Sex Differences in the Control of Adipose Tissue Function

This thesis illustrates intrinsic properties and sex or stress steroid-induced alterations of adipose tissue function. In addition, this thesis reveals sex differences in thermal perception, a contributing factor for the control of brown adipose tissue activity

Knowledge of obstetric danger signs and associated factors among pregnant women attending antenatal care services at Thai community hospital [version 2; peer review: 2 approved]

Background: To decrease preventable maternal mortality, providing health education to all parties is mandatory. Good knowledge, including awareness of pregnant women regarding obstetric danger signs (ODS), leads to appropriate practices and services. The knowledge of ODS varies among countries and regions. Since the data in rural regions of Thailand remains unavailable, this study aimed to identify the prevalence of good ODS knowledge and associated factors among pregnant women attending antenatal services at a Thai community hospital. Methods: We performed a cross-sectional, analytical study in 415 singleton pregnant women who visited the antenatal clinic at Wang Saphung Hospital, Loei, Thailand. A well-trained research assistant interviewed all participants using the data record form containing twenty items on the demographic and obstetric data and sixteen items on ODS knowledge. An ODS score of at least 75% (12 points) was considered a good level of knowledge. Results: A total of 275 participants (66.27%) had good knowledge of ODS. The most recognized ODS was vaginal bleeding whereas the least recognized ODS during pregnancy was convulsion; the least recognized ODS during labor and delivery was retained placenta. Multivariate regression analysis showed that the predictive factors of good OBS knowledge included a higher education level, maternal age of at least 20 years, and having medical personnel as a source of knowledge. Conclusions: In a rural setting of Thailand, two-thirds of pregnant women had good ODS knowledge. Identifying those at risk for fair and poor ODS knowledge and prompt management for the vulnerable subgroups might help decrease maternal mortality

Sex Difference in Corticosterone-Induced Insulin Resistance in Mice

Prolonged exposure to glucocorticoids (GCs) causes various metabolic derangements. These include obesity and insulin resistance, as inhibiting glucose utilization in adipose tissues is a major function of GCs. Although adipose tissue distribution and glucose homeostasis are sexdependently regulated, it has not been evaluated whether GCs affect glucose metabolism and adipose tissue functions in a sex-dependent manner. In this study, high-dose corticosterone (rodent GC) treatment in C57BU6J mice resulted in nonfasting hyperglycemia in male mice only, whereas both sexes displayed hyperinsulinemia with normal fasting glucose levels, indicative of insulin resistance. Metabolic testing using stable isotope-labeled glucose techniques revealed a sex-specific corticosterone-driven glucose intolerance. Corticosterone treatment increased adipose tissue mass in both sexes, which was reflected by elevated serum leptin levels. However, female mice showed more metabolically protective adaptations of adipose tissues than did male mice, demonstrated by higher serum total and high-molecular-weight adiponectin levels, more hyperplastic morphological changes, and a stronger increase in mRNA expression of adipogenic differentiation markers. Subsequently, in vitro studies in 3T3-L1 (white) and T37i (brown) adipocytes suggest that the increased leptin and adiponectin levels were mainly driven by the elevated insulin levels. In summary, this study demonstrates that GC-induced insulin resistance is more severe in male mice than in female mice, which can be partially explained by a sex-dependent adaptation of adipose tissues.</p

Sex difference in thermal preference of adult mice does not depend on presence of the gonads

Background: The thermoneutral zone (TNZ) is a species-specific range of ambient temperature (T a), at which mammals can maintain a constant body temperature with the lowest metabolic rate. The TNZ for an adult mouse is between 26 and 34 °C. Interestingly, female mice prefer a higher T a than male mice although the underlying mechanism for this sex difference is unknown. Here, we tested whether gonadal hormones are dominant factors controlling temperature preference in male and female mice. Methods: We performed a temperature preference test in which 10-week-old gonadectomized and sham-operated male and female C57BL/6J mice were allowed to choose to reside at the thermoneutral cage of 29 °C or an experimental cage of 26, 29, or 32 °C. Results: All mice preferred a T a higher than 26 °C, especially in the inactive phase. Choosing between 29 and 32 °C, female mice resided more at 32 °C while male mice had no preference between the temperatures. Hence, the preferred T a for female mice was significantly higher (0.9 ± 0.2 °C) than that for male mice. However, gonadectomy did not

