Uncovering the mechanisms of host mitochondrial cardiolipin release in syphilis: Insights from human microvascular endothelial cells.

The release of host mitochondrial cardiolipin is believed to be the main factor that contributes to the production of anti-cardiolipin antibodies in syphilis. However, the precise mechanism by which mitochondria release cardiolipin in this context remains elusive. This study aimed to elucidate the mechanisms underlying mitochondrial cardiolipin release in syphilis. We conducted a cardiolipin quantitative assay and immunofluorescence analysis to detect mitochondrial cardiolipin release in human microvascular endothelial cells (HMEC-1), with and without Treponema pallidum (Tp) infection. Furthermore, we explored apoptosis, a key mechanism for mitochondrial cardiolipin release. The potential mediator molecules were then analyzed through RNA-sequence and subsequently validated using in vitro knockout techniques mediated by CRISPR-Cas9 and pathway-specific inhibitors. Our findings confirm that live-Tp is capable of initiating the release of mitochondrial cardiolipin, whereas inactivated-Tp does not exhibit this capability. Additionally, apoptosis detection further supports the notion that the release of mitochondrial cardiolipin occurs independently of apoptosis. The RNA-sequencing results indicated that microtubule-associated protein2 (MAP2), an axonogenesis and dendrite development gene, was up-regulated in HMEC-1 treated with Tp, which was further confirmed in syphilitic lesions by immunofluorescence. Notably, genetic knockout of MAP2 inhibited Tp-induced mitochondrial cardiolipin release in HMEC-1. Mechanically, Tp-infection regulated MAP2 expression via the MEK-ERK-HES1 pathway, and MEK/ERK phosphorylation inhibitors effectively block Tp-induced mitochondrial cardiolipin release. This study demonstrated that the infection of live-Tp enhanced the expression of MAP2 via the MEK-ERK-HES1 pathway, thereby contributing to our understanding of the role of anti-cardiolipin antibodies in the diagnosis of syphilis.

Effects of KEAP1 Silencing on NRF2 and NOTCH Pathways in SCLC Cell Lines.

The KEAP1/NRF2 pathway is a master regulator of several redox-sensitive genes implicated in the resistance of tumor cells against therapeutic drugs. The dysfunction of the KEAP1/NRF2 system has been correlated with neoplastic patients' outcomes and responses to conventional therapies. In lung tumors, the growth and the progression of cancer cells may also involve the intersection between the molecular NRF2/KEAP1 axis and other pathways, including NOTCH, with implications for antioxidant protection, survival of cancer cells, and drug resistance to therapies. At present, the data concerning the mechanism of aberrant NRF2/NOTCH crosstalk as well as its genetic and epigenetic basis in SCLC are incomplete. To better clarify this point and elucidate the contribution of NRF2/NOTCH crosstalk deregulation in tumorigenesis of SCLC, we investigated genetic and epigenetic dysfunctions of the KEAP1 gene in a subset of SCLC cell lines. Moreover, we assessed its impact on SCLC cells' response to conventional chemotherapies (etoposide, cisplatin, and their combination) and NOTCH inhibitor treatments using DAPT, a γ-secretase inhibitor (GSI). We demonstrated that the KEAP1/NRF2 axis is epigenetically controlled in SCLC cell lines and that silencing of KEAP1 by siRNA induced the upregulation of NRF2 with a consequent increase in SCLC cells' chemoresistance under cisplatin and etoposide treatment. Moreover, KEAP1 modulation also interfered with NOTCH1, HES1, and DLL3 transcription. Our preliminary data provide new insights about the downstream effects of KEAP1 dysfunction on NRF2 and NOTCH deregulation in this type of tumor and corroborate the hypothesis of a cooperation of these two pathways in the tumorigenesis of SCLC.

The Neurog2-Tbr2 axis forms a continuous transition to the neurogenic gene expression state in neural stem cells.

