Blog – Page 10

The treatment of depression has long faced the challenges of a low treatment rate, significant drug side effects and a high relapse rate. Recent studies have revealed that the gut microbiota and neuronal mitochondrial dysfunction play central roles in the pathogenesis of depression: the gut microbiota influences the course of depression through multiple pathways, including immune regulation, HPA axis modulation and neurotransmitter metabolism. Mitochondrial function serves as a key hub that mediates mood disorders through mechanisms such as defective energy metabolism, impaired neuroplasticity and amplified neuroinflammation. Notably, a bidirectional regulatory network exists between the gut microbiota and mitochondria: the flora metabolite butyrate enhances mitochondrial biosynthesis through activation of the AMPK–PGC1α pathway, whereas reactive oxygen species produced by mitochondria counteract the flora composition by altering the intestinal epithelial microenvironment. In this study, we systematically revealed the potential pathways by which the gut microbiota improves neuronal mitochondrial function by regulating neurotransmitter synthesis, mitochondrial autophagy, and oxidative stress homeostasis and proposed the integration of probiotic supplementation, dietary fiber intervention, and fecal microbial transplantation to remodel the flora–mitochondrial axis, which provides a theoretical basis for the development of novel antidepressant therapies targeting gut–brain interactions.

Depression is a disorder that severely affects the mental health of the global population and is characterized by persistent low mood, loss of interest and cognitive dysfunction (GBD 2017 Disease and Injury Incidence and Prevalence Collaborators, 2018; COVID-19 Mental Disorders Collaborators, 2021; Salari et al., 2020). Globally, depression is one of the leading causes of mental disability. According to the World Health Organization (WHO), the global prevalence of depression is approximately 4.4%, which means that more than 300 million people worldwide suffer from depression (Xu et al., 2024). In addition, depression is one of the major causes of suicide deaths, with nearly 800,000 people worldwide dying by suicide each year (World Health Organization, 2021).

Scientists from the Lee Kong Chian School of Medicine at Nanyang Technological University, Singapore, have uncovered how different brain regions work together to enable self-control—the ability to suppress impulsive behaviors and wait for the right moment to act. Their findings advance the understanding of conditions such as attention-deficit hyperactivity disorder (ADHD) and addiction, and could lead to more effective management of these disorders.

According to the researchers, this is the first time that this interplay underlying self-control has been found in the brain. The findings were reported in Science Advances.

A study by investigators at Mass General Brigham has found that a blood test of plasma phosphorylated tau 217 (pTau217), an Alzheimer’s disease biomarker, can predict the progression of amyloid PET scan changes and cognitive decline in cognitively healthy older adults. The findings may help push back the clock to enable simpler, earlier disease prediction and indicate who may be at risk for cognitive decline. The results are published in Nature Communications.

“We used to think that PET scan detection was the earliest sign of Alzheimer’s disease progression, revealing amyloid accumulation in the brain 10 to 20 years before symptoms appear,” said lead author Hyun-Sik Yang, MD, a neurologist with Mass General Brigham Neuroscience Institute and an associate member of the Broad Institute of MIT and Harvard. “But now we are seeing that pTau217 can be detected years earlier, well before clear abnormalities appear on amyloid PET scans.”

Last year, the U.S. Food and Drug Administration cleared the first blood test for Alzheimer’s disease, paving the way for a cheaper, less invasive alternative to lumbar punctures and PET scans. The new study by Yang and colleagues adds important evidence about the predictive potential of these kinds of blood tests.

Background Raised cardiac troponin-I is a common finding in patients hospitalised with acute viral infections, including but not limited to COVID-19. This often occurs in the absence of overt myocardial injury presenting a challenge for interpretation. The mechanisms underlying troponin elevation are uncertain.

Methods The CISCO-19 (Cardiovascular Imaging in SARS-CoV-19) study (NCT04403607) is a prospective, multicentre cohort study, in which hospitalised PCR-confirmed COVID-19 participants (N=267) underwent multisystem evaluation at enrolment and at 28–60 days. The study incorporated plasma proteomics (SOMAscan V.4.1), cardiovascular MRI and clinical biomarkers. Of these, 211 had baseline plasma proteomic data and 185 completed follow-up sampling. Matched proteomic and imaging data were available for 155 participants (mean age: 55 years (SD 12); 43% female).

Results A high likelihood of myocarditis was identified in 13.2% (N=21/159) of participants. High-sensitivity troponin-I was modestly elevated at enrolment (median 3 ng/L; IQR 2–6; n=159). Among males (n=90), 9.3% had a high-sensitivity troponin that exceeded 34 ng/L. Among females (n=69), 4.5% exceeded 16 ng/L. Smooth muscle myosin light chain proteins were downregulated at follow-up (log2 fold change −0.12 to −0.6; all adjusted p0.02) and positively correlated with high-sensitivity troponin-I, but not N-terminal brain natriuretic peptide or cardiac MRI indices (n=155).