KDM3A Senses Oxygen Availability to Regulate PGC-1α-Mediated Mitochondrial Biogenesis.

Hypoxia, which occurs during tumor growth, triggers complex adaptive responses in which peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) plays a critical role in mitochondrial biogenesis and oxidative metabolism. However, how PGC-1α is regulated in response to oxygen availability remains unclear. We demonstrated that lysine demethylase 3A (KDM3A) binds to PGC-1α and demethylates monomethylated lysine (K) 224 of PGC-1α under normoxic conditions. Hypoxic stimulation inhibits KDM3A, which has a high KM of oxygen for its activity, and enhances PGC-1α K224 monomethylation. This modification decreases PGC-1α's activity required for NRF1- and NRF2-dependent transcriptional regulation of TFAM, TFB1M, and TFB2M, resulting in reduced mitochondrial biogenesis. Expression of PGC-1α K224R mutant significantly increases mitochondrial biogenesis, reactive oxygen species (ROS) production, and tumor cell apoptosis under hypoxia and inhibits brain tumor growth in mice. This study revealed that PGC-1α monomethylation, which is dependent on oxygen availability-regulated KDM3A, plays a critical role in the regulation of mitochondrial biogenesis.

Regulation of endogenous hormone and miRNA in leaves of alfalfa (Medicago sativa L.) seedlings under drought stress by endogenous nitric oxide.

BACKGROUND: Alfalfa (Medicago sativa. L) is one of the best leguminous herbage in China and even in the world, with high nutritional and ecological value. However, one of the drawbacks of alfalfa is its sensitivity to dry conditions, which is a global agricultural problem. The objective of this study was to investigate the regulatory effects of endogenous nitric oxide (NO) on endogenous hormones and related miRNAs in alfalfa seedling leaves under drought stress. The effects of endogenous NO on endogenous hormones such as ABA, GA3, SA, and IAA in alfalfa leaves under drought stress were studied. In addition, high-throughput sequencing technology was used to identify drought-related miRNAs and endogenous NO-responsive miRNAs in alfalfa seedling leaves under drought stress. RESULT: By measuring the contents of four endogenous hormones in alfalfa leaves, it was found that endogenous NO could regulate plant growth and stress resistance by inducing the metabolism levels of IAA, ABA, GA3, and SA in alfalfa, especially ABA and SA in alfalfa. In addition, small RNA sequencing technology and bioinformatics methods were used to analyze endogenous NO-responsive miRNAs under drought stress. It was found that most miRNAs were enriched in biological pathways and molecular functions related to hormones (ABA, ETH, and JA), phenylpropane metabolism, and plant stress tolerance. CONCLUSION: In this study, the analysis of endogenous hormone signals and miRNAs in alfalfa leaves under PEG and PEG + cPTIO conditions provided an important basis for endogenous NO to improve the drought resistance of alfalfa at the physiological and molecular levels. It has important scientific value and practical significance for endogenous NO to improve plant drought resistance.

Dehydrocostus lactone (DHC) promotes osteoblastic differentiation and mineralization through p38/RUNX-2 signaling.

Dysregulation of osteoblastic differentiation is an important risk factor of osteoporosis, the therapy of which is challenging. Dehydrocostus lactone (DHC), a sesquiterpene isolated from medicinal plants, has displayed anti-inflammatory and antitumor properties. In this study, we investigated the effects of DHC on osteoblastic differentiation and mineralization of MC3T3-E1 cells. Interestingly, we found that DHC increased the expression of marker genes of osteoblastic differentiation, such as alkaline phosphatase (ALP), osteocalcin (OCN), and osteopontin (OPN). Additionally, DHC increased the expressions of collagen type I alpha 1 (Col1a1) and collagen type I alpha 2 (Col1a2). We also demonstrate that DHC increased ALP activity. Importantly, the Alizarin Red S staining assay revealed that DHC enhanced osteoblastic differentiation of MC3T3-E1 cells. Mechanistically, it is shown that DHC increased the expression of Runx-2, a central regulator of osteoblastic differentiation. Treatment with DHC also increased the levels of phosphorylated p38, and its blockage using its specific inhibitor SB203580 abolished the effects of DHC on runt-related transcription factor 2 (Runx-2) expression and osteoblastic differentiation, suggesting the involvement of p38. Based on these findings, we concluded that DHC might possess a capacity for the treatment of osteoporosis by promoting osteoblastic differentiation.