Neural stem cells (NSCs) differentiate into neuron-fated intermediate progenitor cells (IPCs) via cell division. Although differentiation from NSCs to IPCs is a discrete process, recent transcriptome analyses identified a continuous transcriptional trajectory during this process, raising the question of how to reconcile these contradictory observations. In mouse NSCs, Hes1 expression oscillates, regulating the oscillatory expression of the proneural gene Neurog2, while Hes1 expression disappears in IPCs. Thus, the transition from Hes1 oscillation to suppression is involved in the differentiation of NSCs to IPCs. Here, we found that Neurog2 oscillations induce the accumulation of Tbr2, which suppresses Hes1 expression, generating an IPC-like gene expression state in NSCs. In the absence of Tbr2, Hes1 expression is up-regulated, decreasing the formation of IPCs. These results indicate that the Neurog2-Tbr2 axis forms a continuous transcriptional trajectory to an IPC-like neurogenic state in NSCs, which then differentiate into IPCs via cell division.

RIP140 regulates transcription factor HES1 oscillatory expression and mitogenic activity in colon cancer cells.

The transcription factor receptor-interacting protein 140 (RIP140) regulates intestinal homeostasis and tumorigenesis through Wnt signaling. In this study, we investigated its effect on the Notch/HES1 signaling pathway. In colorectal cancer (CRC) cell lines, RIP140 positively regulated HES1 gene expression at the transcriptional level via a recombining binding protein suppressor of hairless (RBPJ)/neurogenic locus notch homolog protein 1 (NICD)-mediated mechanism. In support of these in vitro data, RIP140 and HES1 expression significantly correlated in mouse intestine and in a cohort of CRC samples, thus supporting the positive regulation of HES1 gene expression by RIP140. Interestingly, when the Notch pathway is fully activated, RIP140 exerted a strong inhibition of HES1 gene transcription controlled by the level of HES1 itself. Moreover, RIP140 directly interacts with HES1 and reversed its mitogenic activity in human CRC cells. In line with this observation, HES1 levels were associated with a better patient survival only when tumors expressed high levels of RIP140. Our data identify RIP140 as a key regulator of the Notch/HES1 signaling pathway, with a dual effect on HES1 gene expression at the transcriptional level and a strong impact on colon cancer cell proliferation.

HES1 induces ITPR1-mediated autophagy to exert anti-metastatic effects in pituitary adenomas.

Background: Pituitary adenomas (PAs) are prevalent intracranial tumors necessitating a comprehensive exploration of their molecular intricacies. This study delved into the molecular interactions among HES1 (hairy and enhancer of split 1), ITPR1 (inositol 1,4,5-trisphosphate receptor, type 1), and autophagy to elucidate their contributions to PA progression. Methods: Our in-depth bioinformatics analysis identified ITPR1 as a central hub gene in the PA-associated dataset. It exhibited reduced expression in PA and held significant clinical diagnostic relevance. Motivated by this discovery, we investigated the consequences of ITPR1 overexpression, as well as the use of autophagy inhibitors 3-Methyladenine (3-MA) and Baf A1, while considering the transcriptional influence of HES1. Results: In vitro experiments utilizing PA cell lines revealed that ITPR1 overexpression significantly hindered tumorigenic activities. In contrast, both 3-MA and Baf A1 exacerbated these tumorigenic properties, confirmed by a decreased LC3 II/LC3 I ratio, indicative of autophagy inhibition. Intriguingly, the concurrent introduction of ITPR1 and these inhibitors mitigated these intensified effects, implying a tumor-suppressive role for ITPR1. Further investigations pinpoint HES1 as a potential upstream regulator of ITPR1 transcription. Silencing HES1 lead to reduced ITPR1 promoter activity, weakening the impact of ITPR1 overexpression on autophagy. This neutralized the ITPR1-mediated suppressions on PA cell activities, including proliferation, invasion, and migration. Conclusions: In summary, our research uncovered a complex regulatory interplay among HES1, ITPR1, and autophagy in the context of PA progression. These findings opened up promising avenues for novel therapeutic interventions targeting this intricate network to enhance PA treatment.

NOTCH1 as a Negative Regulator of Avian Adipocyte Differentiation: Implications for Fat Deposition.

