Metformin accelerates myelin recovery and ameliorates behavioral deficits in the animal model of multiple sclerosis via adjustment of AMPK/Nrf2/mTOR signaling and maintenance of endogenous oligodendrogenesis during brain self-repairing period

BACKGROUND: Multiple sclerosis (MS) is a devastating autoimmune disorder characterized by oligodendrocytes (OLGs) loss and demyelination. In this study, we have examined the effects of metformin (MET) on the oligodendrogenesis, redox signaling, apoptosis, and glial responses during a self-repairing period (1-week) in the animal model of MS. METHODS: For induction of demyelination, C57BL/6 J mice were fed a 0.2% cuprizone (CPZ) for 5 weeks. Thereafter, CPZ was removed for 1-week and molecular and behavioral changes were monitored in the presence or absence of MET (50 mg/kg body weight/day). RESULTS: MET remarkably increased the localization of precursor OLGs (NG2+/O4+ cells) and subsequently the renewal of mature OLGs (MOG+ cells) in the corpus callosum via AMPK/mammalian target of rapamycin (mTOR) pathway. Moreover, we observed a significant elevation in the antioxidant responses, especially in mature OLGs (MOG+/nuclear factor erythroid 2-related factor 2 (Nrf2+) cells) after MET intervention. MET also reduced brain apoptosis markers and lessened motor dysfunction in the open-field test. While MET was unable to decrease active astrogliosis (GFAP mRNA), it reduced microgliosis by down-regulation of Mac-3 mRNA a marker of pro-inflammatory microglia/macrophages. Molecular modeling studies, likewise, confirmed that MET exerts its effects via direct interaction with AMPK. CONCLUSIONS: Altogether, our study reveals that MET effectively induces lesion reduction and elevated molecular processes that support myelin recovery via direct activation of AMPK and indirect regulation of AMPK/Nrf2/mTOR pathway in OLGs. These findings facilitate the development of new therapeutic strategies based on AMPK activation for MS in the near future. KEYWORDS: AMPK; Cuprizone; Multiple sclerosis; Nrf2; mTO

Associations of Environmental Factors and Prevalence of Vitamin D Deficiency in Iran

Introduction: Vitamin D deficiency is a major health problem, which is unexpectedly prevalent in Iran. The ultraviolet (UV) rays of the sun are considered to be the foremost source of vitamin D in humans. In contrast, several environmental factors could decrease UV transmission to the earth, thereby reducing vitamin D absorption. Considering that the key role of environmental factors in vitamin deficiency has been neglected, the present study aimed to investigate the associations between environmental factors (e.g., geographical and air pollution parameters) with the prevalence of vitamin D deficiency in Iran. Methods: The duration of the prevalence of vitamin D deficiency were extracted from the previous studies conducted in different cities in Iran, where vitamin D deficiency was reported. Afterwards, the environmental factors that were reported to affect sunlight transmission through the atmosphere were collected based on the place and time of vitamin D deficiency as mentioned in the reviewed studies via different geographic databases. The associations between the environmental factors and prevalence of vitamin D deficiency were determined. In total, 35 studies were reviewed completely. Results: The results indicated significant correlations between the prevalence of vitamin D deficiency and some environmental factors (e.g., cloudy and clear days). However, no significant association was observed between vitamin D deficiency and other environmental factors, such as geographical parameters (e.g., sunshine, longitude, latitude, elevation, humidity, and temperature) and air pollution (e.g., number of days with dust and visibility of ≤2 km). Conclusion: According to the results, there were significant associations between the prevalence of vitamin D deficiency andenvironmental factors, such as cloudy and clear days. Therefore, adequate exposure to sunlight for the absorption of vitamin D is strongly recommended

The Effects of Different Dose of Chronic Ritalin on the Brain of Prepubertal Female Balb/C Mice

Background Methylphenidate (MPH) is commonly prescribed for children who have been diagnosed with attention deficit hyperactivity disorder (ADHD); however, the action mechanisms of methylphenidate have not been fully elucidated. Studies have shown a relationship between apoptosis signaling pathways and psychiatric disorders, as well as therapeutic targets for such disorders. So, we examined the effects of chronic methylphenidate administration on the brain of mice. Materials and Methods Animals were administered MPH at doses of 2, 5 and 10 mg/kg for 60 days.  At the age of three months and in estrous phase, brian tissues were removed and washed in cold phosphate-buffered saline and some of them were frozen at -80oC for Western blot analysis. We measured the levels of pro-apoptotic protein, Bax and anti-apoptoticprotein, Bcl-2, in the brain of neonate female Balb/c mice. The rest of the brains were fixed in formalin (10% phosphate-buffered, pH = 7.4). Then samples were embedded in paraffin according to routine histologic procedures. Results: Our results showed that MPH with a dose of 10 mg/kg causes a considerable increase in the level of the Bax protein as compared with other groups. In contrast, in the partial cortex of female mice under treatment with high dose of MPH (10 mg/kg) could less Bcl2 levels as compared with 5 mg/kg MPH. However, 5 mg/kg MPH have a significant effect on Bcl2 levels compare with each of mentioned doses (

Panel 7: otitis media:treatment and complications

Objective: We aimed to summarize key articles published between 2011 and 2015 on the treatment of (recurrent) acute otitis media, otitis media with effusion, tympanostomy tube otorrhea, chronic suppurative otitis media and complications of otitis media, and their implications for clinical practice. Data Sources: PubMed, Ovid Medline, the Cochrane Library, and Clinical Evidence (BMJ Publishing). Review Methods: All types of articles related to otitis media treatment and complications between June 2011 and March 2015 were identified. A total of 1122 potential related articles were reviewed by the panel members; 118 relevant articles were ultimately included in this summary. Conclusions: Recent literature and guidelines emphasize accurate diagnosis of acute otitis media and optimal management of ear pain. Watchful waiting is optional in mild to moderate acute otitis media; antibiotics do shorten symptoms and duration of middle ear effusion. The additive benefit of adenoidectomy to tympanostomy tubes in recurrent acute otitis media and otitis media with effusion is controversial and age dependent. Topical antibiotic is the treatment of choice in acute tube otorrhea. Symptomatic hearing loss due to persistent otitis media with effusion is best treated with tympanostomy tubes. Novel molecular and biomaterial treatments as adjuvants to surgical closure of eardrum perforations seem promising. There is insufficient evidence to support the use of complementary and alternative treatments. Implications for Practice: Emphasis on accurate diagnosis of otitis media, in its various forms, is important to reduce overdiagnosis, overtreatment, and antibiotic resistance. Children at risk for otitis media and its complications deserve special attention