CCAAT Enhancer Binding Protein Research Articles

GDF15 inhibits early-stage adipocyte differentiation by enhancing HOP2 expression and suppressing C/EBPα expression.

Excessive adipocyte differentiation and accumulation contribute to the development of metabolic disorders. Growth differentiation factor 15 (GDF15) plays an essential role in energy homeostasis and is considered an anti-obesity factor; however, elevated serum levels of endogenous GDF15 have been reported in certain individuals with obesity. In this study, to gain a better understanding of this complex relationship between GDF15 levels and obesity, we investigated GDF15 expression and function during adipogenesis. Compared with mice fed a normal diet, those fed a short-term high-fat diet exhibited a reduction in epididymal white adipose tissue and serum GDF15 expression. These results were confirmed in human adipose-derived stem cells that showed reduced GDF15 expression during adipogenesis differentiation. During adipogenesis, GDF15 was primarily degraded via the autophagy lysosomal pathway, and GDF15 overexpression in pre-adipocytes inhibited adipogenesis by suppressing CCAAT enhancer binding protein alpha (C/EBPα). Furthermore, whereas we detected a reduction in homologous-pairing protein 2 (HOP2) expression during adipogenesis, expression increased in response to an overexpression of GDF15. Furthermore, following knockdown of HOP2 during GDF15 overexpression, there was no suppression of C/EBPα expression. These findings indicate that GDF15 undergoes lysosomal degradation via an autophagic pathway and suppresses adipocyte differentiation via the HOP2-mediated inhibition of C/EBPα expression. Collectively, our findings indicate that GDF15 could serve as a potential therapeutic target for the treatment of metabolic disorders.

Umbilical cord-derived mesenchymal stem cells preferentially modulate macrophages to alleviate pulmonary fibrosis

BackgroundIdiopathic Pulmonary Fibrosis (IPF) is a type of interstitial lung disease characterized by chronic inflammation due to persistent lung damage. Mesenchymal stem cells (MSCs), including those derived from the umbilical cord (UCMSCs) and placenta (PLMSCs), have been utilized in clinical trials for IPF treatment. However, the varying therapeutic effectiveness between these two MSC types remains unclear.MethodsIn this study, we examined the therapeutic differences between UCMSCs and PLMSCs in treating lung damage using a bleomycin (BLM)-induced pulmonary injury mouse model.ResultsWe showed that UCMSCs had a superior therapeutic impact on lung damage compared to PLMSCs. Upon cytokine stimulation, UCMSCs expressed higher levels of inflammation-related genes and more effectively directed macrophage polarization towards the M2 phenotype than PLMSCs, both in vitro and in vivo. Furthermore, UCMSCs showed a preference for expressing CC motif ligation 2 (CCL2) and C-X-C motif chemokine ligand 1 (CXCL1) compared to PLMSCs. The expression of secreted phosphoprotein 1 (SPP1), triggering receptor expressed on myeloid cells 2 (Trem2), and CCAAT enhancer binding protein beta (Cebpb) in macrophages from mice with the disease treated with UCMSCs was significantly reduced compared to those treated with PLMSCs. Conclusions: Therefore, UCMSCs demonstrated superior anti-fibrotic abilities in treating lung damage, potentially through inducing a more robust M2 polarization of macrophages than PLMSCs.

C/EBPβ-dependent autophagy inhibition hinders NK cell function in cancer

NK cells are endowed with tumor killing ability, nevertheless most cancers impair NK cell functionality, and cell-based therapies have limited efficacy in solid tumors. How cancers render NK cell dysfunctional is unclear, and overcoming resistance is an important immune-therapeutic aim. Here, we identify autophagy as a central regulator of NK cell anti-tumor function. Analysis of differentially expressed genes in tumor-infiltrating versus non-tumor NK cells from our previously published scRNA-seq data of advanced human prostate cancer shows deregulation of the autophagic pathway in tumor-infiltrating NK cells. We confirm this by flow cytometry in patients and in diverse cancer models in mice. We further demonstrate that exposure of NK cells to cancer deregulates the autophagic process, decreases mitochondrial polarization and impairs effector functions. Mechanistically, CCAAT enhancer binding protein beta (C/EBPβ), downstream of CXCL12-CXCR4 interaction, acts as regulator of NK cell metabolism. Accordingly, inhibition of CXCR4 and C/EBPβ restores NK cell fitness. Finally, genetic and pharmacological activation of autophagy improves NK cell effector and cytotoxic functions, which enables tumour control by NK and CAR-NK cells. In conclusion, our study identifies autophagy as an intracellular checkpoint in NK cells and introduces autophagy regulation as an approach to strengthen NK-cell-based immunotherapies.