The NOTCH signaling pathway plays a pivotal role in diverse developmental processes, including cell proliferation and differentiation. In this study, we investigated whether this signaling molecules also contribute to avian adipogenesis. Using previous mRNA-seq datasets, we examined the expression of 11 signaling members during avian adipocyte differentiation. We found most members are down-regulated throughout differentiation (p < 0.05). As a representative, NOTCH1 was decreased in cultured chicken abdominal adipocytes during adipogenesis at mRNA and protein levels (p < 0.05). Moreover, using an overexpression plasmid for NOTCH1's intracellular domain (NICD1), as well as siRNA and DAPT to activate or deplete NOTCH1 in cells, we investigated the role of NOTCH1 in avian adipogenesis. Our findings illuminate that NOTCH1 activates the expression of HES1 and SOCS3 while it decreases NR2F2 and NUMB (p < 0.05), as well as inhibits oleic acid-induced adipocyte differentiation (p < 0.01). We further demonstrate that HES1, a downstream transcription factor activated by NOTCH1, also significantly inhibits adipogenesis by suppressing PPARγ and C/EBPα (p < 0.01). Collectively, these findings establish NOTCH1 as a negative regulator of avian adipocyte differentiation, unveiling NOTCH signaling as a potential target for regulating avian fat deposition.

Neural stem cell-derived exosomes regulate cell proliferation, migration, and cell death of brain microvascular endothelial cells via the miR-9/Hes1 axis under hypoxia.

BACKGROUND: Our previous study found that mouse embryonic neural stem cell (NSC)-derived exosomes (EXOs) regulated NSC differentiation via the miR-9/Hes1 axis. However, the effects of EXOs on brain microvascular endothelial cell (BMEC) dysfunction via the miR-9/Hes1 axis remain unknown. Therefore, the current study aimed to determine the effects of EXOs on BMEC proliferation, migration, and death via the miR-9/Hes1 axis. METHODS: Immunofluorescence, quantitative real-time polymerase chain reaction, cell counting kit-8 assay, wound healing assay, calcein-acetoxymethyl/propidium iodide staining, and hematoxylin and eosin staining were used to determine the role and mechanism of EXOs on BMECs. RESULTS: EXOs promoted BMEC proliferation and migration and reduced cell death under hypoxic conditions. The overexpression of miR-9 promoted BMEC proliferation and migration and reduced cell death under hypoxic conditions. Moreover, miR-9 downregulation inhibited BMEC proliferation and migration and also promoted cell death. Hes1 silencing ameliorated the effect of amtagomiR-9 on BMEC proliferation and migration and cell death. Hyperemic structures were observed in the regions of the hippocampus and cortex in hypoxia-induced mice. Meanwhile, EXO treatment improved cerebrovascular alterations. CONCLUSION: NSC-derived EXOs can promote BMEC proliferation and migration and reduce cell death via the miR-9/Hes1 axis under hypoxic conditions. Therefore, EXO therapeutic strategies could be considered for hypoxia-induced vascular injury.

Astragalus Polysaccharide Promotes Neuronal Injury Repair via the Notch1/NFκB Signaling Axis in the Ventroposterior Thalamic Nucleus in Rats with Focal Cerebral Ischemia.

BACKGROUND: Ischemic stroke is the most common form of stroke and the second most common cause of death and incapacity worldwide. Its pathogenesis and treatment have been the focus of considerable research. In traditional Chinese medicine, the root of Mongolian astragalus has been important in the treatment of stroke since ancient times. Astragalus polysaccharide (APS) is a key active ingredient of astragalus and offers therapeutic potential for conditions affecting the neurological system, the heart, cancer, and other disorders. However, it is not yet known how APS works to protect against ischemic stroke. METHODS: Rats were subjected to middle cerebral artery occlusion (MCAO) to imitate localized cerebral ischemia. Each of four experimental groups (normal, sham, MCAO, and MCAO+APS) contained 12 adult male Sprague-Dawley (SD) rats selected randomly from a total of 48 rats. Following successful establishment of the model, rats in the MCAO+APS group received intraperitoneal injection of APS (50 mg/kg) once daily for 14 days, whereas all other groups received no APS. The Bederson nerve function score and the forelimb placement test were used to detect motor and sensory function defects, while Nissl staining was used to investigate pathological defects in the ventroposterior thalamic nucleus (VPN). Immunohistochemical staining and Western blot were used to evaluate the expression of Neurogenic locus notch homolog protein 1 (Notch1), hairy and enhancer of split 1 (Hes1), phospho-nuclear factor-κB p65 (p-NFκB p65), and nuclear factor-κB p65 (NFκB p65) proteins in the VPN on the ischemic side of MCAO rats. RESULTS: APS promoted the recovery of sensory and motor function, enhanced neuronal morphology, increased the number of neurons, and inhibited the expression of Notch1/NFκB signaling pathway proteins in the VPN of rats with cerebral ischemia. CONCLUSION: After cerebral ischemia, APS can alleviate symptoms of secondary damage to the VPN, which may be attributed to the suppression of the Notch1/NFκB pathway.

