Constitutive activation of a nuclear-localized calcium channel complex in Medicago truncatula.

Nuclear Ca2+ oscillations allow symbiosis signaling, facilitating plant recognition of beneficial microsymbionts, nitrogen-fixing rhizobia, and nutrient-capturing arbuscular mycorrhizal fungi. Two classes of channels, DMI1 and CNGC15, in a complex on the nuclear membrane, coordinate symbiotic Ca2+ oscillations. However, the mechanism of Ca2+ signature generation is unknown. Here, we demonstrate spontaneous activation of this channel complex, through gain-of-function mutations in DMI1, leading to spontaneous nuclear Ca2+ oscillations and spontaneous nodulation, in a CNGC15-dependent manner. The mutations destabilize a hydrogen-bond or salt-bridge network between two RCK domains, with the resultant structural changes, alongside DMI1 cation permeability, activating the channel complex. This channel complex was reconstituted in human HEK293T cell lines, with the resultant calcium influx enhanced by autoactivated DMI1 and CNGC15s. Our results demonstrate the mode of activation of this nuclear channel complex, show that DMI1 and CNGC15 are sufficient to create oscillatory Ca2+ signals, and provide insights into its native mode of induction.

Nicardipine-chitosan nanoparticles alleviate thioacetamide-induced acute liver injury by targeting NFκB/NLRP3/IL-1ß signaling in rats: Unraveling new roles beyond calcium channel blocking.

Liver inflammatory diseases are marked by serious complications. Notably, nicardipine (NCD) has demonstrated anti-inflammatory properties, but its benefits in liver inflammation have not been studied yet. However, the therapeutic efficacy of NCD is limited by its short half-life and low bioavailability. Therefore, we aimed to evaluate the potential of NCD-loaded chitosan nanoparticles (ChNPs) to improve its pharmacokinetic profile and hepatic accumulation. Four formulations of NCD-ChNPs were synthesized and characterized. The optimal formulation (NP2) exhibited a mean particle diameter of 172.6 ± 1.94 nm, a surface charge of +25.66 ± 0.93 mV, and an encapsulation efficiency of 88.86 ± 1.17 %. NP2 showed good physical stability as a lyophilized powder over three months. It displayed pH-sensitive release characteristics, releasing 77.15 ± 5.09 % of NCD at pH 6 (mimicking the inflammatory microenvironment) and 52.15 ± 3.65 % at pH 7.4, indicating targeted release in inflamed liver tissues. Pharmacokinetic and biodistribution studies revealed that NCD-ChNPs significantly prolonged NCD circulation time and enhanced its concentration in liver tissues compared to plain NCD. Additionally, the study investigated the protective effects of NCD-ChNPs in thioacetamide-induced liver injury in rats by modulating the NFκB/NLRP3/IL-1ß signaling axis. NCD-ChNPs effectively inhibited NFκB activation, reduced NLRP3 inflammasome activation, and subsequent release of IL-1ß, which correlated with improved hepatic function and reduced inflammation and oxidative stress. These findings highlight the potential of NCD-ChNPs as a promising nanomedicine strategy for the treatment of liver inflammatory diseases, warranting further investigation into their clinical applications, particularly in hypertensive patients with liver inflammatory conditions.

Hydroxytyrosol mitigates Mycoplasma gallisepticum-induced pulmonary injury through downregulation of the NF-κB/NLRP3/IL-1ß signaling pathway in chicken.