Angiopoietin-like protein 8 directs DNA damage responses towards apoptosis by stabilizing PARP1-DNA condensates.

Upon genotoxic stresses, cells employ various DNA damage responses (DDRs), including DNA damage repair or apoptosis, to safeguard genome integrity. However, the determinants among different DDRs choices are largely unknown. Here, we report angiopoietin-like protein 8 (ANGPTL8), a secreted regulator of lipid metabolism, localizes to the nucleus and acts as a dynamic switch that directs DDRs towards apoptosis rather than DNA repair after genotoxin exposure. ANGPTL8 deficiency alleviates DNA damage and apoptosis in cells exposed to genotoxins, as well as in the liver or kidney of mice injured by hepatic ischemia/reperfusion or cisplatin treatment. Mechanistically, ANGPTL8 physically interacts with Poly (ADP-ribose) polymerase 1 (PARP1), in a PARylation-independent manner, and reduces the fluidity of PARP1-DNA condensates, thereby enhancing the pro-apoptotic accumulation of PARP1 and PAR chains on DNA lesions. However, the transcription of ANGPTL8 is gradually decreased following genotoxin treatment, partly due to downregulation of CCAAT enhancer binding protein alpha (CEBPA), presumably to avoid further cytotoxicity. Together, we provide new insights by which genotoxic stress induced DDRs are channeled to suicidal apoptosis to safeguard genome integrity.

Olaparib promotes FABP4 expression and reduces antitumor effect in ovarian cancer cells with a BRCA1 mutation.

Olaparib (AZD2281) is used as a first-line maintenance treatment for patients with ovarian cancer (OC) with a breast cancer susceptibility gene (BRCA) mutation. Fatty acid binding protein 4 (FABP4) may serve an important role in cancer, but its role in olaparib-treated OC with a BRCA mutation requires further clarification. To explore the function of FABP4 and enhance the efficacy of AZD2281 in OC, cell counting kit-8, cell apoptosis, cell cycle, colony formation, cell transfection, western blotting, reverse transcription-quantitative polymerase chain reaction, chromatin immunoprecipitation, seahorse and reactive oxygen species assays were performed. In the present study, AZD2281 significantly promoted cell apoptosis, and inhibited cell cycle progression and colony formation in COV362 cells. In addition, AZD2281 significantly upregulated the levels of CCAAT enhancer binding protein α (CEBPα), peroxisome proliferator activated receptor γ (PPARγ) and FABP4. AZD2281 markedly promoted fold enrichment of CEBPα in the promoters of PPARγ and FABP4. Furthermore, FABP4 overexpression significantly decreased cell apoptosis and promoted cell cycle progression and colony formation. In contrast, FABP4 knockdown demonstrated the opposite effects. In addition, FABP4 significantly regulated levels of reactive oxygen species, adenosine triphosphate, aerobic glycolysis, basal respiration rate and fatty acid oxidation. The combination of AZD2281 with the FABP4 inhibitor BM S309403 further significantly increased cell apoptosis and decreased colony formation. In conclusion, the findings of the present study demonstrated that AZD2281 significantly enhanced FABP4 expression, leading to diminished antitumor efficacy in OC cells with a BRCA mutation by regulating CEBPα-PPARγ. Conversely, the combination of AZD2281 and FABP4 inhibitor BM S309403 demonstrated heightened antitumor effectiveness, presenting a promising therapeutic strategy for treating patients with OC with a BRCA mutation.

Multiparameter Flow Cytometry-Based Measurable Residual Disease Assessment in the Patients with CCAAT Enhancer-Binding Protein a Gene (CEBPA) Mutated Acute Myeloid Leukemia

Multiparameter Flow Cytometry-Based Measurable Residual Disease Assessment in the Patients with CCAAT Enhancer-Binding Protein a Gene (CEBPA) Mutated Acute Myeloid Leukemia

Cebpa is required for haematopoietic stem and progenitor cell generation and maintenance in zebrafish.

