Chloride intracellular channel 4 blockade improves cognition in mice with Alzheimer's disease: CLIC4 protein expression and tau protein hyperphosphorylation.

Numerous academic literature suggests that amyloid-ß (Aß) deposition, tau protein phosphorylation, and irreversible neuronal death are the three major causes of AD. The chloride intracellular channel (CLIC) protein family not only regulates the polarisation of neurons, but also has important implications for neuronal survival. Chloride intracellular channel 4 (CLIC4) can be pathologically activated by cyclin-dependent kinase 5 (Cdk5), which causes a significant increase in the expression of CLIC4 and mediates neuronal apoptosis. CLIC4 knockdown inhibits H2O2-induced neuronal apoptosis; however, the relationship between CLIC4 and AD remains unknown. In the present study, we showed that CLIC4 expression was elevated in the hippocampus of AD mice; knockdown of hippocampal CLIC4 alleviated Aß25-35-induced cognitive impairment in mice; overexpression of hippocampal CLIC4 accelerated Aß deposition and tau protein hyperphosphorylation in young AD mice (APP/PS1 mice at three months of age). CLIC4 overexpressing mice had a longer escape latency compared to controls in behavioural testing (Morris water maze and T-maze tests). By Co-immunoprecipitation/mass spectrometry (Co-IP/MS) of HT22 cells to identify proteins that specifically bind to CLIC4, we found interactions with CCAAT enhancer binding protein (C/EBPß); a critical pathway involved in the development of various neurodegenerative diseases. In addition, the knockdown of hippocampal CLIC4 alleviated AD-like pathology by inhibiting the C/EBPß/AEP signaling pathway. These data suggest an essential role for high CLIC4 expression in the pathophysiology of AD and reveal that inhibition of CLIC4 expression may provide an opportunity for treatment.

Short-term cold exposure induces persistent epigenomic memory in brown fat.

Deficiency of the epigenome modulator histone deacetylase 3 (HDAC3) in brown adipose tissue (BAT) impairs the ability of mice to survive in near-freezing temperatures. Here, we report that short-term exposure to mild cold temperature (STEMCT: 15°C for 24 h) averted lethal hypothermia of mice lacking HDAC3 in BAT (HDAC3 BAT KO) exposed to 4°C. STEMCT restored the induction of the thermogenic coactivator PGC-1α along with UCP1 at 22°C, which is greatly impaired in HDAC3-deficient BAT, and deletion of either UCP1 or PGC-1α prevented the protective effect of STEMCT. Remarkably, this protection lasted for up to 7 days. Transcriptional activator C/EBPß was induced by short-term cold exposure in mouse and human BAT and, uniquely, remained high for 7 days following STEMCT. Adeno-associated virus-mediated knockdown of BAT C/EBPß in HDAC3 BAT KO mice erased the persistent memory of STEMCT, revealing the existence of a C/EBPß-dependent and HDAC3-independent cold-adaptive epigenomic memory.

Pentamethylquercetin attenuates angiotensin II-induced abdominal aortic aneurysm formation by blocking nuclear translocation of C/EBPß at Lys253.

BACKGROUND: Pentamethylquercetin (PMQ) is a natural polymethyl flavonoid that possesses anti-apoptotic and other biological properties. Abdominal aortic aneurysm (AAA), a fatal vascular disease with a high risk of rupture, is associated with phenotypic switching and apoptosis of medial vascular smooth muscle cells (VSMCs). This study aimed to investigate the protective effects of PMQ on the development of AAA and the underlying mechanism. METHODS: ApoE-/- mice were continuously infused with angiotensin II (Ang II) for 4 weeks to develop the AAA model. Intragastric administration of PMQ was initiated 5 days before Ang II infusion and continued for 4 weeks. In vitro, VSMCs were cultured and pretreated with PMQ, stimulated with Ang II. Real-time PCR, western blotting, and immunofluorescence staining were used to examine the roles and mechanisms of PMQ on the phenotypic switching and apoptosis of VSMCs. RESULTS: PMQ dose-dependently reduced the incidence of Ang II-induced AAA, aneurysm diameter enlargement, elastin degradation, VSMCs phenotypic switching and apoptosis. Furthermore, PMQ also inhibited phenotypic switching and apoptosis in Ang II-stimulated VSMCs. PMQ exerted protective effects by regulating the C/EBPß/PTEN/AKT/GSK-3ß axis. AAV-mediated overexpression of PTEN reduced the therapeutic effects of PMQ in the AAA model mice, suggesting that the effects of PMQ on Ang II-mediated AAA formation were related to the PTEN/AKT/GSK-3ß axis. PMQ inhibited VSMCs phenotypic switching and apoptosis by bounding to C/EBPß at Lys253 with hydrogen bond to regulate C/EBPß nuclear translocation and PTEN/AKT/GSK-3ß axis, thereby inhibiting Ang II-induced AAA formation. CONCLUSIONS: Pentamethylquercetin inhibits angiotensin II-induced abdominal aortic aneurysm formation by bounding to C/EBPß at Lys253. Therefore, PMQ prevents the formation of AAA and reduces the incidence of AAA.

