Notch1 Expression Research Articles

FGFR2 and NOTCH1 Expression Inversely Correlated in Progressive Cutaneous Carcinogenesis in an Experimental Mouse Model.

Cutaneous squamous cell carcinoma (cSCC) is a common and increasingly prevalent form of skin cancer, posing significant health challenges. Understanding the molecular mechanisms involved in cSCC progression is crucial for developing effective treatments. The primary aim of this research was to evaluate the activation of NOTCH1 and FGFR2 oncogenes in inducing skin cancer in FVB/N mice through a stepwise chemical process. Forty female FVB/N mice, aged four weeks, were randomly divided into a control group (n = 8) and two experimental groups (group A: n = 16, group B: n = 16). This study involved subjecting the groups to a two-stage carcinogenesis procedure. This included an initial application of 97.4 nmol DMBA on shaved skin on their backs, followed by applications of 32.4 nmol TPA after thirteen weeks for group A and after twenty weeks for group B. The control group did not receive any treatment. Their skin conditions were monitored weekly to detect tumor development. After the experiment, the animals were euthanized for further tissue sampling. The examination of skin lesions in the experimental groups showed a correlation with tumor progression, ranging from dysplasia to carcinoma. Tumor samples were assessed both histologically and immunohistochemically. Notably, FGFR2 expression was higher in benign, precancerous, and malignant tumors compared to normal tissue. NOTCH1 expression was only elevated in benign tumors compared to normal tissue. This study demonstrates a clear correlation of FGFR2 expression and the progression of cutaneous neoplasms, while NOTCH 1 expression is inversely correlated in FVB/N mice. This suggests an early involvement of these oncogenes in the development of skin tumors.

Constituents of alexander’s celery (Smyrnium olusatrum) extracts and their antioxidant, enzyme inhibitory and anticancer effects based on in vitro, in silico and network pharmacology methods

This research delves into the medicinal significance of Smyrnium olusatrum by investigating ethyl acetate, ethanol, ethanol/water, and infusion extracts. The chemical composition analysed through LC-MS-qTOF metabolomic analysis, determine total phenolic and flavonoid contents, evaluate antioxidant potential using six in vitro tests (DPPH, ABTS, FRAP, CUPRAC, phosphomolybdenum assay (PBD), and metal chelating assay (MCA)), assess enzyme inhibition activity against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, α-amylase, and α-glucosidase, and explore their anticancer effects on HEp-2 cells. Additionally, qPCR analysis is conducted on HEp-2 larynx cancer cells to examine the impact of S. olusatrum on self-renewal and apoptosis pathways, along with the expression levels of key genes associated with these pathways. The findings indicated that the infusion extraction method demonstrated the highest levels, with a recorded TPC of 35.02 mg GAE/g and a TFC of 15.08 mg RE/g. All four extracts of S. olusatrum exhibited a total of 328 entities. The most significant metabolites, primarily comprising polyphenolics, flavonoids, non-structural carbohydrates, and amino acids in negative ionization mode, as well as sesquiterpene lactone and amino acids in positive ionization, were identified. Infusion exhibited the highest antioxidant effect among the extracts, with peak values ranged from 55.55 mg TE/g (DPPH) to 100.07 mg TE/g (ABTS). The extracts exhibited variable enzyme activities. Notably, ethyl acetate also demonstrated superior α-Amylase inhibition (0.69 mmol ACAE/g), while the ethanol extract exhibited higher α-Glucosidase inhibition (1.70 mmol ACAE/g). The HEp-2 cells demonstrated the quickest attainment of half maximal inhibitory concentration values with ethanol and ethanol/water extracts, yielding IC50 values of 250 µg/mL (24 h) and 125 µg/mL (24 h), respectively, among the applied extracts. The qPCR results revealed that S. olusatrum inhibited all self-renewal pathways and activated the apoptotic pathway. The ethanol and ethanol/water extracts of S. olusatrum significantly suppressed WNT1, APC, LEF1, and TCF7 genes. Furthermore, the downregulation of NOTCH1, SHH, and SMO gene expressions in all extracts suggests the activation of the Type 1 non-canonical hedgehog pathway in laryngeal cancer. The findings not only underscore the therapeutic potential of these extracts but also open the way for further exploration of their applications in combating oxidative stress, enzyme-related disorders, and potential anti-cancer effects through modulation of crucial cellular pathways.

Chlorogenic acid alleviates renal fibrosis by reducing lipid accumulation in diabetic kidney disease through suppressing the Notch1 and Stat3 signaling pathway

