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Glioblastoma is the most aggressive primary brain tumor in adults. Androgens are reported to influence the development of glioblastoma. Dihydrotestosterone (DHT) is formed from testosterone by action of the enzyme steroid 5α-reductase and is the most potent growth-inducing androgen metabolite. 24-Hydroxycholesterol, another steroid in the brain, is pivotal for brain cholesterol homeostasis and has been suggested to influence glioblastoma cells. However, a connection between 24-hydroxycholesterol and androgen metabolism related to glioblastoma has not previously been reported. The present study reports that human T98G glioblastoma cells metabolize testosterone into DHT, 3αandrostanediol and androstenedione. The 5α-reductase pathway converted testosterone to DHT and further to 3α-androstanediol. The 17β-hydroxysteroid dehydrogenase pathway metabolized testosterone to androstenedione. Results indicated that the 5α-reductase pathway is the major pathway for testosterone metabolism in this cell line. 24-Hydroxycholesterol significantly suppressed the conversion of testosterone to DHT and 3α-androstanediol, to a similar degree as the synthetic 5α-reductase inhibitor finasteride. Suppression of DHT formation resulted in increased metabolism to androstenedione. Similar effects on DHT formation were observed with the LXR agonist T0901317 as with 24-hydroxycho-lesterol. In addition, 24-hydroxycholesterol suppressed DHT formation in patient-derived primary GB cell lines U3009 and U3013, indicating that the observed connection between 24-hydroxycholesterol and androgen metabolism is not unique for T98G cells. Furthermore, 24-hydroxycholesterol-mediated suppression of DHT formation was also observed in human neuroblastoma SH-SY5Y cells. To summarize, the present data provide information on androgen metabolism in glioblastoma cells and indicate a previously unknown link between cholesterol homeostasis and growth-inducing androgens in glioblastoma and potentially other cell types.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterised by progressive muscle weakness in both bulbar and extremity muscles, leading to a diverse clinical phenotype with motor and non-motor symptoms. Approximately 85% of ALS cases are sporadic (sALS), while the remaining 10%-15% are familial (fALS). Biological biomarkers of sporadic ALS remain poorly understood, hindering precise patient screening, delaying diagnosis and negatively affecting prognosis. This study aims to identify potential proteomic biomarkers by comparing the cerebrospinal fluid (CSF) of sALS patients with that of patients suffering from other neurological diseases. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for proteomic profiling of CSF samples from 24 sALS patients and 26 patients with other neurological diseases. The complete protein expression profiles were compared using a two-tailed Student's t-test, with a p < 0.05 considered statistically significant with additional FDR correction at the 0.1 level. Proteomic analysis of CSF samples identified significant quantitative changes in 96 proteins with threshold p < 0.05 and 74 proteins with FDR < 0.1 between sALS and non-ALS patients, including alterations in proteins associated with neurodegenerative processes, such as amyloid precursor proteins and inflammatory markers. CSF proteomic analysis reveals altered inflammatory and neurodegenerative metabolic pathways, providing valuable insights into the proteomic landscape of sALS. Several dysregulated proteins were consistent with the disease mechanisms highlighted in previous studies. These findings represent a step forward in developing personalised approaches for diagnosing and managing the disease.

Adrenocortical carcinoma (ACC) is a devastating disease with few effective treatments. The underlying molecular pathways remain largely unknown. To identify potential pathways and drivers relevant to ACC pathogenesis, we utilized histologically normal adrenals from heterozygous multiple endocrine neoplasia type 1 (Men1) mice to study early adrenocortical tumorigenesis. Employing mass spectrometry-based proteomic profiling, we identified 681 proteins, of which 52 displayed significant differential regulation in the adrenal tissues of heterozygous Men1 mice in comparison with their wild-type counterparts. Among these were fatty acid synthase (FASN) and ATP-citrate lyase (ACLY), two enzymes previously shown to be upregulated in several other types of tumors. To assess the functional impact of ACLY and FASN in ACC, we used H295R cells as the primary model. Cells were treated with SB-204990 (ACLY inhibitor) or C75 (FASN inhibitor), which both showed a dose-dependent antiproliferative effect. Lipidomic analysis revealed a significant reduction in palmitic acid and palmitoleic acid in treated cells compared to controls, supporting a mechanistic link between ACLY/FASN activity and lipid biosynthesis. Finally, data from The Cancer Genome Atlas showed significantly diminished survival outcomes among ACC patients exhibiting high ACLY or FASN expression. These findings underscore the potential importance of exploring the inhibition of lipid synthesis as a promising avenue for further research in the context of human ACC.