Titanium-Oxygen Clusters Brazing Li with Li6.5La3Zr1.5Ta0.5O12 for High-Performance All-Solid-State Li Batteries.

Garnet-based solid-state electrolytes are considered crucial candidates for solid-state Li batteries due to their high Li+ conductivity and nonflammability; however, poor interfacial contact with the Li anode and growth of Li dendrites limit their application. Herein, a high-activity titanium-oxygen cluster is used as a brazing filler to braze the Li6.5La3Zr1.5Ta0.5O12 (LLZTO) with an Li anode into the whole unit. The brazing layer leads to a significantly lower interfacial impedance of 8.32 Ω cm2. Furthermore, the brazing layer is an isotropic amorphous ion-electron hybrid conductive layer, which significantly promotes Li+ transport and regulates the distribution of the electric field, therefore inhibiting the growth of Li dendrites. The cell exhibits an ultrahigh critical current density of 2.3 mA cm-2 and stable cycling of over 4000 h at 0.5 mA cm-2 (25 °C).

Carbon and nitrogen metabolism affects kentucky bluegrass rhizome expansion.

BACKGROUND: Rhizome is vital for carbon and nitrogen metabolism of the whole plant. However, the effect of carbon and nitrogen in the rhizome on rhizome expansion remains unclear. RESULTS: Three wild Kentucky bluegrass (Poa pratensis L.) germplasms with different rhizome expansion capacity (strong expansion capacity, 'YZ'; medium expansion capacity, 'WY'; and weak expansion capacity, 'AD') were planted in the field and the rhizomes number, tiller number, rhizome dry weight, physiological indicators and enzyme activity associated carbon and nitrogen metabolisms were measured. Liquid chromatography coupled to mass spectrometry (LC-MS) was utilized to analyze the metabolomic of the rhizomes. The results showed that the rhizome and tiller numbers of the YZ were 3.26 and 2.69-fold of that of the AD, respectively. The aboveground dry weight of the YZ was the greatest among all three germplasms. Contents of soluble sugar, starch, sucrose, NO3--N, and free amino acid were significantly higher in rhizomes of the YZ than those of the WY and AD (P < 0.05). The activities of glutamine synthetase (GS), glutamate dehydrogenase (GDH) and sucrose phosphate synthase (SPS) of the YZ were the highest among all three germplasm, with values of 17.73 A·g- 1 h- 1, 5.96 µmol·g- 1 min- 1, and 11.35 mg·g- 1 h- 1, respectively. Metabolomics analyses revealed that a total of 28 differentially expressed metabolites (DEMs) were up-regulated, and 25 DEMs were down-regulated in both comparison groups (AD vs. YZ group and WY vs. YZ group). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis demonstrated that metabolites related to histidine metabolism, tyrosine metabolism, tryptophan metabolism, and phenylalanine metabolism were associated with rhizomes carbon and nitrogen metabolism. CONCLUSIONS: Overall, the results suggest that soluble sugar, starch, sucrose, NO3--N, and free amino acid in rhizome are important to and promote rhizome expansion in Kentucky bluegrass, while tryptamine, 3-methylhistidine, 3-indoleacetonitrile, indole, and histamine may be key metabolites in promoting carbon and nitrogen metabolism of rhizome.

Exo-miR-1290-induced by COX-2 overexpression promotes cancer-associated fibroblasts activation and tumor progression by CUL3-Nrf2 pathway in lung adenocarcinoma.