The CCAAT enhancer binding protein alpha (CEBPA) is crucial for myeloid differentiation and the balance of haematopoietic stem and progenitor cell (HSPC) quiescence and self-renewal, and its dysfunction can drive leukemogenesis. However, its role in HSPC generation has not been fully elucidated. Here, we utilized various zebrafish cebpa mutants to investigate the function of Cebpa in the HSPC compartment. Co-localization analysis showed that cebpa expression is enriched in nascent HSPCs. Complete loss of Cebpa function resulted in a significant reduction in early HSPC generation and the overall HSPC pool during embryonic haematopoiesis. Interestingly, while myeloid differentiation was impaired in cebpa N-terminal mutants expressing the truncated zP30 protein, the number of HSPCs was not affected, indicating a redundant role of Cebpa P42 and P30 isoforms in HSPC development. Additionally, epistasis experiments confirmed that Cebpa functions downstream of Runx1 to regulate HSPC emergence. Our findings uncover a novel role of Cebpa isoforms in HSPC generation and maintenance, and provide new insights into HSPC development.

Difenoconazole Induced Damage of Bovine Mammary Epithelial Cells via ER Stress and Inflammatory Response.

Difenoconazole (DIF) is a fungicide used to control various fungi. It is absorbed on the surface of different plants and contributes significantly to increased crop production. However, DIF is reported to exhibit toxicity to fungi and to aquatic plants, fish, and mammals, including humans, causing adverse effects. However, research on the impact of DIF on the mammary epithelial cells of herbivorous bovines is limited. DIF-induced damage and accumulation in the mammary glands can have direct and indirect effects on humans. Therefore, we investigated the effects and mechanisms of DIF toxicity in MAC-T cells. The current study revealed that DIF reduces cell viability and proliferation while triggering apoptotic cell death through the upregulation of pro-apoptotic proteins, including cleaved caspase 3 and Bcl-2-associated X protein (BAX), and the downregulation of leukemia type 2 (BCL-2). DIF also induced endoplasmic reticulum (ER) stress by increasing the expression of genes or proteins of Bip/GRP78, protein disulfide isomerase (PDI), activating transcription factor 4 (ATF4), C/EBP homologous protein (CHOP), and endoplasmic reticulum oxidoreductase 1 Alpha (ERO1-Lα). We demonstrated that DIF induces mitochondria-mediated apoptosis in MAC-T cells by activating ER stress pathways. This cellular damage resulted in a significant increase in the expression of inflammatory response genes and proteins, including cyclooxygenase 2 (COX2), transforming growth factor beta 3 (TGFB3), CCAAT enhancer binding protein delta (CEBPD), and iNOS, in DIF-treated groups. In addition, spheroid formation by MAC-T cells was suppressed by DIF treatment. Our findings suggest that DIF exposure in dairy cows may harm mammary gland function and health and may indirectly affect human consumption of milk.

In Vitro Investigation of HIF-1α as a Therapeutic Target for Thyroid-Associated Ophthalmopathy.

Thyroid-associated ophthalmopathy (TAO) involves tissue expansion and inflammation, potentially causing a hypoxic microenvironment. Hypoxia-inducible factor (HIF)-1α is crucial in fibrosis and adipogenesis, which are observed in TAO progression. We investigated the effects of hypoxia on orbital fibroblasts (OFs) in TAO, focusing on the role of HIF-1α in TAO progression. OFs were isolated from TAO and non-TAO patients (as controls). In addition to HIF-1α, adipogenic differentiation markers including peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein (CEBP) were measured by Western blot, and phenotype changes were evaluated by Oil Red O staining under both normoxia and hypoxia. To elucidate the effect of HIF-1α inhibition, protein expression changes after HIF-1α inhibitor treatment were evaluated under normoxia and hypoxia. TAO OFs exhibited significantly higher HIF-1α expression than non-TAO OFs, and the difference was more distinct under hypoxia than under normoxia. Oil Red O staining showed that adipogenic differentiation of TAO OFs was prominent under hypoxia. Hypoxic conditions increased the expression of adipogenic markers, namely PPARγ and CEBP, as well as HIF-1α in TAO OFs. Interleukin 6 levels also increased in response to hypoxia. The effect of hypoxia on adipogenesis was reduced at the protein level after HIF-1α inhibitor treatment, and this inhibitory effect was sustained even with IGF-1 stimulation in addition to hypoxia. Hypoxia induces tissue remodeling in TAO by stimulating adipogenesis through HIF-1α activation. These data could provide insights into new treatment strategies and the mechanisms of adipose tissue remodeling in TAO.

