Chronic stress causes ovarian fibrosis to impair female fertility in mice.

OBJECTIVE: Chronic psychological stress is associated with impaired follicular development and ovarian dysfunction. Many aspects of this dysfunction and the underlying mechanisms remain unclear. Using a chronic unpredictable mild stress (CUMS) mouse model, we investigate the influence of chronic stress on ovarian function and explore potential mechanisms. METHODS: A CUMS mouse model was constructed over eight months, covering the period from sexual maturity to the onset of declining fertility in mice. At the end of the 2nd, 4th, 6th, and 8th months of exposure to CUMS, behavioral and physiological assays, including the sucrose preference test, tail suspension test, and serum corticosterone levels, were conducted to validate the effectiveness of the stress model. Fertility and ovarian function were assessed by analyzing the estrous cycle, number of offspring, sex hormone levels, follicle counts, granulosa cell proliferation and apoptosis, and the expression levels of fibrosis markers. Furthermore, proteomic analyses were performed on the ovaries to investigate the molecular mechanisms of ovarian fibrosis induced by CUMS. RESULTS: With continued CUMS exposure, there was a gradual decline in both the ovary-to-body weight ratio and the number of offspring. Moreover, the percentage of atretic follicles was notably higher in the CUMS-exposed groups compared to the control groups. It is noticeable that CUMS triggered granulosa cell apoptosis and halted proliferation. Additionally, increased expression of α-SMA and Collagen I in the ovaries of CUMS-exposed mice indicated that CUMS could induce ovarian fibrosis. Proteomic analysis provided insights into the activation of specific biological processes and molecules associated with fibrosis induced by chronic stress. CONCLUSIONS: Our results strongly suggest that exposure to CUMS induces ovarian fibrosis, which influences follicular development and ultimately contributes to fertility decline. These findings offer novel perspectives on the impact of chronic stress on ovarian dysfunction.

Early life malnutrition and risk of T2DM adulthood: evidence from the lower socioeconomic status of northwest Chinese population.

Objective: This study aimed to explore whether famine exposure during early life are associated with a high risk of Type 2 Diabetes Mellitus (T2DM) in adulthood and the role of socioeconomic status (SES) on this effect. Materials and methods: We conducted a secondary data analysis based on data from a cross-sectional survey, collected 3,355 participants born between January 1, 1941 and December 31, 1966. Participants were categorized into four groups based on their date of birth, unexposed (individuals born in 1963-1966), infant exposed (individuals born in 1959-1962), childhood exposed (individuals born in 1949-1958), and adolescent exposed (born in 1941-1948). The association of famine exposure with T2DM risk in adults and conducted separately in plain area and mountain area was assessed using logistics regression model. Result: 22.35% of participants were diagnosed with T2DM, of which 43.47% were from the childhood famine-exposed group, representing the highest proportion among all subgroups (p < 0.001). Participants exposed to famine during childhood and adolescence from the lower SES mountain areas showed a significantly higher prevalence of T2DM in adulthood than those from the plain areas (p < 0.001). The adolescence stage exposed famine will increase the risk of T2DM in the mountain area (OR 2.46, 95% CI 1.61, 3.77). Conclusion: No strong evidence demonstrates that exposure to famine during the early life stage increases the risk of developing T2DM in adulthood. However, populations with lower SES are likely to be exposed to more risk factors for T2DM.

Exploring the long-term sustainability of school-based nutrition and food programs: What works, where and why?

ISSUE ADDRESSED: Most food and nutrition programs cease within 2 years. Understanding the determinants of program sustainability is crucial to maximise output from funding, whilst allowing sufficient time for program benefits to be achieved. This study applied the Consolidated Framework for Implementation Research (CFIR) to map the barriers and enablers of successful long-term implementation of school-based nutrition and food programs. METHODS: Qualitative methods with purposive and snowball sampling were used to recruit experts who were identified as being influential in implementing and sustaining long-term (>2 years) school-based food and nutrition programs. Semi-structured interviews with global experts were conducted, transcribed verbatim and coded deductively (by applying the CFIR constructs) and inductively when required. Thematic analysis informed the development of themes. RESULTS: Interviews were conducted with 11 experts including researchers, government employees, and a consultant of an international agency, from seven countries. Forty-eight deductive codes and eight inductive codes identified six main themes: (1) funding and integrity of its source; (2) political landscape; (3) nutrition policies and their monitoring; (4) involvement of community actors; (5) adaptability of the program and (6) effective program evaluation. Themes related mainly to the 'outer setting' domain of the CFIR. CONCLUSIONS: The CFIR highlighted pertinent factors that influence the successful long-term implementation of school-based food and nutrition programs. SO WHAT?: The findings suggest that to sustain program implementation beyond its initial funding, relationships across government departments, local organisations and communities, need to be nurtured and prioritised from the outset.

Inverted U-shaped associations between serum uric acid and fasting - plasma glucose level in non-diabetic, pre-diabetic, and diabetic adults: A population-based study in China.

OBJECTIVE: This study was designed to examine the correlation between serum uric acid (SUA) and fasting plasma glucose (FPG) levels across non-diabetic, pre-diabetic, and diabetic adults from Northwest China. MATERIALS AND METHODS: This study utilized data from a cross-sectional survey conducted in Ningxia Hui Autonomous Region, which investigated the prevalence and risk factors of cardiovascular disease. All subjects underwent tests for SUA and FPG levels. Generalized additive models and two-piecewise linear regression models were applied to explore the relationships between SUA and FPG level. The triglyceride-glucose (TyG) index was examined as a measure of insulin resistance, with an analysis of its mediating effects on the association between SUA and FPG level. RESULTS: A total of 10,217 individuals aged 18 and over were included. Generalized additive models verified the inverted U-shaped association between SUA and FPG levels, and the inflection points of FPG levels in the curves were 6.5 mmol/L in males and 8.8 mmol/L in females. The TyG index is an intermediate variable in the relationship between SUA levels and elevated FPG levels, with mediating effects of 12.82% (P < 0.001) for males and 34.02% (P < 0.001) for females. CONCLUSIONS: An inverted U-shaped association between FPG and SUA levels was observed in both genders. The threshold of FPG level was lower in males than in females. The relationship between these variables seems to be partially mediated by serum insulin levels.

Reversible domain closure modulates GlnBP ligand binding affinity.

Glutamine binding protein (GlnBP) is an Escherichia Coli periplasmic binding protein, which binds and carries glutamine to the inner membrane ATP-binding cassette (ABC) transporter. GlnBP binds the ligand with affinity around 0.1µM measured by isothermal titration calorimetry (ITC) and ligand binding stabilizes protein structure shown by its increase in thermodynamic stability. However, the molecular determinant of GlnBP ligand binding is not known. Electrostatic and hydrophobic interaction between GlnBP and glutamine are critical factors. We propose that the freedome of closure movement is also vital for ligand binding. In order to approve this hypothesis, we generate a series of mutants with different linker length that has different magnitude of domain closure. Mutants show different ligand binding affinity, which indicates that the propensity of domain closure determines the ligand binding affinity. Ligand binding triggers gradual ensemble conformational change. Structural changes upon ligand binding are monitored by combination of small angle x-ray scattering (SAXS) and NMR spectroscopy. Detailed structure characterization of GlnBP contributes to a better understanding of ligand binding and provides the structural basis for biosensor design.