BACKGROUND: Cancer-associated fibroblasts (CAFs) are critically involved in tumor progression by maintaining extracellular mesenchyma (ECM) production and improving tumor development. Cyclooxygenase-2 (COX-2) has been proved to promote ECM formation and tumor progression. However, the mechanisms of COX-2 mediated CAFs activation have not yet been elucidated. Therefore, we conducted this study to identify the effects and mechanisms of COX-2 underlying CAFs activation by tumor-derived exosomal miRNAs in lung adenocarcinoma (LUAD) progression. METHODS: As measures of CAFs activation, the expressions of fibroblasts activated protein-1 (FAP-1) and α-smooth muscle actin (α-SMA), the main CAFs markers, were detected by Western blotting and Immunohistochemistry. And the expression of Fibronectin (FN1) was used to analyze ECM production by CAFs. The exosomes were extracted by ultracentrifugation and exo-miRNAs were detected by qRT-PCR. Herein, we further elucidated the implicated mechanisms using online prediction software, luciferase reporter assays, co-immunoprecipitation, and experimental animal models. RESULTS: In vivo, a positive correlation was observed between the COX-2 expression levels in parenchyma and α-SMA/FN1 expression levels in mesenchyma in LUAD. However, PGE2, one of major product of COX-2, did not affect CAFs activation directly. COX-2 overexpression increased exo-miR-1290 expression, which promoted CAFs activation. Furthermore, Cullin3 (CUL3), a potential target of miR-1290, was found to suppress COX-2/exo-miR-1290-mediated CAFs activation and ECM production, consequently impeding tumor progression. CUL3 is identified to induce the Nuclear Factor Erythroid 2-Related Factor 2 (NFE2L2, Nrf2) ubiquitination and degradation, while exo-miR-1290 can prevent Nrf2 ubiquitination and increase its protein stability by targeting CUL3. Additionally, we identified that Nrf2 is direcctly bound with promoters of FAP-1 and FN1, which enhanced CAFs activation by promoting FAP-1 and FN1 transcription. CONCLUSIONS: Our data identify a new CAFs activation mechanism by exosomes derived from cancer cells that overexpress COX-2. Specifically, COX-2/exo-miR-1290/CUL3 is suggested as a novel signaling pathway for mediating CAFs activation and tumor progression in LUAD. Consequently, this finding suggests a novel strategy for cancer treatment that may tackle tumor progression in the future. Video Abstract.

Desert hedgehog mediates the proliferation of medaka spermatogonia through Smoothened signaling.

Desert hedgehog (DHH) signaling has been reported to be involved in spermatogenesis and the self-renewal of spermatogonial stem cells (SSCs). However, the role of DHH in proliferation of spermatogonia including SSCs remains to be elucidated. Here, we report that Dhh from medaka (Oryizas latipes) (named as OlDhh) could directly mediate the proliferation of spermatogonia via Smoothened (Smo) signaling. Oldhh is 1362 bp in length and encodes 453 amino acid (aa) residues with more than 50% identity with the homologs in other species. It has expression predominantly restricted to testis. The soluble and tag-free 176-aa mature OlDhh (named as mOlDhh) were successfully obtained by fusing with the N-terminal tag of cleavable 6-histidine and small ubiquitin-related modifier and then removing the tag. Notably, mOlDhh significantly promoted the proliferation of SG3 (a spermatogonial stem cell line from medaka testis) in a dose-dependent manner and spermatogonia in testicular organ culture. Furthermore, the proliferation of SG3 in the presence of mOlDhh could be inhibited by Smo antagonist (cyclopamine) resulting in apoptosis. Additionally, mOlDhh significantly upregulated the expression of smo as well as the pluripotent-related genes bcl6b and sall4. These data suggest that Smo is an indispensable downstream component in the Dhh signaling pathway. In conclusion, our findings unambiguously demonstrate that Dhh could directly mediate the proliferation of spermatogonia through Smo signaling. This study provides new knowledge about the proliferation regulation of spermatogonia.

TBX15/miR-152/KIF2C pathway regulates breast cancer doxorubicin resistance via promoting PKM2 ubiquitination.

BACKGROUND: Chemoresistance is a critical risk problem for breast cancer treatment. However, mechanisms by which chemoresistance arises remains to be elucidated. The expression of T-box transcription factor 15 (TBX-15) was found downregulated in some cancer tissues. However, role and mechanism of TBX15 in breast cancer chemoresistance is unknown. Here we aimed to identify the effects and mechanisms of TBX15 in doxorubicin resistance in breast cancer. METHODS: As measures of Drug sensitivity analysis, MTT and IC50 assays were used in DOX-resistant breast cancer cells. ECAR and OCR assays were used to analyze the glycolysis level, while Immunoblotting and Immunofluorescence assays were used to analyze the autophagy levels in vitro. By using online prediction software, luciferase reporter assays, co-Immunoprecipitation, Western blotting analysis and experimental animals models, we further elucidated the mechanisms. RESULTS: We found TBX15 expression levels were decreased in Doxorubicin (DOX)-resistant breast cancer cells. Overexpression of TBX15 reversed the DOX resistance by inducing microRNA-152 (miR-152) expression. We found that KIF2C levels were highly expressed in DOX-resistant breast cancer tissues and cells, and KIF2C was a potential target of miR-152. TBX15 and miR-152 overexpression suppressed autophagy and glycolysis in breast cancer cells, while KIF2C overexpression reversed the process. Overexpression of KIF2C increased DOX resistance in cancer cells. Furthermore, KIF2C directly binds with PKM2 for inducing the DOX resistance. KIF2C can prevent the ubiquitination of PKM2 and increase its protein stability. In addition, we further identified that Domain-2 of KIF2C played a major role in the binding with PKM2 and preventing PKM2 ubiquitination, which enhanced DOX resistance by promoting autophagy and glycolysis. CONCLUSIONS: Our data identify a new mechanism by which TBX15 abolishes DOX chemoresistance in breast cancer, and suggest that TBX15/miR-152/KIF2C axis is a novel signaling pathway for mediating DOX resistance in breast cancer through regulating PKM2 ubiquitination and decreasing PKM2 stability. This finding suggests new therapeutic target and/or novel strategy development for cancer treatment to overcome drug resistance in the future.