Aims Abnormal renal lipid metabolism causes renal lipid deposition, which leads to the development of renal fibrosis in diabetic kidney disease (DKD). The aim of this study was to investigate the effect and mechanism of chlorogenic acid (CA) on reducing renal lipid accumulation and improving DKD renal fibrosis. Methods This study evaluated the effects of CA on renal fibrosis, lipid deposition and lipid metabolism by constructing in vitro and in vivo models of DKD, and detected the improvement of Notch1 and Stat3 signaling pathways. Molecular docking was used to predict the binding between CA and the extracellular domain NRR1 of Notch1 protein. Results In vitro studies have shown that CA decreased the expression of Fibronectin, α-smooth muscle actin (α-SMA), p-smad3/smad3, alleviated lipid deposition, promoted the expression of carnitine palmitoyl transferase 1 A (CPT1A), and inhibited the expression of cholesterol regulatory element binding protein 1c (SREBP1c). The expression of Notch1, Cleaved Notch1, Hes1, and p-stat3/stat3 were inhibited. These results suggested that CA might reduce intercellular lipid deposition in human kidney cells (HK2) by inhibiting Notch1 and stat3 signaling pathways, thereby improving fibrosis. Further, in vivo studies demonstrated that CA improved renal fibrosis and renal lipid deposition in DKD mice by inhibiting Notch1 and stat3 signaling pathways. Finally, molecular docking experiments showed that the binding energy of CA and NRR1 was −6.6 kcal/mol, which preliminarily predicted the possible action of CA on Notch1 extracellular domain NRR1. Conclusion CA reduces renal lipid accumulation and improves DKD renal fibrosis by inhibiting Notch1 and stat3 signaling pathways.

Significance of Runt-related transcription factor 1 and Notch1 expression in non-small-cell lung cancer: involvement in epithelial-mesenchymal transition and epidermal growth factor receptor-tyrosine kinase inhibitor therapy resistance

Objective One of the main obstacles to treating patients with non-small-cell lung cancers (NSCLC) is the emergence of drug resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy. Aim To investigate the prognostic relevance of Runt-related transcription factor 1 (RUNX1) and Notch1 in NSCLC and to evaluate their potential involvement in induction of epithelial-mesenchymal transition and resistance to EGFR-TKI therapy. Materials and methods Immunohistochemical study of RUNX1, Notch1, E-cadherin, and hypoxia-inducible factor 1α (HIF-1α) was conducted upon 83 cases diagnosed as NSCLC. The research was conducted in the departments of pathology, chest, and medical oncology of the Faculty of Medicine, Benha University. Results A significant relation was found between RUNX1 and sex (P=0.001), smoking history (P=0.002), and tumor grade (P=0.002). High RUNX1 expression was associated with poor OS and DFS (P=0.003 and 0.005), respectively. Cases with positive Notch1 expression were significantly associated with tumor grade (P=0.005) and tumor stage (P=0.024). A significant association was detected between Notch1 expression and poor OS and DFS (P=0.025 and 0.011), respectively. A statistically significant correlation was found between RUNX1 and Notch1 expressions (P=0.040). Moreover, high RUNX1 and positive Notch1 expressions were significantly associated with negative E-cadherin and positive HIF-1α expressions. Resistance against EGFR–TKI therapy was significantly associated with high RUNX1, positive Notch1, negative E-cadherin, and positive HIF-1α expressions, in EGFR-mutated cases. Conclusions RUNX1 and Notch1 may be involved in therapy resistance through the induction of epithelial–mesenchymal transition and may serve as prognostic markers in patients with NSCLC.

MFAP2 induces epithelial-mesenchymal transformation of osteosarcoma cells by activating the Notch1 pathway.

Osteosarcoma (OS) is a malignancy originating from mesenchymal tissue. Microfibril-associated protein 2 (MFAP2) plays a crucial role in cancer, notably promoting epithelial-mesenchymal transition (EMT). However, its involvement in OS remains unexplored. MFAP2 was silenced in U2OS cells using shRNA targeting MFAP2 (sh-MFAP2) and validated by quantitative real-time polymerase chain reaction (qRT-PCR). We extracted gene chip data of MFAP2 from multiple databases (GSE28424, GSE42572, and GSE126209). Correlation analyses between MFAP2 and the Notch1 pathway identified through the gene set variation analysis (GSVA) enrichment analysis were conducted using the Pearson correlation method. Cellular behaviors (viability, migration, and invasion) were assessed via the Cell Counting Kit-8 (CCK-8), wound healing, and Transwell assays. EMT markers (N-cadherin, vimentin, and β-catenin) and Notch1 levels were examined by western blotting and qRT-PCR. Cell morphology was observed microscopically to evaluate EMT. Finally, the role of MFAP2 in OS was validated through a xenograft tumor model. OS cell lines exhibited higher MFAP2 mRNA expression than normal osteoblasts. MFAP2 knockdown in U2OS cells significantly reduced viability, migration, and invasion, along with downregulation of N-cadherin and vimentin, as well as upregulation of β-catenin. MFAP2 significantly correlated with the Notch1 pathway in OS and its knockdown inhibited Notch1 protein expression. Furthermore, Notch1 activation reversed the inhibitory effects of MFAP2 knockdown on the malignant characteristic of U2OS cells. Additionally, MFAP2 knockdown inhibited tumor growth, expression levels of EMT markers, and Notch1 expression in OS tumor tissues. Our study revealed that MFAP2 was an upstream regulator of the Notch1 signaling pathway to promote EMT in OS. These findings suggested MFAP2 as a potential OS therapy target.

