NRN1 interacts with Notch to increase oncogenic STAT3 signaling in melanoma.

BACKGROUND: Melanoma is a highly heterogeneous cancer, in which frequent changes in activation of signaling pathways lead to a high adaptability to ever changing tumor microenvironments. The elucidation of cancer specific signaling pathways is of great importance, as demonstrated by the inhibitor of the common BrafV600E mutation PLX4032 in melanoma treatment. We therefore investigated signaling pathways that were influenced by neurotrophin NRN1, which has been shown to be upregulated in melanoma. METHODS: Using a cell culture model system with an NRN1 overexpression, we investigated the influence of NRN1 on melanoma cells' functionality and signaling. We employed real time cell analysis and spheroid formation assays, while for investigation of molecular mechanisms we used a kinase phosphorylation kit as well as promotor activity analysis followed by mRNA and protein analysis. RESULTS: We revealed that NRN1 interacts directly with the cleaved intracellular domain (NICD) of Notch1 and Notch3, causing a potential retention of NICD in the cytoplasm and thereby reducing the expression of its direct downstream target Hes1. This leads to decreased sequestration of JAK and STAT3 in a Hes1-driven phosphorylation complex. Consequently, our data shows less phosphorylation of STAT3 while presenting an accumulation of total protein levels of STAT3 in association with NRN1 overexpression. The potential of the STAT3 signaling pathway to act in both a tumor suppressive and oncogenic manner led us to investigate specific downstream targets - namely Vegf A, Mdr1, cMet - which were found to be upregulated under oncogenic levels of NRN1. CONCLUSIONS: In summary, we were able to show that NRN1 links oncogenic signaling events between Notch and STAT3 in melanoma. We also suggest that in future research more attention should be payed to cellular regulation of signaling molecules outside of the classically known phosphorylation events.

Pathophysiology of cerebral small vessel disease: a journey through recent discoveries.

Cerebral small vessel disease (cSVD) encompasses a heterogeneous group of age-related small vessel pathologies that affect multiple regions. Disease manifestations range from lesions incidentally detected on neuroimaging (white matter hyperintensities, small deep infarcts, microbleeds, or enlarged perivascular spaces) to severe disability and cognitive impairment. cSVD accounts for approximately 25% of ischemic strokes and the vast majority of spontaneous intracerebral hemorrhage and is also the most important vascular contributor to dementia. Despite its high prevalence and potentially long therapeutic window, there are still no mechanism-based treatments. Here, we provide an overview of the recent advances in this field. We summarize recent data highlighting the remarkable continuum between monogenic and multifactorial cSVDs involving NOTCH3, HTRA1, and COL4A1/A2 genes. Taking a vessel-centric view, we discuss possible cause-and-effect relationships between risk factors, structural and functional vessel changes, and disease manifestations, underscoring some major knowledge gaps. Although endothelial dysfunction is rightly considered a central feature of cSVD, the contributions of smooth muscle cells, pericytes, and other perivascular cells warrant continued investigation.

Association of NOTCH3 Variant Risk Category With 2-Year Clinical and Radiologic Small Vessel Disease Progression in Patients With CADASIL.

