Mental health differences in medical students based on curriculum and gender.

BACKGROUND: The prevalence of mental health struggles among students in medical school is widely reported; however, little is known about how it is impacted by the medical school curriculum. This study aimed to evaluate differences in anxiety, depression, and emotional exhaustion in medical students based on gender, class year, and curriculum. METHODS: An anonymous online survey consisting of questions from established, validated questionnaires about demographics, anxiety, depression, emotional exhaustion, and personal health behaviors was sent to 817 medical students who attended Rowan-Virtua School of Osteopathic Medicine during the Spring of 2021. When applying to this school, each of these students had the option to choose either the problem-based learning (PBL) or lecture-based learning (LBL) curriculum track. RESULTS: The survey was completed by 222 students. Females experienced higher levels of anxiety, depression, and emotional exhaustion than males. Students in the PBL had lower levels of emotional exhaustion than their peers in the LBL. Increase in emotional exhaustion was most pronounced between 1st and 2nd year students. Emotional exhaustion was inversely correlated with sleep and exercise. CONCLUSIONS: On average, students who were either male or in the PBL curriculum experienced less mental distress in the form of anxiety, depression, and emotional exhaustion than their peers. While gender continues to be an established factor in how mental distress is experienced, the reduced levels of emotional exhaustion in PBL students is a novel finding that can potentially shed light on how to better optimize medical education. Despite the inherent selection bias and lower number of PBL students, to our knowledge, this is the first study comparing two different curricula within a single institution. This finding along with a focus on good sleep and exercise habits may provide a path for improving mental health in medical students.

Mitochondrial disease disrupts hepatic allostasis and lowers the threshold for immune-mediated liver toxicity.

OBJECTIVE: In individuals with mitochondrial disease, respiratory viral infection can result in metabolic decompensation with mitochondrial hepatopathy. Here, we used a mouse model of liver-specific Complex IV deficiency to study hepatic allostasis during respiratory viral infection. METHODS: Mice with hepatic cytochrome c oxidase deficiency (LivCox10-/-) were infected with aerosolized influenza, A/PR/8 (PR8), and euthanized on day five after infection following three days of symptoms. This time course is marked by a peak in inflammatory cytokines and mimics the timing of a common clinical scenario in which caregivers may first attempt to manage the illness at home before seeking medical attention. Metabolic decompensation and mitochondrial hepatopathy in mice were characterized by serum hepatic testing, histology, electron microscopy, biochemistry, metabolomics, and bioenergetic profiling. RESULTS: Following influenza infection, LivCox10-/- mice displayed marked liver disease including hepatitis, enlarged mitochondria with cristae loss, and hepatic steatosis. This pathophysiology was associated with viremia. Primary hepatocytes from LivCox10-/- mice cocultured with WT Kupffer cells in the presence of PR8 showed enhanced lipid accumulation. Treatment of hepatocytes with recombinant TNFα implicated Kupffer cell-derived TNFα as a precipitant of steatosis in LivCox10-/- mice. Eliminating Kupffer cells or blocking TNFα in vivo during influenza infection mitigated the steatosis and mitochondrial morphologic changes. CONCLUSIONS: Taken together, our data shift the narrative of metabolic decompensation in mitochondrial hepatopathy beyond the bioenergetic costs of infection to include an underlying susceptibility to immune-mediated damage. Moreover, our work suggests that immune modulation during metabolic decompensation in mitochondrial disease represents a future viable treatment strategy needing further exploration.

Macrophage derived TNFα promotes hepatic reprogramming to Warburg-like metabolism.

During infection, hepatocytes must undergo a reprioritization of metabolism, termed metabolic reprogramming. Hepatic metabolic reprogramming in response to infection begins within hours of infection, suggesting a mechanism closely linked to pathogen recognition. Following injection with polyinosinic:polycytidylic acid, a mimic of viral infection, a robust hepatic innate immune response could be seen involving the TNFα pathway at 2 h. Repeated doses led to the adoption of Warburg-like metabolism in the liver as determined by in vivo metabolic imaging, expression analyses, and metabolomics. Hepatic macrophages, Kupffer cells, were able to induce Warburg-like metabolism in hepatocytes in vitro via TNFα. Eliminating macrophages in vivo or blocking TNFα in vitro or in vivo resulted in abrogation of the metabolic phenotype, establishing an immune-metabolic axis in hepatic metabolic reprogramming. Overall, we suggest that macrophages, as early sensors of pathogens, instruct hepatocytes via TNFα to undergo metabolic reprogramming to cope with challenges to homeostasis initiated by infection. This work not only addresses a key component of end-organ physiology, but also raises questions about the side effects of biologics in the treatment of inflammatory diseases. KEY MESSAGES: • Hepatocytes develop Warburg-like metabolism in vivo during viral infection. • Macrophage TNFα promotes expression of glycolytic enzymes in hepatocytes. • Blocking this immune-metabolic axis abrogates Warburg-like metabolism in the liver. • Implications for patients being treated for inflammatory diseases with biologics.