Therapeutic effect of ginkgetin on smoke-induced airway inflammation by down-regulating the c/EBPß signaling pathway and CCL2 expression.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginkgo biloba leaf and seed have been traditionally used in ancient China for the treatment of cough and asthma. However, there is limited literature available on the anti-COPD effects and mechanisms of Ginkgo biloba. AIMS OF THE STUDY: The aim of this study was to comprehensively investigate the therapeutic potential of ginkgo extracts in COPD through a combination of in vivo and in vitro functional experiments. Transcriptomic analyses were also employed to uncover novel molecular mechanisms underlying the therapeutic effects of ginkgetin in COPD. MATERIALS AND METHODS: The therapeutic efficacy of ginkgo extracts was assessed in a COPD model. The anti-inflammatory effects of ginkgetin and its underlying molecular mechanisms were examined in A549 cells treated with cigarette smoke extract (CSE). Additionally, transcriptomic analyses were conducted to identify novel molecular pathways influenced by ginkgetin. These findings were further validated using quantitative real-time polymerase chain reaction (qPCR) and Western blot techniques. RESULTS: The ethyl acetate extract of Ginkgo biloba L. seeds and ginkgetin treatment significantly reduced cytokine production in COPD mice. Following drug administration, lung function improved in different groups. The transcriptome data strongly supports the inhibitory effect of ginkgetin on CSE-induced inflammation through the downregulation of the c/EBPß signaling pathway and subsequent inhibition of CCL2 expression. CONCLUSION: Our results demonstrate that ginkgetin, one of the biflavones found in Ginkgo biloba, exhibits inhibitory effects on smoke-induced airway inflammation. This effect is achieved through the downregulation of the c/EBPß signaling pathway and the reduction of CCL2 expression.

Gallic Acid Attenuates Sepsis-Induced Liver Injury through C/EBPß-Dependent MAPK Signaling Pathway.

SCOPE: Liver injury is a major complication associated with sepsis. Together with others, the study has shown that gallic acid (GA) exerts anti-inflammatory and antioxidant effects in vivo. However, the role of GA in sepsis-mediated hepatic impairment and the underlying mechanisms remains to be elucidated. METHODS AND RESULTS: C57BL/6J mice are pretreated with saline or GA and subjected to sham or cecal ligation and puncture (CLP). The pathological alterations are assessed by hematoxylin and eosin staining as well as immunohistochemical staining. RNA sequencing is employed to analyze hepatic transcriptome modifications. The study finds that GA supplementation significantly ameliorates CLP-induced mortality, liver dysfunction, and inflammation. RNA sequencing reveals that 1324 genes are markedly differentially regulated in livers of saline- or GA-treated sham or CLP mice. Gene ontology analysis demonstrates that the differentially expressed genes regulated by GA are predominantly correlated with the immune system process, oxidation-reduction process, and inflammatory response. Furthermore, mitogen-activated protein kinase (MAPK) signaling is localized in the center of the GA-mediated pathway network. Notably, activation of MAPK by C16-PAF significantly blocks GA-mediated protective effects on hepatic injury, inflammation, as well as CCAAT/enhancer-binding protein-ß (C/EBPß) dependent extracellular signal-regulated kinase 1/2 (ERK1/2) and nuclear factor-κB (NF-κB) signaling. CONCLUSION: Therefore, this study indicates that GA may offer a promising therapeutic opportunity for sepsis-associated liver injury.