The effect of <i>NOTCH1</i> knockdown on the phenotype of human lung and colon cancer stem cells

Introduction. Lung and colorectal cancers are the most common cancer types, characterized by a poor prognosis. Tumor progression is also caused by the aberrant activity of intercellular signaling pathways, which can arise due to mutations in genes encoding their components. In particular, the oncogenic role of NOTCH1 receptor of Notch signaling pathway has been proven for various cancer types, including lung and colorectal cancers. In this research, we delved deeper into the importance of NOTCH1 receptor expression for the progression of these malignancies. Aim. To investigate the importance of NOTCH1 expression in maintaining the cancer stem cell (CSC) pool and phenotype of human lung and colon cancers. Materials and methods. Experiments were performed on previously obtained NOTCH1 knockdown cell lines of human lung A549 and colon HCT116 carcinomas. First of all, we studied the effect of NOTCH1 knockdown on the metastatic ability of A549 cells and the tumorigenicity of A549 and HCT116 cells when injected to immunodeficient BALB/c nu/nu mice. Next, we carried out in vitro tests to determine CSC pool and phenotype in tumor cell culture: cytofluorimetric analysis of ABC-transporters activity to exclude dye to the external environment and analysis of colony formation in a semi-liquid medium. In conclusion, we assessed the proportion of cells in the culture producing the CSC marker – CD133 using flow cytometry and the expression level of some genes associated with CSC phenotype (NANOG, POU5F1, SOX2) using real-time polymerase chain reaction. Results. NOTCH1 knockdown decreased the number of experimental animals with metastases, the number of formed metastatic foci and increased in the minimum cell inoculation dose. The activity of ABC-transporters, the ability for unattached growth, the proportion of CD133-positive cells in culture, and the expression of genes associated with maintaining of CSC pool and phenotype decreased under NOTCH1 knockdown in both cell lines. Conclusion. NOTCH1 expression is important for maintaining CSC pool and phenotype of human lung and colon carcinomas. The obtained data may be valuable in the development of anticancer therapies.

Agrimonolide mitigated DSS-induced colitis by modulating the balance between Treg and Th17 cells through the suppression of the Notch and JAK2/STAT3 signaling pathways

PurposeThe objective of this study was to investigate the effects of agrimonolide (AM) on mice with dextran sulfate sodium (DSS)-induced colitis and elucidate its protective mechanisms. MethodsA 3 % DSS solution was used to induce colitis, and intragastric administration of AM at doses of 25 and 50 mg/kg was performed. A comprehensive assessment was conducted to evaluate inflammatory responses and mucosal integrity in the colon. Inflammatory factors were quantified using enzyme-linked immunosorbent assay (ELISA). The proportions of T helper cell 17 (Th17) and regulatory T cells (Treg) cells in mesenteric lymph nodes (MLNs) was analyzed through RT-qPCR and flow cytometry. Proteins associated with the Notch and JAK2/STAT3 pathways were examined via RT-qPCR, western blotting, and immunofluorescence. Additionally, the impact of AM on Treg and Th17 cell differentiation was investigated in vitro. ResultsPre-treatment with AM significantly alleviated colon inflammation in mice, as evidenced by reduced body weight loss, shorter colon length, lower disease activity index (DAI) score, and decreased myeloperoxidase (MPO) content. Notably, AM pre-treatment attenuated the production of pro-inflammatory cytokines, including interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6, in mice with DSS-induced colitis. Additionally, AM pre-treatment significantly enhanced the expression of tight junction proteins (Occludin and ZO-1), thereby preserving gut barrier function. Moreover, we observed that AM administration decreased the ratio of Th17 cells while increasing the frequency of colonic Treg cells, thus modulating the Th17/Treg balance both in vivo and in vitro. Furthermore, in the AM-treated group, the expression of Notch-1, Jagged1, delta like 4 (DLL4), phospho-janus kinases 2 (p-JAK2)/JAK2, and p-signal transducer and activator of transcription 3 (STAT3)/STAT3 in colonic tissue was reduced compared to the DSS group. Remarkably, the therapeutic effects of AM in colitis mice were blocked by a Notch activator. ConclusionThese findings underscore the effectiveness of AM in alleviating symptoms and pathological damage in DSS-induced colitis mice by rebalancing Th17/Treg cell homeostasis through modulation of the Notch and JAK2/STAT3 signaling pathways. These insights into AM's mechanisms of action offer potential avenues for novel therapeutic strategies.

ADAM10 Alleviates Hypoxia/Reoxygenation-Induced Cardiomyocyte Injury by Activating the Notch Signaling Pathway.