miR-423-3p activates FAK signaling pathway to drive EMT process and tumor growth in lung adenocarcinoma through targeting CYBRD1.

BACKGROUND: Lung adenocarcinoma (LUAD) is a malignant tumor with a high fatality rate and poor overall survival, while molecular targets diagnosing and alleviating lung cancer remain inadequate. METHODS: In this article, we highlighted the upregulation of microRNA-423-3p (miR-423-3p) in LUAD, especially in smokers aged over 40, and revealed that the high expression of miR-423-3p was significantly associated with smoker, age, and pathologic stage of LUAD patients. RESULTS: Moreover, overexpressing miR-423-3p could facilitate LUAD cell proliferation, invasion, adhesion, and epithelial-mesenchymal transition (EMT) process, while depleted miR-423-3p caused repressive influence upon it. Mechanically, we identified that miR-423-3p could activate FAK signaling pathway through binding to the 3'-UTR of cytochrome B reductase 1 (CYBRD1). Furthermore, we demonstrated that CYBRD1 was lowly expressed in LUAD, and miR-423-3p overexpression could rescue the impairment of LUAD cell proliferation, invasion, adhesion, and EMT caused by CYBRD1 depletion. Noticeably, miR-423-3p depletion efficiently hindered LUAD tumor growth in vivo. CONCLUSION: Collectively, our findings demonstrated that miR-423-3p/CYBRD1 axis could be regarded as a promising biomarker to alleviate the poor LUAD prognosis.

Rictor positively regulates B cell receptor signaling by modulating actin reorganization via ezrin.

As the central hub of the metabolism machinery, the mammalian target of rapamycin complex 2 (mTORC2) has been well studied in lymphocytes. As an obligatory component of mTORC2, the role of Rictor in T cells is well established. However, the role of Rictor in B cells still remains elusive. Rictor is involved in B cell development, especially the peripheral development. However, the role of Rictor on B cell receptor (BCR) signaling as well as the underlying cellular and molecular mechanism is still unknown. This study used B cell-specfic Rictor knockout (KO) mice to investigate how Rictor regulates BCR signaling. We found that the key positive and negative BCR signaling molecules, phosphorylated Brutons tyrosine kinase (pBtk) and phosphorylated SH2-containing inositol phosphatase (pSHIP), are reduced and enhanced, respectively, in Rictor KO B cells. This suggests that Rictor positively regulates the early events of BCR signaling. We found that the cellular filamentous actin (F-actin) is drastically increased in Rictor KO B cells after BCR stimulation through dysregulating the dephosphorylation of ezrin. The high actin-ezrin intensity area restricts the lateral movement of BCRs upon stimulation, consequently reducing BCR clustering and BCR signaling. The reduction in the initiation of BCR signaling caused by actin alteration is associated with a decreased humoral immune response in Rictor KO mice. The inhibition of actin polymerization with latrunculin in Rictor KO B cells rescues the defects of BCR signaling and B cell differentiation. Overall, our study provides a new pathway linking cell metablism to BCR activation, in which Rictor regulates BCR signaling via actin reorganization.

X-linked lymphoproliferative syndrome in mainland China: review of clinical, genetic, and immunological characteristic.