BACKGROUND AND OBJECTIVES: Pathogenic variants in NOTCH3 are the main cause of hereditary cerebral small vessel disease (SVD). SVD-associated NOTCH3 variants have recently been categorized into high risk (HR), moderate risk (MR), or low risk (LR) for developing early-onset severe SVD. The most severe NOTCH3-associated SVD phenotype is also known as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). We aimed to investigate whether NOTCH3 variant risk category is associated with 2-year progression rate of SVD clinical and neuroimaging outcomes in CADASIL. METHODS: A single-center prospective 2-year follow-up study was performed of patients with CADASIL. Clinical outcomes were incident stroke, disability (modified Rankin Scale), and executive function (Trail Making Test B given A t-scores). Neuroimaging outcomes were mean skeletonized mean diffusivity (MSMD), normalized white matter hyperintensity volume (nWMHv), normalized lacune volume (nLV), and brain parenchymal fraction (BPF). Cox regression and mixed-effect models, adjusted for age, sex, and cardiovascular risk factors, were used to study 2-year changes in outcomes and differences in disease progression between patients with HR-NOTCH3 and MR-NOTCH3 variants. RESULTS: One hundred sixty-two patients with HR (n = 90), MR (n = 67), and LR (n = 5) NOTCH3 variants were included. For the entire cohort, there was 2-year mean progression for MSMD (ß = 0.20, 95% CI 0.17-0.23, p = 7.0 × 10-24), nLV (ß = 0.13, 95% CI 0.080-0.19, p = 2.1 × 10-6), nWMHv (ß = 0.092, 95% CI 0.075-0.11, p = 8.8 × 10-20), and BPF (ß = -0.22, 95% CI -0.26 to -0.19, p = 3.2 × 10-22), as well as an increase in disability (p = 0.002) and decline of executive function (ß = -0.15, 95% CI -0.30 to -3.4 × 10-5, p = 0.05). The HR-NOTCH3 group had a higher probability of 2-year incident stroke (hazard ratio 4.3, 95% CI 1.4-13.5, p = 0.011), and a higher increase in MSMD (ß = 0.074, 95% CI 0.013-0.14, p = 0.017) and nLV (ß = 0.14, 95% CI 0.034-0.24, p = 0.0089) than the MR-NOTCH3 group. Subgroup analyses showed significant 2-year progression of MSMD in young (n = 17, ß = 0.014, 95% CI 0.0093-0.019, p = 1.4 × 10-5) and premanifest (n = 24, ß = 0.012, 95% CI 0.0082-0.016, p = 1.1 × 10-6) individuals. DISCUSSION: In a trial-sensitive time span of 2 years, we found that patients with HR-NOTCH3 variants have a significantly faster progression of major clinical and neuroimaging outcomes, compared with patients with MR-NOTCH3 variants. This has important implications for clinical trial design and disease prediction and monitoring in the clinic. Moreover, we show that MSMD is a promising outcome measure for trials enrolling premanifest individuals.

Identification of MUC1-C as a Target for Suppressing Progression of Head and Neck Squamous Cell Carcinomas.

The MUC1-C protein is aberrantly expressed in adenocarcinomas of epithelial barrier tissues and contributes to their progression. Less is known about involvement of MUC1-C in the pathogenesis of squamous cell carcinomas (SCC). Here, we report that the MUC1 gene is upregulated in advanced head and neck SCCs (HNSCC). Studies of HNSCC cell lines demonstrate that the MUC1-C subunit regulates expression of (i) RIG-I and MDA5 pattern recognition receptors, (ii) STAT1 and IFN regulatory factors, and (iii) downstream IFN-stimulated genes. MUC1-C integrates chronic activation of the STAT1 inflammatory pathway with induction of the ∆Np63 and SOX2 genes that are aberrantly expressed in HNSCCs. In extending those dependencies, we demonstrate that MUC1-C is necessary for NOTCH3 expression, self-renewal capacity, and tumorigenicity. The findings that MUC1 associates with ∆Np63, SOX2 and NOTCH3 expression by single-cell RNA sequencing analysis further indicate that MUC1-C drives the HNSCC stem cell state and is a target for suppressing HNSCC progression. SIGNIFICANCE: This work reports a previously unrecognized role for MUC1-C in driving STAT1-mediated chronic inflammation with the progression of HNSCC and identifies MUC1-C as a druggable target for advanced HNSCC treatment.

Notch3 as a novel therapeutic target for the treatment of ADPKD by regulating cell proliferation and renal cyst development.