The occurrence of myocardial ischemia/reperfusion injury is commonly observed during cardiac surgery; however, there remains a dearth of effective therapeutic strategies to mitigate this injury. The a disintegrin and metallopeptidase domain 10 (ADAM10) is a transmembrane protein anchored on the cell membrane surface, and its precise mechanism of action in myocardial ischemia/reperfusion injury remains incompletely understood. This study aims to investigate the impact of ADAM10 on cardiomyocyte injury induced by hypoxia/reoxygenation (H/R) and elucidate the underlying mechanisms. The ADAM10 overexpression plasmid was transfected into H9c2 cells, which were subsequently treated with the Notch signaling pathway inhibitor DAPT and cultured under H/R conditions. Cell proliferation activity was assessed using the CCK-8 assay. The levels of LDH, SOD, and MDA were quantified through colorimetric analysis. The levels of ROS and the rate of apoptosis were measured using flow cytometry. The morphological changes in the nucleus of H9c2 cells were observed by employing Hoechst 33258 staining. The mRNA expression levels of ADAM10, Notch1, NICD, and Hes1 in H9c2 cells were determined using qRT-PCR. The expressions of Notch signaling pathway and apoptosis-related proteins were analyzed by Western blot. Overexpression of ADAM10 provided protection to H9c2 cells against injury induced by H/R, leading to an increase in SOD levels and alleviation of oxidative stress caused by the accumulation of ROS and the decrease of SOD activity. Meanwhile, overexpression of ADAM10 inhibited apoptosis in H9c2 cells exposed to H/R by regulating the expression of apoptosis-related proteins, such as Bax, Bcl-2 and Cleaved-caspase-3. Additionally, overexpression of ADAM10 facilitated the activation of the Notch1 signaling pathway in H9c2 cells exposed to H/R by upregulating the protein expression of Notch1, NICD, and Hes1. However, the protective effect of ADAM10 on H/R-induced H9c2 cells was partially reversed by DAPT. Our findings demonstrate that ADAM10 exerts protective effects in H/R-induced H9c2 cells by suppressing oxidative stress and apoptosis via the activation of the Notch signaling pathway.

Notch1 is required to maintain supporting cell identity and vestibular function during maturation of the mammalian balance organs.

The inner ear houses two sensory modalities: the hearing organ, located in the cochlea, and the balance organs, located throughout the vestibular regions of the ear. Both hearing and vestibular sensory regions are composed of similar cell types, including hair cells and associated supporting cells. Recently, we showed that Notch1 is required for maintaining supporting cell survival postnatally during cochlear maturation. However, it is not known whether Notch1 plays a similar role in the balance organs of the inner ear. To characterize the role of Notch during vestibular maturation, we conditionally deleted Notch1 from Sox2-expressing cells of the vestibular organs in the mouse at P0/P1. Histological analyses showed a dramatic loss of supporting cells accompanied by an increase in type II hair cells without cell death, indicating the supporting cells are converting to hair cells in the maturing vestibular regions. Analysis of 6-week old animals indicate that the converted hair cells survive, despite the reduction of supporting cells. Interestingly, measurements of vestibular sensory evoked potentials (VsEPs), known to be generated in the striolar regions of the vestibular afferents in the maculae, failed to show a response, indicating that NOTCH1 expression is critical for striolar function postnatally. Consistent with this, we find that the specialized type I hair cells in the striola fail to develop the complex calyces typical of these cells. These defects are likely due to the reduction in supporting cells, which have previously been shown to express factors critical for the striolar region. Similar to other mutants that lack proper striolar development, Notch1 mutants do not exhibit typical vestibular behaviors such as circling and head shaking, but do show difficulties in some vestibular tests, including the balance beam and forced swim test. These results indicate that, unlike the hearing organ in which the supporting cells undergo cell death, supporting cells in the balance regions retain the ability to convert to hair cells during maturation, which survive into adulthood despite the reduction in supporting cells.

The effect of bisphenol A on the Notch (Notch2 and Jagged2) signaling pathway in the follicular development of the neonatal rat ovary

ABSTRACT The formation of primordial follicles determines the pool size of follicles in the ovary, and is crucial for female reproductivity. Oocyte nest breakdown, and the formation of primordial follicles, largely depend upon the communication between oocytes and the surrounding pregranulosa cells. The neurogenic locus notch homolog protein (Notch) signaling pathway is the key player for this cell-to-cell communication, and is responsible for primordial folliculogenesis. However, different endocrine disruptors, including bisphenol A (BPA; a plasticizer and a constituent of reusable plastic containers) may affect the Notch signaling pathway, and might induce ovary dysfunction via Notch signaling. Consequently, we investigated the possible influence of BPA treatment on the proportional distribution of the follicular stages, follicle numbers, levels of apoptosis, and on Notch2 and Jagged2 expressions in the ovary. BPA was administered at doses of either 50 µg/kg/day or 50 mg/kg/day, at different time intervals, during neonatal and fetal periods in vivo. After collecting the ovaries from the various experimental groups, follicles were counted, and frequency of apoptosis was determined by TUNEL assay. In addition, Notch2 and Jagged2 expressions were assessed by immunohistochemical staining and qPCR. In summary, BPA treatment affected the follicle numbers and apoptosis level, and Notch2 and Jagged2 expressions varied with follicular stage. It was also observed that these parameters were dose and time dependent with respect to BPA exposure.

Abstract B028: Expression of NOTCH1 in head and neck tumours at selected hospitals in Ghana

