Verapamil modulates NFAT2 to inhibit tumor growth and potentiates PD1ab immune checkpoint inhibitor therapy in cervical cancer treatment.

PURPOSE: Current evidence suggests a high co-prevalence of hypertension and cervical cancer. Accordingly, blood pressure control is indicated during anti-tumor drug therapy in this patient population. Over the past few years, immunotherapy has made great strides in treating different cancers. However, the role and clinical significance of verapamil as a first-line anti-hypertensive drug during immunotherapy remain poorly understood, emphasizing the need for further studies. METHODS: Murine cervical cancer models were employed to assess the effect of verapamil monotherapy and combination with PD1ab. Immunohistochemistry was conducted to quantify the abundance of CD8+ T cell and Ki67+ cells. Several in-vitro and in-vivo assays were used to study the effects of verapamil and explore the preliminary mechanism. RESULTS: Monotherapy with verapamil or PD1ab immune checkpoint inhibitor significantly suppressed the growth of subcutaneously grafted U14 cells in WT BABL/c mice, respectively, with increased survival time of mice. Consistent results were observed in the melanoma model. Furthermore, we substantiated that verapamil significantly impaired tumor proliferation and migration of SiHa human cervical cancer cells in vitro and in vivo. In silico analysis using TCGA data revealed that NFAT2 expression negatively correlated with patient survival. The CCK8 assay revealed that verapamil abrogated the stimulatory effect of NFAT2 after knockdown of NFAT2. CONCLUSIONS: Our results suggest that verapamil inhibits tumor growth by modulating NFAT2 expression and enhancing tumor immune responses to PD1ab, which can be harnessed for cervical cancer therapy, especially for patients with comorbid hypertension. Indeed, further clinical trials are warranted to increase the robustness of our findings.

NFAT inhibitor 11R-VIVIT ameliorates mouse renal fibrosis after ischemia-reperfusion-induced acute kidney injury.

Acute kidney injury (AKI) with maladaptive tubular repair leads to renal fibrosis and progresses to chronic kidney disease (CKD). At present, there is no curative drug to interrupt AKI-to-CKD progression. The nuclear factor of the activated T cell (NFAT) family was initially identified as a transcription factor expressed in most immune cells and involved in the transcription of cytokine genes and other genes critical for the immune response. NFAT2 is also expressed in renal tubular epithelial cells (RTECs) and podocytes and plays an important regulatory role in the kidney. In this study, we investigated the renoprotective effect of 11R-VIVIT, a peptide inhibitor of NFAT, on renal fibrosis in the AKI-to-CKD transition and the underlying mechanisms. We first examined human renal biopsy tissues and found that the expression of NFAT2 was significantly increased in RTECs in patients with severe renal fibrosis. We then established a mouse model of AKI-to-CKD transition using bilateral ischemia-reperfusion injury (Bi-IRI). The mice were treated with 11R-VIVIT (5 mg/kg, i.p.) on Days 1, 3, 10, 17 and 24 after Bi-IRI. We showed that the expression of NFAT2 was markedly increased in RTECs in the AKI-to-CKD transition. 11R-VIVIT administration significantly inhibited the nuclear translocation of NFAT2 in RTECs, decreased the levels of serum creatinine and blood urea nitrogen, and attenuated renal tubulointerstitial fibrosis but had no toxic side effects on the heart and liver. In addition, we showed that 11R-VIVIT administration alleviated RTEC apoptosis after Bi-IRI. Consistently, preapplication of 11R-VIVIT (100 nM) and transfection with NFAT2-targeted siRNA markedly suppressed TGFß-induced HK-2 cell apoptosis in vitro. In conclusion, 11R-VIVIT administration inhibits IRI-induced NFAT2 activation and prevents AKI-to-CKD progression. Inhibiting NFAT2 may be a promising new therapeutic strategy for preventing renal fibrosis after IR-AKI.

Transient receptor potential canonical 6 knockdown ameliorated diabetic kidney disease by inhibiting nuclear factor of activated T cells 2 expression in glomerular mesangial cells.