GDNF facilitates the differentiation of ADSCs to Schwann cells and enhances nerve regeneration through GDNF/MTA1/Hes1 axis.

Adipose tissue-derived stem cells (ADSCs) are a kind of stem cells with multi-directional differentiation potential, which mainly restore tissue repair function and promote cell regeneration. It can be directionally differentiated into Schwann-like cells to promote the repair of peripheral nerve injury. Glial cell line-derived neurotrophic factor (GDNF) plays an important role in the repair of nerve injury, but the underlying mechanism remains unclear, which seriously limits its further application.The study aimed to identify the molecular mechanism by which overexpression of glial cell line-derived neurotrophic factor (GDNF) facilitates the differentiation of ADSCs into Schwann cells, enhancing nerve regeneration after injury. In vitro, ADSCs overexpressing GDNF for 48 h exhibited changes in their morphology, with 80% of the cells having two or more prominences. Compared with that of ADSCs, GDNF-ADSCs exhibited increased expression of the Schwann cell marker S100, nerve damage repair-related factors.ADSC cells in normal culture and ADSC cells were overexpressing GDNF(GDNF-ADSCs) were analysed using TMT-Based Proteomic Analysis and revealed a significantly higher expression of MTA1 in GDNF-ADSCs than in control ADSCs. Hes1 expression was significantly higher in GDNF-ADSCs than in ADSCs and decreased by MTA1 silencing, along with a simultaneous decrease in the expression of S100 and nerve damage repair factors. These findings indicate that GDNF promotes the differentiation of ADSCs into Schwann cells and induces factors that accelerate peripheral nerve damage repair.

bHLH transcription factors Hes1, Ascl1 and Oligo2 exhibit different expression patterns in the process of physiological electric fields-induced neuronal differentiation.

BACKGROUND: Recent studies have shown that the expression of bHLH transcription factors Hes1, Ascl1, and Oligo2 has an oscillating balance in neural stem cells (NSCs) to maintain their self-proliferation and multi-directional differentiation potential. This balance can be disrupted by exogenous stimulation. Our previous work has identified that electrical stimulation could induce neuronal differentiation of mouse NSCs. METHODS: To further evaluate if physiological electric fields (EFs)-induced neuronal differentiation is related to the expression patterns of bHLH transcription factors Hes1, Ascl1, and Oligo2, mouse embryonic brain NSCs were used to investigate the expression changes of Ascl1, Hes1 and Oligo2 in mRNA and protein levels during EF-induced neuronal differentiation. RESULTS: Our results showed that NSCs expressed high level of Hes1, while expression of Ascl1 and Oligo2 stayed at very low levels. When NSCs exited proliferation, the expression of Hes1 in differentiated cells began to decrease and oscillated at the low expression level. Oligo2 showed irregular changes in low expression level. EF-stimulation significantly increased the expression of Ascl1 at mRNA and protein levels accompanied by an increased percentage of neuronal differentiation. What's more, over-expression of Hes1 inhibited the neuronal differentiation induced by EFs. CONCLUSION: EF-stimulation directed neuronal differentiation of NSCs by promoting the continuous accumulation of Ascl1 expression and decreasing the expression of Hes1.

Endothelial cell flow-mediated quiescence is temporally regulated and utilizes the cell cycle inhibitor p27.

