The protective effects of icariin against testicular dysfunction in type 1 diabetic mice Via AMPK-mediated Nrf2 activation and NF-κB p65 inhibition.

BACKGROUND: Owing to the early suffering age and the rising incidence of type 1 diabetes (T1D), the resulting male reproductive dysfunction and fertility decline have become a disturbing reality worldwide, with no effective strategy being available. Icariin (ICA), a flavonoid extracted from Herba Epimedium, has been proved its promising application in improving diabetes-related complications including diabetic nephropathy, endothelial dysfunction and erectile dysfunction. Ensuring the future reproductive health of children and adolescents with T1D is crucial to improve global fertility. However, its roles in the treatment of T1D-induced testicular dysfunction and the potential mechanisms remain elusive. PURPOSE: The purpose of this present study was to investigate whether ICA ameliorates T1D-induced testicular dysfunction as well as its potential mechanisms. METHODS: T1D murine model was established by intraperitoneal injection of STZ with or without treated with ICA for eleven weeks. Morphological, pathological and serological experiments were used to determine the efficacy of ICA on male reproductive function of T1D mice. Western blotting, Immunohistochemistry analysis, qRT-PCR and kit determination were performed to investigated the underlying mechanisms. RESULTS: We found that replenishment of ICA alleviated testicular damage, promoted testosterone production and spermatogenesis, ameliorated apoptosis and blood testis barrier impairment in streptozotocin-induced T1D mice. Functionally, ICA treatment triggered adenosine monophosphate protein kinase (AMPK) activation, which in turn inhibited the nuclear translocation of nuclear factor kappa B p65 (NF-κB p65) to reduce inflammatory responses in the testis and activated nuclear factor erythroid 2-related factor 2(Nrf2), thereby enhancing testicular antioxidant capacity. Further studies revealed that supplementation with the AMPK antagonist Compound C or depletion of Nrf2 weakened the beneficial effects of ICA on testicular dysfunction of T1D mice. CONCLUSION: Collectively, these results demonstrate the feasibility of ICA in the treatment of T1D-induced testicular dysfunction, and reveal the important role of AMPK-mediated Nrf2 activation and NF-κB p65 inhibition in ICA-associated testicular protection during T1D.

Novel compound heterozygous SUCLG1 variants may contribute to mitochondria DNA depletion syndrome-9.

BACKGROUND: Succinate-CoA ligase/synthetase (SCS) deficiency is responsible for encephalomyopathy with mitochondrial DNA depletion and mild methylmalonic aciduria. Variants in SUCLG1, the nuclear gene encoding the alpha subunit of the SCS enzyme playing a pivotal role in maintaining mtDNA integrity and stability, are associated with mitochondrial DNA depletion syndrome 9 (MTDPS9). METHODS: In this study, we reported an infant with clinical features of MTDPS9 from China. Whole exome sequencing (WES) was used to identify the genetic cause. Bioinformatic analysis and mtDNA level detection were performed to assess pathogenicity. RESULTS: The proband manifested with hypotonia, lactic acidosis, mild methylmalonic aciduria, hearing loss and psychomotor retardation. WES identified new compound heterozygous SUCLG1 variants of c.601A>G (p.R201G) in exon 6 and c.871G>C (p.A291P) in exon 8. Computational analysis predicted that these missense variants might alter structure stability and mitochondrial translocation of SUCLG1. qRT-PCR showed 68% depletion of mtDNA content in proband as compared to controls. CONCLUSION: Novel compound heterozygous variants c.601A>G (p.R201G) and c.871G>C (p.A291P) in SUCLG1 may cause MTDPS9 in this family. Our finding should be helpful for molecular diagnosis, genetic counseling and clinical management of SCS deficiency disorders.

Fibroblast growth factor 21 attenuates salt-sensitive hypertension-induced nephropathy through anti-inflammation and anti-oxidation mechanism.

BACKGROUND: Patients with salt-sensitive hypertension are often accompanied with severe renal damage and accelerate to end-stage renal disease, which currently lacks effective treatment. Fibroblast growth factor 21 (FGF21) has been shown to suppress nephropathy in both type 1 and type 2 diabetes mice. Here, we aimed to investigate the therapeutic effect of FGF21 in salt-sensitive hypertension-induced nephropathy. METHODS: Changes of FGF21 expression in deoxycorticosterone acetate (DOCA)-salt-induced hypertensive mice were detected. The influence of FGF21 knockout in mice on DOCA-salt-induced nephropathy were determined. Recombinant human FGF21 (rhFGF21) was intraperitoneally injected into DOCA-salt-induced nephropathy mice, and then the inflammatory factors, oxidative stress levels and kidney injury-related indicators were observed. In vitro, human renal tubular epithelial cells (HK-2) were challenged by palmitate acid (PA) with or without FGF21, and then changes in inflammation and oxidative stress indicators were tested. RESULTS: We observed significant elevation in circulating levels and renal expression of FGF21 in DOCA-salt-induced hypertensive mice. We found that deletion of FGF21 in mice aggravated DOCA-salt-induced nephropathy. Supplementation with rhFGF21 reversed DOCA-salt-induced kidney injury. Mechanically, rhFGF21 induced AMPK activation in DOCA-salt-treated mice and PA-stimulated HK-2 cells, which inhibited NF-κB-regulated inflammation and Nrf2-mediated oxidative stress and thus, is important for rhFGF21 protection against DOCA-salt-induced nephropathy. CONCLUSION: These findings indicated that rhFGF21 could be a promising pharmacological strategy for the treatment of salt-sensitive hypertension-induced nephropathy.