Autosomal dominant polycystic kidney disease (ADPKD) is a common monogenic kidney disease. Emerging research indicates that the Notch signaling pathway plays an indispensable role in the pathogenesis of numerous kidney diseases, including ADPKD. Herein, we identified that Notch3 but not other Notch receptors was overexpressed in renal tissues from mice with ADPKD and ADPKD patients. Inhibiting Notch3 with γ-secretase inhibitors, which block a proteolytic cleavage required for Notch3 activation, or shRNA knockdown of Notch3 significantly delayed renal cyst growth in vitro and in vivo. Subsequent mechanistic study elucidated that the cleaved intracellular domain of Notch3 (N3ICD) and Hes1 could bind to the PTEN promoter, leading to transcriptional inhibition of PTEN. This further activated the downstream PI3K-AKT-mTOR pathway and promoted renal epithelial cell proliferation. Overall, Notch3 was identified as a novel contributor to renal epithelial cell proliferation and cystogenesis in ADPKD. We envision that Notch3 represents a promising target for ADPKD treatment.

Pro-Hemorrhagic Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy Associated with NOTCH3 p.R75P Mutation with Low Vascular NOTCH3 Aggregation Property.

OBJECTIVES: Intracerebral hemorrhage (ICH) and cerebral microbleeds (CMB) in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy are more common in East Asian populations than in people of white European ancestry. We hypothesized that the ethnic difference is explained by the East Asian-specific NOTCH3 p.R75P mutation. METHODS: This retrospective observational study included 118 patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy in Japanese and Korean cohorts. We investigated whether the p.R75P mutation is associated with symptomatic ICH and multiple CMB (>5) using quasi-Poisson regression models. We predicted the NOTCH3 extracellular domain protein structures in silico and graded NOTCH3 extracellular domain immunostaining in skin vessels of some patients, with subsequent comparisons between p.R75P and other conventional mutations. RESULTS: Among 63 Japanese patients (median age 55 years; 56% men), 15 had a p.R75P mutation, significantly associated with symptomatic ICH (adjusted relative risk 9.56, 95% CI 2.45-37.31), multiple CMB (3.00, 1.34-6.71), and absence of temporopolar lesions (4.91, 2.29-10.52) after adjustment for age, sex, hypertension, and antithrombotics. In the Korean cohort (n = 55; median age 55 years; 51% men), the p.R75P mutation (n = 13) was also associated with symptomatic ICH (8.11, 1.83-35.89), multiple CMB (1.90, 1.01-3.56), and absence of temporopolar lesions (2.32, 1.08-4.97). Structural analysis revealed solvent-exposed free cysteine thiols in conventional mutations, directly causing aggregation, whereas a stereochemically incompatible proline residue structure in p.R75P lowers correct disulfide bond formation probability, indirectly causing aggregation. Pathologically, the p.R75P mutation resulted in less vascular NOTCH3 extracellular domain accumulation than the other conventional mutations. INTERPRETATION: NOTCH3 p.R75P mutation is associated with hemorrhagic presentations, milder temporopolar lesions, and distinct mutant protein structure properties. ANN NEUROL 2024;95:1040-1054.

Villus myofibroblasts are developmental and adult progenitors of mammalian gut lymphatic musculature.

Inside the finger-like intestinal projections called villi, strands of smooth muscle cells contract to propel absorbed dietary fats through the adjacent lymphatic capillary, the lacteal, sending fats into the systemic blood circulation for energy production. Despite this vital function, mechanisms of formation, assembly alongside lacteals, and maintenance of villus smooth muscle are unknown. By combining single-cell RNA sequencing and quantitative lineage tracing of the mouse intestine, we identified a local hierarchy of subepithelial fibroblast progenitors that differentiate into mature smooth muscle fibers via intermediate contractile myofibroblasts. This continuum persists as the major mechanism for villus musculature renewal throughout adult life. The NOTCH3-DLL4 signaling axis governs the assembly of smooth muscle fibers alongside their adjacent lacteals and is required for fat absorption. Our studies identify the ontogeny and maintenance of a poorly defined class of intestinal smooth muscle, with implications for accelerated repair and recovery of digestive function following injury.

Peculiar CADASIL phenotype in monozygotic twins carrying a novel NOTCH3 pathogenetic variant.

BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominantly inherited cerebral small vessel disease caused by Neurogenic locus notch homolog protein 3 (NOTCH3) gene mutations. The main clinical features include migraine with aura, recurrent ischemic strokes and dementia. Brain MRI typically shows multiple small lacunar infarcts and severe, diffuse, symmetrical white matter hyperintensities (WMHs), with characteristic involvement of the anterior temporal pole, external capsule, and superior frontal gyrus. Reports of twins with CADASIL are scarce. Herein we describe a pair of monozygotic twins with peculiar CADASIL phenotype, carrying a new NOTCH3 variant. CASE PRESENTATION: Twin A was a 45-year-old male suffering from migraine, obesity, arterial hypertension, and polycythemia (with negative genetic analysis), who complained of a transient, short-lasting (~ 5 minutes) episode of speech difficulties. Brain MRI showed diffuse, symmetrical, confluent periventricular WMHs involving frontal, parietal, and temporal lobes and external capsules, with sparing of anterior temporal poles. Genetic analysis of NOTCH3 gene demonstrated the presence of missense c.3329G>A, p.(Cys1110Tyr) variant, confirming CADASIL diagnosis. Twin B, affected by migraine and polycythemia, as well as his monozygotic twin, presented with a 2-month history of trigeminal neuralgia. Brain MRI demonstrated diffuse WMHs with a pattern of distribution like his twin. Genetic analysis revealed the same NOTCH3 pathogenic variant. CONCLUSIONS: Our monozygotic twins have a strikingly similar neuroimaging picture with sparing of anterior temporal poles. They also have a peculiar phenotype, both presenting polycythemia without genetically confirmed cause. Twin B had trigeminal neuralgia, that is unusual in CADASIL. The possible association of the peculiar findings with the newly reported NOTCH3 variant needs to be confirmed with further observations.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) with multiple different onset forms of frequent recurrent attacks: A case report and literature review.

INTRODUCTION: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is one kind of monogenic hereditary small-vessel disease in the brain caused by mutations in the NOTCH3 gene. However, it is rare for CADASIL to recur with different clinical manifestations in 1 patient, and some atypical clinical manifestations can easily lead to misdiagnosis by clinical physicians. CASE CONCERN: A 34-year-old male presented with transient speech disorder accompanied by weakness in the left side of the body for 1 day in June 2020. Magnetic resonance imaging showed acute ischemic infarction in right centrum semiovale, along with multiple abnormal white matter hyperintensities in the brain. Genetic sequencing identified a heterozygous mutation in the NOTCH3 gene. The patient experienced recurrent episodes in 2021 and 2023, with varying clinical symptoms including visual blurring, abnormal limb sensation, and sudden cognitive dysfunction. DIAGNOSIS: The diagnoses of CADASIL is based on clinical manifestations, imaging results, and genetic reports. INTERVISION AND OUTCOMES: The patient was received symptomatic treatment including antiplatelet aggregation therapy, lipid regulation, and plaque stabilization, resulting in improved symptoms. OUTCOMES: During the course of the disease, after medication treatment and rehabilitation exercise, the patient clinical symptoms have significantly improved. Currently, the patient is closely following up and regularly undergoing relevant examinations. LESSONS: In this rare case, we found that CADASIL can recur multiple times in a patient with different clinical symptoms, which can easily lead to clinical misdiagnosis. Clinicians should consider the possibility of CADASIL in young patients with sudden typical neurological dysfunction.

Protein aggregates containing wild-type and mutant NOTCH3 are major drivers of arterial pathology in CADASIL.