PURPOSE: Glomerular mesangial cell (GMC) dysfunction plays a vital role in the pathogenesis of diabetic kidney disease (DKD). Transient receptor potential canonical 6 (TRPC6) has been demonstrated to be involved in the development of DKD. However, the underlying mechanism remains unclear. The present study investigated the role of TRPC6 in GMC dysfunction and the related mechanism. METHODS: Diabetic rats and cultured GMCs were used in the experiment. The diabetic rat model was created by intraperitoneal injection of streptozotocin. Protein and mRNA levels were assessed by Western blotting and quantitative RT-PCR, respectively. Histological changes in the kidneys were observed by immunochemistry and hematoxylin and eosin. TRPC6 knockdown was achieved by adenovirus-mediated TRPC6 shRNA delivery in vivo and TRPC6 siRNA transfection in vitro. RESULTS: TRPC6 expression was increased in diabetic rat kidneys. Knockdown of TRPC6 attenuated diabetes-induced kidney functional deterioration. In addition, the increases in extracellular matrix components, including collagen IV, collagen I, and fibronectin production, as well as NFAT2 expression were also suppressed. In cultured GMCs, high glucose (25 mM, HG) treatment increased the expression of TRPC6. Knockdown of TRPC6 alleviated HG-induced increases in collagen IV, fibronectin, and NFAT2 expression. Knockdown of NFAT2 also inhibited the upregulation of proteins, including collagen IV and fibronectin, in HG-treated GMCs. CONCLUSION: These results demonstrate that inhibition of TRPC6/NFAT2 signaling attenuates GMC dysfunction and the development of DKD and suggest that pharmacological targeting of TRPC6/NFAT2 in GMCs may provide beneficial effects for DKD.

Genetic loss of NFAT2 (NFATc1) impairs B cell development of B1 and B2 B cells.

NFAT2 activity was shown to be of critical importance in B cell receptor signaling, development and proliferation; however its role in B cell development in the periphery is still not completely understood. We confirmed that NFAT2 deletion leads to impaired B1 B cell development, supported by our finding of limited B1 progenitors in the bone marrow and spleen of NFAT2 deficient mice. Moreover, we show for the first time that loss of NFAT2 increases immature B cells in particular transitional T2 and T3 as well as mature follicular B cells while marginal zone B cells are decreased. We further demonstrate that NFAT2 regulates the expression of B220, CD23, CD38, IgM/IgD and ZAP70 in murine B cells. In vivo analyses revealed decreased proliferation and increased apoptosis of NFAT2 deficient B cells. In summary, this study provides an extensive analysis of the role of NFAT2 in peripheral B lymphocyte development.

NFAT2 overexpression suppresses the malignancy of hepatocellular carcinoma through inducing Egr2 expression.

BACKGROUND: Nuclear factor of activated T cells 2 (NFAT2) has been reported to regulate the development and malignancy of few tumors. In this study, we aimed to explore the effect of NFAT2 expression on cell fate of HepG2 cell and its potential mechanisms. METHODS: Firstly, the pcDNA3.1-NFAT2 plasmid was transfected into HepG2 cells to construct NFAT2 overexpressed HepG2 cells. Then, the chemical count kit-8 cell viability assay, Annexin V-FITC apoptosis detection, EdU labeling proliferation detection, transwell and wound healing experiments were performed. The expression of Egr2 and FasL, and the phosphorylation of AKT and ERK, after ionomycin and PMA co-stimulation, was detected, while the Ca2+ mobilization stimulated by K+ solution was determined. At last, the mRNA and protein expression of NFAT2, Egr2, FasL, COX-2 and c-myc in carcinoma and adjacent tissues was investigated. RESULTS: The NFAT2 overexpression suppressed the cell viability, invasion and migration capabilities, and promoted apoptosis of HepG2 cells. NFAT2 overexpression induced the expression of Egr2 and FasL and suppressed the phosphorylation of AKT and ERK. The sensitivity and Ca2+ mobilization of HepG2 cells was also inhibited by NFAT2 overexpression. Compared with adjacent tissues, the carcinoma tissues expressed less NFAT2, Egr2, FasL and more COX-2 and c-myc. CONCLUSION: The current study firstly suggested that NFAT2 suppressed the aggression and malignancy of HepG2 cells through inducing the expression of Egr2. The absence of NFAT2 and Egr2 in carcinoma tissues reminded us that NFAT2 may be a promising therapeutic target for hepatocellular carcinoma treatment.

