Targeting immune cell glutamyl-prolyl-transfer RNA synthetase 1 (EPRS1) to prevent fibrosis after tubulointerstitial nephritis.

Glutamyl-prolyl-transfer RNA synthetase 1 is an enzyme that connects glutamic acid and proline to transfer RNA during protein synthesis. In this issue, a study by Kang et al. examined the role of the immune cell glutamyl-prolyl-transfer RNA synthetase 1 in toxin-induced tubulointerstitial nephritis mice. The study demonstrated that blocking glutamyl-prolyl-transfer RNA synthetase 1 may be a therapeutic target to attenuate fibrosis after toxin-induced tubulointerstitial nephritis.

Microbiome modulation after severe acute kidney injury accelerates functional recovery and decreases kidney fibrosis.

Targeting gut microbiota has shown promise to prevent experimental acute kidney injury (AKI). However, this has not been studied in relation to accelerating recovery and preventing fibrosis. Here, we found that modifying gut microbiota with an antibiotic administered after severe ischemic kidney injury in mice, particularly with amoxicillin, accelerated recovery. These indices of recovery included increased glomerular filtration rate, diminution of kidney fibrosis, and reduction of kidney profibrotic gene expression. Amoxicillin was found to increase stool Alistipes, Odoribacter and Stomatobaculum species while significantly depleting Holdemanella and Anaeroplasma. Specifically, amoxicillin treatment reduced kidney CD4+T cells, interleukin (IL)-17 +CD4+T cells, and tumor necrosis factor-α double negative T cells while it increased CD8+T cells and PD1+CD8+T cells. Amoxicillin also increased gut lamina propria CD4+T cells while decreasing CD8+T and IL-17+CD4+T cells. Amoxicillin did not accelerate repair in germ-free or CD8-deficient mice, demonstrating microbiome and CD8+T lymphocytes dependence for amoxicillin protective effects. However, amoxicillin remained effective in CD4-deficient mice. Fecal microbiota transplantation from amoxicillin-treated to germ-free mice reduced kidney fibrosis and increased Foxp3+CD8+T cells. Amoxicillin pre-treatment protected mice against kidney bilateral ischemia reperfusion injury but not cisplatin-induced AKI. Thus, modification of gut bacteria with amoxicillin after severe ischemic AKI is a promising novel therapeutic approach to accelerate recovery of kidney function and mitigate the progression of AKI to chronic kidney disease.

Standardized extract of Bacopa monnieri (CDRI-08): Effect on germ cell dynamics and possible mechanisms of its beneficial action on spermatogenesis and sperm quality in male mice.

Bacopa monnieri (BM) is used in traditional medicine as nerve tonic. We have recently shown that CDRI-08, a standardized extract of BM, improves testicular functions and epididymal sperm quality in Parkes (P) mice. The aim of the present study was to investigate the effect of CDRI-08 on germ cell dynamics and mechanisms of its action on spermatogenesis and sperm quality in P mice, and to determine the chemical profile of the extract. CDRI-08 (40 and 80 mg/kg body weight) was orally administered to male mice for 28 days. Germ cell dynamics, oxidative stress parameters in testis and sperm, and expressions of nuclear factor-erythroid-2-related factor-2 (Nrf2), phosphorylated protein kinase B (p-Akt) and upstream kinases in mitogen-activated protein kinase (MAPK) pathway namely MAP2K1, MAP2K2 and MKK4 in the testis were evaluated. The treatment potentiated germ cell dynamics and improved sperm quality by enhancing antioxidant enzymes activities. The beneficial effects of CDRI-08 in the testis involve p-Akt-mediated activation of Nrf2, thereby enhancing antioxidant enzymes activities; upregulation of MAP2K1 and MAP2K2 and suppression of MKK4 are also implicated in this action. A total of 26 phytocomponents were identified in CDRI-08 by GC-MS. The results suggest that CDRI-08 also may prove useful in improving reproductive health in males.