X-linked lymphoproliferative syndrome (XLP) is a rare primary immunodeficiency disease that can be divided into two types: SAP deficiency (XLP1) and XIAP deficiency (XLP2), caused by mutations in the SH2D1A and XIAP genes, respectively. Few cases of XLP (particularly XIAP deficiency) have been reported in mainland China; hence, little is known about the characteristics of Chinese patients with XLP. We identified 13 and 7 patients with SAP and XIAP deficiency, respectively, in our center. Of our 20 patients, 19/20 (95%) presented with disease symptoms at a very early age: six in infancy and 13 in childhood. One XIAP- and three SAP-deficient patients died, while 3/7(42.9%) and 4/13(30.8%), respectively, developed hemophagocytic lymphohistiocytosis (HLH). Epstein-Barr virus (EBV) infection was significantly more common in SAP-deficient 10/13 (76.9%) than XIAP-deficient 2/7 (28.6%) patients, as was hypogammaglobulinemia (10/13 (76.9%) vs. 1/7 (14.3%)). None of the seven XIAP-deficient patients had colitis or lymphoma. Nine SAP-deficient patients and five XIAP-deficient patients showed markedly deficient SAP and XIAP expression, respectively, in lymphocytes. Significantly reduced levels of switched memory B cells were observed in six SAP-deficient patients with persistent hypogammaglobulinemia. One of 13 (7.7%) SAP-deficient patients and 1 of 7 (12.3%) XIAP-deficient patients have received HSCT treatment and are now alive and well; the other alive patients were waiting for HSCT. We also summarized clinical, genetic, and immunological characteristics of all 55 patients (including our 20 patients) reported in the literature in mainland China today.Conclusion: The overall characteristics of SAP deficiency in mainland China were consistent with those in previous reports, whereas manifestations of XIAP deficiency varied significantly. None of inflammatory bowel disease (IBD) has been reported among XIAP-deficient patients in our center; however, whether Chinese XIAP-deficient patients will develop colitis in the future warrants further investigation. HSCT is the only curative therapy for XLP and this therapy should be urgently considered.What is Known:• SAP and XIAP deficiencies share common clinical feature, HLH, whereas they also have their own specific manifestations.• IBD affects 25-30% of XIAP-deficient patients, which has been reported in other countries especially in European country and Japan.What is New:• This is the largest patient cohort study of XLP in China.• We firstly summarized the clinical features and outcomes of Chinese XIAP-deficient patients and found only 1 in 22 patients developed IBD and diet background may contribute to it; Asian SAP-deficient patients carrying SH2D1A R55X mutation were more prone to HLH.

Construction and Application of Functional Brain Network Based on Entropy.

Functional brain network (FBN) is an intuitive expression of the dynamic neural activity interaction between different neurons, neuron clusters, or cerebral cortex regions. It can characterize the brain network topology and dynamic properties. The method of building an FBN to characterize the features of the brain network accurately and effectively is a challenging subject. Entropy can effectively describe the complexity, non-linearity, and uncertainty of electroencephalogram (EEG) signals. As a relatively new research direction, the research of the FBN construction method based on EEG data of fatigue driving has broad prospects. Therefore, it is of great significance to study the entropy-based FBN construction. We focus on selecting appropriate entropy features to characterize EEG signals and construct an FBN. On the real data set of fatigue driving, FBN models based on different entropies are constructed to identify the state of fatigue driving. Through analyzing network measurement indicators, the experiment shows that the FBN model based on fuzzy entropy can achieve excellent classification recognition rate and good classification stability. In addition, when compared with the other model based on the same data set, our model could obtain a higher accuracy and more stable classification results even if the length of the intercepted EEG signal is different.

Estrogen-induced miR-196a elevation promotes tumor growth and metastasis via targeting SPRED1 in breast cancer.

BACKGROUND: Estrogen plays a critical role in breast cancer (BC) progression through estrogen receptor (ER)-mediated gene regulation. Emerging studies suggest that the malignant progress of BC cells is influenced by the cross talk between microRNAs (miRNAs) and ER-α signaling. However, the mechanism and functional linkage between estrogen and miRNAs remain unclear. METHODS: The expression levels of miR-196a and SPRED1 in BC were tested by qRT-PCR in 46 paired BC and adjacent tissues and by the GEO datasets. The role of miR-196a in estrogen-induced BC development was examined by CCK-8 assay, wound healing assay, Matrigel invasion assay and tumorigenicity assay in nude mice. The binding site of ER-α in miR-196a promoter region was analyzed by ChIP-seq, ChIP assay and luciferase reporter assay. The potential targets of miR-196a in BC cells were explored using the luciferase reporter assay and western blot analysis, and the correlation between miR-196a and SPRED1 was analyzed by Spearman's correlation analysis in BC specimens and GEO dataset. TCGA BRCA data was used to characterize the ESR1 signatures according to MSigDB gene set. RESULTS: The expression levels of miR-196a were higher in ER-positive (ER+) breast tumors compared to ER-negative (ER-) tumor tissue samples. Besides, miR-196a was involved in estrogen-induced BC cell proliferation, migration and invasion. Notably, the up-regulation of miR-196a was mediated by a direct interaction with estrogen receptor α (ER-α) but not estrogen receptor ß (ER-ß) in its promoter region, and miR-196a expression levels were positively correlated to ER-α signature scores. Furthermore, SPRED1 was a new direct target of miR-196a which participated in miR-196a-promoted BC development and was suppressed by ligand-activated ER-α signal pathway. Finally, forced expression of miR-196a induced tumor growth of MCF7 cells, while inhibition of miR-196a significantly suppressed the tumor progress in vivo. CONCLUSIONS: Overall, the identification of estrogen/miR-196a/SPRED1 cascade will shed light on new molecular mechanism of estrogen signaling in BC development and therapy.