Background: Endothelial cells regulate their cell cycle as blood vessels remodel and transition to quiescence downstream of blood flow-induced mechanotransduction. Laminar blood flow leads to quiescence, but how flow-mediated quiescence is established and maintained is poorly understood. Methods: Primary human endothelial cells were exposed to laminar flow regimens and gene expression manipulations, and quiescence depth was analyzed via time to cell cycle re-entry after flow cessation. Mouse and zebrafish endothelial expression patterns were examined via scRNA seq analysis, and mutant or morphant fish lacking p27 were analyzed for endothelial cell cycle regulation and in vivo cellular behaviors. Results: Arterial flow-exposed endothelial cells had a distinct transcriptome, and they first entered a deep quiescence, then transitioned to shallow quiescence under homeostatic maintenance conditions. In contrast, venous-flow exposed endothelial cells entered deep quiescence early that did not change with homeostasis. The cell cycle inhibitor p27 (CDKN1B) was required to establish endothelial flow-mediated quiescence, and expression levels positively correlated with quiescence depth. p27 loss in vivo led to endothelial cell cycle upregulation and ectopic sprouting, consistent with loss of quiescence. HES1 and ID3, transcriptional repressors of p27 upregulated by arterial flow, were required for quiescence depth changes and the reduced p27 levels associated with shallow quiescence. Conclusions: Endothelial cell flow-mediated quiescence has unique properties and temporal regulation of quiescence depth that depends on the flow stimulus. These findings are consistent with a model whereby flow-mediated endothelial cell quiescence depth is temporally regulated downstream of p27 transcriptional regulation by HES1 and ID3. The findings are important in understanding endothelial cell quiescence mis-regulation that leads to vascular dysfunction and disease.

Effects of arctigenin on the proliferation, apoptosis, and invasion of oral squamous cell carcinoma HSC-3 cells by regulating the Notch/Hes-1 signaling pathway / 中国肿瘤生物治疗杂志

@#[摘 要] 目的：探究牛蒡子苷元（ARC）通过调控Notch/Hes-1信号通路对口腔鳞状细胞癌（OSCC）HSC-3细胞增殖、凋亡和侵袭的影响及其机制。方法：使用不同质量浓度的ARC处理人HSC-3细胞，CCK-8法检测ARC对细胞增殖活力的影响，以选择适宜的药物浓度。将HSC-3细胞分为对照组、ARC-L组（10 mg/L ARC）、ARC-M组（20 mg/L ARC）、ARC-H组（40 mg/L ARC）和ARC-H+Jagged1/FC组（40 mg/L ARC+1.2 μg/mL Jagged1/FC）。采用EdU法检测细胞增殖能力，划痕愈合实验、Transwell实验和流式细胞术分别检测细胞的迁移、侵袭能力及细胞周期和细胞凋亡率，WB法检测增殖（c-Myc、cyclin D1）、凋亡（BAX、Bcl-2、survivin）、EMT（E-cadherin、vimentin、Snail）及Notch/Hes-1通路（Notch 1、Hes-1、NICD）相关蛋白的表达水平。结果：与0 mg/L相比，10~80 mg/L的ARC均能显著降低HSC-3细胞增殖活力（均P<0.05）。与对照组相比，ARC-L组、ARC-M组和ARC-H组HSC-3细胞EdU阳性率、划痕愈合率、侵袭细胞数、S期和G2/M期细胞占比及c-Myc、cyclin D1、Bcl-2、survivin、vimentin、Snail、Notch 1、Hes-1和NICD蛋白表达均显著降低（均P<0.05），细胞凋亡率、G0/G1期细胞占比及BAX、E-cadherin的蛋白表达均显著升高（均P<0.05），且呈浓度梯度依赖性。同时使用Notch激动剂Jagged1/FC，则可部分逆转ARC对HSC-3细胞增殖、迁移、侵袭、凋亡及相关蛋白表达的作用（均P<0.05）。结论：ARC可能通过抑制Notch/Hes-1信号通路抑制OSCC细胞HSC-3增殖和侵袭并促进细胞凋亡。

NBP Cytoprotective Effects Promoting Neuronal Differentiation in BMSCs by Inhibiting the p65/Hes1 Pathway.