Abstract Head and neck tumors (HNT) are of paranasal sinuses origin (the salivary glands and the upper aerodigestive tract). It constitutes the sixth most common tumors. Studies have shown that, factors such as tobacco and alcohol intake and viral infections may increase the relative risk to the tumor. Notch1 pathways are frequently altered in many tumors, however, the clinical significance of NOTCH1dysregulation in head and neck tumors is poorly understood. METHOD: The aim of this study was to investigate the expression NOTCH1 in head and neck tumor and also to elucidate the various anatomical pattern of the head and neck tumors in selected hospitals in Ghana. NOTCH1 expression were analyzed using quantitative real-time PCR (qRT-PCR) and immunohistochemical staining on tissue samples from a consecutive series of head and neck tumor patients resections over a four-year period. RESULTS: The percentage of low expression of Notch1 were 71.4% in the malignant tissue (n=98) and 76.9% (n=52) in the benign tissue. The anatomical site with high of low expression of the NOTCH1 was found in oral cavity (37.1%) followed by respiratory (27.1%) followed by mandible (14.3%). CONCLUSION: There were low expression of NOTCH1 in head and neck tumour tissues suggesting that NOTCH1may be a tumor suppressor gene. We further propose that, NOTCH1 offers a potential tool as a target molecule in the development of therapies for head and neck tumors. Citation Format: Precious Barnes, Roland Osei Saahene. Expression of NOTCH1 in head and neck tumours at selected hospitals in Ghana [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Expanding and Translating Cancer Synthetic Vulnerabilities; 2024 Jun 10-13; Montreal, Quebec, Canada. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(6 Suppl):Abstract nr B028.

Cardiomyocyte Notch1 signaling is essential for protection of the maternal heart from peripartum stress

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Deutsche Forschungsgemeinschaft Background Peripartum cardiomyopathy (PPCM) is a life-threatening disease in women without known cardiovascular disease and is characterized by a sudden onset of heart failure (HF) before, under or after delivery. Previous studies suggest impaired endothelial to cardiomyocyte crosstalk as a major pathomechanism of the disease. Purpose Analyses of the role of Notch1 signaling for the endothelial-cardiomyocyte crosstalk in PPCM. Methods and results Serum from PPCM patients with acute HF reduced Notch1 expression in induced pluripotent stem cell derived cardiomyocytes (-20%, P<0.05) compared to serum from postpartum-matched healthy controls (PP-Ctrl). Beside miRNA-146a previously described to be up-regulated in PPCM plasma (6.8-fold, P<0.01), additional miRNAs targeting Notch1 signaling (miR-30a-3p, miR-34a, miR-200b-3p, miR-200c-3p, miR-429-3p, miR-449a) were up-regulated in PPCM plasma. Overexpression of these miRNAs in cardiomyocytes (CM) reduces Notch1 protein levels. Mice with a CM-restricted knockout of Notch1 (N1-KO) are born at the expected Mendelian ratio and nulli pari (NP) N1-KO female mice do not show a distinct cardiac phenotype at the age of 3 to 4 months compared to WT female mice (%FS WT: 41±5 vs N1-KO: 37±6; n= 9-12). However, they develop mild HF at the age of 6 months (%FS WT: 44±4 vs N1-KO: 31±8; n=11-14; P<0.01). Mated N1-KO females displayed normal cardiac function and LV dimensions in the last week of the first pregnancy. After 3 pregnancies and nursing periods, N1-KO developed severe HF (%FS WT PP: 30±5 vs N1-KO PP: 16±5; n=8-12; P<0.01), and show enhanced mortality (P<0.01). N1-KO-NP and N1-KO-PP displayed significant increase in the cardiac expression of the stress markers ANP and BNP compared to respective WT-NP and WT-PP. RNA-Seq analysis of N1-KO-PP revealed 1380 transcripts (adj. P<0.01) differently regulated genes, among them down-regulation of ErbB4, a known driver in PPCM onset. SiRNA-mediated knockdown of Notch1 in CM were associated with a decrease in ErbB4 protein expression. Treatment with bromocriptin (BR) was not able to improve survival and to rescue cardiac function and LV dimensions in postpartum N1-KO females (WT: 37±4, N1-KO: 23±10; n=7-8). Moreover, RNA-Seq analysis revealed that BR had no effect on the dysregulated cardiac mRNA. In conclusion, the pathophysiology of PPCM is associated with reduced cardiac Notch1 expression, which results in part from 16-kDa-prolactin mediated upregulation of miRNAs targeting Notch1. The reduced cardiac Notch1 expression contributes to PPCM as indicated with severe postpartum HF and high mortality in N1-KO mice. Inhibition of prolactin secretion with BR failed to rescue the development of PPCM in N1-KO mice suggesting that deregulated Notch1 is downstream of the 16-kDa prolactin-miRNA pathophysiology.

MiR-449a: A Promising Biomarker and Therapeutic Target in Cancer and Other Diseases.

In the regulation of gene expression, epigenetic factors like non-coding RNAs (ncRNAs) play an equal role in genetics. The role of microRNAs (miRNAs), which are members of the ncRNA family, in post-transcriptional gene regulation is well-documented and has important implications for both normal and abnormal biological processes, such as angiogenesis, proliferation, survival, and apoptosis. The purpose of this study was to synthesize previous research on miR-449a by analyzing published results from various databases, as there have been a number of investigations on miR-449's potential involvement in the development of human disorders. Based on our findings, miR-449 is strongly dysregulated in a wide range of diseases, from various cancers to cardiovascular diseases, cognitive impairments, and respiratory diseases, and it may play a pivotal role in the development of these problems. In addition, miR-449a functions as a crucial regulator of the expression of several well-known genes, including E2F-3, BCL2, NOTCH1, and SOX4. This, in turn, modulates various pathways and processes related to cancer, including Notch, PI3K, and TGF-β, and contributes to the improvement of cancer drug sensitivity. Curiously, abnormalities in the expression of this miRNA may serve as diagnostic or prognostic indicators for distinguishing between healthy people and patients or to evaluate the survival rates for specific disorders. This article provides a synopsis of the current understanding of miR-449a's role in human disease development through its regulation of gene expression and the biological processes related to these genes and their linked processes. In addition, we have covered the topic of miR-449a's potential as a clinical feature (diagnosis and prognosis) indicator for a range of disorders, both neoplastic and non-neoplastic. In general, our goal was to gain a thorough comprehension of the numerous functions of miR-449a in different disorders.