Loss of arterial smooth muscle cells (SMCs) and abnormal accumulation of the extracellular domain of the NOTCH3 receptor (Notch3ECD) are the 2 core features of CADASIL, a common cerebral small vessel disease caused by highly stereotyped dominant mutations in NOTCH3. Yet the relationship between NOTCH3 receptor activity, Notch3ECD accumulation, and arterial SMC loss has remained elusive, hampering the development of disease-modifying therapies. Using dedicated histopathological and multiscale imaging modalities, we could detect and quantify previously undetectable CADASIL-driven arterial SMC loss in the CNS of mice expressing the archetypal Arg169Cys mutation. We found that arterial pathology was more severe and Notch3ECD accumulation greater in transgenic mice overexpressing the mutation on a wild-type Notch3 background (TgNotch3R169C) than in knockin Notch3R170C/R170C mice expressing this mutation without a wild-type Notch3 copy. Notably, expression of Notch3-regulated genes was essentially unchanged in TgNotch3R169C arteries. We further showed that wild-type Notch3ECD coaggregated with mutant Notch3ECD and that elimination of 1 copy of wild-type Notch3 in TgNotch3R169C was sufficient to attenuate Notch3ECD accumulation and arterial pathology. These findings suggest that Notch3ECD accumulation, involving mutant and wild-type NOTCH3, is a major driver of arterial SMC loss in CADASIL, paving the way for NOTCH3-lowering therapeutic strategies.

Association of Rare NOTCH3 Variants With Prevalent and Incident Stroke and Dementia in the General Population.

BACKGROUND: It is uncertain whether rare NOTCH3 variants are associated with stroke and dementia in the general population and whether they lead to alterations in cognitive function. This study aims to determine the associations of rare NOTCH3 variants with prevalent and incident stroke and dementia, as well as cognitive function changes. METHODS AND RESULTS: In the prospective community-based Shunyi Study, a total of 1007 participants were included in the baseline analysis. For the follow-up analysis, 1007 participants were included in the stroke analysis, and 870 participants in the dementia analysis. All participants underwent baseline brain magnetic resonance imaging, carotid ultrasound, and whole exome sequencing. Rare NOTCH3 variants were defined as variants with minor allele frequency <1%. A total of 137 rare NOTCH3 carriers were enrolled in the baseline study. At baseline, rare NOTCH3 variant carriers had higher rates of stroke (8.8% versus 5.6%) and dementia (2.9% versus 0.8%) compared with noncarriers. After adjustment for associated risk factors, the epidermal growth factor-like repeats (EGFr)-involving rare NOTCH3 variants were associated with a higher risk of prevalent stroke (odds ratio [OR], 2.697 [95% CI, 1.266-5.745]; P=0.040) and dementia (OR, 8.498 [95% CI, 1.727-41.812]; P=0.032). After 5 years of follow-up, we did not find that the rare NOTCH3 variants increased the risk of incident stroke and dementia. There was no statistical difference in the change in longitudinal cognitive scale scores. CONCLUSIONS: Rare NOTCH3 EGFr-involving variants are genetic risk factors for stroke and dementia in the general Chinese population.

Single-Cell Analysis Identifies NOTCH3-Mediated Interactions between Stromal Cells That Promote Microenvironment Remodeling and Invasion in Lung Adenocarcinoma.

Cancer immunotherapy has revolutionized the treatment of lung adenocarcinoma (LUAD); however, a significant proportion of patients do not respond. Recent transcriptomic studies to understand determinants of immunotherapy response have pinpointed stromal-mediated resistance mechanisms. To gain a better understanding of stromal biology at the cellular and molecular level in LUAD, we performed single-cell RNA sequencing of 256,379 cells, including 13,857 mesenchymal cells, from 9 treatment-naïve patients. Among the mesenchymal cell subsets, FAP+PDPN+ cancer-associated fibroblasts (CAF) and ACTA2+MCAM+ pericytes were enriched in tumors and differentiated from lung-resident fibroblasts. Imaging mass cytometry revealed that both subsets were topographically adjacent to the perivascular niche and had close spatial interactions with endothelial cells (EC). Modeling of ligand and receptor interactomes between mesenchymal and ECs identified that NOTCH signaling drives these cell-to-cell interactions in tumors, with pericytes and CAFs as the signal receivers and arterial and PLVAPhigh immature neovascular ECs as the signal senders. Either pharmacologically blocking NOTCH signaling or genetically depleting NOTCH3 levels in mesenchymal cells significantly reduced collagen production and suppressed cell invasion. Bulk RNA sequencing data demonstrated that NOTCH3 expression correlated with poor survival in stroma-rich patients and that a T cell-inflamed gene signature only predicted survival in patients with low NOTCH3. Collectively, this study provides valuable insights into the role of NOTCH3 in regulating tumor stroma biology, warranting further studies to elucidate the clinical implications of targeting NOTCH3 signaling. SIGNIFICANCE: NOTCH3 signaling activates tumor-associated mesenchymal cells, increases collagen production, and augments cell invasion in lung adenocarcinoma, suggesting its critical role in remodeling tumor stroma.

