Biology subjects

Breithaupt, L.

Publications and source records attributed to Breithaupt, L..

3 recordsLinked to original sources

bioRxiv2025

Changes in muscle strength and moderators of protein turnover in a rodent model of anorexia nervosa and recovery

Anorexia nervosa (AN) is a psychiatric disorder characterized by severe caloric restriction, leading to health complications. In addition to fat loss, AN also results in profound skeletal muscle loss, yet molecular pathways underlying these musculoskeletal complications or how long-lasting these musculoskeletal consequences may be are currently unknown. The purpose of this study was to investigate the effects of AN and subsequent weight recovery on muscle strength, size, and moderators of protein turnover in a rat model of AN. Female Sprague Dawley rats (n=11/group, 8 weeks of age) underwent 30 days of simulated AN (50-60% food restriction) followed by varying recovery periods. Muscle mass, strength, and protein synthesis/degradation pathways were assessed. AN led to substantial reductions in muscle mass and strength. While muscle mass recovered within 30 days, muscle strength remained depressed in rats with a prior history of AN, suggesting alterations to muscle quality. Moreover, moderators of protein synthesis (Igf1, Redd1, Deptor) remained altered following 30 days of AN and subsequent recovery. These findings suggest muscle impairments in AN may be longer-lasting than previously thought and may contribute to increased health complications and reduced quality of life in those with a history of AN.

physiology↗

bioRxiv2025

New niches for larger phytoplankton in a warmer, more resource-limited ocean

Warming and nutrient limitation are major stressors that affect primary production in the ocean, with cascading impacts on the food web. Yet, we lack a mechanistic understanding of how phytoplankton manage multiple stressors and the implications of these responses for phytoplankton biogeography. By combining theory, proteome allocation modeling, and climate projections, we identified two potential competing strategies for multi-stressor growth: (1) nutrient efficient smaller cells, or (2) heat-tolerant larger cells. We found that Prochlorococcus are more vulnerable in warmer, "heat-stressed", tropical regions due to greater heat sensitivity and lower lipid storage capacity to buffer oxidative stress, indicating a potential ecological niche for larger phytoplankton with lower sensitivity to oxidative stress, such as Synechococcus and picoeukaryotes. Our findings advocate for the inclusion of phytoplankton heat-stress responses in global models to more accurately predict their ecological niches as the climate warms.

ecology↗

bioRxiv2023

Identification of State Markers in Anorexia Nervosa: Replication and Extension of Inflammation Associated Biomarkers Using Multiplex Profiling in Anorexia Nervosa and Atypical Anorexia Nervosa

Proteomics provides an opportunity for detection and monitoring of anorexia nervosa (AN) and its related variant, atypical-AN (atyp-AN). However, research to date has been limited by the small number of proteins explored, exclusive focus on adults with AN, and lack of replication across studies. This study performed Olink Proseek Multiplex profiling of 92 proteins involved in inflammation among females with AN and atyp-AN (N = 64), all < 90% of expected body weight, and age-matched healthy controls (HC; N=44). After correction for multiple testing, nine proteins differed significantly in the AN/atyp-AN group relative to HC group (lower levels: CXCL1, HGF, IL-18R1, TNFSF14, TRANCE; higher levels: CCL23, Flt3L, LIF-R, MMP-1). The expression levels of three proteins (lower IL-18R1, TRANCE; higher LIF-R) were uniquely disrupted in females with AN. No unique expression levels emerged for atyp-AN. Across the whole sample, twenty-one proteins correlated positively with BMI (ADA, AXIN1, CD5, CD244, CD40, CD6, CXCL1, FGF-21, HGF, IL-10RB, IL-12B, IL18, IL-18R1, IL6, LAP TGF-beta-1, SIRT2, STAMBP, TNFRSF9, TNFSF14, TRAIL, TRANCE) and six (CCL11, CCL23, FGF-19, IL8, LIF-R, OPG) were negatively correlated with BMI. Overall, our results replicate the prior study demonstrating a dysregulated inflammatory status in AN, and extend these results to atyp-AN (AN/atyp-AN all < 90% of expected body weight). Of the 27 proteins correlated with BMI, 18 were replicated from a prior study using similar methods, highlighting the promise of inflammatory protein expression levels as biomarkers of disease monitoring. Additional studies of individuals across the entire weight spectrum are needed to understand the role of inflammation in atyp-AN.

immunology↗