Leptin modulates human Sertoli cells acetate production and glycolytic profile: a novel mechanism of obesity-induced male infertility?

AbstractHuman feeding behavior and lifestyle are gradually being altered, favoring the development of metabolic diseases, particularly type 2 diabetes and obesity. Leptin is produced by the adipose tissue acting as a satiety signal. Its levels have been positively correlated with fat mass and hyperleptinemia has been proposed to negatively affect male reproductive function. Nevertheless, the molecular mechanisms by which this hormone affects male fertility remain unknown. Herein, we hypothesize that leptin acts on human Sertoli cells (hSCs), the “nurse cells” of spermatogenesis, altering their metabolism. To test our hypothesis, hSCs were cultured without or with leptin (5, 25 and 50ng/mL). Leptin receptor was identified by qPCR and Western blot. Protein levels of glucose transporters (GLUT1, GLUT2 and GLUT3), phosphofructokinase, lactate dehydrogenase (LDH) and monocarboxylate transporter 4 (MCT4) were determined by Western Blot. LDH activity was assessed and metabolite production/consumption determined by proton nuclear magnetic resonance. Oxidative damage was evaluated by assessing lipid peroxidation, protein carbonilation and nitration. Our data shows that leptin receptor is expressed in hSCs. The concentration of leptin found in lean, healthy patients, upregulated GLUT2 protein levels and concentrations of leptin found in lean and obese patients increased LDH activity. Of note, all leptin concentrations decreased hSCs acetate production illustrating a novel mechanism for this hormone action. Moreover, our data shows that leptin does not induce or protect hSCs from oxidative damage. We report that this hormone modulates the nutritional support of spermatogenesis, illustrating a novel mechanism that may be linked to obesity-induced male infertility

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities 1,2 . This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity 3�6 . Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55 of the global rise in mean BMI from 1985 to 2017�and more than 80 in some low- and middle-income regions�was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing�and in some countries reversal�of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories. © 2019, The Author(s)

Hyperoside Supplementation in Preservation Media Surpasses Vitamin C Protection Against Oxidative Stress-Induced Damages in Human Spermatozoa

Oxidative Stress (OS) is reported as one of the main causes of male infertility. Infertile couples often resort to assisted reproductive technology (ART) to achieve parenthood. However, preparation for ART protocols increases the exposer of gametes to OS. Thus, it is crucial to find suitable preservation media that can counteract the OS-induced damages in spermatozoa. In this work, we tested and compared the efficiency of vitamin C (VC) and hyperoside (HYP) as potential antioxidant supplements for sperm preservation media

8 de março: conquistas e controvérsias The 8th of March: Gains and Controversies

O Dia Internacional da Mulher foi proposto por Clara Zetkin em 1910 no II Congresso Internacional de Mulheres Socialistas. Nos anos posteriores a 1970 este Dia passou a ser associado a um incêndio que ocorreu em Nova Iorque em 1911. Neste artigo procuro recuperar a história do Dia 8 de Março e as distorções que têm sido feitas sobre ele e sobre a luta feminista.<br>Clara Zetkin suggested the creation of the International Women's Day during the 2nd Socialist Women's International Conference in 1910. After 1970 this date became increasingly associated with a fire that took place in New York City in 1911. In this paper I review the history of the 8th of March, pointing out some of the distortions of its meanings and the repercussions these distortions have had for an understanding of feminist struggles

Narrativas fundadoras do feminismo: poderes e conflitos (1970-1978)

A forma como foram definidas as datas do ressurgimento do feminismo de 'Segunda Onda', na década de 1970, no Brasil, reflete interpretações oriundas de diferentes lugares. A narrativa de 'origem' desse feminismo foi resultado de disputas de poder entre diversos grupos feministas e entre estes e os diversos personagens envolvidos na luta contra a ditadura militar, instalada no país entre 1964 e 1985. As dicotomias entre 'lutas gerais e lutas específicas', de um lado, e entre 'verdadeiramente feministas e não-feministas', de outro, presentes nessas disputas, falam de poderes e de conflitos.<br>The way the 'Second Wave' feminism re-emergence was defined in the seventies, in Brazil, reflects interpretations that come from different places. The narrative of 'origin' of this feminism was result of contests of power among diverse feminists groups and among these and the diverse characters involved in the fight against the military dictatorship, present in the country between 1964 and 1985. The dichotomy between "general fights versus specific fights", in one side, and "true feminists versus not-feminists" in the other side, present in these contests, talks about powers and conflicts. I intend to discuss, in this article, the invention of these origins and their contests for power