Transcription factor Ets-2 regulates the expression of key lymphotropic factors.

Transcription factor Ets-2 downregulates the expression of cytokine genes and HIV-1 in resting T-cells. Herein, we studied whether Ets-2 regulates the expression of lymphotropic factors (LFs) NFAT2, NF-κΒ/p65, c-Jun, c-Fos, which regulate the activation/differentiation of T-cells, and kinase CDK10, which controls Ets-2 degradation and repression activity. In silico analysis revealed Ets-2 binding sites on the promoters of NFAT2, c-Jun, c-Fos. The T-cell lines Jurkat (models T-cell signaling/activation) and H938 (contains the HIV-1-LTR) were transfected with an Ets-2 overexpressing vector, in the presence/absence of mitogens. mRNA and protein levels were assessed by qPCR and Western immunoblotting, respectively. Ets-2 overexpression in unstimulated Jurkat increased NFAT2 and c-Jun mRNA/protein, c-Fos mRNA and NF-κΒ/p65 protein, and decreased CDK10 protein. In unstimulated H938, Ets-2 upregulated NFAT2, c-Jun and CDK10 mRNA/protein and NF-κΒ/p65 protein. In stimulated Jurkat, Ets-2 increased NFAT2, c-Jun and c-Fos mRNA/protein and decreased CDK10 mRNA/protein. In stimulated H938 Ets-2 increased NFAT2, c-Jun and c-Fos protein and reduced CDK10 protein levels. Furthermore, Ets-2 overexpression modulated the expression of pro- and anti-apoptotic genes in both cell lines. Ets-2 upregulates the expression of key LFs involved in the activation of cytokine genes or HIV-1 in T-cells, either through its physical interaction with gene promoters or through its involvement in signaling pathways that directly impact their expression. The effect of Ets-2 on CDK10 expression in H938 vs Jurkat cells dictates that, additionally to Ets-2 degradation, CDK10 may facilitate Ets-2 repression activity in cells carrying the HIV-1-LTR, contributing thus to the regulation of HIV latency in virus-infected T-cells.

High expression of NFAT2 contributes to carboplatin resistance in lung cancer.

Carboplatin is a platinum-based chemotherapy drug in lung cancer treatment. However, its efficacy is frequently limited by intrinsic and acquired drug resistance. Recently, nucleus factor of activated T cells, cytoplasmic 1 (NFAT2) has been recognized as an oncogene and involved in disease progression and drug resistance in various cancers. In the current study, we found that overexpression of NFAT2 was associated with poor prognosis in lung cancer patients, and is observed in a carboplatin resistant lung cancer cell line, indicative of its role in regulating drug response. We further showed that NFAT2 played a critical role in promoting cell proliferation and overcome carboplatin-induced DNA damage and cell cycle arrest. NFAT2 knockdown or inhibition of its nucleus translation via cyclosporine A largely restored the sensitivity to carboplatin in the resistant line by inducing DNA damage, blocking cell cycle progression and activating apoptotic cell death. We thus suggest that NFAT2 is a putative therapeutic target to overcome carboplatin resistance in lung cancers.

Human papillomavirus (HPV) oncoprotein E6 facilitates Calcineurin-Nuclear factor for activated T cells 2 (NFAT2) signaling to promote cellular proliferation in cervical cell carcinoma.

The calcineurin-NFAT signaling pathway regulates cell proliferation, differentiation, and development in diverse cell types and organ systems. Deregulation of calcineurin-NFAT signaling has been reported in leukaemias and few solid tumors such as breast and colon. In the present study, we found elevated calcineurin protein levels and phosphatase activity in cervical cancer cell lines and depletion of the same attenuated cell proliferation. Additionally, nuclear levels of NFAT2, a downstream target of calcineurin, viz, was found elevated in human papillomavirus (HPV) infected cells, HeLa and SiHa, compared to the HPV negative cells, HaCaT and C33A, indicative of its higher DNA binding activity. The nuclear levels of both NFAT1 and NFAT3 remain unaltered implicating they have little role in cervical carcinogenesis. Similar to the in vitro studies, the HPV infected human squamous cell carcinoma specimens showed higher NFAT2 levels compared to the normal cervical epithelium. Depletion of NFAT2 by RNAi attenuated growth of SiHa cells. Overexpression of HPV16 oncoproteins viz, E6 and E7 increased NFAT2 expression levels and DNA binding activity, while knockdown of E6 by RNAi decreased the same. Briefly, we now report an activation of calcineurin-NFAT2 axis in cervical cancer and a novel role of HPV oncoprotein in facilitating NFAT2 dependent cell proliferation.