EGCG Suppresses Adipogenesis and Promotes Browning of 3T3-L1 Cells by Inhibiting Notch1 Expression.

With the changes in lifestyle and diet structure, the incidence of obesity has increased year by year, and obesity is one of the inducements of many chronic metabolic diseases. Epigallocatechin gallate (EGCG), which is the most abundant component of tea polyphenols, has been used for many years to improve obesity and its complications. Though it has been reported that EGCG can improve obesity through many molecular mechanisms, EGCG may have many mechanisms yet to be explored. In this study, we explored other possible mechanisms through molecular docking and in vitro experiments. AutoDock Vina was selected for conducting the molecular docking analysis to elucidate the interaction between EGCG and Notch1, while molecular dynamics simulations were employed to validate this interaction. Then, the new regulation mechanism of EGCG on obesity was verified with in vitro experiments, including a Western blot experiment, immunofluorescence experiment, oil red O staining, and other experiments in 3T3-L1 adipocytes. The molecular docking results showed that EGCG could bind to Notch1 protein through hydrogen bonding. In vitro cell experiments demonstrated that EGCG can significantly reduce the sizes of lipid droplets of 3T3-L1 adipocytes and promote UCP-1 expression by inhibiting the expression of Notch1 in 3T3-L1 adipocytes, thus promoting mitochondrial biogenesis. In this study, molecular docking and in vitro cell experiments were used to explore the possible mechanism of EGCG to improve obesity by inhibiting Notch1.

Inhibition of NOTCH4 sensitizes FLT3/ITD acute myeloid leukemia cells to FLT3 tyrosine kinase inhibition.

Internal tandem duplication mutations of FLT3 (FLT3/ITD) confer poor prognosis in AML. FLT3 tyrosine kinase inhibitors (TKIs) alone have limited and transient clinical efficacy thus calling for new targets for more effective combination therapy. In a loss-of-function RNAi screen, we identified NOTCH4 as one such potential target whose inhibition proved cytotoxic to AML cells, and also sensitized them to FLT3 inhibition. Further investigation found increased NOTCH4 expression in FLT3/ITD AML cell lines and primary patient samples. Inhibition of NOTCH4 by shRNA knockdown, CRISPR-Cas9-based knockout or γ-secretase inhibitors synergized with FLT3 TKIs to kill FLT3/ITD AML cells in vitro. NOTCH4 inhibition sensitized TKI-resistant FLT3/ITD cells to FLT3 TKI inhibition. The combination reduced phospho-ERK and phospho-AKT, indicating inhibition of MAPK and PI3K/AKT signaling pathways. It also led to changes in expression of genes involved in regulating cell cycling, DNA repair and transcription. A patient-derived xenograft model showed that the combination reduced both the level of leukemic involvement of primary human FLT3/ITD AML cells and their ability to engraft secondary recipients. In summary, these results demonstrate that NOTCH4 inhibition synergizes with FLT3 TKIs to eliminate FLT3/ITD AML cells, providing a new therapeutic target for AML with FLT3/ITD mutations.

Irisin prevents trabecular bone damage and tumor invasion in a mouse model of multiple myeloma

Abstract Bone disease associated with multiple myeloma (MM) is characterized by osteolytic lesions and pathological fractures, which remain a therapeutic priority despite new drugs improving MM patient survival. Antiresorptive molecules represent the main option for the treatment of MM-associated bone disease (MMBD), whereas osteoanabolic molecules are under investigation. Among these latter, we here focused on the myokine irisin, which is able to enhance bone mass in healthy mice, prevent bone loss in osteoporotic mouse models, and accelerate fracture healing in mice. Therefore, we investigated irisin effect on MMBD in a mouse model of MM induced by intratibial injection of myeloma cells followed by weekly administration of 100 μg/kg of recombinant irisin for 5 wk. By micro-Ct analysis, we demonstrated that irisin improves MM-induced trabecular bone damage by partially preventing the reduction of femur Trabecular Bone Volume/Total Volume (P = .0028), Trabecular Number (P = .0076), Trabecular Fractal Dimension (P = .0044), and increasing Trabecular Separation (P = .0003) in MM mice. In cortical bone, irisin downregulates the expression of Sclerostin, a bone formation inhibitor, and RankL, a pro-osteoclastogenic molecule, while in BM it upregulates Opg, an anti-osteoclastogenic cytokine. We found that in the BM tibia of irisin-treated MM mice, the percentage of MM cells displays a reduction trend, while in the femur it decreases significantly. This is in line with the in vitro reduction of myeloma cell viability after 48 h of irisin stimulation at both 200 and 500 ng/mL and, after 72 h already at 100 ng/mL rec-irisin. These results could be due to irisin ability to downregulate the expression of Notch 3, which is important for cell-to-cell communication in the tumor niche, and Cyclin D1, supporting an inhibitory effect of irisin on MM cell proliferation. Overall, our findings suggest that irisin could be a new promising strategy to counteract MMBD and tumor burden in one shot.