Background

Critical illness myopathy is a common and devastating consequence of critical care, causing dramatic loss of muscle mass and function in intensive care unit patients. Functional deficits often exceed the loss in muscle mass and myosin content. However, the mechanisms underlying the loss of force and emergence of myosin-expressing non-force-generating fibers remain elusive.

Methods

Myosin dysfunction was investigated in six intensive care unit patients exposed to a 12-day mechanical ventilation and immobilization period using mass spectrometry-based proteomics and molecular dynamics simulations.

Results

Previous single muscle fiber analyses revealed decreased fiber size and specific force from the 1st to the 12th days in all patients. A subset of myosin-expressing fibers exhibiting a complete loss of contractile function was identified in three of the patients despite similar atrophy levels (similar to 30%, p < 0.05) after 12 days. All fibers had decreased specific force after 12 days of mechanical ventilation, but 9% to 21% of the fibers were non-force generating. The decline in specific force was linked to 27 post-translational myosin modifications, including oxidation, ubiquitination, acetylation, and methylation. Molecular dynamics simulations indicated oxidation-induced rigidity of the myosin head, predicted to compromise the flexibility of the actin-binding and converter domains. Non-force-generating fibers exhibited a unique proteomic signature predicted to enhance myosin motor domain exposure and rigidity.

Conclusion

In addition to muscle wasting and myosin loss, abnormal myosin post-translational modifications contribute to muscle weakness in ICU patients with CIM, including the development of muscle fibers incapable of generating contractile force.

Plasma proteomic profiling of 92 individuals with Post-Acute Sequelae of SARS-CoV-2 infection (PASC), assessed a mean of 34 months after acute infection, revealed a distinct inflammatory signature. Using proximity extension assay technology, 358 proteins were quantified, identifying 26 differentially expressed proteins (DEPs) in PASC: 23 upregulated and 3 downregulated. The most upregulated proteins were Oncostatin M (OSM) and IL-1 receptor antagonist (IL1RN). Additional increases were observed in IL-6, IL-12B, IL-2, CCL22, CSF3, CSF1, and HLA-DRA, as well as proteins involved in tissue remodeling and angiogenesis such as ANGPTL2 and TGFA. Random forest analysis confirmed IL1RN, OSM, ANGPTL2, HLA-DRA, and CLEC4A as strong discriminators between patients and controls. Gene set enrichment analysis demonstrated activation of multiple immune pathways, including Inflammatory Response, TNF-alpha/NF-kappa B signaling, IL-6/JAK/STAT3, IL-2/STAT5, and Allograft Rejection, indicating persistent activation of innate and adaptive immunity. STRING network analysis highlighted a tightly connected cytokine-driven inflammatory module. Plasma spike protein levels did not differ between patients and controls, suggesting that PASC-related inflammation may persist independently of ongoing viral replication. Overall, the findings indicate a consistent low-grade inflammatory state in PASC without evidence for distinct biological subtypes.

This study evaluated the cerebrospinal fluid (CSF) proteomes from 31 patients diagnosed with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). We quantified 902 proteins, each expressed in at least eleven samples, and systematically categorized clinical factors relevant to ME/CFS symptoms-including autonomic dysfunction, neuroinflammation and metabolic disturbances. Differentially expressed protein and pathway analyses evaluated protein features associated with both postural orthostatic tachycardia syndrome (POTS) status and disease severity among the patients, while ratio-based analysis further explored associations with severity ratings. Data are available via ProteomeXchange with identifier PXD076216. Neutrophil degranulation and platelet activation were enriched in patients with POTS, and several pathways, such as the complement cascade, coagulation-related pathways and IGFBP-mediated insulin-like growth factor transport, were enriched in severe cases. Ratio-based analysis identified four biologically interpretable severity-associated protein ratios related to cellular stress, extracellular remodelling and immune-neuronal interaction. Together, these findings provide insight into the biological processes associated with clinical heterogeneity in ME/CFS and generate hypotheses for future validation in larger independent cohorts.