AKAP150 involved in paclitaxel-induced neuropathic pain via inhibiting CN/NFAT2 pathway and downregulating IL-4.

Antitubulin chemotherapeutics agents, such as paclitaxel, are effective chemotherapy drugs for cancer treatment. However, painful neuropathy is a major adverse effect limiting the wider application of chemotherapeutics. In this study, we found that A-kinase anchor protein 150 (AKAP150) was significantly upregulated after paclitaxel injection. Inhibition of AKAP150 via siRNA or AKAP150flox/flox in rodents alleviated the pain behavior induced by paclitaxel, and partly restored the decreased calcineurin (CN) phosphatase activity after paclitaxel treatment. Paclitaxel decreased the expression of anti-inflammatory cytokine interleukin-4 (IL-4), and intrathecal injections of IL-4 effectively alleviated paclitaxel-induced hypersensitivity and the frequency of dorsal root ganglion (DRG) neurons action potential. The decreased CN enzyme activity, resulted in reduced protein expression of nuclear factor of activated T cells 2 (NFAT2) in cell nuclei. Chromatin immunoprecipitation showed that, NFAT2 binds to the IL-4 gene promoter regulating the protein expression of IL-4. Overexpression of NFAT2 by intrathecal injection of the AAV5-NFAT2-GFP virus alleviated the pain behavior induced by paclitaxel via increasing the expression of IL-4. Knocked down AKAP150 by siRNA or AAV5-Cre-GFP partly restored the expression of IL-4 in DRG. Our results indicated that regulation of IL-4 via the CN/NFAT2 pathway mediated by AKAP150 could be a pivotal treatment target for paclitaxel-induced neuropathic pain and or other neuropsychiatric disorders.

Chemerin neutralization blocks hematopoietic stem cell osteoclastogenesis.

Bone is a dynamic tissue that is continuously remodeled through the action of formative osteoblasts and resorptive osteoclasts. Chemerin is a secreted protein that activates chemokine-like receptor 1 (CMKLR1), a G protein-coupled receptor expressed by various cell types including adipocytes, osteoblasts, mesenchymal stem cells (MSCs), and macrophages. Previously, we identified chemerin as a regulator of adipocyte and osteoblast differentiation of MSCs. Herein we examined the role of chemerin in Lin(-) Sca1(+) c-kit(+) CD34(+) hematopoietic stem cell (HSC) osteoclastogenesis. We found that HSCs expressed both chemerin and CMKLR1 mRNA and secreted chemerin protein into the extracellular media. Neutralization of chemerin with a blocking antibody beginning prior to inducing osteoclast differentiation resulted in a near complete loss of osteoclastogenesis as evidenced by reduced marker gene expression and matrix resorption. This effect was conserved in an independent model of RAW264.7 cell osteoclastogenesis. Reintroduction of chemerin by reversal of neutralization rescued osteoclast differentiation indicating that chemerin signaling is essential to permit HSC differentiation into osteoclasts but following blockade the cells maintained the potential to differentiate into osteoclasts. Mechanistically, neutralization of chemerin blunted the early receptor activator of nuclear factor-kappa B ligand induction of nuclear factor of activated T-cells 2 (NFAT2), Fos, Itgb3, and Src associated with preosteoclast formation. Consistent with a central role for NFAT2, induction or activation of NFAT2 by forced expression or stimulation of intracellular calcium release rescued the impairment of HSC osteoclastogenesis caused by chemerin neutralization. Taken together, these data support a novel autocrine/paracrine role for chemerin in regulating osteoclast differentiation of HSCs through modulating intracellular calcium and NFAT2 expression/activation.