Dysregulation of TNF-induced protein 3 and CCAAT/enhancer-binding protein ß in alveolar macrophages: Implications for systemic sclerosis-associated interstitial lung disease.

OBJECTIVES: This study investigates the role of TNF-induced protein 3 (TNFAIP3) and CCAAT/enhancer-binding protein ß (C/EBPß) in alveolar macrophages (AMs) of patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD) and their influence on pulmonary fibrosis. METHODS: Transfection of HEK293T cells and AMs with plasmids carrying TNFAIP3 and C/EBPß was performed, followed by co-culturing AMs with pulmonary fibroblasts. Immunoblotting analysis was then utilized to assess the expression of TNFAIP3, C/EBPß, and collagen type 1 (Col1). Quantitative PCR analysis was conducted to quantify the mRNA levels of C/EBPß, IL-10, and TGF-ß1. STRING database analysis, and immunoprecipitation assays were employed to investigate the interactions between TNFAIP3 and C/EBPß. RESULTS: TNFAIP3 expression was significantly reduced in SSc-ILD AMs, correlating with increased Col1 production in fibroblasts. Overexpression of TNFAIP3 inhibited this pro-fibrotic activity. Conversely, C/EBPß expression was elevated in SSc-ILD AMs, and its reduction through TNFAIP3 restoration decreased pro-fibrotic cytokines IL-10 and TGFß1 levels. Protein-protein interaction studies confirmed the regulatory relationship between TNFAIP3 and C/EBPß. CONCLUSIONS: This study highlights the important role of TNFAIP3 in regulating pulmonary fibrosis in SSc-ILD by modulating C/EBPß expression in AMs. These findings suggest that targeting TNFAIP3 could be a potential therapeutic strategy for managing SSc-ILD patients.

Hydrangea paniculata coumarins alleviate adriamycin-induced renal lipotoxicity through activating AMPK and inhibiting C/EBPß.

ETHNOPHARMACOLOGICAL RELEVANCE: Throughout Chinese history, Hydrangea paniculata Siebold has been utilized as a traditional medicinal herb to treat a variety of ailments associated to inflammation. In a number of immune-mediated kidney disorders, total coumarins extracted from Hydrangea paniculata (HP) have demonstrated a renal protective effect. AIM OF THE STUDY: To investigate renal beneficial effect of HP on experimental Adriamycin nephropathy (AN), and further clarify whether reversing lipid metabolism abnormalities by HP contributes to its renoprotective effect and find out the underlying critical pathways. MATERIALS AND METHODS: After establishment of rat AN model, HP was orally administrated for 6 weeks. Biochemical indicators related to kidney injury were determined. mRNAs sequencing using kidney tissues were performed to clarify the underlying mechanism. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis, western blot, molecular docking, and drug affinity responsive target stability (DARTS) assay was carried out to further explore and confirm pivotal molecular pathways and possible target by which HP and 7-hydroxylcoumarin (7-HC) played their renal protection effect via modulating lipid metabolism. RESULTS: HP could significantly improve renal function, and restore renal tubular abnormal lipid metabolism and interstitial fibrosis in AN. In vitro study demonstrated that HP and its main metabolite 7-HC could reduce ADR-induced intracellular lipid deposition and fibrosis characteristics in renal tubular cells. Mechanically, HP and 7-HC can activate AMP-activated protein kinase (AMPK) via direct interaction, which contributes to its lipid metabolism modulation effect. Moreover, HP and 7-HC can inhibit fibrosis by inhibiting CCAAT/enhancer binding protein beta (C/EBPß) expression in renal tubular cells. Normalization of lipid metabolism by HP and 7-HC further provided protection of mitochondrial structure integrity and inhibited the nuclear factor kappa-B (NF-κB) pathway. Long-term toxicity using beagle dogs proved the safety of HP after one-month administration. CONCLUSION: Coumarin derivates from HP alleviate adriamycin-induced lipotoxicity and fibrosis in kidney through activating AMPK and inhibiting C/EBPß.