Pyroglutamylated RFamide peptide (QRFP): Role in early testicular development in relation to Sertoli cell maturation in prepubertal mice.

QRFP, an orexigenic neuropeptide, binds to its cognate receptor GPR103 and regulates various biological functions. We have recently shown that QRFP and its receptor are present in mice testes and that their expression is high during early postnatal period. The present study aimed to investigate the effect of sustained high level of QRFP on Sertoli cells proliferation and differentiation and to relate these events with germ cell differentiation and lumen formation in the seminiferous tubules in mice testes during prepubertal period. QRFP was injected intraperitoneally to male mice from postnatal day 5 to 16. Morphometric analysis and various markers related to Sertoli cell maturation (WT1, p27kip1, AMH, AR and CYP19A1) and germ cell proliferation and differentiation (PCNA, GDNF and c-Kit) were evaluated. QRFP administration caused an early lumen formation in the seminiferous tubules in testis of treated mice. Further, there was a significant increase in p27kip1 expression and a marked decrease in AMH expression in QRFP-treated mice compared to controls. However, no appreciable change was noted in AR expression in treated mice. QRFP treatment also caused an increase in c-Kit expression in treated mice compared to controls, suggesting an accelerated spermatogonial differentiation in testis of QRFP-treated mice. Taken together, the present results suggest that the prolonged high level of QRFP increases Sertoli cell maturation, which, in turn, plays a contributory role in increasing the pace of germ cell differentiation and formation of lumen in the seminiferous tubules.

Role of pyroglutamylated RFamide peptide43 in germ cell dynamics in mice testes in relation to energy metabolism.

QRFP is a neuropeptide that regulates glucose homeostasis and increases insulin sensitivity in tissues. We have previously shown that QRFP and its receptor (GPR103) are predominantly expressed in germ cells and Sertoli cells, respectively, in mice testes. In the present study, we report that QRFP caused an increase in PCNA and a decrease in p27Kip1 expressions in the testis under both in vivo and ex vivo conditions. Besides, via an in vivo study, cell cycle analysis by FACS showed an increase in 2C cells and a decrease in 1C cells. QRFP also induced expression of GDNF and phosphorylation of Akt and ERK-1/2. Together these results suggest that QRFP has a proliferative effect on germ cells in mice testes, since it caused a proportional increase in the mitotic activity and the number of spermatogonial cells. Further, observations of increased expressions of STAT-3 and Neurog3 in treated mice suggest that QRFP treatment regulates priming of undifferentiated spermatogonia to undergo differentiation, while a decrease in c-Kit expression indicate that spermatogonia at this time point are in an undifferentiated state. In addition, QRFP administration also caused an increase in intratesticular levels of glucose and lactate, and in LDH activity accompanied by increased expressions of GLUT-3 and LDH-C in the testis. Also, the phosphorylation of IR-ß and expressions of p-Akt and p-mTOR were increased under ex vivo conditions in testicular tissue. In conclusion, our findings suggest that QRFP treatment caused proliferation of germ cells independently from the hypothalamic-pituitary axis via regulation of testicular energy metabolism.

Ontogeny of QRFP and its receptor expression in mouse testis during post-natal development.

Pyroglutamylated RFamide peptide (QRFP), a neuropeptide, binds to its receptor GPR103 and influences various biological functions. In the present study, expression and localization of QRFP and GPR103 in mouse testis during post-natal development were investigated. The results showed that QRFP and GPR103 and also the isoforms of the receptor, viz. GPR103A and GPR103B were expressed in mouse testis during post-natal development. Expression of QRFP and its receptor was high during the early periods of post-natal development. Immunohistochemical study demonstrated the localization of QRFP and GPR103 in both interstitial and tubular compartments of the testis throughout post-natal development. A shift in the germ cell types expressing QRFP and its receptor along the course of testicular development and also a prominent immunoreactivity of QRFP in germ cells and of GPR103 in Sertoli cells was observed. Further, the immunoreactivity of QRFP and GPR103 appeared to be stage-specific in spermatogenetically active testis. Besides in intercellular spaces, localization of QRFP was also noticed in nuclei of germ cells. In conclusion, the present results suggest potential involvement of QRFP system in the development, proliferation and differentiation of testicular cells, possibly by regulating the energy requirement for these processes.