The early activation of memory B cells from Wiskott-Aldrich syndrome patients is suppressed by CD19 downregulation.

Wiskott-Aldrich syndrome (WAS) pediatric patients exhibit a deficiency in humoral immune memory. However, the mechanism by which Wiskott-Aldrich syndrome protein (WASP) regulates the differentiation and activation of memory B cells remains elusive. Here we examine the early activation events of memory B cells from the peripheral blood mononuclear cells of WAS patients and age-matched healthy controls (HCs) using total internal reflection fluorescence microscopy. In response to stimulation through the B-cell receptor (BCR), memory B cells from HCs showed significantly higher magnitudes of BCR clustering and cell spreading than naive B cells from the same individuals. This was associated with increases in CD19 recruitment to the BCR and the activation of its downstream signaling molecule Btk and decreases in FcγRIIB recruitment and the activation of its downstream molecule Src homology 2-containing inositol 5' phosphatase (SHIP). However, these enhanced signaling activities mediated by CD19 and Btk are blocked in memory B cells from WAS patients, whereas the activation of FcγRIIB and SHIP was increased. Although the expression levels of CD19, Btk, and FcγRIIB did not change between CD27(-) and CD27(+) B cells of HCs, the protein and mRNA levels of CD19 but not Btk and FcγRIIB were significantly reduced in both CD27(-) and CD27(+) B cells of WAS patients, compared with those of HCs. Overall, our study suggests that WASP is required for memory B-cell activation, promoting the activation by positive regulating CD19 transcription and CD19 recruitment to the BCR.

Research on Recognition Method of Driving Fatigue State Based on Sample Entropy and Kernel Principal Component Analysis.

In view of the nonlinear characteristics of electroencephalography (EEG) signals collected in the driving fatigue state recognition research and the issue that the recognition accuracy of the driving fatigue state recognition method based on EEG is still unsatisfactory, this paper proposes a driving fatigue recognition method based on sample entropy (SE) and kernel principal component analysis (KPCA), which combines the advantage of the high recognition accuracy of sample entropy and the advantages of KPCA in dimensionality reduction for nonlinear principal components and the strong non-linear processing capability. By using support vector machine (SVM) classifier, the proposed method (called SE_KPCA) is tested on the EEG data, and compared with those based on fuzzy entropy (FE), combination entropy (CE), three kinds of entropies including SE, FE and CE that merged with KPCA. Experiment results show that the method is effective.

[Mechanisms for the regulatory effect of prostaglandin E2/prostaglandin E receptor 4 on high mobility group box-1 protein in lipopolysaccharide-induced sepsis in mouse peritoneal macrophage].

OBJECTIVE: To explore the effect of prostaglandin E2 (PGE2) on the expression of high mobility group box-1 protein (HMGB1) in peritoneal macrophages of septic mice and its possible mechanisms.
 Methods: The mouse peritoneal macrophages were isolated and cultured by conventional methods.The model of inflammation was established by using lipopolysaccharide (LPS) to incubate with mouse peritoneal macrophages. The PGE2, prostaglandin E receptor (EP) 4 agonist, EP4 RNAi, and DN.CREB inhibitory plasmid were used to interfere with the LPS-treated mouse peritoneal macrophage. The levels of HMGB1 was determined by Western blot.
 Results: Compared with LPS alone treatment, the expression of HMGB1 in peritoneal macrophages was increased obviously after 24 h by treatment with PGE2 and LPS, and it was also increased after the combined treatment of EP4 receptor agonist with LPS for 24 h (both P<0.05); compared with the PGE2+LPS treatment, the level of HMGB1 was decreased after knockdown of EP4 receptor expression (P<0.05); compared with EP4 receptor agonist +LPS treatment, there was no difference in HMGB1 levels in mice after the treatment with DN.CREB plasmid to suppress CREB function (P>0.05); compared with LPS alone treatment, the combined treatment of EP4 receptor agonist with LPS for 24 h could up-regulate the phosphorylation of epidermal growth factor receptor (EGFR) and protein kinase B (Akt) thr308 (P<0.05), which were blocked by EGFR inhibitor. Once Akt specific inhibitor was used before EP4 and LPS treatment, the expression of HMGB1 was declined (P<0.05).
 Conclusion: PGE2 can up-regulate the expression of HMGB1 in sepsis of peritoneal macrophages through EP4 receptor, which may be related to the activation of EGFR/PI3K/Akt signaling pathway.