Transcriptome Analysis Reveals the Early Development in Subcutaneous Adipose Tissue of Laiwu Piglets.

Adipose tissue plays an important role in pig production efficiency. Studies have shown that postnatal development has a vital impact on adipose tissue; however, the mechanisms behind pig adipose tissue early-life programming remain unknown. In this study, we analyzed the transcriptomes of the subcutaneous adipose tissue (SAT) of 1-day and 21-day old Laiwu piglets. The results showed that the SAT of Laiwu piglets significantly increased from 1-day to 21-day, and transcriptome analysis showed that there were 2352 and 2596 differentially expressed genes (DEGs) between 1-day and 21-day SAT in male and female piglets, respectively. Expression of genes in glycolysis, gluconeogenesis, and glycogen metabolism such as pyruvate kinase M1/2 (PKM), phosphoenolpyruvate carboxy kinase 1 (PCK1) and amylo-alpha-1, 6-glucosidase, 4-alpha-glucanotransferase (AGL) were significantly different between 1-day and 21-day SAT. Genes in lipid uptake, synthesis and lipolysis such as lipase E (LIPE), acetyl-CoA carboxylase alpha (ACACA), Stearoyl-CoA desaturase (SCD), and 3-hydroxy-3-methylglutaryl-CoA synthase 1 (HMGCS1) were also differentially expressed. Functional analysis showed enrichment of DEGs in transcriptional regulation, protein metabolism and cellular signal transduction. The protein-protein interaction (PPI) networks of these DEGs were analyzed and potential hub genes in these pathways were identified, such as transcriptional factors forkhead box O4 (FOXO4), CCAAT enhancer binding protein beta (CEBPB) and CCAAT enhancer binding protein delta (CEBPD), signal kinases BUB1 mitotic checkpoint serine/threonine kinase (BUB1) and cyclin-dependent kinase 1 (CDK1), and proteostasis-related factors ubiquitin conjugating enzyme E2 C (UBE2C) and cathepsin D (CTSD). Moreover, we further analyzed the transcriptomes of SAT between genders and the results showed that there were 54 and 72 DEGs in 1-day and 21-day old SAT, respectively. Genes such as KDM5D and KDM6C showed gender-specific expression in 1-day and 21-day SAT. These results showed the significant changes in SAT between 1-day and 21-day in male and female Laiwu pigs, which would provide information to comprehensively understand the programming of adipose tissue early development and to regulate adipose tissue function.

A comprehensive analysis of CEBPA on prognosis and function in uterine corpus endometrial carcinoma

Uterine corpus endometrial carcinoma (UCEC) is one of the most common tumours of the female reproductive system. CCAAT enhancer-binding protein alpha (CEBPA) is a member of the transcription factor family involved in regulating processes such as cell proliferation, differentiation, metabolism, and the immune response. However, the role of CEBPA in UCEC has not been clarified. Here, we performed a comprehensive analysis to explore the expression level, prognostic value, immune infiltration and biological function of CEBPA in UCEC. In this study, we found that CEBPA expression was upregulated and associated with poor prognosis in UCEC patients. KEGG and GO analyses revealed that the genes positively correlated with CEBPA were enriched primarily in immune regulation and oxidative phosphorylation. Immune infiltration analysis revealed that CEBPA is strongly correlated with immune cell infiltration in UCEC. RT-qPCR indicated that CEBPA may regulate the OXPHOS level in Ishikawa cells. CCK-8, cell cycle, Transwell and scratch wound healing assays revealed that CEBPA promoted Ishikawa cell proliferation, invasion and migration. In addition, PPI and survival analyses suggested that CEBPG may be a potential target of CEBPA in UCEC. These results demonstrated that CEBPA may be a potential therapeutic target in UCEC.

C/EBPδ deficiency delays infection-induced preterm birth.

