This study integrates metabolomics and transcriptomics to explore the immediate effects of Angong Niuhuang Pills(ANP) in intervening traumatic brain injury(TBI) in rats. A TBI model was successfully established in rats using the optimized Feeney free-fall impact technique. Rats were randomly divided into sham operation(sham) group, model(Mod) group, positive drug(piracetam) group, ANP low-dose(ANP-L) group, and ANP high-dose(ANP-H) group according to a random number table. Nissl staining and immunofluorescence were used to count the number of Nissl bodies and detect B-cell lymphoma-2(Bcl-2) gene, caspase-3, and tumor protein 53(TP53) expression in brain tissue, and enzyme-linked immunosorbent assay(ELISA) was used to measure prostaglandin-endoperoxide synthase 2(PTGS2) level in rat brain tissue. Metabolomics and transcriptomics analyses were conducted for brain tissue from sham, Mod, and ANP-H groups. Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analyses were carried out to indicate the mechanisms of ANP in the intervention of TBI. Integrative metabolomics and transcriptomics analysis revealed the metabolic pathways involved in ANP's intervention in TBI. The results showed that ANP significantly increased the number of Nissl bodies in TBI rat brain tissue, upregulated Bcl-2 expression, and downregulated the levels of caspase-3, TP53, and PTGS2. Compared to the Mod group, the ANP-H group significantly upregulated 12 differential metabolites(DMs) and downregulated 25 DMs. Five key metabolic pathways were identified, including glycerophospholipid metabolism, pyrimidine metabolism, glycine, threonine, and serine metabolism, arginine and proline metabolism, and D-amino acid metabolism. Transcriptomics identified 730 upregulated and 612 downregulated differentially expressed genes(DEGs). Enrichment analysis highlighted that biological functions related to inflammatory responses and apoptotic processes, and key signaling pathways, including phosphoinositide 3-kinase(PI3K)/protein kinase B(Akt) and mitogen-activated protein kinase(MAPK) were significantly enriched. The data of transcriptomics and metabolomics pinpointed three key metabolic pathways, i.e., glycerophospholipid metabolism, pyrimidine metabolism, and glycine, threonine, and serine metabolism.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Rats ; Brain Injuries, Traumatic/metabolism* ; Male ; Metabolomics ; Rats, Sprague-Dawley ; Transcriptome/drug effects* ; Cyclooxygenase 2/genetics* ; Brain/metabolism* ; Caspase 3/genetics* ; Humans ; Tumor Suppressor Protein p53/genetics*

This study aims to explore the intervention effects of isorhamnetin(Isor) on acute lung injury(ALI) and its regulatory effects on pyroptosis mediated by the NOD-like receptor family pyrin domain containing 3(NLRP3)/apoptosis-associated speck-like protein containing a CARD(ASC)/cysteine aspartate-specific protease-1(caspase-1) axis. In the in vivo experiments, 60 BALB/c mice were divided into five groups. Except for the control group, the other groups were administered Isor by gavage 1 hour before intratracheal instillation of LPS to induce ALI, and tissues were collected after 12 hours. In the in vitro experiments, RAW264.7 cells were divided into five groups. Except for the control group, the other groups were pretreated with Isor for 2 hours before LPS stimulation and subsequent assessments. Hematoxylin-eosin(HE) staining was used to observe pathological changes in lung tissue, while lung swelling, protein levels in bronchoalveolar lavage fluid(BALF), and myeloperoxidase(MPO) levels in lung tissue were measured. Cell proliferation toxicity and viability were assessed using the cell counting kit-8(CCK-8) method. Enzyme-linked immunosorbent assay(ELISA) was used to detect the levels of interleukin-1β(IL-1β), IL-6, IL-18, and tumor necrosis factor-α(TNF-α). Protein levels of NLRP3, ASC, cleaved caspase-1, and the N-terminal fragment of gasdermin D(GSDMD-N) were evaluated using immunohistochemistry, immunofluorescence, and Western blot. The results showed that in the in vivo experiments, Isor significantly improved pathological damage in lung tissue, reduced lung swelling, protein levels in BALF, MPO levels in lung tissue, and levels of inflammatory cytokines such as IL-1β, IL-6, IL-18, and TNF-α, and inhibited the high expression of the NLRP3/ASC/caspase-1 axis and the pyroptosis core gene GSDMD-N. In the in vitro experiments, the safe dose of Isor was determined through cell proliferation toxicity assays. Isor reduced cell death and inhibited the expression levels of the NLRP3/ASC/caspase-1 axis, GSDMD-N, and inflammatory cytokines. In conclusion, Isor may alleviate ALI by modulating pyroptosis mediated by the NLRP3/ASC/caspase-1 axis.