TG-interacting factor 1 regulates mitotic clonal expansion during adipocyte differentiation.

Obesity is one of the significant health challenges in the world and is highly associated with abnormal adipogenesis. TG-interacting factor 1 (TGIF1) is essential for differentiating murine adipocytes and human adipose tissue-derived stem cells. However, the mode of action needs to be better elucidated. To investigate the roles of TGIF1 in differentiation in-depth, CRISPR/Cas9 knockout technology was performed to generate TGIF1-silenced preadipocytes. The absence of TGIF1 in 3 T3-F442A preadipocytes abolished lipid accumulation throughout the differentiation using Oil Red O staining. Conversely, we established 3 T3-F442A preadipocytes stably expressing TGIF1 and doxycycline-inducible TGIF1 in TGIF1-silenced 3 T3-F442A preadipocytes. Remarkably, the induction of TGIF1 by doxycycline during the initial differentiation phase successfully promoted lipid accumulation in TGIF1-silenced 3 T3-F442A cells. We further explored the mechanisms of TGIF1 in early differentiation. We demonstrated that TGIF1 promoted the mitotic clonal expansion via upregulation of CCAAT/enhancer-binding proteins ß expression, interruption with peroxisome proliferators activated receptor γ downstream regulation, and inhibition of p27kip1 expression. In conclusion, we strengthen the pivotal roles of TGIF1 in early differentiation, which might contribute to resolving obesity-associated metabolic syndromes.

C/EBPß: A transcription factor associated with the irreversible progression of Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disorder distinguished by a swift cognitive deterioration accompanied by distinctive pathological hallmarks such as extracellular Aß (ß-amyloid) peptides, neuronal neurofibrillary tangles (NFTs), sustained neuroinflammation, and synaptic degeneration. The elevated frequency of AD cases and its proclivity to manifest at a younger age present a pressing challenge in the quest for novel therapeutic interventions. Numerous investigations have substantiated the involvement of C/EBPß in the progression of AD pathology, thus indicating its potential as a therapeutic target for AD treatment. AIMS: Several studies have demonstrated an elevation in the expression level of C/EBPß among individuals afflicted with AD. Consequently, this review predominantly delves into the association between C/EBPß expression and the pathological progression of Alzheimer's disease, elucidating its underlying molecular mechanism, and pointing out the possibility that C/EBPß can be a new therapeutic target for AD. METHODS: A systematic literature search was performed across multiple databases, including PubMed, Google Scholar, and so on, utilizing predetermined keywords and MeSH terms, without temporal constraints. The inclusion criteria encompassed diverse study designs, such as experimental, case-control, and cohort studies, restricted to publications in the English language, while conference abstracts and unpublished sources were excluded. RESULTS: Overexpression of C/EBPß exacerbates the pathological features of AD, primarily by promoting neuroinflammation and mediating the transcriptional regulation of key molecular pathways, including δ-secretase, apolipoprotein E4 (APOE4), acidic leucine-rich nuclear phosphoprotein-32A (ANP32A), transient receptor potential channel 1 (TRPC1), and Forkhead BoxO (FOXO). DISCUSSION: The correlation between overexpression of C/EBPß and the pathological development of AD, along with its molecular mechanisms, is evident. Investigating the pathways through which C/EBPß regulates the development of AD reveals numerous multiple vicious cycle pathways exacerbating the pathological progression of the disease. Furthermore, the exacerbation of pathological progression due to C/EBPß overexpression and its molecular mechanism is not limited to AD but also extends to other neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), and multiple sclerosis (MS). CONCLUSION: The overexpression of C/EBPß accelerates the irreversible progression of AD pathophysiology. Additionally, C/EBPß plays a crucial role in mediating multiple pathways linked to AD pathology, some of which engender vicious cycles, leading to the establishment of feedback mechanisms. To sum up, targeting C/EBPß could hold promise as a therapeutic strategy not only for AD but also for other degenerative diseases.

TMF inhibits extracellular matrix degradation by regulating the C/EBPß/ADAMTS5 signaling pathway in osteoarthritis.