Background: Bone marrow-derived mesenchymal stem cell (BMSC) transplantation has become an effective method for treating neurodegenerative diseases. Objectives: This study investigated the effect of 3-N-butylphthalide (NBP) on the neuronal differentiation of BMSCs and its potential mechanism. Methods: In this study, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to detect cell proliferation and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining was conducted to detect the apoptosis of BMSCs. Quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot analysis were performed to detect the messenger RNA (mRNA) and protein expression levels, respectively. An enzyme-linked immunosorbent serologic assay assessed the levels of interleukin-1ß, tumor necrosis factor-α, and cyclic adenosine monophosphate (cAMP). Moreover, a flow cytometry assay was used to detect the proportion of active ß-tubulin III (TUJ-1) cells, and TUJ-1 expression was observed by immunofluorescence assay. Results: The results showed that a low concentration of NBP promoted the proliferation and induction of BMSC neuronal differentiation while inhibiting apoptosis, the production of inflammatory factors, and p65 expression. Compared with differentiation induction alone, combined NBP treatment increased the levels of nestin, neuron-specific enolase (NSE), TUJ-1, and microtubule-associated protein 2 (MAP2) protein, as well as the ratio of TUJ-1-positive cells and cAMP expression. Furthermore, p65 overexpression weakened the effect of NBP, and the overexpression of hairy and enhancer of split homolog-1 (HES1) reversed the effect of NBP in the induction of BMSC neuronal differentiation in vitro. Conclusions: We confirmed that NBP exhibited potential therapeutic properties in the stem cell transplantation treatment of neurodegenerative diseases by protecting cells and promoting BMSC neuronal differentiation by inhibiting the p65/HES 1 pathway.

[High homocysteine level promotes autophagy and apoptosis of mouse hippocampal HT22 cells through the Notch1/Hes1 signaling pathway].

OBJECTIVE: To explore the mechanism of neuronal injury caused by hyperhomocysteinemia. METHODS: Mouse hippocampal HT22 cells were treated with homocysteine (Hcy, 100 µmol/L), Hcy+folic acid+vitamin B12 (100+fv group) or folic acid+vitamin B12 (0+fv group), and the changes in cell autophagy and apoptosis were detected using transmission electron microscope (TEM) and flow cytometry. The expressions of Hes1, Hes5, Notch1, Jagged1, Bcl-2, Bax, P62 and LC3 in the treated cells were detected with Western blotting and real-time PCR. RESULTS: Treatment with Hcy for 48 h significantly increased the number of dead cells in HT22 cell cultures. Flow cytometry showed that the percentage of apoptotic cells was significantly higher in cells treated with Hcy alone than in other treatment groups (P<0.05). TEM revealed obvious mitochondrial swelling and vacuolation and increased autophagy in Hcy-treated cells. Western blotting showed that the Bax/Bcl-2 ratio was significantly higher in Hcy-treated cells than in the blank control cells and cells in 100+fv group (P<0.05). The Hcy-treated cells showed a significantly lower relative expression of P62 than the blank control cells (P<0.05), a higher LC3II/LC3I ratio than the cells in the blank control and 100+fv groups (P<0.05), and lower expressions of HES1, HES5, Notch1 and Jagged1 proteins than the blank control cells (P<0.05). Interference with Hes1 siRNA significantly lowered the expression levels of Hes1 and Jagged1 without obviously affecting Notch1 expression in HT22 cells (P>0.05). CONCLUSION: High Hcy levels promote autophagy and apoptosis and down-regulate Hes1 and Jagged1 expressions in HT22 cells.

Study on the mechanism of PM2.5 affecting Th1/Th2 immune imbalance through the notch signaling pathway in asthmatic mice.

Some research has shown that PM2.5 causes Th1/Th2 immune imbalance and aggravates asthma. However, the exact mechanism of PM2.5 causing aggravation of asthma remains unclear. The purpose of this study was to investigate whether exposure to PM2.5 exacerbates Th1/Th2 immune imbalance through the Notch signaling pathway. Eight-week-old SPF female BALF/c mice were sensitized by ovalbumin to establish an asthma mouse model. PM2.5 exposure was carried out by aerosol inhalation of PM2.5 (510 µg/m3) after each provocation. The lung function of mice was measured and Splenic T lymphocyte subsets were detected. Notch signaling pathway was tested. The levels of interferon (IFN)-γ and interleukin (IL)-4 in serum and bronchoalveolar lavage fluid were determined. The results showed that the expression of the mRNA and protein of Notch1 and Hes1 in the asthma group were significantly higher than those in healthy controls. The levels of IL-4 were also remarkably high; while the levels of IFN-γ were remarkably low in serum and BALF, the Th1% and Th1/Th2 ratios were significantly lower, and Th2% was significantly higher in the asthma group than in the healthy controls. PM2.5 promoted further activation of the Notch signaling pathway and aggravated Th1/Th2 immune imbalance in asthmatic mice. γ-secretase inhibitor can partially inhibit the activation of the Notch signaling pathway and alleviate aggravation of immune imbalance. In conclusion, the asthmatic mice had a Th1/Th2 immune imbalance and an overactivated Notch signaling pathway. PM2.5 further aggravated Th1/Th2 immune imbalance by activating the Notch signaling pathway.