Animals ; Pyroptosis/drug effects* ; NLR Family, Pyrin Domain-Containing 3 Protein/genetics* ; Acute Lung Injury/physiopathology* ; Mice ; Mice, Inbred BALB C ; Quercetin/pharmacology* ; Caspase 1/genetics* ; CARD Signaling Adaptor Proteins/genetics* ; Male ; RAW 264.7 Cells ; Humans ; Lung/metabolism*

This study aims to explore whether Albiziae Cortex-Tribuli Fructus can exert an anti-hepatic fibrosis effect by regulating the nuclear factor E2-related factor 2(Nrf2)/NOD-like receptor protein 3(NLRP3)/cysteine protease-1(caspase-1) pathway and analyze its potential mechanism. In the in vivo experiment, a mouse model of hepatic fibrosis was established by subcutaneous injection of carbon tetrachloride. The levels of alanine aminotransferase(ALT), aspartate aminotransferase(AST), collagen type Ⅳ(ColⅣ), laminin(LN), procollagen type Ⅲ(PCⅢ), and hyaluronic acid(HA) in the serum of mice were measured using a fully automated biochemical analyzer and ELISA. Hematoxylin and eosin(HE) and Masson staining were used to observe inflammation and collagen fiber deposition in the liver tissue. Western blot and RT-qPCR were employed to detect the protein and mRNA expression of collagen type Ⅰ(collagen Ⅰ), α-smooth muscle actin(α-SMA), Nrf2, NLRP3, gasdermin D(GSDMD), and caspase-1 in the hepatic tissue. In the in vitro experiment, human hepatic stellate cells(HSC-LX2) were pretreated with Nrf2 agonist or inhibitor, followed by the addition of blank serum, AngⅡ + blank serum, and AngⅡ + Albiziae Cortex-Tribuli Fructus-containing serum for intervention. Western blot was used to detect the protein expression of Nrf2, NLRP3, GSDMD, caspase-1, α-SMA, GSDMD-N, and apoptosis-associated speck-like protein(ASC) in cells. DCFH-DA fluorescence probe was used to detect the cellular ROS levels. The results from the in vivo experiment showed that, compared with the model group, Albiziae Cortex-Tribuli Fructus significantly reduced the serum levels of AST, ALT, ColⅣ, LN, PCⅢ, and HA, reduced the infiltration of inflammatory cells and collagen fiber deposition in the liver tissue, significantly upregulated the protein and mRNA expression of Nrf2 in the liver tissue, and significantly downregulated the protein and mRNA expression of collagen I, α-SMA, NLRP3, GSDMD, and caspase-1 in the liver tissue. The results from the in vitro experiment showed that Nrf2 activation decreased the protein expression of NLRP3, GSDMD, caspase-1, α-SMA, GSDMD-N, ASC, and ROS levels in HSC-LX2, while Nrf2 inhibition showed the opposite trend. Furthermore, Albiziae Cortex-Tribuli Fructus-containing serum directly decreased the expression of the above proteins and ROS levels. In conclusion, Albiziae Cortex-Tribuli Fructus can effectively improve hepatic fibrosis, and its mechanism of action may involve inhibiting pyroptosis through the regulation of the Nrf2/NLRP3/caspase-1 pathway.