Osteoarthritis (OA) is a chronic joint disease, characterized by degenerative destruction of articular cartilage. Chondrocytes, the unique cell type in cartilage, mediate the metabolism of extracellular matrix (ECM), which is mainly constituted by aggrecan and type II collagen. A disintegrin and metalloproteinase with thrombospondin 5 (ADAMTS5) is an aggrecanase responsible for the degradation of aggrecan in OA cartilage. CCAAT/enhancer binding protein ß (C/EBPß), a transcription factor in the C/EBP family, has been reported to mediate the expression of ADAMTS5. Our previous study showed that 5,7,3',4'-tetramethoxyflavone (TMF) could activate the Sirt1/FOXO3a signaling in OA chondrocytes. However, whether TMF protected against ECM degradation by down-regulating C/EBPß expression was unknown. In this study, we found that aggrecan expression was down-regulated, and ADAMTS5 expression was up-regulated. Knockdown of C/EBPß could up-regulate aggrecan expression and down-regulate ADAMTS5 expression in IL-1ß-treated C28/I2 cells. TMF could compromise the effects of C/EBPß on OA chondrocytes by activating the Sirt1/FOXO3a signaling. Conclusively, TMF exhibited protective activity against ECM degradation by mediating the Sirt1/FOXO3a/C/EBPß pathway in OA chondrocytes.

Engineered human osteoarthritic cartilage organoids.

The availability of human cell-based models capturing molecular processes of cartilage degeneration can facilitate development of disease-modifying therapies for osteoarthritis [1], a currently unmet clinical need. Here, by imposing specific inflammatory challenges upon mesenchymal stromal cells at a defined stage of chondrogenesis, we engineered a human organotypic model which recapitulates main OA pathological traits such as chondrocyte hypertrophy, cartilage matrix mineralization, enhanced catabolism and mechanical stiffening. To exemplify the utility of the model, we exposed the engineered OA cartilage organoids to factors known to attenuate pathological features, including IL-1Ra, and carried out mass spectrometry-based proteomics. We identified that IL-1Ra strongly reduced production of the transcription factor CCAAT/enhancer-binding protein beta [2] and demonstrated that inhibition of the C/EBPß-activating kinases could revert the degradative processes. Human OA cartilage organoids thus represent a relevant tool towards the discovery of new molecular drivers of cartilage degeneration and the assessment of therapeutics targeting associated pathways.

Hypoxia/inflammation-induced upregulation of HIF-1α and C/EBPß promotes nephroblastoma cell EMT by improving HOXA11-AS transcription.

Background: Homeobox (HOX) A11 antisense RNA (HOXA11-AS) has been identified as a cancer promoting lncRNA and is overexpressed in nephroblastoma. However, how HOXA11-AS is regulated in a hypoxic inflammatory environment has not been studied. Methods: In this study, gene expression and epithelial-mesenchymal transition (EMT) ability were detected in the nephroblastoma cell line WiT49 under conditions of hypoxia and inflammation. Next, HOXA11-AS transcription factors were predicted by datasets and subsequently confirmed by CHIP-QPCR, EMSA, and dual-luciferase reporter assays. Moreover, the regulatory relationships of HOXA11-AS and its transcription factors were further confirmed by rescue experiments. Results: Our results showed that a hypoxic microenvironment promoted HOXA11-AS expression and nephroblastoma progression, induced EMT, and activated the Wnt signaling pathway. Combined hypoxia and inflammation had a more substantial effect on nephroblastoma than either hypoxia or inflammation alone. HIF-1α and C/EBPß were confirmed to be the transcription factors for HOXA11-AS. Silencing of HIF-1α or C/EBPß downregulated HOXA11-AS expression and suppressed EMT and the Wnt signaling pathway in nephroblastoma cells exposed to a hypoxic or inflammatory microenvironment. HOXA11-AS overexpression partly reversed the effect of HIF-1α or C/EBPß knockdown. Conclusion: We demonstrated that hypoxia/inflammation-induced upregulation of HIF-1α and C/EBPß promoted nephroblastoma EMT by improving HOXA11-AS transcription. HOXA11-AS might be a therapy target for nephroblastoma.

