reproduction, potentially contributing to male infertility. Targeting these pathways, particularly through pretreatment with hesperidin (HES), offers a promising strategy to counteract UVC-induced male infertility. In conclusion, the present findings emphasize the importance of understanding the molecular mechanisms behind UVC-induced male infertility and offer valuable insights into the protective mechanisms and prospective role of HES in safeguarding male reproductive health.

Physiologically, autophagy is an evolutionarily conserved and self-degradative process in cells. Autophagy carries out normal physiological roles throughout mammalian life. Accumulating evidence shows autophagy as a mechanism for cellular growth, development, differentiation, survival, and homeostasis. In male reproductive systems, normal spermatogenesis and steroidogenesis need a balance between degradation and energy supply to preserve cellular metabolic homeostasis. The main process of autophagy includes the formation and maturation of the phagophore, autophagosome, and autolysosome. Autophagy is controlled by a group of autophagy-related genes that form the core machinery of autophagy. Three types of autophagy mechanisms have been discovered in mammalian cells: macroautophagy, microautophagy, and chaperone-mediated autophagy. Autophagy is classified as non-selective or selective. Non-selective macroautophagy randomly engulfs the cytoplasmic components in autophagosomes that are degraded by lysosomal enzymes. While selective macroautophagy precisely identifies and degrades a specific element, current findings have shown the novel functional roles of autophagy in male reproduction. It has been recognized that dysfunction in the autophagy process can be associated with male infertility. Overall, this review provides an overview of the cellular and molecular basics of autophagy and summarizes the latest findings on the key role of autophagy in mammalian male reproductive physiology.

Objective: The perfusion index (PI) derived from plethysmographic signals provides a noninvasive indication of peripheral perfusion. This study aimed to investigate changes in PI and other hemodynamic variables in pigs subjected to endotoxemia.Design: Prospective experimental study.Setting: University teaching hospital.Animals: Twelve healthy pigs weighing a mean (± standard deviation [SD]) of 31.7 ± 2.0 kg.Interventions: Pigs were divided into control and endotoxin groups (n = 6 each). Endotoxemia was induced by IV infusion of lipopolysaccharide. Heart rate, mean arterial pressure, cardiac index (CI), central venous pressure, systemic vascular resistance index (SVRI), extravascular lung water index (ELWI), Global end‐diastolic volume (GEDV) index, and pulmonary permeability index were measured using a transpulmonary thermodilution monitor in all pigs. PI was measured using a pulse oximeter probe attached to the tail. Pao₂, Paco₂, and plasma lactate concentration were measured by blood gas analysis. Measurements were taken at baseline (T₀). Saline or lipopolysaccharide was then administered for 30 min to all pigs (control or endotoxemia group, respectively), and each parameter was measured every 30 min up to 270 min. Data were analyzed by analysis of variance and Student's t‐tests.Measurements and Main Results: There were no significant changes in any variables in the control group, but CI, SVRI, PI, ELWI, blood lactate concentration, and Pao₂ changed significantly from baseline in the endotoxin group (P < 0.001, P = 0.0048, P < 0.001, P = 0.0064, P < 0.001, and P = 0.0220, respectively). In the endotoxin group, mean (± SD) %PI increased from T₀ to 154 ± 34% at T₆₀ (P = .001) and 135 ± 50% at T₉₀ (P =0 .004), which mirrored significant changes in %CI and %SVRI.Conclusion: The PI may be useful to detect changes in CI and SVRI.

Bacterial genome is characterized by frequent unmethylated cytosine-phosphate-guanine (CpG) motifs. Deleterious effects can occur when synthetic oligodeoxynucleotides (ODN) with unmethylated CpG dinucleotides (CpG-ODN) are administered in a systemic fashion. We aimed to evaluate the effect of intratracheal CpG-ODN on lung inflammation and systemic inflammatory response. C57BL/6J mice received intratracheal administration of CpG-ODN (0.01, 0.1, 1.0, 10, or 100 μM) or control ODN without CpG motif. Bronchoalveolar lavage (BAL) fluid was obtained 3 or 6 h or 1, 2, 7, or 14 days after the instillation and subjected to a differential cell count and cytokine measurement. Lung permeability was evaluated as the BAL fluid-to-plasma ratio of the concentration of human serum albumin that was injected 1 h before euthanasia. Nuclear factor (NF)-κB DNA binding activity was also evaluated in lung homogenates. Intratracheal administration of 10 μM or higher concentration of CpG-ODN induced significant inflammatory cell accumulation into the airspace. The peak accumulation of neutrophils and lymphocytes occurred 1 and 2 days after the CpG-ODN administration, respectively. Lung permeability was increased 1 day after the 10 μM CpG-ODN challenge. CpG-ODN also induced nuclear translocation of NF-κB and upregulation of various inflammatory cytokines in BAL fluid and plasma. Histopathology of the lungs and liver revealed acute lung injury and liver damage with necrosis, respectively. Control ODN without CpG motif did not induce any inflammatory change. Since intratracheal CpG-ODN induced acute lung injury as well as systemic inflammatory response, therapeutic strategies to neutralize bacterial DNA that is released after administration of bactericidal agents should be considered.

Introduction: Anticoagulant therapy attracts much attention for the treatment of severe sepsis since recent studies have revealed that some anticoagulants have the ability to regulate the inflammatory response. The purpose of this study was to examine whether danaparoid sodium (DA) is effective for the treatment of organ dysfunction in sepsis. Methods: Sixty-four Wistar rats were intravenously injected with 5.0 mg/kg of lipopolysaccharide (LPS) and then divided into two groups: the DA group and the control group (n = 32 each). The DA group was injected intravenously with 400 U/kg of DA immediately after LPS injection, whereas the control group received saline. Blood samples were drawn at 1, 6, 12, and 24 hours after LPS injection, and organ damage markers and coagulation markers were measured. In the other series, 10 rats treated with LPS were divided into DA and control groups (n = 5 each). Blood samples were collected at 1, 3, and 6 hours after LPS injection and served for the cytokine measurements. Results: The elevation of the organ damage markers, such as alanine aminotransferase and lactate dehydrogenase, was significantly suppressed in the DA group. Coagulation markers, such as AT activity and fibrinogen levels, were maintained better in the DA group at 6 hours. The elevation of proinflammatory cytokines such as tumor necrosis factor-alpha, interleukin (IL)-1, and IL-6 was significantly suppressed in the DA group. On the other hand, there was no significant difference in anti-inflammatory cytokines such as IL-4 and IL-10. Conclusion: DA preserves the organ dysfunction in LPS-challenged rats. Although the mechanism is not fully elucidated, not only the improvement of coagulation disorder but also the regulation of circulating levels of proinflammatory cytokines may play a role in the mechanism.