Tanshinone IIA induces ER stress and JNK activation to inhibit tumor growth and enhance anti-PD-1 immunotherapy in non-small cell lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) remains at the forefront of new cancer cases, and there is an urgent need to find new treatments or improve the efficacy of existing therapies. In addition to the application in the field of cerebrovascular diseases, recent studies have revealed that tanshinone IIA (Tan IIA) has anticancer activity in a variety of cancers. PURPOSE: To investigate the potential anticancer mechanism of Tan IIA and its impact on immunotherapy in NSCLC. METHODS: Cytotoxicity and colony formation assays were used to detect the Tan IIA inhibitory effect on NSCLC cells. This research clarified the mechanisms of Tan IIA in anti-tumor and programmed death-ligand 1 (PD-L1) regulation by using flow cytometry, transient transfection, western blotting and immunohistochemistry (IHC) methods. Besides, IHC was also used to analyze the nuclear factor of activated T cells 1 (NFAT2) expression in NSCLC clinical samples. Two animal models including xenograft mouse model and Lewis lung cancer model were used for evaluating tumor suppressive efficacy of Tan IIA. We also tested the efficacy of Tan IIA combined with programmed cell death protein 1 (PD-1) inhibitors in Lewis lung cancer model. RESULTS: Tan IIA exhibited good NSCLC inhibitory effect which was accompanied by endoplasmic reticulum (ER) stress response and increasing Ca2+ levels. Moreover, Tan IIA could suppress the NFAT2/ Myc proto oncogene protein (c-Myc) signaling, and it also was able to control the Jun Proto-Oncogene(c-Jun)/PD-L1 axis in NSCLC cells through the c-Jun N-terminal kinase (JNK) pathway. High NFAT2 levels were potential factors for poor prognosis in NSCLC patients. Finally, animal experiments data showed a stronger immune activation phenotype, when we performed treatment of Tan IIA combined with PD-1 monoclonal antibody. CONCLUSION: The findings of our research suggested a novel mechanism for Tan IIA to inhibit NSCLC, which could exert anti-cancer effects through the JNK/NFAT2/c-Myc pathway. Furthermore, Tan IIA could regulate tumor PD-L1 levels and has the potential to improve the efficacy of PD-1 inhibitors.

Fluid shear force and hydrostatic pressure jointly promote osteogenic differentiation of BMSCs by activating YAP1 and NFAT2.

Natural bone tissue features a complex mechanical environment, with cells responding to diverse mechanical stimuli, including fluid shear stress (FSS) and hydrostatic pressure (HP). However, current in vitro experiments commonly employ a singular mechanical stimulus to simulate the mechanical environment in vivo. The understanding of the combined effects and mechanisms of multiple mechanical stimuli remains limited. Hence, this study constructed a mechanical stimulation device capable of simultaneously applying FSS and HP to cells. This study investigated the impact of FSS and HP on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and examined the distinctions and interactions between the two mechanisms. The results demonstrated that both FSS and HP individually enhanced the osteogenic differentiation of BMSCs, with a more pronounced effect observed through their combined application. BMSCs responded to external FSS and HP stimulation through the integrin-cytoskeleton and Piezo1 ion channel respectively. This led to the activation of downstream biochemical signals, resulting in the dephosphorylation and nuclear translocation of the intracellular transcription factors Yes Associated Protein 1 (YAP1) and nuclear factor of activated T cells 2 (NFAT2). Activated YAP1 could bind to NFAT2 to enhance transcriptional activity, thereby promoting osteogenic differentiation of BMSCs more effectively. This study highlights the significance of composite mechanical stimulation in BMSCs' osteogenic differentiation, offering guidance for establishing a complex mechanical environment for in vitro functional bone tissue construction.

Suppression of T-cell activation in vitro and in vivo by cordycepin from Cordyceps militaris.