N-wasp is essential for the negative regulation of B cell receptor signaling.

Negative regulation of receptor signaling is essential for controlling cell activation and differentiation. In B-lymphocytes, the down-regulation of B-cell antigen receptor (BCR) signaling is critical for suppressing the activation of self-reactive B cells; however, the mechanism underlying the negative regulation of signaling remains elusive. Using genetically manipulated mouse models and total internal reflection fluorescence microscopy, we demonstrate that neuronal Wiskott-Aldrich syndrome protein (N-WASP), which is coexpressed with WASP in all immune cells, is a critical negative regulator of B-cell signaling. B-cell-specific N-WASP gene deletion causes enhanced and prolonged BCR signaling and elevated levels of autoantibodies in the mouse serum. The increased signaling in N-WASP knockout B cells is concurrent with increased accumulation of F-actin at the B-cell surface, enhanced B-cell spreading on the antigen-presenting membrane, delayed B-cell contraction, inhibition in the merger of signaling active BCR microclusters into signaling inactive central clusters, and a blockage of BCR internalization. Upon BCR activation, WASP is activated first, followed by N-WASP in mouse and human primary B cells. The activation of N-WASP is suppressed by Bruton's tyrosine kinase-induced WASP activation, and is restored by the activation of SH2 domain-containing inositol 5-phosphatase that inhibits WASP activation. Our results reveal a new mechanism for the negative regulation of BCR signaling and broadly suggest an actin-mediated mechanism for signaling down-regulation.

Prostaglandin E2 accelerates invasion by upregulating Snail in hepatocellular carcinoma cells.

Our previous studies showed that prostaglandin E2 (PGE2) promotes hepatoma cell growth and migration, as well as invasion; however, the precise mechanism remains elusive. Snail and p65 protein levels were detected in human samples with hepatocellular carcinoma (HCC) by immunohistochemistry (IHC) staining. HCC cell lines (Huh-7 and Hep3B) were used for in vitro experiments. PGE2/Akt/NF-κB pathway was investigated in Huh-7 and Hep3B cells after treatment with PGE2, EP4 receptor (EP4R) agonist, Akt inhibitor, and NF-κB inhibitor, respectively, by real-time reverse transcription (RT)-PCR, Western blotting, and immunofluorescence (IF) staining. In vitro cell invasion assay was performed to evaluate the effect of PGE2 on tumor invasiveness. Knockdown of EP4R was carried out in Huh-7 cells through plasmid-based small interfering RNA (siRNA) approach to confirm the regulation of PGE2 on Snail by EP4R. Dual luciferase reporter assay was performed to assess Snail promoter activity in Huh-7 cell after treatment with EP4R agonist. We found that the protein levels of Snail were higher in HCC tissues than those in control and that PGE2 and EP4R agonist treatment significantly increased Snail expression in Huh-7 and Hep3B cells. EP4R agonist also profoundly promoted invasiveness of Huh-7 cells. Knockdown of the EP4R by siRNA completely blocked the PGE2-induced upregulation of Snail expression and reduced invasiveness of Huh-7 cells. We failed to find that EP4R-induced upregulation of Snail was reversed by inhibition of cAMP response element-binding protein (CREB), a canonical downstream target of EP4R. Alternatively, EP4R agonist treatment significantly increased the levels of phosphorylated EGFR and Akt both in Huh-7 and Hep3B cells. AG1478, an EGFR inhibitor, blocked the phosphorylation of Akt. The levels of phosphorylated IκB increased in Huh-7 cells after treatment with EP4R agonist for 30 min. The levels of phosphorylated p65 started to increase in Huh-7 cells treated with EP4R agonist for 4 h, and p65 translocated into the nucleus. In EP4R-agonist-treated Hep3B, the levels of phosphorylated p65 were also increased compared to the control group. The phosphorylation levels of p65 were significantly decreased in Huh-7 and Hep3B cells after treatment with the Akt signaling inhibitor LY294002 and EP4R agonist for 24 h. Treatment with the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) at 10 µM for 24 h blocked EP4R-agonist-induced Snail upregulation in Huh-7 and Hep3B cells. Furthermore, we obtained human Snail promoter sequence from TRED-Promoter Database and identified a putative binding site of NF-κB in the sequence through TFSEARCH analysis. Subsequently, we treated Huh-7 cells with EP4R agonist or EP4R agonist and PDTC (NF-κB antagonist) and found significantly increased Snail promoter activity after EP4R agonist treatment for 12 h. The increased Snail promoter activity could be partially abolished by additional PDTC treatment. In addition, p65 protein levels were found increased together with Snail in HCC tissues compared to normal liver tissues. In conclusion, PGE2 activates Akt/NF-κB signaling and then upregulates Snail via the EP4R/EGFR to promote migration and invasion in hepatoma cells. These findings may help future evaluation of novel chemo-preventive strategies for HCC.