Parturition is an inflammation process. Exaggerated inflammatory reactions in infection lead to preterm birth. Although nuclear factor kappa B (NF-κB) has been recognized as a classical transcription factor mediating inflammatory reactions, those mediated by NF-κB per se are relatively short-lived. Therefore, there may be other transcription factors involved to sustain NF-κB-initiated inflammatory reactions in gestational tissues in infection-induced preterm birth. Cebpd-deficient mice were generated to investigate the role of CCAAT enhancer-binding protein δ (C/EBPδ) in lipopolysaccharide (LPS)-induced preterm birth, and the contribution of fetal and maternal C/EBPδ was further dissected by transferring Cebpd-/- or WT embryos to Cebpd-/- or WT dams. The effects of C/EBPδ pertinent to parturition were investigated in mouse and human myometrial and amnion cells. The interplay between C/EBPδ and NF-κB was examined in cultured human amnion fibroblasts. The mouse study showed that LPS-induced preterm birth was delayed by Cebpd deficiency in either the fetus or the dam, with further delay being observed in conceptions where both the dam and the fetus were deficient in Cebpd. Mouse and human studies showed that the abundance of C/EBPδ was significantly increased in the myometrium and fetal membranes in infection-induced preterm birth. Furthermore, C/EBPδ participated in LPS-induced upregulation of pro-inflammatory cytokines as well as genes pertinent to myometrial contractility and fetal membrane activation in the myometrium and amnion respectively. A mechanistic study in human amnion fibroblasts showed that C/EBPδ, upon induction by NF-κB, could serve as a supplementary transcription factor to NF-κB to sustain the expression of genes pertinent to parturition. C/EBPδ is a transcription factor to sustain the expression of gene initiated by NF-κB in the myometrium and fetal membranes in infection-induced preterm birth. Targeting C/EBPδ may be of therapeutic value in the treatment of infection-induced preterm birth.

Neonatal vitamin A but not retinoic acid administration increases intramuscular adipocyte number in sheep by promoting vascularization

This study investigated whether vitamin A (VA) administration during the neonatal stage could increase the number of intramuscular adipocytes in Hu sheep by promoting vascularity. A total of 56 newborn male Hu sheep were divided into four groups and received intramuscular injections of either 0, 7500 IU retinoic acid (RA), 7500 IU VA, or a combination of 7500 IU VA and 5 mg SU5416 (an angiogenic inhibitor), at 1, 7, 14, and 21 days of age. At 15 days of age, 6 sheep from each group were randomly selected and sacrificed for intramuscular adipogenic capacity analysis. The remaining 8 sheep in each group were raised until they were 8 months old. VA-treated sheep exhibited an increase in preadipocytes, elevated expression of adipogenic genes (CCAAT enhancer binding protein alpha [CEBPA] and CCAAT enhancer binding protein beta [CEBPB]) and angiogenic genes (vascular endothelial growth factor A [VEGFA]), and stromal vascular fraction cells in the longissimus dorsi (LD) muscle with enhanced adipogenic capacity (P ＜ 0.05). These effects were entirely negated by SU5416. Upon slaughter, VA increased final weight, carcass weight, and average daily gain (P ＜ 0.05) but did not affect feed intake at 21 to 32 weeks (P = 0.824). VA increased the number of intramuscular adipocytes in the LD and semitendinosus (ST) muscle (P ＜ 0.05) without changing the adipocyte number of the omentum, perirenal and subcutaneous fats (P ＞ 0.05). VA injections also increased intramuscular triglyceride (TG) content (P = 0.016) without changing the omentum fat weight or subcutaneous fat thickness (P ＞ 0.05), but it did increase the perirenal fat weight (P = 0.011). Consistently, SU5416 mitigated the effects of VA on intramuscular TG content and adipocyte count, correlating with a decrease in vascularity. In contrast, RA injections didn't affect the intramuscular fat (P = 0.744) but reduced the TG content of the omentum and perirenal fat (P ＜ 0.05). In conclusion, intramuscular injections of VA but not RA at the neonatal stage improved the growth performance of Hu sheep, increasing the number of intramuscular adipocytes and marbling by promoting angiogenesis.

Spatiotemporal Dysregulation of Neuron-Glia Related Genes and Pro-/Anti-Inflammatory miRNAs in the 5xFAD Mouse Model of Alzheimer's Disease.