BACKGROUND: In addition to achieving a balance between the positive (controlling rejection) and the negative (infection and malignancy) aspects of drug-induced immunodeficiency, new immunosuppressive combinations must address the issue of nonimmune drug toxicity that may be dose limiting. Cordycepin is a type of adenosine analog extracted from Cordyceps militaris. In the present study, we investigated its immunosuppressive effect on T cell both in vitro and in vivo. METHODS: We evaluated the effects of cordycepin on concanavalin A-induced production of immune mediators in mouse splenocyte by enzyme-linked immunosorbent assay and flow cytometry. Furthermore, using Western blotting, we studied signal transduction mechanisms to determine how cordycepin inhibited T-cell activation in purified mouse T lymphocytes. To confirm the immunosuppressive activity of cordycepin in vivo, we induced the T cell-mediated delayed-type hypersensitivity reaction in a 2,4-dinitro-1-fluorobenzene-induced mouse model. RESULTS: The in vitro results showed that cordycepin markedly suppressed concanavalin A-induced splenocyte proliferation, Th1 and Th2 cytokine production, and the ratio of CD4(+)-to-CD8(+) T cells. The administration of cordycepin in vivo markedly suppressed the T cell-mediated delayed-type hypersensitivity reaction. The data revealed that cordycepin effectively shocked the nuclear factor kappa B and nuclear factor of activated T cells 2 signal transduction pathways but had no effect on the mitogen activated protein kinase signal transduction pathway. CONCLUSIONS: These observations indicated that cordycepin has a potential role in downregulating the immune system and could be developed as a useful immunosuppressive agent for treating undesired immune responses.

Mitochondrial calcium signaling mediated transcriptional regulation of keratin filaments is a critical determinant of melanogenesis.

Mitochondria are versatile organelles that regulate several physiological functions. Many mitochondria-controlled processes are driven by mitochondrial Ca2+ signaling. However, role of mitochondrial Ca2+ signaling in melanosome biology remains unknown. Here, we show that pigmentation requires mitochondrial Ca2+ uptake. In vitro gain and loss of function studies demonstrated that Mitochondrial Ca2+ Uniporter (MCU) is crucial for melanogenesis while the MCU rheostats, MCUb and MICU1 negatively control melanogenesis. Zebrafish and mouse models showed that MCU plays a vital role in pigmentation in vivo. Mechanistically, MCU controls activation of transcription factor NFAT2 to induce expression of three keratins (keratin 5, 7 and 8), which we report as positive regulators of melanogenesis. Interestingly, keratin 5 in turn modulates mitochondrial Ca2+ uptake thereby this signaling module acts as a negative feedback loop that fine-tunes both mitochondrial Ca2+ signaling and melanogenesis. Mitoxantrone, an FDA approved drug that inhibits MCU, decreases physiological melanogenesis. Collectively, our data demonstrates a critical role for mitochondrial Ca2+ signaling in vertebrate pigmentation and reveal the therapeutic potential of targeting MCU for clinical management of pigmentary disorders. Given the centrality of mitochondrial Ca2+ signaling and keratin filaments in cellular physiology, this feedback loop may be functional in a variety of other pathophysiological conditions.

miR-125b-5p alleviates the damage of myocardial infarction by inhibiting the NFAT2 to reduce F2RL2 expression.

Aim: To explore the effect of miR-125b-5p/nuclear factor of activated T cells 1 (NFAT2)/F2RL2 on myocardial infarction (MI). Method: After establishment of MI mouse model and oxygen glucose deprivation (OGD)-induced cell model, the effects of NFAT2 on the process of MI were observed, the effects of miR-125b-5p/NFAT2/F2RL2 on the cell viability, apoptosis, and inflammatory factors levels were determined. Result: NFAT2 silencing relieved MI and inhibited the inflammation in MI model mice. In OGD-induced human coronary artery endothelial cells and human cardiac microvascular endothelial cells, miR-125b-5p enhanced cell viability, yet repressed cell apoptosis and inflammatory factors and NFAT2 levels. NFAT2 overexpression reversed the effects of miR-125b-5p, while F2RL2 silencing offset the effects of NFAT2 overexpression. Conclusion: MiR-125b-5p alleviates MI injury by inhibiting NFAT2 level to reduce F2RL2 expression.

This research proves that miR-125b-5p reduces the level of F2RL2 by preventing the activation of NFAT2 pathway, thereby reducing cardiogenic vascular endothelial cell damage and inflammation (heat, swelling and redness). This may provide a new treatment for heart attacks.

HIV-1 Transcriptional Activator Tat Inhibits IL2 Expression by Preventing the Presence of Pol II on the IL2 Promoter.