Hormonal dysregulation is increasingly reported in ME/CFS and Long COVID, yet the broader role of neuroendocrine disruption in these conditions remains underexplored. While changes in steroid, peptide, and neuropeptide hormones have been identified, these findings are often considered in isolation and without attention to their timing or integration within broader physiological systems. The hypothalamic-pituitary axes regulate endocrine, immune, autonomic, nervous, and metabolic functions, systems commonly affected in both conditions, yet their circadian and menstrual dynamics are rarely investigated.

In this review, we examine the evidence for neuroendocrine dysfunction in ME/CFS and Long COVID, focusing on hormone output, functional assays, receptor expression, and the coordination of endocrine biorhythms. Sex hormone signalling emerges as a key area of vulnerability, particularly given the female predominance in both conditions and the complexity of reproductive hormone regulation.

We argue that accurate hormone measurement and time-structured sampling, including circadian and menstrual rhythms, are essential for detecting meaningful biological differences. By embedding chronobiologyaware, dense-sampling strategies and integrating multi-omic analyses into multi-system study designs, we outline a framework for investigating dynamic endocrine mechanisms underlying symptom variability and multisystem dysfunction, which may ultimately support the development of more targeted, personalised interventions.

The number of people seeking help for mental illness is increasing across all ages, creating a major burden for individuals, families, and the society. While personalized medicine is advancing in other fields, diagnosis and treatment of mental disorders remain largely symptom-based and fail to capture individual, sex, and gender differences in risk, manifestation, and treatment response. Early signs of illness often go unnoticed due to the lack of monitoring tools, and stigma continues to hinder prevention and care. In some phases of life, an individual's susceptibility to mental illness is heightened and may be influenced by changes in endocrine signalling. To address these challenges, the research project Building REsilience against MEntal illness during ENDocrine-sensitive life stages (RE-MEND) has implemented an interdisciplinary approach focusing on four critical endocrine-sensitive life stages: prenatal, puberty, peripartum, and older age. The project integrates longitudinal population-based cohorts with experimental and clinical studies to identify genetic, environmental, and endocrine factors shaping susceptibility and resilience to mental illness. Multi-omics data (genomics, epigenomics, transcriptomics, proteomics, metabolomics, lipidomics, and adductomics) will be combined with neurobiological, clinical, and behavioural measures, analysed using advanced biostatistics and machine learning. RE-MEND seeks to i) identify risk and resilience factors affecting mental health; ii) deliver biomarker panels for susceptibility, disease progression, and treatment response across sensitive life stages; iii) discover novel drug targets through repurposing strategies, and iv) promote mental health literacy and reduce stigma. The integration of biological research with communication science is anticipated to result in translatable findings, supporting earlier intervention and more effective care.

Recent developments in mass spectrometry-based proteomics have established it as a robust tool for system-wide analyses essential for pathophysiological research. While post-mortem samples are a critical source for these studies, our understanding of how body decomposition influences the proteome remains limited. Here, we have revisited published data and conducted a clinically relevant time-course experiment in mice, revealing organ-specific proteome regulation after death, with only a fraction of these changes linked to protein autolysis. The liver and spleen exhibit significant proteomic alterations within hours post-mortem, whereas the heart displays only modest changes. Additionally, subcellular compartmentalization leads to an unexpected surge in proteome alterations at the earliest post-mortem interval (PMI). Additionally, we have conducted a comprehensive analysis of semi-tryptic peptides, revealing distinct consensus motifs for different organs, indicating organ-specific post-mortem protease activity. In conclusion, our findings emphasize the critical importance of considering PMI effects when designing proteomics studies, as these effects may significantly overshadow the impacts of diseases. Preferably, the samples should be taken in the operation room, especially for studies including subcellular compartmentalization or trans-organ comparison. In single-organ studies, the planning should involve careful control of PMI.