Zishen Qingre Lishi Huayu recipe promotes proliferation and inhibits apoptosis of GCs of PCOS via KLF4-C/EBPß pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Zishen Qingre Lishi Huayu recipe (ZQLHR) is a herbal recipe created on the basis on the theory of traditional Chinese medicine and clinical practice, and is mainly used in the treatment of polycystic ovary syndrome (PCOS). However, the underlying mechanism for this fact has not been clearly elucidated. AIM OF THE STUDY: To verify whether ZQLHR regulates granulosa cells (GCs) proliferation and apoptosis through the Krüppel-like factor 4 (KLF4) - CCATT enhancer-binding proteinß (C/EBPß) pathway, and to provide in vitro molecular mechanism supporting for the effects of ZQLHR to enhance follicular development and treat patients with PCOS. MATERIALS AND METHODS: Based on previous experiments, we performed the following experiments. Firstly, we treated KGN cells (a steroidogenic human granulosa-like tumor cell line) for 48 h using different concentrations of ZQLHR in order to observe apoptosis in each group. Secondly, the mRNA and protein expression levels of KLF4 and C/EBPß in KGN cells after administrated with ZQLHR were examined by quantitative real-time PCR(q-PCR) and Western blot assay. Thirdly, after knocking down KLF4 and C/EBPß using siRNAs, the relationship between KLF4 and C/EBPß in KGN cells was detected. Further, cell counting kit-8 assay, colony formation assay and flow cytometry were used to verify whether ZQLHR promotes proliferation and facilitates apoptosis in KGN cells through the KLF4-C/EBPß pathway. Finally, q-PCR and Western blot were used to test whether ZQLHR mediated proliferation and apoptosis-related factors such as B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X (BAX), proliferating cell nuclear antigen (PCNA) and cleaved caspase-3 to affect the proliferation and apoptosis of KGN cells through the KLF4-C/EBPß pathway. CONCLUSIONS: ZQLHR, containing 0.2% by volume, administered to KGN cells resulted in the lowest rate of apoptosis. The expression levels of KLF4 and C/EBPß were increased in KGN cells following ZQLHR treatment. Additionally, ZQLHR promoted proliferation and inhibited apoptosis of KGN cells by modulating proliferation and apoptosis-related factors via the KLF4-C/EBPß pathway. Furthermore, we confirmed that KLF4 and C/EBPß regulate each other in KGN cells. These findings indicate that ZQLHR enhances the proliferation of GCs and suppresses their apoptosis, which constitutes a therapeutic mechanism for treating patients with PCOS.

IL-37d enhances COP1-mediated C/EBPß degradation to suppress spontaneous neutrophil migration and tumor progression.

The spontaneous migration of bone marrow neutrophils (BMNs) is typically induced by distant tumor cells during the early stage of the tumor and critically controls tumor progression and metastases. Therefore, identifying the key molecule that prevents this process is extremely important for suppressing tumors. Interleukin-37 (IL-37) can suppress pro-inflammatory cytokine generation via an IL-1R8- or Smad3-mediated pathway. Here, we demonstrate that human neutrophil IL-37 is responsively reduced by tumor cells and the recombinant IL-37 isoform d (IL-37d) significantly inhibits spontaneous BMN migration and tumor lesion formation in the lung by negatively modulating CCAAT/enhancer binding protein beta (C/EBPß) in a Lewis lung carcinoma (LLC)-inducing lung cancer mouse model. Mechanistically, IL-37d promotes C/EBPß ubiquitination degradation by facilitating ubiquitin ligase COP1 recruitment and disrupts C/EBPß DNA binding abilities, thereby reducing neutrophil ATP generation and migration. Our work reveals an anti-tumor mechanism for IL-37 via destabilization of C/EBPß to prevent spontaneous BMN migration and tumor progression.

[C/EBPß mediates expressions of downstream inflammatory factors of the tumor necrosis factor-α signaling pathway in renal tubular epithelial cells with NPHP1 knockdown].