Case report: successful response to bevacizumab combined with erlotinib for a novel FH gene mutation hereditary leiomyoma and renal cell carcinoma.

FH-deficient Renal Cell Carcinoma (FH-deficient RCC) are inherited tumors caused by mutations in the fumarate hydratase (FH) gene, which plays a role in the tricarboxylic acid cycle. These mutations often result in aggressive forms of renal cell carcinoma (RCC) and other tumors. Here, we present a case of FH-deficient RCC in a 43-year-old woman with a history of uterine fibroids. She exhibited a new heterozygous mutation in exon six of the FH gene (c.799_803del, c.781_796del). The patient had multiple bone metastases and small subcutaneous nodules in various areas such as the shoulders, back, and buttocks. Biopsy of a subcutaneous nodule on the right side revealed positive expression of 2-succinate-cysteine (2SC), and FH staining indicated FH expression deletion. The patient underwent treatment with a combination of erlotinib and bevacizumab, which resulted in significant efficacy with moderate side effects. This treatment combination may be recommended as a standard regimen. This case underscores the importance of genetic testing in patients with advanced renal cancer to enhance diagnostic accuracy. Furthermore, it provides insights into potential treatment approaches for FH-deficient RCC.

The association of systemic immune-inflammation index with lung function, risk of COPD and COPD severity: A population-based study.

PURPOSE: The relationship between the levels of Systemic Immune-inflammation Index (SII) and chronic obstructive pulmonary disease (COPD), lung function, and COPD severity were not fully understood. We conducted this cross-sectional, population-based study to investigate the complex association between SII and COPD, lung function, and COPD severity among the US adults. METHODS: Overall, 18,349 participants were included in the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2018. The exposure variable was SII, calculated from platelet counts, neutrophil counts, and lymphocyte counts. Weighted univariable and multivariable logistic regression, subgroup analysis, and restricted cubic spline (RCS) regression were performed to assess the relationship between COPD, lung function, COPD severity and SII. Last, we used a propensity score matching (PSM) analysis to reduce selective bias and validate these relationships. RESULTS: Approximately 1,094 (5.96%) of the participants were diagnosed as COPD. The multivariable-adjusted odds ratio (OR) (95% confidence interval, CI) for the Q2 group (Log-SII > 2.740) was 1.39 (1.16 to 1.68). Before and after matching, multivariable logistic regression models revealed that increased Log-SII levels (SII Logarithmic transformation) associated positively with the risk of COPD. The subgroup analysis showed no interaction between Log-SII and a variety of variables (P for interaction > 0.05). RCS showed a reversed L-shaped relationship between Log-SII with COPD (P for nonlinear = 0.001) in individuals. In addition, we observed negative significant correlations between forced expiratory volume in one second (FEV1) / forced vital capacity (FVC) %, FEV1/FVC% predicted and SII, and reversed U-shaped curve relationships between FEV1, FEV1% predicted and SII. High SII level is associated with severity of COPD, especially at Global Initiative on Obstructive Lung Disease (GOLD) 1 and GOLD 3. CONCLUSIONS: In summary, the Log-SII level is associated with COPD risk, lung function, and COPD severity.