Long-term exposure of 2450 MHz electromagnetic radiation induces stress and anxiety like behavior in rats.

Long term exposure of electromagnetic radiations (EMR) from cell phones and Wi-Fi hold greater propensity to cause anxiety disorders. However, the studies investigating the effects of repeated exposure of EMR are limited. Therefore, we investigated the effects of repeated exposure of discrete frequencies of EMR in experimental animals. Male rats were exposed to EMR (900, 1800 and 2450 MHz) for 28 (1 h/day) days. Long term exposure of EMR (2450 MHz) induced anxiety like behavior. It deregulated the hypothalamic pituitary adrenal (HPA) axis in rats as observed by increase in plasma corticosterone levels apart from decreased corticotrophin releasing hormone-2 (CRH-2) and Glucocorticoid receptor (GR) expression in amygdala. Further, it impaired mitochondrial function and integrity. The expression of Bcl2 showed significant decrease while Bax and ratio of Bax: Bcl2 were increased in the mitochondria and vice versa in cytoplasm indicating altered regulation of apoptosis. EMR exposure caused release of cytochrome-c and expression of caspase-9 ensuing activation of apoptotic cell death. Additional set of experiments performed to estimate the pattern of cell death showed necrotic and apoptotic amygdalar cell death after EMR exposure. Histopathological studies also revealed a significant decrease in neuronal cells in amygdala. The above findings indicate that long-term exposure of EMR radiation (2450 MHz) acts as a stressor and induces anxiety-like behaviors with concomitant pathophysiological changes in EMR subjected rats.

Effect of standardized extract of Bacopa monnieri (CDRI-08) on testicular functions in adult male mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Bacopa monnieri (BM) has been used in India since the time of Rig-Veda for augmentation of learning, memory, brain health etc. AIM OF THE STUDY: The memory augmenting effect of BM is well documented. CDRI-08 is a standardized extract of Bacopa monnieri, but its effect on the male reproductive health has not been investigated. Therefore, the aim of the present study was to examine the effect of CDRI-08 administration on the male reproductive organs with special emphasis on testis in adult mice. MATERIALS AND METHODS: CDRI-08, containing at least 55% bacosides (the major constituent of BM), was investigated for its effect on testicular functions in adult Parkes (P) mice. A suspension of CDRI-08 was orally administered in doses of 40 and 80mgkg-1 body weight day-1 for 28 days and various male reproductive end points were evaluated. RESULTS: Compared to control, CDRI-08 treatment caused a significant increase (p<0.05) in spermatogenic cell density (germinal epithelial height: control, 55.03±4.22 vs 40mg, 67.15±2.65 and 80mg, 69.93±3.76; and tubular diameter: control, 206.55±2.62 vs 80mg, 253.23±12.19), PCNA index (control, 59.85±2.09 vs 40mg, 82.17±1.56 and 80mg, 84.05±3.51) and in steroidogenic indices in the testis, and in sperm viability (control, 0.67±0.010 vs 80mg, 0.80±0.04) in cauda epididymidis of the treated mice. On the other hand, however, the same treatment caused a significant decrease (p<0.05) in abnormal sperm morphology (control, 21.72±1.06 vs 40mg, 10.63±1.50 and 80mg, 15.86±0.87) in cauda epididymidis, and in lipid peroxidation level in testis of the treated mice compared to controls. CONCLUSION: The results suggest that treatment with CDRI-08 extract improves sperm quality, and spermatogenic cell density and steroidogenic indices in the testis of P mice.