OBJECTIVE: To explore the activation of tumor necrosis factor-α (TNF-α) signaling pathway and the expressions of the associated inflammatory factors in NPHP1-defective renal tubular epithelial cells. METHODS: A human proximal renal tubular cell (HK2) model of lentivirus-mediated NPHP1 knockdown (NPHP1KD) was constructed, and the expressions of TNF-α, p38, and C/EBPß and the inflammatory factors CXCL5, CCL20, IL-1ß, IL-6 and MCP-1 were detected using RT-qPCR, Western blotting or enzyme-linked immunosorbent assay. A small interfering RNA (siRNA) was transfected in wild-type and NPHP1KDHK2 cells, and the changes in the expressions of TNF-α, p38, and C/EBPß and the inflammatory factors were examined. RESULTS: NPHP1KDHK2 cells showed significantly increased mRNA expressions of TNF-α, C/EBPß, CXCL5, IL-1ß, and IL-6 (P < 0.05), protein expressions of phospho-p38 and C/EBPß (P < 0.05), and IL-6 level in the culture supernatant (P < 0.05), and these changes were significantly blocked by transfection of cells with siRNA-C/EBPß (P < 0.05). CONCLUSION: TNF-α signaling pathway is activated and its associated inflammatory factors are upregulated in NPHP1KDHK2 cells, and C/EBPß may serve as a key transcription factor to mediate these changes.

The paracrine isthmin1 transcriptionally regulated by C/EBPß exacerbates pulmonary vascular leakage in murine sepsis.

It is known that pulmonary vascular leakage, a key pathological feature of sepsis-induced lung injury, is largely regulated by perivascular cells. However, the underlying mechanisms have not been fully uncovered. In the present study, we aimed to evaluate the role of isthmin1, a secretory protein originating from alveolar epithelium, in the pulmonary vascular leakage during sepsis and to investigate the regulatory mechanisms of isthmin1 gene transcription. We observed an elevated isthmin1 gene expression in the pulmonary tissue of septic mice induced by cecal ligation and puncture (CLP), as well as in primary murine alveolar type II epithelial cells (ATII) exposed to lipopolysaccharide (LPS). Furthermore, we confirmed that isthmin1 derived from ATII contributes to pulmonary vascular leakage during sepsis. Specifically, adenovirus-mediated isthmin1 disruption in ATII led to a significant attenuation of the increased pulmonary microvascular endothelial cell (PMVEC) hyperpermeability in a PMVEC/ATII coculture system when exposed to LPS. In addition, adeno-associated virus 9 (AAV9)-mediated knockdown of isthmin1 in the alveolar epithelium of septic mice significantly attenuated pulmonary vascular leakage. Finally, mechanistic studies unveiled that nuclear transcription factor CCAAT/enhancer binding protein (C/EBP)ß participates in isthmin1 gene activation by binding directly to the cis-regulatory element of isthmin1 locus and may contribute to isthmin1 upregulation during sepsis. Collectively, the present study highlighted the impact of the paracrine protein isthmin1, derived from ATII, on the exacerbation of pulmonary vascular permeability in sepsis and revealed a new regulatory mechanism for isthmin1 gene transcription.NEW & NOTEWORTHY This article addresses the role of the alveolar epithelial-secreted protein isthmin1 on the exacerbation of pulmonary vascular permeability in sepsis and identified nuclear factor CCAAT/enhancer binding protein (C/EBP)ß as a new regulator of isthmin1 gene transcription. Targeting the C/EBPß-isthmin1 regulatory axis on the alveolar side would be of great value in the treatment of pulmonary vascular leakage and lung injury induced by sepsis.

Suppression of lipopolysaccharide-induced COX-2 expression via p38MAPK, JNK, and C/EBPß phosphorylation inhibition by furomagydarin A, a benzofuran glycoside from Magydaris pastinacea.

The phytochemical investigation of the methanol extract of the seeds of Magydaris pastinacea afforded two undescribed benzofuran glycosides, furomagydarins A-B (1, 2), together with three known coumarins. The structures of the new isolates were elucidated after extensive 1D and 2D NMR experiments as well as HR MS. Compound 1 was able to inhibit the COX-2 expression in RAW264.7 macrophages exposed to lipopolysaccharide, a pro-inflammatory stimulus. RT-qPCR and luciferase reporter assays suggested that compound 1 reduces COX-2 expression at the transcriptional level. Further studies highlighted the capability of compound 1 to suppress the LPS-induced p38MAPK, JNK, and C/EBPß phosphorylation, leading to COX-2 down-regulation in RAW264.7 macrophages.

