Tuberous sclerosis complex 1 (Tsc1) is a tumor suppressor that functions together with Tsc2 to negatively regulate the mechanistic target of rapamycin complex 1 (mTORC1) activity. Here, we show that Tsc1 has a critical role in the tight junction (TJ) formation of epithelium, independent of its role in Tsc2 and mTORC1 regulation. When an epithelial cell establishes contact with neighboring cells, Tsc1, but not Tsc2, migrates from the cytoplasm to junctional membranes, in which it binds myosin 6 to anchor the perijunctional actin cytoskeleton to β-catenin and ZO-1. In its absence, perijunctional actin cytoskeleton fails to form. In mice, intestine-specific or inducible, whole-body Tsc1 ablation disrupts adherens junction/TJ structures in intestine or skin epithelia, respectively, causing Crohn's disease-like symptoms in the intestine or psoriasis-like phenotypes on the skin. In patients with Crohn's disease or psoriasis, junctional Tsc1 levels in epithelial tissues are markedly reduced, concomitant with the TJ structure impairment, suggesting that Tsc1 deficiency may underlie TJ-related diseases. These findings establish an essential role of Tsc1 in the formation of cell junctions and underpin its association with TJ-related human diseases.
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http://dx.doi.org/10.1073/pnas.2020891118 | DOI Listing |
Pathol Res Pract
January 2025
Department of Orthopaedics, the second Affiliated Hospital of Wannan Medical College, Wuhu 241000, China. Electronic address:
Background: Renal hemangioblastoma (HB) is a rare extra-central nervous system (CNS) tumor, typically not linked to Von Hippel-Lindau (VHL) Syndrome, and its underlying genetic drivers and molecular mechanisms remain elusive. The objective of this study is to investigate the clinicopathological features and molecular genetic changes of primary renal hemangioblastomas.
Methods: Herein, the clinical, imaging, clinicopathological features, and immunophenotype in 3 cases of renal HB were retrospectively analyzed.
Mol Biol Rep
January 2025
Department of Pathology and Laboratory Medicine, Baylor Scott and White Medical Center, Baylor College of Medicine, Temple, TX, USA.
Background: Brain intraparenchymal schwannoma is a rare clinical entity, generally curable with adequate resection.
Methods And Results: We describe a case in a male patient first presenting at 19 months of age, the youngest reported age for this lesion. It also appears to be the first case connected to a germline TSC2 p.
Sci Rep
January 2025
Department of Anesthesiology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563000, China.
As one of the most commonly used general anesthetics (GAs) in surgery, numerous studies have demonstrated the detrimental effects of sevoflurane exposure on myelination in the developing and elderly brain. However, the impact of sevoflurane exposure on intact myelin structure in the adult brain is barely discovered. Here, we show that repeated sevoflurane exposure, but not single exposure, causes hypomyelination and abnormal ultrastructure of myelin sheath in the prefrontal cortex (PFC) of adult male mice, which is considered as a critical brain region for general anesthesia mediated consciousness change.
View Article and Find Full Text PDFPediatr Dermatol
January 2025
Department of Dermatology, Venereology and Leprology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
Orphanet J Rare Dis
January 2025
Division of Pediatric Epileptology, Department of Pediatrics I, Medical Faculty of Heidelberg, Heidelberg University, Heidelberg, Germany.
Background: Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder affecting multiple organ systems, with a prevalence of 1:6,760-1:13,520 live births in Germany. On the molecular level, TSC is caused by heterozygous loss-of-function variants in either of the genes TSC1 or TSC2, encoding the Tuberin-Hamartin complex, which acts as a critical upstream suppressor of the mammalian target of rapamycin (mTOR), a key signaling pathway controlling cellular growth and metabolism. Despite the therapeutic success of mTOR inhibition in treating TSC-associated manifestations, studies with mTOR inhibitors in children with TSC above two years of age have failed to demonstrate beneficial effects on disease-related neuropsychological deficits.
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