Notch1/Akt/Foxo1 Pathway Regulated by Kisspeptin Is Involved in Endometrial Decidualization in Patients With Recurrent Spontaneous Abortion

Kisspeptin, a protein encoded by the KISS1 gene, functions as an essential factor in suppressing tumor growth. The intricate orchestration of cellular processes such as proliferation and differentiation is governed by the Notch1/Akt/Foxo1 signaling pathway, which assumes a central role in maintaining cellular homeostasis. In the specific context of this investigation, the focal point lies in a meticulous exploration of the intricate mechanisms underlying the regulatory effect of kisspeptin on the process of endometrial decidualization. This investigation delves into the interplay between kisspeptin and the Notch1/Akt/Foxo1 signaling pathway, aiming to elucidate its significance in the pathophysiology of recurrent spontaneous abortion (RSA). We enrolled a cohort comprising 45 individuals diagnosed with RSA, who were admitted to the outpatient clinic of the Reproductive Center at the Second Affiliated Hospital of Soochow University between June 2020 and December 2020. On the other hand, an additional group of 50 women undergoing elective abortion at the outpatient clinic of the Family Planning Department during the same timeframe was also included. To comprehensively assess the molecular landscape, Western blot and RT-qPCR were performed to analyze the expression levels of kisspeptin (and its gene KISS1), IGFBP1 (an established marker of decidualization), Notch1, Akt, and Foxo1 within the decidua. Human endometrial stromal cells (hESC) were given targeted interventions, including treatment with siRNA to disrupt KISS1 or exposure to kisspeptin10 (the bioactive fragment of kisspeptin), and were subsequently designated as the siKP group or the KP10 group, respectively. A control group comprised hESC was transfected with blank siRNA, and cell proliferation was meticulously evaluated with CCK8 assay. Following in vitro induction for decidualization across the three experimental groups, immunofluorescence assay was performed to identify differences in Notch1 expression and decidualization morphology between the siKP and the KP10 groups. Furthermore, RT-qPCR and Western blot were performed to gauge the expression levels of IGFBP1, Notch1, Akt, and Foxo1 across the three cell groups. Subsequently, decidualization was induced in hESC by adding inhibitors targeting Notch1, Akt, and Foxo1. The expression profiles of the aforementioned proteins and genes in the four groups were then examined, with hESC induced for decidualization without adding inhibitors serving as the normal control group. To establish murine models of normal pregnancy (NP) and RSA, CBA/J×BALB/c and CBA/J×DBA/2 mice were used. The mice were respectively labeled as the NP model and RSA model. The experimental groups received intraperitoneal injections of kisspeptin10 and kisspeptin234 (acting as a blocker) and were designated as RSA-KP10 and NP-KP234 groups. On the other hand, the control groups received intraperitoneal injections of normal saline (NS) and were referred to as RSA-NS and NP-NS groups. Each group comprised 6 mice, and uterine tissues from embryos at 9.5 days of gestation were meticulously collected for observation of embryo absorption and examination of the expression of the aforementioned proteins and genes. The analysis revealed that the expression levels of kisspeptin, IGFBP1, Notch1, Akt, and Foxo1 were significantly lower in patients diagnosed with RSA compared to those in women with NP (P<0.01 for kisspeptin and P<0.05 for IGFBP1, Notch1, Akt, and Foxo1). After the introduction of kisspeptin10 to hESC, there was an observed enhancement in decidualization capability. Subsequently, the expression levels of Notch1, Akt, and Foxo1 showed an increase, but they decreased after interference with KISS1. Through immunofluorescence analysis, it was observed that proliferative hESC displayed a slender morphology, but they transitioned to a rounder and larger morphology post-decidualization. Concurrently, the expression of Notch1 increased, suggesting enhanced decidualization upon the administration of kisspeptin10, but the expression decreased after interference with KISS1. Further experimentation involved treating hESC with inhibitors specific to Notch1, Akt, and Foxo1 separately, revealing a regulatory sequence of Notch1/Akt/Foxo1 (P<0.05). In comparison to the NS group, NP mice administered with kisspeptin234 exhibited increased fetal absorption rates (P<0.001) and decreased expression of IGFBP1, Notch1, Akt, and Foxo1 (P<0.05). Conversely, RSA mice administered with kisspeptin10 demonstrated decreased fetal absorption rates (P<0.001) and increased expression levels of the aforementioned molecules (P<0.05). It is suggested that kisspeptin might exert its regulatory influence on the process of decidualization through the modulation of the Notch1/Akt/Foxo1 signaling cascade. A down-regulation of the expression levels of kisspeptin could result in suboptimal decidualization, which in turn might contribute to the development or progression of RSA.

Increased H19/miR-675 Expression in Adult T-Cell Leukemia Is Associated with a Unique Notch Signature Pathway.

