Preventive effect of non-mitogenic acidic fibroblast growth factor on diabetes-induced testicular cell death

Investigating the therapeutic options for diabetes-associated male infertility as illustrated in animal experimental models

Diabetes is a rising global health concern and an increasingly common cause of male infertility. Although the definitive pathophysiological mechanisms underpinning the association between diabetes and infertility is unclear, there are several animal studies showing diabetes to be a detrimental factor on reproductive health through apoptosis, oxidative stress and impairment of steroidogenesis. Furthermore, as reflected in animal models, antidiabetic strategies and relevant treatments are beneficial in the management of infertile men with diabetes as the recovery of euglycemic status affects positively the spermatogenesis. However, the available data are still evolving and specific conclusion in human populations are not possible yet. In this review, we are discussing the current literature concerning the association of diabetes and male infertility, focusing on the therapeutic approach as illustrated in animals' models.

aFGF alleviates diabetic endothelial dysfunction by decreasing oxidative stress via Wnt/β-catenin-mediated upregulation of HXK2

Vascular complications of diabetes are a serious challenge in clinical practice, and effective treatments are an unmet clinical need. Acidic fibroblast growth factor (aFGF) has potent anti-oxidative properties and therefore has become a research focus for the treatment of diabetic vascular complications. However, the specific mechanisms by which aFGF regulates these processes remain unclear. The purpose of this study was to investigate whether aFGF alleviates diabetic endothelial dysfunction by suppressing mitochondrial oxidative stress. We found that aFGF markedly decreased mitochondrial superoxide generation in both db/db mice and endothelial cells incubated with high glucose (30 mM) plus palmitic acid (PA, 0.1 mM), and restored diabetes-impaired Wnt/β-catenin signaling. Pretreatment with the Wnt/β-catenin signaling inhibitors IWR-1-endo (IWR) and ICG-001 abolished aFGF-mediated attenuation of mitochondrial superoxide generation and endothelial protection. Furthermore, the effects of aFGF on endothelial protection under diabetic conditions were suppressed by c-Myc knockdown. Mechanistically, c-Myc knockdown triggered mitochondrial superoxide generation, which was related to decreased expression and subsequent impaired mitochondrial localization of hexokinase 2 (HXK2). The role of HXK2 in aFGF-mediated attenuation of mitochondrial superoxide levels and EC protection was further confirmed by si-Hxk2 and a cell-permeable form of hexokinase II VDAC binding domain (HXK2VBD) peptide, which inhibits mitochondrial localization of HXK2. Taken together, these findings suggest that the endothelial protective effect of aFGF under diabetic conditions could be partly attributed to its role in suppressing mitochondrial superoxide generation via HXK2, which is mediated by the Wnt/β-catenin/c-Myc axis.

FGF1 protects against APAP-induced hepatotoxicity via suppression of oxidative and endoplasmic reticulum stress

Acetaminophen (APAP) overdose/abuse is the leading cause of acute liver failure in many countries. Fibroblast growth factor 1 (FGF 1) is a metabolic regulator with several physiological functions. Previous studies suggested that FGF1 promotes differentiation and maturation of liver-derived stem cells. In this study, we investigated the protective effects of FGF1 against APAP-induced hepatotoxicity in mice. APAP markedly increased circulating levels of ALT and AST, while FGF1 significantly inhibited increases in the serum levels of ALT and AST, as compared to littermates. In addition, histopathological evaluation of the livers revealed that FGF1 prevented APAP-induced centrilobular necrosis. Livers exhibited severe inflammation, apoptosis, oxidative stress and endoplasmic reticulum stress in response to APAP toxicity, whereas these changes were reversed by a single injection of FGF1. In conclusion, our findings suggest that FGF1 protects mice from APAP-induced hepatotoxicity through suppression of inflammation, apoptosis, and oxidative and endoplasmic reticulum stress. Therefore, FGF1 may represent a promising therapeutic agent for APAP-induced acute liver injury.

Inhibition of endoplasmic reticulum stress is involved in the neuroprotective effect of aFGF in neonatal hypoxic-ischaemic brain injury

Acidic fibroblast growth factor (aFGF) has been shown to exert neuroprotective effects in experimental models and human patients. In this study, we investigated whether aFGF intranasal-treatment protected against neonatal hypoxic-ischaemic brain injury and evaluated the role of endoplasmic reticulum stress. The Rice-Vannucci model of neonatal hypoxic-ischaemic brain injury was used in 7-day-old rats, which were subjected to unilateral carotid artery ligation followed by 2.5 h of hypoxia. Intranasal aFGF or vehicle was administered immediately after hypoxic-ischaemic injury (100 ng/g) and then twice a day for 1 week to evaluate the long-term effects. Here we reported that intranasal-treatment with aFGF significantly reduced hypoxic-ischaemic brain infarct volumes and the protective effects were at least partially via inhibiting endoplasmic reticulum stress. In addition, aFGF exerted long-term neuroprotective effects against brain atrophy and neuron loss at 7-day after injury. Our data indicate that therapeutic strategies targeting endoplasmic reticulum stress may be promising to the treatment of neonatal hypoxic-ischaemic brain injury.