In this study, the anti-inflammatory and antiapoptotic effects of hydroxytyrosol (HT) in Mycoplasma gallisepticum (MG)-infected chicken were investigated, and the underlying molecular mechanisms were explored. The results revealed severe ultrastructural pathological changes after MG infection in the lung tissue of chicken, including inflammatory cell infiltration, thickening of the lung chamber wall, visible cell swelling, mitochondrial cristae rupture, and ribosome shedding. MG possibly activated the nuclear factor κB (NF-κB)/nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3)/interleukin (IL)-1ß signaling pathway in the lung. However, HT treatment significantly ameliorated MG-induced pathological damage of the lung. HT reduced the magnitude of pulmonary injury after MG infection by reducing apoptosis and releasing the proinflammatory factors. Compared with the MG-infected group, the HT-treated group exhibited significant inhibition of the expression of NF-κB/NLRP3/IL-1ß signaling-pathway-related genes; for example, the expressions of NF-κB, NLRP3, caspase-1, IL-1ß, IL-2, IL-6, IL-18, and TNF-α significantly decreased (P < 0.01 or <0.05). In conclusion, HT effectively inhibited MG-induced inflammatory response and apoptosis and protected the lung by blocking the activation of NF-κB/NLRP3/IL-1ß signaling pathway and reducing the damage caused by MG infection in chicken. This study revealed that HT may be a suitable and effective anti-inflammatory drug against MG infection in chicken.

Cellular and molecular basis of symbiotic nodule development.

Root nodule development plays a vital role in establishing the mutualistic relationship between legumes and nitrogen-fixing rhizobia. Two primary processes are involved in nodule development: formative cell divisions in the root cortex and the subsequent differentiation of nodule cells. The first process involves the mitotic reactivation of differentiated root cortex cells to form nodule primordium after perceiving symbiotic signals. The second process enables the nascent nodule primordium cells to develop into various cell types, leading to the creation of a functional nodule capable of supporting nitrogen fixation. Thus, both division and differentiation of nodule cells are crucial for root nodule development. This review provides an overview of the most recent advancements in comprehending the cellular and molecular mechanisms underlying symbiotic nodule development in legumes.

Chronic chromosome instability induced by Plk1 results in immune suppression in breast cancer.

Chromosome instability (CIN) contributes to resistance to therapies and tumor evolution. Although natural killer (NK) cells can eliminate cells with complex karyotypes, high-CIN human tumors have an immunosuppressive phenotype. To understand which CIN-associated molecular features alter immune recognition during tumor evolution, we overexpress Polo-like kinase 1 (Plk1) in a Her2+ breast cancer model. These high-CIN tumors activate a senescence-associated secretory phenotype (SASP), upregulate PD-L1 and CD206, and induce non-cell-autonomous nuclear factor κB (NF-κß) signaling, facilitating immune evasion. Single-cell RNA sequencing from pre-neoplastic mammary glands unveiled the presence of Arg1+ macrophages, NK cells with reduced effector functions, and increased resting regulatory T cell infiltration. We further show that high PLK1-expressing human breast tumors display gene expression patterns associated with SASP, NF-κß signaling, and immune suppression. These findings underscore the need to understand the immune landscape in CIN tumors to identify more effective therapies, potentially combining immune checkpoint or NF-κß inhibitors with current treatments.

Rhamnocitrin decreases fibrosis of ovarian granulosa cells by regulating the activation of the PPARγ/NF-κB/TGF-ß1/Smad2/3 signaling pathway mediated by Wisp2.

Background: Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility in women. Rhamnocitrin (Rha) has anti-inflammatory and antioxidant actions. The WNT1-inducible-signaling pathway protein 2 (Wisp2) and nuclear factor (NF)-κB are involved in fibrosis in many diseases. We aimed to elucidate the role of Rha in fibrosis of PCOS and the underlying mechanisms. Methods: Dehydroepiandrosterone (DHEA)-incubated ovarian granulosa KGN cells were treated by Rha. Cell proliferation was detected with cell counting kit-8 (CCK-8) and 5-ethynyul-2'-deoxyuridine (EdU) staining. The levels of Wisp2 and transforming growth factor-ß1 (TGF-ß1) in supernatant were measured by enzyme-linked immunosorbent assay (ELISA). We observed α-smooth muscle actin (α-SMA) protein by immunofluorescence (IF). The levels of fibrosis factors were determined using Western blot. We observed p65 nuclear translocation with confocal microscopy. We used Wisp2 overexpression and knockdown in cells treated with DHEA or Rha to validate Wisp2 function. Interaction between Wisp2 and NF-κB, as well as Wisp2 and PPARγ, were assessed by co-immunoprecipitation assay, luciferase reporter assay and chromatin immunoprecipitation (ChIP). Results: The results showed that Rha elevated the reduced proliferation of DHEA-treated cells. In addition, Rha reversed the decreased Wisp2 and the increased TGF-ß1 in supernatant. The proteins CTGF, α-SMA, Collagen I, TGF-ß1, p-Smad2, and p-Smad3 were up-regulated while Wisp2, Sirt1, and PPARγ were down-regulated by DHEA treatment, which were reversed by Rha. Meanwhile, DHEA up-regulated p-IKBa and p-p65 and promoted p65 nuclear translocation, which were inhibited by Rha. These effects of Rha were antagonized by Wisp2 knockdown and were mimicked by Wisp2 overexpression. We confirmed the protein interaction between Wisp2 and NF-κB, along with Wisp2 and PPARγ. Conclusions: Wisp2-mediated PPARγ/NF-κB/TGF-ß1/Smad2/3 signaling contributes to Rha-improved ovarian granulosa cells fibrosis, suggesting Rha as a novel agent for the treatment of PCOS.