Alzheimer's disease (AD), the leading cause of dementia, is a multifactorial disease influenced by aging, genetics, and environmental factors. miRNAs are crucial regulators of gene expression and play significant roles in AD onset and progression. This exploratory study analyzed the expression levels of 28 genes and 5 miRNAs (miR-124-3p, miR-125b-5p, miR-21-5p, miR-146a-5p, and miR-155-5p) related to AD pathology and neuroimmune responses using RT-qPCR. Analyses were conducted in the prefrontal cortex (PFC) and the hippocampus (HPC) of the 5xFAD mouse AD model at 6 and 9 months old. Data highlighted upregulated genes encoding for glial fibrillary acidic protein (Gfap), triggering receptor expressed on myeloid cells (Trem2) and cystatin F (Cst7), in the 5xFAD mice at both regions and ages highlighting their roles as critical disease players and potential biomarkers. Overexpression of genes encoding for CCAAT enhancer-binding protein alpha (Cebpa) and myelin proteolipid protein (Plp) in the PFC, as well as for BCL2 apoptosis regulator (Bcl2) and purinergic receptor P2Y12 (P2yr12) in the HPC, together with upregulated microRNA(miR)-146a-5p in the PFC, prevailed in 9-month-old animals. miR-155 positively correlated with miR-146a and miR-21 in the PFC, and miR-125b positively correlated with miR-155, miR-21, while miR-146a in the HPC. Correlations between genes and miRNAs were dynamic, varying by genotype, region, and age, suggesting an intricate, disease-modulated interaction between miRNAs and target pathways. These findings contribute to our understanding of miRNAs as therapeutic targets for AD, given their multifaceted effects on neurons and glial cells.

Polypeptide N-acetylgalactosaminyltransferase-15 regulates adipogenesis in human SGBS cells

Adipogenesis involves intricate molecular mechanisms regulated by various transcription factors and signaling pathways. In this study, we aimed to identify factors specifically induced during adipogenesis in the human preadipocyte cell line, SGBS, but not in the mouse preadipocyte cell line, 3T3-L1. Microarray analysis revealed distinct gene expression profiles, with 1460 genes induced in SGBS cells and 1297 genes induced in 3T3-L1 cells during adipogenesis, with only 297 genes commonly induced. Among the genes uniquely induced in SGBS cells, we focused on GALNT15, which encodes polypeptide N-acetylgalactosaminyltransferase-15. Its expression increased transiently during adipogenesis in SGBS cells but remained low in 3T3-L1 cells. Overexpression of GALNT15 increased mRNA levels of CCAAT-enhancer binding protein (C/EBPα) and leptin but had no significant impact on adipogenesis in SGBS cells. Conversely, knockdown of GALNT15 suppressed mRNA expression of adipocyte marker genes, reduced lipid accumulation, and decreased the percentage of cells with oil droplets. The induction of C/EBPα and peroxisome proliferator-activated receptor γ during adipogenesis was promoted or suppressed in SGBS cells subjected to overexpression or knockdown of GALNT15, respectively. These data suggest that polypeptide N-acetylgalactosaminyltransferase-15 is a novel regulatory molecule that enhances adipogenesis in SGBS cells.

Oxidative stress and regulation of adipogenic differentiation capacity by sirtuins in adipose stem cells derived from female patients of advancing age

Patient age is critical for mesenchymal stem cell quality and differentiation capacity. We demonstrate that proliferation and adipogenic capacity of subcutaneous adipose stem cells (ASCs) from female patients declined with advanced age, associated with reduction in cell nucleus size, increase in nuclear lamina protein lamin B1/B2, and lamin A, upregulation of senescence marker p16INK4a and senescence-associated β-galactosidase activity. Adipogenic induction resulted in differentiation of adipocytes and upregulation of adipogenic genes CCAAT enhancer binding protein alpha, fatty acid binding protein 4, lipoprotein lipase, and peroxisome proliferator-activated receptor-γ, which was not affected by the Sirt-1 activator YK-3-237 or the Sirt-1 inhibitor EX-527. Protein expression of the stem cell markers Oct4 and Sox2 was not significantly downregulated with advanced patient age. Mitochondrial reactive oxygen species were increased in ASCs from old-aged patients, whereas protein expression of NADPH oxidases NOX1 and NOX4 was downregulated, and dual oxidase isoforms remained unchanged. Generation of nitric oxide and iNOS expression was downregulated. Protein expression of Sirt-1 and Sirt-3 decreased with patient age, whereas Sirt-2 and Sirt-5 remained unchanged. Induction of adipogenesis stimulated protein expression of Sirt-1 and Sirt-3, which was not affected upon pre-incubation with the Sirt-1-activator YK-3-237 or the Sirt-1-inhibitor EX-527. The Sirt-1 inhibitor Sirtinol downregulated adiponectin protein expression and the number of adipocytes, whereas YK-3-237 exerted stimulatory effects. In summary, our data demonstrate increased oxidative stress in ASCs of aging patients, and decline of adipogenic capacity due to Sirt-1- mediated adiponectin downregulation in elderly patients.