HIV-1 infection leads to a gradual loss of T helper cells, chronic immune activation, and eventual immune system breakdown. HIV-1 causes deregulation of the expression of IL-2, a cytokine important for T helper cell growth and survival, which is downregulated in HIV-1 patients. The present study addresses the regulation of IL2 expression via HIV-1 Tat transcriptional activator. We used J-LAT cells, a T cell line that serves as a latency model for studies of HIV-1 expression in T cells, and as controls a T cell line lacking HIV-1 elements and a T cell line with a stably integrated copy of the HIV-1-LTR promoter. We show that endogenously expressed Tat inhibits IL2 transcription in J-Lat cells via its presence in the ARRE-1/2 elements of the IL2 promoter and that the inhibition of IL2 expression is mediated by Tat inhibiting Pol II activity at the IL2 promoter, which is mediated by preventing the presence of Pol II at the ARRE-1/2 elements. Overall, Tat is present at the IL2 promoter, apart from its cognate HIV-1 LTR target. This supports our current knowledge of how HIV-1 affects the host transcriptional machinery and reflects the potential of Tat to disrupt transcriptional regulation of host genes to manipulate cell responses.

Ginsenoside Rg1 attenuates glomerular fibrosis by inhibiting CD36/TRPC6/NFAT2 signaling in type 2 diabetes mellitus mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginsenoside Rg1 (Rg1) is one of the main active components in Panax ginseng C. A. Meyer (ginseng), which has been widely used to delay senescence or improve health conditions for more than 2000 years. Increasing studies have revealed that Rg1 could regulate cell proliferation and differentiation, as well as anti-inflammatory and anti-apoptotic effects, and might have protective effects on many chronic kidney diseases. AIM OF THE STUDY: Diabetic nephropathy (DN) is one of the most dangerous microvascular complications of diabetes and is the leading cause of end-stage renal disease worldwide. However, the role and mechanism of Rg1 against high-glucose and high-fat-induced glomerular fibrosis in DN are not clear. This study aimed to investigate the protective effect of Rg1 on DN and its possible mechanism. MATERIALS AND METHODS: The type 2 diabetes mellitus (T2DM) mice models were established with a high-fat diet (HFD) combined with an intraperitoneal injection of streptozotocin (STZ). Urine protein and serum biochemical indexes were detected by corresponding kits. The kidney was stained with H&E, PAS, and Masson to observe the pathological morphology, glycogen deposition, and fibrosis. The expression of CD36 and p-PLC in the kidney cortex was detected by IHC. The expressions of FN and COL4 were detected by IF. Western blot and PCR were performed to examine protein and mRNA expressions of kidney fibrosis and TRPC6/NFAT2-related pathways in DN mice. Calcium imaging was used to examine the effect of Rg1 on [Ca2+]i in PA + HG-induced human mesangial cells (HMCs). Visualization of the interaction between Rg1 and CD36 was detected by molecular docking. RESULTS: Rg1 treatment for 8 weeks could prominently decrease urinary protein, serum creatinine, and urea nitrogen and downgrade blood lipid levels and renal lipid accumulation in T2DM mice. The pathological results indicated that Rg1 treatment attenuated renal pathological injury and glomerular fibrosis. The further results demonstrated that Rg1 treatment remarkably decreased the expressions of CD36, TRPC6, p-PLC, CN, NFAT2, TGF-ß, p-Smad2/3, COL4, and FN in renal tissues from T2DM mice. Calcium imaging results found that Rg1 downgraded the base levels of [Ca2+]i and ΔRatioF340/F380 after BAPTA and CaCl2 treatment. Molecular docking results showed that Rg1 could interact with CD36 with a good affinity. CONCLUSION: These results revealed that Rg1 could ameliorate renal lipid accumulation, pathological damage, and glomerular fibrosis in T2DM mice. The mechanism may be involved in reducing the overexpression of CD36 and inhibiting the TRPC6/NFAT2 signaling pathway in renal tissues of T2DM mice.

Small-molecule screening identifies Syk kinase inhibition and rutaecarpine as modulators of macrophage training and SARS-CoV-2 infection.