First report of a p.Cys484Tyr Notch3 mutation in a CADASIL patient with acute bilateral multiple subcortical infarcts-case report and brief review.

BACKGROUND: CADASIL(Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)is an inherited small vessel disease caused by mutations in NOTCH3 gene. Although NOTCH3 has numerous hotspots of gene mutations, mutations in exons 9 are rare. The p.C484T gene mutation type associated with it has not been reported in any relevant cases yet. Furthermore, CADASIL patients rarely present with acute bilateral multiple subcortical infarcts. CASE PRESENTATION: We report the case of a Chinese female patient with CADASIL who experienced "an acute bilateral subcortical infarction" because of"hemodynamic changes and hypercoagulability". In genetic testing, we discovered a new Cys484Tyr mutation in exon 9, which has also been found in the patient's two daughters. CONCLUSIONS: It is important to note that this discovery not only expands the mutation spectrum of Notch3 mutations in CADASIL patients, but also examines the mechanism behind acute bilateral subcortical infarction in CADASIL patients via case reviews and literature reviews, in order to provide some clinical recommendations for early intervention, diagnosis, and treatment in similar cases in the future.

Progress to Clarify How NOTCH3 Mutations Lead to CADASIL, a Hereditary Cerebral Small Vessel Disease.

Notch signaling is conserved in C. elegans, Drosophila, and mammals. Among the four NOTCH genes in humans, NOTCH1, NOTCH2, and NOTCH3 are known to cause monogenic hereditary disorders. Most NOTCH-related disorders are congenital and caused by a gain or loss of Notch signaling activity. In contrast, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) caused by NOTCH3 is adult-onset and considered to be caused by accumulation of the mutant NOTCH3 extracellular domain (N3ECD) and, possibly, by an impairment in Notch signaling. Pathophysiological processes following mutant N3ECD accumulation have been intensively investigated; however, the process leading to N3ECD accumulation and its association with canonical NOTCH3 signaling remain unknown. We reviewed the progress in clarifying the pathophysiological process involving mutant NOTCH3.

Notch signaling pathway induces expression of type IV collagen in angiogenesis.

Mural cell adhesion is important for the localization of basement membrane components during angiogenesis, and cell-cell interactions are thought to be critical for basement membrane formation. Type IV collagen, a component of the basement membrane, and non-triple helical type IV collagen α1 chain (NTH α1(IV)) co-localize in the basement membrane of neovascular vessels. However, it remains unclear how type IV collagen and NTH α1(IV) are produced around the basement membrane. In the present study, we developed a de novo angiogenesis model using human umbilical vein endothelial cell spheroids and TIG-1 fibroblast cells and demonstrated that NTH α1(IV), probably with α1(IV) chain before forming triple helix molecule, was localized in the fibroblasts in contact with vascular endothelial cells. This localization was disrupted by DAPT, a Notch signaling inhibitor. DAPT treatment also reduced type IV collagen and NTH α1(IV) secretion in TIG-1 fibroblasts, along with diminished COL4A1 and COL4A2 gene expression. Downregulation of Notch3 in TIG-1 fibroblasts decreased the secretion of type IV collagen and NTH α1(IV). Taken together, these findings suggest that heterogeneous and homogeneous intercellular Notch signaling via Notch3 induces type IV collagen and NTH α1(IV) expression in fibroblasts and contributes to basement membrane formation in neovascular vessels.