Sex difference in cold perception and shivering onset upon gradual cold exposure

To maintain a thermal balance when experiencing cold, humans reduce heat loss and enhance heat production. A potent and rapid mechanism for heat generation is shivering. Research has shown that women prefer a warmer environment and feel less comfortable than men in the same thermal condition. Using the Blanketrol® III, a temperature management device commonly used to study brown adipose tissue activity, we tested whether the experimental temperature (_TE_) at which men and women start to shiver differs. Twenty male and 23 female volunteers underwent a cooling protocol, starting at 24 °C and gradually decreasing by 1–2 °C every 5 min until an electromyogram detected the shivering or the temperature reached 9 °C. Women started shivering at a higher _TE_ than men (11.3 ± 1.8 °C for women _vs_ 9.6 ± 1.8 °C for men, _P_ = 0.003). In addition, women felt cool, scored by a visual analogue scale, at a higher _TE_ than men (18.3 ± 3.0 °C for women _vs_ 14.6 ± 2.6 °C for men, _P_ < 0.001). This study demonstrate

Sex Differences in Brown Adipose Tissue Function: Sex Hormones, Glucocorticoids, and Their Crosstalk

Excessive fat accumulation in the body causes overweight and obesity. To date, research has confirmed that there are two types of adipose tissue with opposing functions: lipid-storing white adipose tissue (WAT) and lipid-burning brown adipose tissue (BAT). After the rediscovery of the presence of metabolically active BAT in adults, BAT has received increasing attention especially since activation of BAT is considered a promising way to combat obesity and associated comorbidities. It has become clear that energy homeostasis differs between the sexes, which has a significant impact on the development of pathological conditions such as type 2 diabetes. Sex differences in BAT activity may contribute to this and, therefore, it is important to address the underlying mechanisms that contribute to sex differences in BAT activity. In this review, we discuss the role of sex hormones in the regulation of BAT activity under physiological and some pathological conditions. Given the increasing number of studies suggesting a crosstalk between sex hormones and the hypothalamic-pituitary-adrenal axis in metabolism, we also discuss this crosstalk in relation to sex differences in BAT activity

Sex difference in the mouse BAT transcriptome reveals a role of progesterone in BAT function: Supplementary data

Supplementary table: Selected genes from the significant functional annotation clusters and their functional descriptio

Additional file 1: Figure S1. of Sex difference in thermal preference of adult mice does not depend on presence of the gonads

Paperwork score shows the nesting material of each score. Table S1. Baseline characteristics indicate the animal data from the adaptation weeks. (PDF 147 kb

Sex difference in the mouse BAT transcriptome reveals a role of progesterone

Brown adipose tissue (BAT) is a metabolically active organ that exhibits sex-differential features, that is, being generally more abundant and active in females than in males. Although sex steroids, particularly estrogens, have been shown to regulate BAT thermogenic function, the underlying molecular mechanisms contributing to sexual dimorphism in basal BAT activity have not been elucidated. Therefore, we assessed the transcriptome of interscapular BAT of male and female C57BL/6J mice by RNA sequencing and identified 295 genes showing ≥2-fold differential expression (adjusted P < 0.05). In silico functional annotation clustering suggested an enrichment of genes encoding proteins involved in cell-cell contact, interaction, and adhesion. Ovariectomy reduced the expression of these genes in female BAT toward a male pattern whereas orchiectomy had marginal effects on the transcriptional pattern, indicating a prominent role of female gonadal hormones in this sex-differential expression pattern. Progesterone was identified as a possible upstream regulator of the sex-differentially expressed genes. Studying the direct effects of progesterone in vitro in primary adipocytes showed that progesterone significantly altered the transcription of several of the identified genes, possibly via the glucocorticoid receptor. In conclusion, this study reveals a sexually dimorphic transcription profile in murine BAT at general housing conditions and demonstrates a role for progesterone in the regulation of the interscapular BAT transcriptome