Catalase as a Molecular Target for Male Infertility Diagnosis and Monitoring: An Overview.

Catalase (CAT) stands out as one of the most efficient natural enzymes when catalysing the split of H2O2 into H2O and O2; H2O2 is one of the reactive oxygen species (ROS) involved in oxidative stress, a process closely related to aging and several health disorders or diseases like male infertility. Some studies have correlated H2O2 with male infertility and catalase with fertility restoration. However, the number of studies conducted with human beings remains scarce. Considering the use of CAT as a molecular target for biochemical analysis, this review summarises the current knowledge on how CAT influences human beings' male fertility. Thus, three different databases were consulted-Scopus, PubMed and WOS-using single keywords and combinations thereof. A total of 40,823 articles were identified. Adopting inclusion and exclusion criteria, a final database of 197 articles served to conduct this work. It follows from this analysis that CAT could play an important role in male fertility and could become a good target for male infertility diagnosis and monitoring. However, that potential role of CAT as a tool in diagnosis must be confirmed by clinical trials. Finally, guidelines are suggested to reinforce the use of CAT in daily clinical tests for male fertility diagnosis and monitoring.

NADPH oxidase 2-mediated NLRP1 inflammasome activation involves in neuronal senescence in hippocampal neurons in vitro.

Oxidative stress and inflammation are closely related to neuron ageing. NADPH oxidase 2 (NOX2) is a major source of reactive oxygen species (ROS) generation in brain. The nucleotide-binding oligomerisation domain (NOD)-like receptor protein 1 (NLRP1) inflammasome is responsible for the formation of proinflammatory molecules in neurons. We hypothesize that NOX2-derived ROS accumulation mediates activation of NLRP1 inflammasome, which is involved in age-related neuronal damage. In the present study, we investigated the changes of NOX2-NLRP1 signaling pathway in primary hippocampal neurons cultured for different time (6, 9 and 12 days, d). Meanwhile, we further examined the effect of ROS inhibitor and NLRP1-siRNA on neuronal senescence. The results showed that, compared with 6 d group, the neuronal apoptosis and ß-Galactosidase (ß-Gal) expression were significantly increased, and the microtubule-associated protein 2 (MAP2) expression significantly decreased in primary hippocampal neurons cultured for 12 d. In addition, the results also showed that the production of ROS, the expressions of NOX2 and NLRP1 inflammasome were significantly increased with the prolongation of culture time in hippocampal neurons. Moreover, the NOX inhibitor (apocynin) and ROS scavenger (tempol) significantly decreased ROS production and alleviated neuronal damage. Meanwhile, the tempol and apocynin treatment significantly decreased the expression of NLRP1 inflammasome in hippocampal neurons. Furthermore, the NLRP1-siRNA and caspase-1 inhibitor treatment also alleviated neuronal damage. These results suggest that NOX2-derived ROS generation may induce brain inflammation via NLRP-1 inflammasome activation and lead to age-related neuronal damage. The NADPH oxidase and NLRP1 inflammasome may be important therapeutic targets for age-related neuronal damage.

Acute dose of melatonin via Nrf2 dependently prevents acute ethanol-induced neurotoxicity in the developing rodent brain.

BACKGROUND: Melatonin is a well-known potent endogenous antioxidant pharmacological agent with significant neuroprotective actions. Here in the current study, we explored the nuclear factor erythroid 2-related factor 2 (Nrf2) gene-dependent antioxidant mechanism underlying the neuroprotective effects of the acute melatonin against acute ethanol-induced elevated reactive oxygen species (ROS)-mediated neuroinflammation and neurodegeneration in the developing rodent brain. METHODS: In vivo rat pups were co-treated with a single dose of acute ethanol (5 g/kg, subcutaneous (S.C.)) and a single dose of acute melatonin (20 mg/kg, intraperitoneal (I.P.)). Four hours after a single S.C. and I.P. injections, all of the rat pups were sacrificed for further biochemical (Western blotting, ROS- assay, LPO-assay, and immunohistochemical) analyses. In order to corroborate the in vivo results, we used the in vitro murine-hippocampal HT22 and microglial BV2 cells, which were subjected to knockdown with small interfering RNA (siRNA) of Nrf2 genes and exposed with melatonin (100 µM) and ethanol (100 mM) and proceed for further biochemical analyses. RESULTS: Our biochemical, immunohistochemical, and immunofluorescence results demonstrate that acute melatonin significantly upregulated the master endogenous antioxidant Nrf2 and heme oxygenase-1, consequently reversing the acute ethanol-induced elevated ROS and oxidative stress in the developing rodent brain, and in the murine-hippocampal HT22 and microglial BV2 cells. In addition, acute melatonin subsequently reduced the activated MAPK-p-P38-JNK pathways and attenuated neuroinflammation by decreasing the expression of activated gliosis and downregulated the p-NF-K-B/p-IKKß pathway and decreased the expression levels of other inflammatory markers in the developing rodent brain and BV2 cells. Of note, melatonin acted through the Nrf2-dependent mechanism to attenuate neuronal apoptosis in the postnatal rodent brain and HT22 cells. Immunohistofluorescence results also showed that melatonin prevented ethanol-induced neurodegeneration in the developing rodent brain. The in vitro results indicated that melatonin induced neuroprotection via Nrf2-dependent manner and reduced ethanol-induced neurotoxicity. CONCLUSIONS: The pleiotropic and potent neuroprotective antioxidant characteristics of melatonin, together with our in vivo and in vitro findings, suppose that acute melatonin could be beneficial to prevent and combat the acute ethanol-induced neurotoxic effects, such as elevated ROS, neuroinflammation, and neurodegeneration in the developing rodent brain.

Protective effect and mechanism of ginsenoside Rg1 on H2O2induced hippocampal neurons aging due to down-regulate NOX2 mediated NLRP1 inflammasome activation in vitro / 中国药理学与毒理学杂志

OBJECTIVE To explore the protective effects and mechanisms of Ginsenoside Rg1 (Rg1) on H2O2-induced hippocampal neurons aging in vitro. METHODS The primary culture hippo-campal neurons(7 d)were randomly placed into six groups:normal control group,H2O2(200 μM)treat-ment group,and H2O2+Rg1(1,5 and 10μM)groups.The neurons were with Rg1(1,5 and 10 μmol·L-1) for 6h. H2O2(200 μmol·L-1) was added to the medium and incubate for 18 h. The Dihydroethidium (DHE) staining was performed for ROS production assessment. The LDH release and Hoechst 33258 were performed to examine the neuronal damage and apoptosis. The immunoblot was used to deter-mine the expression of β-Gal,NOX2,p22phox,p47phox,NLRP-1,ASC and Caspase-1 in hippocampal neurons.The ELISA was performed to detect the levels of IL-1β and IL-18 released in the supernatant in hippocampal neurons.RESULTS Rg1(5 and 10 μmol·L-1)significantly reduced the ROS production, attenuated H2O2-induced neuronal damage and apoptosis (P<0.05, P<0.01). The immunoblot results showed that Rg1(5 and 10 μmol·L-1)treatment significantly decreased the expression of β-Gal,NOX2, p22phox,p47phox,NLRP-1,ASC and Caspase-1 in hippocampal neurons(P<0.05,P<0.01).Additionally, Rg1(5 and 10 μmol·L-1)treatment significantly decreased IL-1β and IL-18 release in the supernatant. CONCLUSION The protective effect of Rg1 in H2O2-induced hippocampal neurons aging may be due to inhibit NOX2-NLRP1 activation.