Age-related loss of Notch3 underlies brain vascular contractility deficiencies, glymphatic dysfunction, and neurodegeneration in mice.

Vascular aging affects multiple organ systems, including the brain, where it can lead to vascular dementia. However, a concrete understanding of how aging specifically affects the brain vasculature, along with molecular readouts, remains vastly incomplete. Here, we demonstrate that aging is associated with a marked decline in Notch3 signaling in both murine and human brain vessels. To clarify the consequences of Notch3 loss in the brain vasculature, we used single-cell transcriptomics and found that Notch3 inactivation alters regulation of calcium and contractile function and promotes a notable increase in extracellular matrix. These alterations adversely impact vascular reactivity, manifesting as dilation, tortuosity, microaneurysms, and decreased cerebral blood flow, as observed by MRI. Combined, these vascular impairments hinder glymphatic flow and result in buildup of glycosaminoglycans within the brain parenchyma. Remarkably, this phenomenon mirrors a key pathological feature found in brains of patients with CADASIL, a hereditary vascular dementia associated with NOTCH3 missense mutations. Additionally, single-cell RNA sequencing of the neuronal compartment in aging Notch3-null mice unveiled patterns reminiscent of those observed in neurodegenerative diseases. These findings offer direct evidence that age-related NOTCH3 deficiencies trigger a progressive decline in vascular function, subsequently affecting glymphatic flow and culminating in neurodegeneration.

Modifiable vascular risk factors contribute to stroke in 1080 NOTCH3 R544C carriers in Taiwan Biobank.

BACKGROUND AND AIM: Previous studies have suggested cardiovascular risk factors increase the risk of not only common sporadic stroke but also of stroke in patients with monogenic stroke disorders including CADASIL. We investigated the effects of the NOTCH3 Arg544Cys (R544C) variant and associated vascular risk factors on stroke in the Taiwanese population. METHODS: This study was conducted using data from the Taiwan Biobank, consisting of at least 130,000 Han Chinese participants. The genotype was derived from customized genome-wide arrays for 650,000 to 750,000 single-nucleotide polymorphisms (SNPs). Individuals with NOTCH3 R544C were subsequently matched with noncarriers based on the propensity score at a 1:10 ratio by demographic and cardiovascular risk factors. The odds ratio (OR) for stroke or other phenotypes in NOTCH3 R544C carriers and matched noncarriers was then calculated. Univariate and multivariate regression analyses were performed on cardiovascular risk factors in NOTCH3 R544C carriers with and without stroke. The polygenic risk score (PRS) model, adopted from the UK Biobank, was then applied to evaluate the role of NOTCH3 R544C in stroke. RESULTS: From the 114,282 participants with both genotype and questionnaire results, 1080 (0.95%) harbored the pathogenic NOTCH3 R544C variant. When compared to the matched controls (n = 10,800), the carriers presented with a history of stroke (OR: 2.52, 95% confidence interval (CI) (1.45, 4.37)), dementia (OR: 30.1, 95% CI (3.13, 289.43)), and sibling history of stroke (OR: 2.48, 95% CI (1.85, 3.34)) phenotypes. The risk of stroke increased with every 10-year increase in age (p = 0.006, Cochran-Mantel-Haenszel test). Among NOTCH3 R544C carriers, 16 (1.3%) of the 1080 carriers with a stroke history were older, male, and more likely to have hypertension, diabetes, dyslipidemia, and a family history of stroke. In the stepwise multivariate analysis, hypertension (OR: 11.28, 95% CI (3.54, 43.3)) and diabetes mellitus (OR: 4.10, 95% CI (1.31, 12.4)) were independently associated with stroke. Harboring the NOTCH3 R544C variant in the Taiwan Biobank is comparable with a 6.74 standard deviations increase in individual's polygenic risk score for stroke. CONCLUSION: While the NOTCH3 R544C variant alone increased the risk of stroke, modifiable vascular risk factors also played a role in the occurrence of stroke in Taiwanese community-dwelling individuals carrying the NOTCH3 variant.