Animals ; NF-E2-Related Factor 2/genetics* ; Liver Cirrhosis/genetics* ; Mice ; Drugs, Chinese Herbal/administration & dosage* ; Caspase 1/genetics* ; Male ; NLR Family, Pyrin Domain-Containing 3 Protein/genetics* ; Signal Transduction/drug effects* ; Humans ; Liver/metabolism* ; Mice, Inbred C57BL ; Plant Extracts ; Tribulus

OBJECTIVE: To investigate the effect of mild hypothermia on neurological function in rats with spinal cord injury (SCI) based on the adenosine monophosphate activated protein kinase (AMPK)/Nod-like receptor protein 3 (NLRP3) pathway. METHODS: Fifty 7-8 weeks old SPF male Sprague Dawley rats were used to establish rat model of SCI by Allen's method. Among them, 48 successfully modeled rats were randomly divided into SCI group, mild hypothermia group (SCI+mild hypothermia treatment), and Compound C group (SCI+mild hypothermia+intraperitoneal injection of 20 mg/kg AMPK/NLRP3 pathway inhibitor Compound C), with 16 rats in each group. Another 16 normal rats with laminectomy were selected as sham-operation group. Basso-Beattie-Bresnahan (BBB) score was used to evaluate the motor ability of rats at 1, 3, 7, 14 days after treatment. After 14 days, the rats were sacrificed, and the spinal cord histopathological morphology was observed by HE staining, the neuronal apoptosis in spinal cord tissue was detected by TUNEL assay, and the serum levels of interleukin 2 (IL-2), IL-6, transforming growth factor β ₁ (TGF-β ₁), malondialdehyde (MDA), and superoxide dismutase (SOD) were detected by ELISA. The expressions of AMPK/NLRP3 pathway proteins in spinal cord tissue, including B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and cleaved-Caspase-9 were detected by Western blot. RESULTS: At 1 day after treatment, the rats in SCI group, mild hypothermia group, and Compound C group did not recover their motor ability. With the prolongation of time, the motor function of rats in each group gradually recovered. Among them, the BBB score of SCI group was significantly lower than that of sham-operation group and mild hypothermia group ( P<0.05), and the BBB score of Compound C group was significantly lower than that of mild hypothermia group ( P<0.05). Compared with the sham-operation group, the SCI group displayed obvious pathological changes in the spinal cord tissue, with disordered tissue architecture, inflammatory infiltration, and blurred interstitial boundaries. The neuronal apoptosis rate, Bax/Bcl-2 ratio, cleaved Caspase-9 expression, NLRP3 protein expression, serum IL-2, IL-6, and MDA levels were elevated, whereas serum TGF-β ₁, SOD levels, and spinal cord phosphorylation AMPK/AMPK protein expression significantly decreased ( P<0.05). Compared with the SCI group, the above phenomena significantly improved in the mild hypothermia group ( P<0.05), while the Compound C group showed the opposite trend of change compared to the mild hypothermia group ( P<0.05). CONCLUSION Mild hypothermia can attenuate neurological dysfunction after SCI in rats, potentially by activating the AMPK/NLRP3 pathway.
Animals ; Spinal Cord Injuries/physiopathology* ; Rats, Sprague-Dawley ; Male ; Rats ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; AMP-Activated Protein Kinases/metabolism* ; Hypothermia, Induced ; Signal Transduction ; Spinal Cord/pathology* ; Apoptosis ; Interleukin-6/metabolism* ; Disease Models, Animal ; bcl-2-Associated X Protein/metabolism* ; Superoxide Dismutase/metabolism* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Caspase 9/metabolism*

Objective To explore the mechanism of lncRNA-BC200 (BC200) targeting the ubiquitination of Beta-site APP cleaving enzyme 1 (BACE1) and regulating the repair of nerve cell injury. Methods Mouse hippocampal neuron cell line HT22 was divided into four groups: control group, oxygen-glucose deprivation/reoxygenation(OGD/R) group, OGD/R+si-NC group and OGD/R+si-BC200 group. In order to further explore the relationship between BC200 and BACE1, HT22 cells were divided into four groups: OGD/R group, OGD/R+si-BC200 group, OGD/R+si-BC200+NC group and OGD/R+si-BC200+ BACE1 group. Twenty male C57BL/6J mice were randomly assigned to the following four groups: control group, middle cerebral artery occlusion (MCAO) group, MCAO+si-BC200 group and MCAO+si-BC200+BACE1 group. The mRNA expression levels of BC200 and BACE1 in cells were measured by real-time quantitative reverse transcription polymerase chain reaction. The expressions of c-caspase-3, B-cell lymphoma 2 (Bcl2), Bcl2 associated X protein(BAX) and BACE1 were detected by western blot, and the apoptotic cells were detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) test. Results Compared with the control group, the activity of HT22 cells in OGD/R group decreased significantly, and the percentage of apoptotic cells increased significantly. Compared with OGD/R+si-NC group, the activity of HT22 cells in OGD/R+si-BC200 group increased significantly, and the percentage of apoptotic cells decreased significantly. Compared with the control group, the expression of BACE1 protein in HT22 cells in OGD/R group was significantly enhanced. Compared with OGD/R+si-NC group, the expression of BACE1 protein in HT22 cells in OGD/R+si-BC200 group decreased significantly. It was observed that after OGD/R treatment, the ubiquitination level of BACE1 decreased significantly and the expression of BACE1 protein increased significantly. After transfection with si-BC200, the ubiquitination level of BACE1 protein increased significantly, while the expression of BACE1 protein decreased significantly. Compared with OGD/R+si-BC200+NC group, the percentage of apoptotic cells, the expression of c-caspase-3 and Bax protein in HT22 cells in OGD/R+si-BC200+BACE1 group increased significantly, and the expression of Bcl2 protein decreased significantly. Compared with the control group, the number of cerebral infarction areas and TUNEL positive cells in MCAO group increased significantly, and the survival number of neurons decreased significantly. Compared with the MCAO group, the number of cerebral infarction areas and TUNEL positive cells in MCAO+si-BC200 group decreased significantly, and the survival number of neurons increased significantly, while the addition of BACE1 reversed the improvement of si-BC200 transfection. Conclusion The combination of BC200 and BACE1 inhibit the ubiquitination of BACE1, and participate in mediating the expression enhancement of BACE1 induced by OGD/R. Specific blocking of BC200/BACE1 axis may be a potential therapeutic target to protect neurons from apoptosis induced by cerebral ischemia/reperfusion.
