Journal of Clinical Investigation最新文献

Colitis-associated cancer (CAC) arises from a complex interplay between host and environmental factors. In this report, we investigated the role of the gut microbiome using Winnie mice, an ulcerative colitis-like (UC-like) model with a missense mutation in the Muc2 gene. Upon rederivation from a conventional (CONV) to a specific pathogen-free (SPF) facility, Winnie mice developed severe colitis and, notably, spontaneous CAC that progressively worsened over time. In contrast, CONV Winnie mice showed only mild colitis but no tumorigenesis. By comparison, when re-derived into germ-free (GF) conditions, SPF Winnie mice were protected from colitis and colon tumors, indicating an essential role for the gut microbiome in the development of CAC in these mice. Using shotgun metagenomics, metabolomics, and lipidomics, we identified a distinct proinflammatory microbial and metabolic signature that potentially drives the transition from colitis to CAC. Using either SPF Winnie or WT (Bl/6) donors, fecal microbiota transplantation (FMT) into GF Winnie recipients demonstrated that, while colitis developed regardless of the donor, only FM from SPF Winnie donors resulted in CAC in recipient mice. Our studies present a relevant model of CAC, providing strong evidence that the microbiome plays a key role in its pathogenesis, thus challenging the concept of colon cancer as a strictly nontransmissible disease.

BACKGROUNDAmyotrophic lateral sclerosis (ALS), the major adult-onset motor neuron disease, is preceded by an early period unrelated to motor symptoms, including altered sleep, with increased wakefulness and decreased deep nonrapid eye movement (NREM). Whether these alterations in sleep macroarchitecture are associated with - or even precede - abnormalities in sleep-related EEG features remains unknown.METHODSHere, we characterize sleep microarchitecture using polysomnography for patients with ALS (n = 33) and controls (n = 32) as well as for asymptomatic carriers of superoxide dismutase 1 (SOD1) or C9ORF72 mutations (n = 57) and noncarrier controls (n = 30). Patients and controls with factors that could confound sleep structure, including respiratory insufficiency, were prospectively excluded. The results were complemented in 3 ALS mouse models (Sod1G86R, FusΔNLS/+, and TDP-43Q331K).RESULTSWe observed a brain-wide reduction in the density of sleep spindles, slow oscillations, and K-complexes in patients with early-stage ALS and in presymptomatic gene carriers. These defects in sleep spindles and slow oscillations correlated with cognitive performance in both cohorts, particularly with scores on memory, verbal fluency, and language function. Alterations in sleep microarchitecture were replicated in 3 mouse models, and decreases in sleep spindles were rescued following intracerebroventricular supplementation of melanin-concentrating hormone (MCH) or by oral administration of a dual orexin receptor antagonist.CONCLUSIONSleep microarchitecture was associated with cognitive deficits and causally linked to aberrant MCH and orexin signaling in ALS.FUNDINGAgence Nationale de la Recherche (ANR); Fondation Thierry Latran; Association Francaise de Recherche sur la sclérose latérale amyotrophique; Association Française contre les myopathies; TargetALS; and Joint Program on Neurodegenerative Diseases Research (JPND).

Demyelination associated microglia (DMAM) orchestrate the regenerative response to demyelination by clearing myelin debris and promoting oligodendrocyte maturation. Peroxisomal metabolism has emerged as a candidate regulator of DMAMs, though the cell-intrinsic contribution in microglia remains undefined. Here we elucidate the role of peroxisome integrity in DMAMs, using cuprizone-mediated demyelination coupled with conditional KO of peroxisome biogenesis factor 5 (PEX5) in microglia. Absent demyelination, PEX5 conditional KO (PEX5cKO) had minimal impact on homeostatic microglia. However, during cuprizone-induced demyelination, the emergence of DMAMs unmasked a critical requirement for peroxisome integrity. At peak demyelination, PEX5cKO DMAMs exhibited increased lipid droplet burden and reduced lipophagy suggestive of impaired lipid catabolism. Although lipid droplet burden declined during the remyelination phase, PEX5cKO DMAMs accumulated intralysosomal crystals and curvilinear profiles, features that were largely absent in controls. Aberrant lipid processing was accompanied by elevated numbers of lysosomal damage markers and downregulation of the lipid exporter gene Apoe, consistent with defective lipid clearance. Furthermore, the disruptions in PEX5cKO DMAMs were associated with defective myelin debris clearance and impaired remyelination. Together, these findings delineate a stage-specific role for peroxisomes in coordinating lipid processing pathways essential to DMAM function and for enabling a pro-remyelinating environment.

NK cells, or natural killer cells, might be interesting players to investigate further in the disease process of patients with deficiency of ADA2, a rare, recently discovered inborn error of immunity.

We have identified a serum biomarker panel for clear cell renal cell carcinoma that suitable for clinical applications such as diagnosis and monitoring treatment response.

Deficits in the mitochondrial energy-generating machinery cause mitochondrial disease, a group of untreatable and usually fatal disorders. Refractory epileptic events are a common neurological presentation of mitochondrial disease, including Leigh syndrome, a severe form of mitochondrial disease associated with epilepsy. However, the neuronal substrates and circuits for mitochondrial disease-induced epilepsy remain unclear. Here, using mouse models of Leigh syndrome that lack mitochondrial complex I subunit NDUFS4 in a constitutive or conditional manner, we demonstrated that mitochondrial dysfunction leads to a reduction of GABAergic neurons in the rostral external globus pallidus (GPe) and identified a specific affectation of pallidal Lhx6-expressing inhibitory neurons contributing to altered GPe excitability. Our findings revealed that viral vector-mediated Ndufs4 reexpression in the GPe effectively prevented seizures and improved survival in the models. Additionally, we highlight the subthalamic nucleus (STN) as a critical structure in the neural circuit involved in mitochondrial epilepsy, as its inhibition effectively reduces epileptic events. Thus, we have identified a role for pallido-subthalamic projections in epilepsy development in the context of mitochondrial dysfunction. Our results suggest STN inhibition as a potential therapeutic intervention for refractory epilepsy in patients with mitochondrial disease, providing promising leads in the quest to identify effective treatments.