NOTCH3 promotes docetaxel resistance of prostate cancer cells through regulating TUBB3 and MAPK signaling pathway.

Docetaxel is the preferred chemotherapeutic agent in patients with castrate-resistant prostate cancer (CRPC). However, patients eventually develop docetaxel resistance and in the absence of effective treatment options. Consequently, it is essential to investigate the mechanisms generating docetaxel resistance and develop novel alternative therapeutic targets. RNA sequencing was undertaken on docetaxel-sensitive and docetaxel-resistant prostate cancer (PCa) cells. Subsequently, chemoresistance, cancer stemness, and lipid metabolism were investigated. To obtain insight into the precise activities and action mechanisms of NOTCH3 in docetaxel-resistant PCa, immunoprecipitation, mass spectrometry, ChIP, luciferase reporter assay, cell metabolism, and animal experiments were performed. Through RNA sequencing analysis, we found that NOTCH3 expression was markedly higher in docetaxel-resistant cells relative to parental cells, and that this trend was continued in docetaxel-resistant PCa tissues. Experiments in vitro and in vivo revealed that NOTCH3 enhanced stemness, lipid metabolism, and docetaxel resistance in PCa. Mechanistically, NOTCH3 is bound to TUBB3 and activates the MAPK signaling pathway. Moreover, NOTCH3 was directly regulated by MEF2A in docetaxel-resistant cells. Notably, targeting NOTCH3 and the MEF2A/TUBB3 signaling axis was related to docetaxel chemoresistance in PCa. Overall, these results demonstrated that NOTCH3 fostered stemness, lipid metabolism, and docetaxel resistance in PCa via the TUBB3 and MAPK signaling pathways. Therefore, NOTCH3 may be employed as a prognostic biomarker in PCa patients. NOTCH3 could be a therapeutic target for PCa patients, particularly those who have developed docetaxel resistance.

Notch3 restricts metastasis of breast cancers through regulation of the JAK/STAT5A signaling pathway.

PURPOSE: To explore the potential role of signal transducer and activator of transcription 5A (STAT5A) in the metastasis of breast cancer, and its mechanism of regulation underlying. METHODS AND RESULTS: TCGA datasets were used to evaluate the expression of STAT5A in normal and different cancerous tissues through TIMER2.0, indicating that STAT5A level was decreased in breast cancer tissues compared with normal ones. Gene Set Enrichment Analysis predicted that STAT5A was associated with the activation of immune cells and cell cycle process. We further demonstrated that the infiltration of immune cells was positively associated with STAT5A level. Influorescence staining revealed the expression and distribution of F-actin was regulated by STAT5A, while colony formation assay, wound healing and transwell assays predicted the inhibitory role of STAT5A in the colony formation, migratory and invasive abilities in breast cancer cells. In addition, overexpression of the Notch3 intracellular domain (N3ICD), the active form of Notch3, resulted in the increased expression of STAT5A. Conversely, silencing of Notch3 expression by siNotch3 decreased STAT5A expression, supporting that STAT5A expression is positively associated with Notch3 in human breast cancer cell lines and breast cancer tissues. Mechanistically, chromatin immunoprecipitation showed that Notch3 was directly bound to the STAT5A promoter and induced the expression of STAT5A. Moreover, overexpressing STAT5A partially reversed the enhanced mobility of breast cancer cells following Notch3 silencing. Low expression of Notch3 and STAT5A predicted poorer prognosis of patients with breast cancer. CONCLUSION: The present study demonstrates that Notch3 inhibits metastasis in breast cancer through inducing transcriptionally STAT5A, which was associated with tumor-infiltrating immune cells, providing a novel strategy to treat breast cancer.