The beneficial effects of l-carnitine and infliximab in methotrexate-induced hepatotoxicity: Emphasis on Notch1/Hes-1 signaling.

Methotrexate (MTX)-induced hepatotoxicity is a serious adverse effect that may limit its use. Therefore, eligible drugs to ameliorate MTX-induced hepatotoxicity are required. l-Carnitine (LC) is a natural molecule with beneficial metabolic effects and infliximab (INF) is an anti-inflammatory monoclonal antibody against tumor necrosis factor-alpha (TNF-α). Recently, Notch1/Hes-1 signaling was found to play a key role in the pathogenesis of liver injury. However, its role in MTX-induced hepatotoxicity is unclear. This study aimed to evaluate the modulatory effects of LC or INF on MTX-induced hepatotoxicity and to explore the underlying mechanism with emphasis on the Notch1/Hes-1 signaling pathway. Sixty rats were randomized into six groups (n = 10): (1) control (saline); (2) MTX (20 mg/kg MTX, intraperitoneal [ip], once); (3) LC group (500 mg/kg ip, 5 days); (4) INF (7 mg/kg INF ip, once); (5) MTX+LC (20 mg/kg ip, once, 500 mg/kg ip, 5 days, respectively); (6) MTX+INF (20 mg/kg ip, once, 7 mg/kg INF ip, once, respectively). Oxidative stress, inflammatory markers, and Notch1/Hes-1 were investigated. MTX induced the expression of Notch1 and Hes-1 proteins and increased the levels of TNF-α, interleukin (IL)-6, and IL-1ß in the liver. Cotreatment with LC or INF showed apparent antioxidant and anti-inflammatory effects. Interestingly, the downregulation of Notch1 and Hes-1 expression was more prominent in LC cotreatment as compared with INF. In conclusion, LC or INF attenuates MTX-induced hepatotoxicity through modulation of Notch1/Hes-1 signaling. The LC ameliorative effect against MTX-induced hepatotoxicity is significantly better than that of INF. Therefore, LC cotreatment may present a safe and therapeutically effective therapy in alleviating MTX-induced hepatotoxicity.

The Notch1/Hes1 signaling pathway affects autophagy by adjusting DNA methyltransferases expression in a valproic acid-induced autism spectrum disorder model.

As a pervasive neurodevelopmental disease, autism spectrum disorder (ASD) is caused by both hereditary and environmental elements. Research has demonstrated the functions of the Notch pathway and DNA methylation in the etiology of ASD. DNA methyltransferases DNMT3 and DNMT1 are responsible for methylation establishment and maintenance, respectively. In this study, we aimed to explore the association of DNA methyltransferases with the Notch pathway in ASD. Our results showed Notch1 and Hes1 were upregulated, while DNMT3A and DNMT3B were downregulated at the protein level in the prefrontal cortex (PFC), hippocampus (HC) and cerebellum (CB) of VPA-induced ASD rats compared with Control (Con) group. However, the protein levels of DNMT3A and DNMT3B were augmented after treatment with 3,5-difluorophenacetyl-L-alanyl-S-phenylglycine-2-butyl ester (DAPT), suggesting that abnormal Notch pathway activation may affect the expression of DNMT3A and DNMT3B. Besides, our previous findings revealed that the Notch pathway may participate in development of ASD by influencing autophagy. Therefore, we hypothesized the Notch pathway adjusts autophagy and contributes to ASD by affecting DNA methyltransferases. Our current results showed that after receiving the DNA methyltransferase inhibitor 5-Aza-2'-deoxycytidine (5-Aza-2'dc), the VPA + DAPT+5-Aza-2'dc (V + D + Aza) group exhibited reduced social interaction ability and increased stereotyped behaviors, and decreased expression of DNMT3A, DNMT3B and autophagy-related proteins, but did not show changes in Notch1 and Hes1 protein levels. Our results indicated that the Notch1/Hes1 pathway may adjust DNMT3A and DNMT3B expression and subsequently affect autophagy in the occurrence of ASD, providing new insight into the pathogenesis of ASD.