MiRNA-223-3p Affects Mantle Cell Lymphoma Development by Regulating the CHUK/NF-ƘB2 Signaling Pathway.

BACKGROUND: Mantle cell lymphoma (MCL) is an aggressive malignancy that accounts for 5-10% of non-Hodgkin's lymphoma. MiRNA-223-3p has been demonstrated to be down-regulated in MCL and is a useful prognostic factor. However, little is known about underlying molecular mechanism of miRNA-233-3p in MCL. METHODS: The expression levels of miRNA-223-3p and CHUK mRNA in MCL cells were detected by real-time quantitative PCR (RT-qPCR). The effects of miRNA-223-3p/CHUK overexpression/knockdown on MCL cell proliferation and apoptosis were measured by CCK-8 assay and annexin V PE/7-AAD-based flow cytometry/TUNEL assay, respectively. A nude mouse subcutaneous xenograft model was used to further evaluate the potential effects in vivo. Dual-luciferase reporter assay was used to verify the inhibitory effect of miRNA-223-3p on CHUK. Furthermore, the regulatory function of miRNA-223-3p on the CHUK/NF-ƘB2 axis was assessed by RT-qPCR, western blot and immunofluorescence. RESULTS: In the present study, miRNA-223-3p overexpression inhibited proliferation and accelerated apoptosis of MCL cells in vitro and in vivo. The results of Luciferase reporter assay showed that CHUK was a direct target of miRNA-223-3p in HEK293T cells. Furthermore, the results of RT-qPCR, western blot confirmed that CHUK was targeted and negatively regulated by miRNA-223-3p for repressing NF-ƘB2 pathway activation in MCL cells. Importantly, CHUK overexpression promoted proliferation and suppressed apoptosis of MCL cells, whereas CHUK knockdown reversed down-regulated miRNA-223-3p -accelerated cell proliferation in vitro. CONCLUSION: In conclusion, miRNA-223-3p affects MCL development by regulating the CHUK/NF-ƘB2 signaling pathway, which is crucial to provide a novel therapeutic strategy.

BLIMP-1 Plays Important Role in the Regulation of Macrophage Pyroptosis for the Growth and Multiplication of Leishmania donovani.

Visceral leishmaniasis, one of the fatal forms of the disease, is caused by Leishmania donovani and presents morbid clinical manifestations. The parasite evades pro-inflammatory immune responses by several reported mechanisms and modulates the host immune system to cause fatal symptoms. A plethora of reports related to the role of BLIMP-1 and its involvement in suppressing the immune response in various infectious diseases have been documented. Higher parasitic burden due to increased BLIMP-1 production has been reported earlier for malaria and leishmaniasis with no detailed information. We report for the first time the role of BLIMP-1 in suppressing macrophage pyroptosis during L. donovani infection and thereby tweaking the tight regulation of the NFκß-NLRP3 signaling pathway. Expression analyses of BLIMP-1 and NFκß have been measured using real-time PCR and Western blotting. The importance of BLIMP-1 has been validated using a siRNA-mediated experiment along with caspase 1 activity, LDH release assay, and infectivity index analyses. An inverse relationship between BLIMP-1 and NFκß expression has been highlighted during L. donovani infection, which is reversed in blimp-1 deficient cells infected with promastigotes. The above fact has been further validated with caspase 1 activity assay, and LDH release along with IFNγ and TNF-α release assay. Finally, resumption of pyroptosis has been concluded in infected blimp-1 deficient cells in contrast to wild type infected cells. We conjecture that parasites modulate the NFκß-NLRP3 signaling pathway by taking advantage of BLIMP-1 dependent IL-10 production and finally disrupting an inflammation-mediated pyroptosis cell death pathway in infected cells.