Biologically active small molecules can impart modulatory effects, in some cases providing extended long-term memory. In a screen of biologically active small molecules for regulators of tumor necrosis factor (TNF) induction, we identify several compounds with the ability to induce training effects on human macrophages. Rutaecarpine shows acute and long-term modulation, enhancing lipopolysaccharide (LPS)-induced pro-inflammatory cytokine secretion and relieving LPS tolerance in human macrophages. Rutaecarpine inhibits ß-glucan-induced H3K4Me3 marks at the promoters of several pro-inflammatory cytokines, highlighting the potential of this molecule to modulate chromosomal topology. Syk kinase inhibitor (SYKi IV), another screen hit, promotes an enhanced response to LPS similar to that previously reported for ß-glucan-induced training. Macrophages trained with SYKi IV show a high degree of resistance to influenza A, multiple variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and OC43 coronavirus infection, highlighting a potential application of this molecule and other SYKis as prophylactic treatments for viral susceptibility.

Transient receptor potential ankyrin 1 mediates cisplatin-induced apoptosis in renal tubular cells via calcium-dependent signaling pathway.

BACKGROUND: Cisplatin has been a vital drug used for tumor treatment because of its excellent effect on numerous malignant solid cancers. Nonetheless, its nephrotoxicity is non-negligible in clinical practice. This study aims to provide a new understanding of the molecular mechanism of transient receptor potential ankyrin 1 (TRPA1) in cisplatin-induced renal apoptosis. METHODS: We evaluated the effect on apoptosis, TRPA1 expression, and intracellular calcium concentration of human kidney 2 (HK-2) cells induced by diamminedichloroplatinum (DDP). Additionally, we also assessed DDP-induced apoptosis, the expression of Bax, caspase3, cleaved-cas3, p53, Bcl-2 and intracellular calcium concentration combined with HC-030031 and/or pifithrin-α. The effect of FK506 on apoptosis of HK-2 cells induced by DDP and the expression of the nuclear factor of activated T cells (NFAT) protein treated with HC-030031, pifithrin-α, and/or FK506 were also explored. RESULTS: The results showed that apoptosis, TRPA1 expression, and intracellular calcium concentration of HK-2 cell induced by DDP were enhanced in a dose-dependent manner. HC-030031 and pifithrin-α relieved apoptosis, and intracellular calcium concentration and the expression of NFAT and phospho-NFAT (p-NFAT) were induced by DDP. HC-030031 combined with pifithrin-α further aggravated the above-mentioned tendency, including relieved apoptosis, intracellular calcium concentration, and NFAT and p-NFAT expression. HC-030031 and FK506 decelerated the apoptosis, and NFAT and p-NFAT expression of HK-2 cells was induced by DDP, while simultaneous treatment with HC-030031 and FK506 further decreased apoptosis and protein expression. However, the expression of Bcl-2 increased when HC-030031, pifithrin-α, or FK506 was used alone, and HC-030031 combined with pifithrin-α or FK506 further improved the expression of Bcl-2. CONCLUSIONS: TRPA1 mediates cisplatin-induced apoptosis in renal tubular cells via the calcineurin-nuclear factor of activated T-cells-p53 signaling pathway.

The role of NFAT2/miR-20a-5p signaling pathway in the regulation of CD8+ naïve T cells activation and differentiation.

T cell dysfunction is a common characteristic in leukemia patients that significantly impacts clinical treatment and prognosis. However, the mechanism underlying T cell dysfunction and its reversal remains unclear. In this study, in accordance with our previous findings, we found that the expression of NFAT2 and pri-miR-17 ~ 92 are lower in peripheral blood CD3+ T cells from chronic myelogenous leukemia (CML) patients by gene expression analysis. We further demonstrate that the NFAT2-induced activation, differentiation, and expression of cytokines in human umbilical cord blood CD8+ naïve T cells are miR-20a-5p dependent. We also preliminarily explored the relationship between NFAT2 and miR-20a-5p in naive T cells. These results suggest that NFAT2 and miR-20a are crucial for regulating functional CD8+ T cells. Additionally, their alteration may be related to CD8+ T cell dysfunction in CML patients; thus, NFAT2 and miR-20a-5p may be considered potential targets for revising T cell function in leukemia immunotherapy.