Loss of LBP triggers lipid metabolic disorder through H3K27 acetylation-mediated C/EBPß- SCD activation in non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is associated with mutations in lipopolysaccharide-binding protein ( LBP), but the underlying epigenetic mechanisms remain understudied. Herein, LBP -/- rats with NAFLD were established and used to conduct integrative targeting-active enhancer histone H3 lysine 27 acetylation (H3K27ac) chromatin immunoprecipitation coupled with high-throughput and transcriptomic sequencing analysis to explore the potential epigenetic pathomechanisms of active enhancers of NAFLD exacerbation upon LBP deficiency. Notably, LBP -/- reduced the inflammatory response but markedly aggravated high-fat diet (HFD)-induced NAFLD in rats, with pronounced alterations in the histone acetylome and regulatory transcriptome. In total, 1 128 differential enhancer-target genes significantly enriched in cholesterol and fatty acid metabolism were identified between wild-type (WT) and LBP -/- NAFLD rats. Based on integrative analysis, CCAAT/enhancer-binding protein ß (C/EBPß) was identified as a pivotal transcription factor (TF) and contributor to dysregulated histone acetylome H3K27ac, and the lipid metabolism gene SCD was identified as a downstream effector exacerbating NAFLD. This study not only broadens our understanding of the essential role of LBP in the pathogenesis of NAFLD from an epigenetics perspective but also identifies key TF C/EBPß and functional gene SCD as potential regulators and therapeutic targets.

C/EBPß: The structure, regulation, and its roles in inflammation-related diseases.

Inflammation, a mechanism of the human body, has been implicated in many diseases. Inflammatory responses include the release of inflammatory mediators by activating various signaling pathways. CCAAT/enhancer binding protein ß (C/EBPß), a transcription factor in the C/EBP family, contains the leucine zipper (bZIP) domain. The expression of C/EBPß is mediated at the transcriptional and post-translational levels, such as phosphorylation, acetylation, methylation, and SUMOylation. C/EBPß has been involved in inflammatory responses by mediating several signaling pathways, such as MAPK/NF-κB and IL-6/JAK/STAT3 pathways. C/EBPß plays an important role in the pathological development of inflammation-related diseases, such as osteoarthritis, pneumonia, hepatitis, inflammatory bowel diseases, and rheumatoid arthritis. Here, we comprehensively discuss the structure and biological effects of C/EBPß and its role in inflammatory diseases.

Role of Oxidative Stress-Dependent C/EBPß Expression on CAF Transformation Inducing HCT116 Colorectal Cancer Cell Progression; Migration and Invasion.

OBJECTIVE: To investigate oxidative stress-related CAF transformation through C/EBPß, which affects CRC progression and may have a potential implication for CRC treatment. METHODS: The conditioned media (CM) from HCT116, CRC cells, was used to activate CCD-18Co, colon fibroblasts, then the ability of activated FBs to induce HCT116 growth and progression was assessed using MTT assay, transwell migration, and matrix invasion assay. Alteration of the cytokine profile and oxidative stress of the activated FBs were studied with cytokine arrays and DCFH-DA assay, respectively. The protein expressions of the CAF markers (α-SMA and FAP) and C/EBPß were investigated with immunofluorescence and western blotting. RESULT: It was found that CM from HCT116 cells induced oxidative stress, change of cytokine profile, CAF markers, and the C/EBPß expression of activated FBs. Furthermore, when the oxidative stress of the activated FBs was suppressed, FAP and C/EBPß expression were downregulated, correlating with the disabling of their capability to support the cancer progression. The C/EBPß and prognosis for CRC patients were accessed using the GEPIA dataset, in which high C/EBPß expression was associated with a poor prognosis. CONCLUSION: These findings suggest that C/EBPß expression has a role in CAF transformation in an oxidative stress-related manner and might be used as a target to improve aggressive CRC treatment outcomes.