NF-Kß Activation in U266 Cells on Mesenchymal Stem Cells.

Purpose: Mesenchymal Stem Cells (MSCs) are one of the essential members of Bone Marrow (BM) microenvironment and the cells affect normal and malignant cells in BM milieu. One of the most important hematological malignancies is Multiple Myeloma (MM). Numerous studies reported various effects of MSCs on myeloma cells. MSCs initiate various signaling pathways in myeloma cells, particularly NF-kß. NF-kß signaling pathway plays pivotal role in the survival, proliferation and resistance of myeloma cells to the anticancer drugs, therefore this pathway can be said to be a vital target for cancer therapy. This study examined the relationship between U266 cells and MSCs. Methods: U266 cells were cultured with Umbilical Cord Blood derived-MSCs (UCB-MSCs) and Conditioned Medium (C.M). Effect of UCB-MSCs and C.M on proliferation rate and CD54 expression of U266 cells were examined with MTT assay and Flowcytometry respectively. Furthermore, expression of CXCL1, PECAM-1, JUNB, CCL2, CD44, CCL4, IL-6, and IL-8 were analyzed by Real Time-PCR (RT-PCR). Moreover, status of p65 protein in NF-kß pathway assessed by western blotting. Results: Our findings confirm that UCB-MSCs support U266 cells proliferation and they increase CD54 expression. In addition, we demonstrate that UCB-MSCs alter the expression of CCL4, IL-6, IL-8, CXCL1 and the levels of phosphorylated p65 in U266 cells. Conclusion: Our study provides a novel sight to the role of MSCs in the activation of NF-kß signaling pathway. So, NF-kß signaling pathway will be targeted in future therapies against MM.

Melatonin prevents lung injury induced by hepatic ischemia-reperfusion through anti-inflammatory and anti-apoptosis effects.

Melatonin is a free radical scavenger and broad-spectrum antioxidant with immunomodulatory effects. The objective of the study is to investigate the effects of melatonin in hepatic ischemia/reperfusion (I/R) induced lung injury and explore its underlying mechanisms. Hepatic I/R injury was induced via portal vein and hepatic artery occlusion for 30min followed by 3-h reperfusion. Male Sprague-Dawley rats were divided into three groups: sham, I/R+ Vehicle and I/R+melatonin. Melatonin (10mg/kg) or vehicle was injected intravenously 15min before ischemia and 10min before reperfusion. The histology of the liver and lung, plasma aminotransferase and cytokine secretion, and apoptosis in the lung were evaluated. The phosphorylation of JNK, p38, and NF-ƙB and Nrf2 nuclear translocation in the lung was examined by Western blotting. We found that melatonin administration significantly attenuated hepatic I/R induced lung injury in rats. Melatonin inhibited the pro-inflammatory responses and enhanced antioxidative responses. Melatonin alleviated pathological changes of the lung and liver, and inhibited apoptosis of cells in the lung. Phosphorylation of JNK, p38 and NF-ƙB and Nrf2 nuclear translocation was increased significantly in the lung by hepatic I/R. Melatonin administration inhibited the activation of JNK, p38, and NF-ƙB, however, melatonin further enhanced Nrf2 activation. We conclude that melatonin exerts a protective effect in hepatic I/R induced lung injury by attenuating the pro-inflammatory responses, inhibiting cell apoptosis, which was mediated in part through JNK, p38 MAPK, NF-ƙB and Nrf2 signaling pathways. Melatonin may be a promising therapeutic strategy for hepatic I/R induced lung injury.