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-β (Aβ) 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 Aβ25–35-induced cognitive impairment in mice; overexpression of hippocampal CLIC4 accelerated Aβ 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/EBPβ); 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/EBPβ/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.

Piperlongumine inhibits the early stage of adipogenesis in 3T3-L1 cells

Piperlongumine (PLM), a natural compound isolated from long peppers, has been reported to possess multiple pharmacological roles, including anti-tumor and anti-diabetic. However, the pharmacological role of PLM on adipogenesis is still unknown. In this study, we found that PLM strongly inhibited 3T3-L1 adipocyte differentiation. This inhibition was determined by the accumulation of lipid droplets and intracellular triglycerides. In addition, PLM downregulated both the mRNA and protein expression of adipogenic transcription factors, including CCAAT-enhancer binding proteins β (C/EBPβ), C/EBPα, and peroxisome proliferator-activated receptor γ (PPARγ). Based on the time-course experiment, we found that the inhibitory effect of PLM on adipogenesis was mainly involved in the early stage of adipogenesis. Studying these differential effects could uncover new mechanisms for regulating adipogenesis and new chemicals for treating obesity.

Proteomic analysis reveals the antiviral effects of baicalin on pseudorabies virus

Pseudorabies virus (PRV) poses a significant threat to livestock and even humans. Baicalin, a bioactive flavonoid glycoside with medicinal potential, has been reported to have various biological activities. However, its inhibitory effect on PRV remains poorly understood. In this study, we proved that baicalin effectively inhibits PRV infection. Proteomic analysis revealed that baicalin reduces the expression of 14 viral proteins, which are associated with virus replication, release and immune evasion. Furthermore, the abundance of 116 host proteins was altered by PRV infection, but restored to normal levels after treatment with baicalin. Pathway analysis indicated that baicalin mitigates reactive oxygen species (ROS) and suppresses abnormal mitochondrion by reducing the expression of NFU1 iron‑sulfur cluster scaffold homolog (NFU1) protein induced by PRV. Notably, baicalin also activates the complete coagulation cascade by increasing the expression of coagulation factor III (F3) protein and enhances nucleoplasm by upregulating the expression of solute carrier family 3 member 2 (SLC3A2) and CCAAT enhancer binding protein beta (CEBPB) proteins, contributing to its inhibitory effects on PRV. Our findings implied that baicalin has the potential to be developed as an anti-PRV drug and provide insights into the underlying molecular basis.

Targeting CEBPA to restore cellular identity and tissue homeostasis in pulmonary fibrosis.

Fibrosis in the lung is thought to be driven by epithelial cell dysfunction and aberrant cell-cell interactions. Unveiling the molecular mechanisms of cellular plasticity and cell-cell interactions is imperative to elucidating lung regenerative capacity and aberrant repair in pulmonary fibrosis. By mining publicly available RNA-Seq data sets, we identified loss of CCAAT enhancer-binding protein alpha (CEBPA) as a candidate contributor to idiopathic pulmonary fibrosis (IPF). We used conditional KO mice, scRNA-Seq, lung organoids, small-molecule inhibition, and potentially novel gene manipulation methods to investigate the role of CEBPA in lung fibrosis and repair. Long-term (6 months or more) of Cebpa loss in AT2 cells caused spontaneous fibrosis and increased susceptibility to bleomycin-induced fibrosis. Cebpa knockout (KO) in these mice significantly decreased AT2 cell numbers in the lung and reduced expression of surfactant homeostasis genes, while increasing inflammatory cell recruitment as well as upregulating S100a8/a9 in AT2 cells. In vivo treatment with an S100A8/A9 inhibitor alleviated experimental lung fibrosis. Restoring CEBPA expression in lung organoids ex vivo and during experimental lung fibrosis in vivo rescued CEBPA deficiency-mediated phenotypes. Our study establishes a direct mechanistic link between CEBPA repression, impaired AT2 cell identity, disrupted tissue homeostasis, and lung fibrosis.