The Notch pathway is a key cancer driver and is important in tumor progression. Early research suggested that Notch activity was highly dependent on the expression of the intracellular cleaved domain of Notch-1 (NICD). However, recent insights into Notch signaling reveal the presence of Notch pathway signatures, which may vary depending on different cancer types and tumor microenvironments. Herein, we perform a comprehensive investigation of the Notch signaling pathway in adult T-cell leukemia (ATL) primary patient samples. Using gene arrays, we demonstrate that the Notch pathway is constitutively activated in ATL patient samples. Furthermore, the activation of Notch in ATL cells remains elevated irrespective of the presence of activating mutations in Notch itself or its repressor, FBXW7, and that ATL cells are dependent upon Notch-1 expression for proliferation and survival. We demonstrate that ATL cells exhibit the expression of pivotal Notch-related genes, including notch-1, hes1, c-myc, H19, and hes4, thereby defining a critical Notch signature associated with ATL disease. Finally, we demonstrate that lncRNA H19 is highly expressed in ATL patient samples and ATL cells and contributes to Notch signaling activation. Collectively, our results shed further light on the Notch pathway in ATL leukemia and reveal new therapeutic approaches to inhibit Notch activation in ATL cells.

Aflatoxin B1 exposure deteriorates immune abnormalities in a BTBR T+ Itpr3tf/J mouse model of autism by increasing inflammatory mediators' production in CD19-expressing cells

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by deficiencies in communication, repetitive and stereotyped behavioral patterns, and difficulties in reciprocal social engagement. The presence of immunological dysfunction in ASD has been well established. Aflatoxin B1 (AFB1) is a prevalent mycotoxin found in food and feed, causing immune toxicity and hepatotoxicity. AFB1 is significantly elevated in several regions around the globe. Existing research indicates that prolonged exposure to AFB1 results in neurological problems. The BTBR T+ Itpr3tf/J (BTBR) mice, which were used as an autism model, exhibit the primary behavioral traits that define ASD, such as repeated, stereotyped behaviors and impaired social interactions. The main objective of this work was to assess the toxic impact of AFB1 in BTBR mice. This work aimed to examine the effects of AFB1 on the expression of Notch-1, IL-6, MCP-1, iNOS, GM-CSF, and NF-κB p65 by CD19+ B cells in the spleen of the BTBR using flow cytometry. We also verified the impact of AFB1 exposure on the mRNA expression levels of Notch-1, IL-6, MCP-1, iNOS, GM-CSF, and NF-κB p65 in the brain of BTBR mice using real-time PCR. The findings of our study showed that the mice treated with AFB1 in the BTBR group exhibited a substantial increase in the presence of CD19+Notch-1+, CD19+IL-6+, CD19+MCP-1+, CD19+iNOS+, CD19+GM-CSF+, and CD19+NF-κB p65+ compared to the mice in the BTBR group that were treated with saline. Our findings also confirmed that administering AFB1 to BTBR mice leads to elevated mRNA expression levels of Notch-1, IL-6, MCP-1, iNOS, GM-CSF, and NF-κB p65 in the brain, in comparison to BTBR mice treated with saline. The data highlight that exposure to AFB1 worsens immunological abnormalities by increasing the expression of inflammatory mediators in BTBR mice.

Cathepsin K deficiency prevented stress-related thrombosis in a mouse FeCl3 model

BackgroundExposure to chronic psychological stress (CPS) is a risk factor for thrombotic cardiocerebrovascular diseases (CCVDs). The expression and activity of the cysteine cathepsin K (CTSK) are upregulated in stressed cardiovascular tissues, and we investigated whether CTSK is involved in chronic stress-related thrombosis, focusing on stress serum-induced endothelial apoptosis.Methods and resultsEight-week-old wild-type male mice (CTSK+/+) randomly divided to non-stress and 3-week restraint stress groups received a left carotid artery iron chloride3 (FeCl3)-induced thrombosis injury for biological and morphological evaluations at specific timepoints. On day 21 post-stress/injury, the stress had enhanced the arterial thrombi weights and lengths, in addition to harmful alterations of plasma ADAMTS13, von Willebrand factor, and plasminogen activation inhibitor-1, plus injured-artery endothelial loss and CTSK protein/mRNA expression. The stressed CTSK+/+ mice had increased levels of injured arterial cleaved Notch1, Hes1, cleaved caspase8, matrix metalloproteinase-9/-2, angiotensin type 1 receptor, galactin3, p16IN4A, p22phox, gp91phox, intracellular adhesion molecule-1, TNF-α, MCP-1, and TLR-4 proteins and/or genes. Pharmacological and genetic inhibitions of CTSK ameliorated the stress-induced thrombus formation and the observed molecular and morphological changes. In cultured HUVECs, CTSK overexpression and silencing respectively increased and mitigated stressed-serum- and H2O2-induced apoptosis associated with apoptosis-related protein changes. Recombinant human CTSK degraded γ-secretase substrate in a dose-dependent manor and activated Notch1 and Hes1 expression upregulation.ConclusionsCTSK appeared to contribute to stress-related thrombosis in mice subjected to FeCl3 stress, possibly via the modulation of vascular inflammation, oxidative production and apoptosis, suggesting that CTSK could be an effective therapeutic target for CPS-related thrombotic events in patients with CCVDs.