Early induction of Hes1 by bone morphogenetic protein 9 plays a regulatory role in osteoblastic differentiation of a mesenchymal stem cell line.

Bone morphogenic protein 9 (BMP9) is one of the most potent inducers of osteogenic differentiation among the 14 BMP members, but its mechanism of action has not been fully demonstrated. Hes1 is a transcriptional regulator with basic helix-loop-helix (bHLH) domain and is a well-known Notch effector. In this study, we investigated the functional roles of early induction of Hes1 by BMP9 in a mouse mesenchymal stem cell line, ST2. Hes1 mRNA was transiently and periodically induced by BMP9 in ST2, which was inhibited by BMP signal inhibitors but not by Notch inhibitor. Interestingly, Hes1 knockdown in ST2 by siRNA increased the expression of osteogenic differentiation markers such as Sp7 and Ibsp and matrix mineralization in comparison with control siRNA transfected ST2. In contrast, forced expression of Hes1 by using the Tet-On system suppressed the expression of osteogenic markers and matrix mineralization by BMP9. We also found that the early induction of Hes1 by BMP9 suppressed the expression of Alk1, an essential receptor for BMP9. In conclusion, BMP9 rapidly induces the expression of Hes1 via the SMAD pathway in ST2 cells, which plays a negative regulatory role in osteogenic differentiation of mesenchymal stem cells induced by BMP9.

Translocation of Oocytic HES1 into Surrounding Cumulus Cells in Bovine: Mechanism of Cellular Interaction during IVM?

HES1 (hairy and enhancer of split-1, effector of the NOTCH pathway) plays a role in oocyte maturation and has been detected so far mainly in somatic follicular cells. In this study, we aimed to investigate whether HES1 is present in both compartments of bovine cumulus oocyte complexes (COCs) and whether in vitro maturation itself has an effect on its distribution. We investigated the abundance of HES1 mRNA and protein in bovine COCs characterized by Brilliant-Cresyl-Blue (BCB) stainability by RT-PCR and immunofluorescence before and after in vitro maturation (IVM). To study the interaction of the compartments and the possible translocation of HES1, we injected GFP-HES1 mRNA into oocytes before maturation and analyzed fluorescence recovery after photobleaching (FRAP). The results showed that HES1 mRNA was detectable in oocytes but not in cumulus cells. The number of transcripts increased with maturation, especially in BCB-positive oocytes. In contrast, the protein was mainly visible in cumulus cells both before and after maturation. After GFP-HES1-mRNA injection into oocytes, a signal could be detected not only in the oocytes but also in cumulus cells. Our result shows a nearly exclusive distribution of HES1 mRNA and protein in oocytes and cumulus cells, respectively, that might be explained by the transfer of the protein from the oocyte into cumulus cells.

JAG-1/Notch signaling axis in the spinal cord contributes to bone cancer pain in rats.

Notch signal plays an important role in regulating cell-cell interactions with the adjacent cells. However, it remains unknown whether Jagged1 (JAG-1) mediated Notch signaling regulates bone cancer pain (BCP) via the spinal cell interactions mechanism. Here, we showed that intramedullary injection of Walker 256 breast cancer cells increased the expression of JAG-1 in spinal astrocytes and knockdown of JAG-1 reduced BCP. The supplementation of exogenous JAG-1 to the spinal cord induced BCP-like behavior and promoted expression of c-Fos and hairy and enhancer of split homolog-1 (Hes-1) in the spinal cord of the naïve rats. These effects were reversed when the rats were administered intrathecal injections of N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT). The intrathecal injection of DAPT reduced BCP and inhibited Hes-1 and c-Fos expression in the spinal cord. Furthermore, our results showed that JAG-1 up-regulated Hes-1 expression by inducing the recruitment of Notch intracellular domain (NICD) to the RBP-J/CSL-binding site located within the Hes-1 promoter sequence. Finally, the intrathecal injection of c-Fos-antisense oligonucleotides (c-Fos-ASO) and administration of sh-Hes-1 to the spinal dorsal horn also alleviated BCP. The study indicates that inhibition of the JAG-1/Notch signaling axis may be a potential strategy for the treatment of BCP.