Rezaei, A. | Search bioRxiv

bioRxiv2022

Protective effects of different doses of MitoQ separately and combined with trehalose on sperm function and antioxidative status of cryopreserved Markhoz goat semen

The mitochondria-targeted antioxidant MitoQ has been regarded as an effective antioxidant agent against cryo-induced oxidative cellular damage. This study aimed to evaluate the use of different doses of MitoQ combined with trehalose to minimize mitochondrial impairment and oxidative stress during sperm cryopreservation of Markhoz goat. For this, semen collection was performed every 5 days from 5 bucks (10 ejaculates per buck). The ejaculates were pooled and then diluted in eight different Tris-based extenders as follows: no additives (control), 20, 200, 2000 nM of MitoQ (MT20, MT200, MT 2000, respectively), 150 mM of trehalose (Tr), MT20+Tr, MT200+Tr, MT2000+Tr. Each semen sample was frozen using a standard protocol, and sperm function and antioxidative status were evaluated after thawing. Results indicated higher total and progressive motility, acrosome and membrane integrity, superoxide dismutase, glutathione peroxidase, total antioxidant capacity, and lower DNA fragmentation and malondialdehyde in MT200+Tr than for all other groups except MT200; meanwhile, MT200 was also greater in these parameters than in the control group (P < 0.05). Furthermore, MT200 and MT200+Tr showed higher (P < 0.05) percentages of live cryopreserved sperm with high membrane mitochondrial potential than other groups. However, abnormality percentage and catalase activity of frozen-thawed sperm were not affected by treatments (P > 0.05). To conclude, we have found that supplementation of 200 nM MitoQ alone or in combination with 150 mM trehalose to semen extender improves the quality of cryopreserved sperm in goats, which is associated with enhanced antioxidant enzymatic defense and mitochondrial activity and reduced DNA fragmentation.

cell biology↗

bioRxiv2021

Proteomic signature of the Dravet syndrome in the genetic Scn1a-A1783V mouse model

BackgroundDravet syndrome is a rare, severe pediatric epileptic encephalopathy associated with intellectual and motor disabilities. Proteomic profiling in a mouse model of Dravet syndrome can provide information about the molecular consequences of the genetic deficiency and about pathophysiological mechanisms developing during the disease course. MethodsA knock-in mouse model of Dravet syndrome with Scn1a haploinsufficiency was used for whole proteome, seizure and behavioral analysis. Hippocampal tissue was dissected from two-(prior to epilepsy manifestation) and four-(following epilepsy manifestation) week-old male mice and analyzed using LC-MS/MS with label-free quantification. Proteomic data sets were subjected to bioinformatic analysis including pathway enrichment analysis. The differential expression of selected proteins was confirmed by immunohistochemical staining. ResultsThe findings confirmed an increased susceptibility to hyperthermia-associated seizures, the development of spontaneous seizures, and behavioral alterations in the novel Scn1a-A1873V mouse model of Dravet syndrome. As expected, proteomic analysis demonstrated more pronounced alterations following epilepsy manifestation. In particular, proteins involved in neurotransmitter dynamics, receptor and ion channel function, synaptic plasticity, astrogliosis, neoangiogenesis, and nitric oxide signaling showed a pronounced regulation in Dravet mice. Pathway enrichment analysis identified several significantly regulated pathways at the later time point, with pathways linked to synaptic transmission and glutamatergic signaling dominating the list. ConclusionIn conclusion, the whole proteome analysis in a mouse model of Dravet syndrome demonstrated complex molecular alterations in the hippocampus. Some of these alterations may have an impact on excitability or may serve a compensatory function, which, however, needs to be further confirmed by future investigations. The proteomic data indicate that, due to the molecular consequences of the genetic deficiency, the pathophysiological mechanisms may become more complex during the course of the disease. Resultantly, the management of Dravet syndrome may need to consider further molecular and cellular alterations. Ensuing functional follow-up studies, this data set may provide valuable guidance for the future development of novel therapeutic approaches.

neuroscience↗