Animals ; Amyloid Precursor Protein Secretases/genetics* ; RNA, Long Noncoding/physiology* ; Aspartic Acid Endopeptidases/genetics* ; Male ; Neurons/pathology* ; Mice ; Mice, Inbred C57BL ; Apoptosis/genetics* ; Ubiquitination ; Cell Line ; Hippocampus/metabolism* ; bcl-2-Associated X Protein/genetics* ; Caspase 3/genetics* ; Infarction, Middle Cerebral Artery/metabolism*

Objective To investigate the impact of Qizhi Jiangtang Capsule (QZJT) on renal damage in diabetic nephropathy (DN) mice via NOD like receptors family pyrin domain containing 3/caspase-1/ Gasdermin D (NLRP3/caspase-1/GSDMD) signaling pathway. Methods Mice were randomly allocated into six experimental groups: a normal control group (NC), a diabetic nephropathy model group (DN), a low-dose QZJT treatment group (L-QZJT), a high-dose QZJT treatment group (H-QZJT), a positive control group administered Shenqi Jiangtang Granules (SQJT), and an ML385 group (treated with an inhibitor of nuclear factor erythroid 2-related factor 2, Nrf2). Upon successful model induction, therapeutic interventions were commenced. Renal function impairment in the mice was evaluated through quantification of fasting blood glucose (FBG), 24-hour urinary albumin (UAlb), serum creatinine (SCr), blood urea nitrogen (BUN), and the kidney-to-body mass ratio (K/B). Renal tissue pathology was evaluated using HE and PAS staining. Serum levels of inflammatory cytokines IL-1β and IL-18 were quantified by ELISA. Levels of podocyte markers and proteins involved in relevant pathways were assessed using Western blot analysis. Results Compared with the NC group, FBG, 24 h UAlb, SCr, and BUN were increased in the DN group, and the K/B mass ratio was also increased. In contrast, compared with the DN group, FBG, 24 h UAlb, SCr, and BUN in both the low-dose (L-QZJT) and high-dose Quanzhou Jintang (H-QZJT) groups were decreased, and the K/B mass ratio was decreased as well. The therapeutic efficacy of H-QZJT was comparable to that of Shenqi Jiangtang Granules. QZJT ameliorated renal histopathological injury in DN mouse, increased the protein levels of Nephrin (a podocyte marker), and decreased the protein levels of NLRP3, apoptosis-associated speck-like protein containing CARD (ASC), pro-caspase-1, and GSDMD-N. After ML385 treatment, renal cells exhibited swelling and morphological changes, the inflammatory infiltrate area was enlarged, the protein levels of NLRP3, ASC, pro-caspase-1, and GSDMD-N were up-regulated, and the levels of IL-1β and IL-18 were increased. Conclusion QZJT may inhibit podocyte pyroptosis by acting on the Nrf2 to regulate the NLRP3/caspase-1/GSDMD pathway, thus improving renal damage in DN mouse.
Animals ; Diabetic Nephropathies/pathology* ; Podocytes/pathology* ; NLR Family, Pyrin Domain-Containing 3 Protein/genetics* ; Pyroptosis/drug effects* ; Drugs, Chinese Herbal/administration & dosage* ; Caspase 1/genetics* ; Signal Transduction/drug effects* ; Mice ; Phosphate-Binding Proteins/genetics* ; Male ; Intracellular Signaling Peptides and Proteins/metabolism* ; Mice, Inbred C57BL ; Kidney/pathology* ; Gasdermins

OBJECTIVE: To investigate the role of MK2 inhibitor MMI-0100 on inflammatory response after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and related mechanisms. METHODS: An allo-HSCT mouse model was established. Recipient rats were randomly divided into BMT+NaCl group and BMT+MMI-0100 group, and were injected with NaCl and MMI-0100 every day after transplantation, respectively. Samples of the two groups were collected on d 7 and 14, femur paraffin sections were stained with HE, and pathological changes in the bone marrow cavity were observed under the light microscope. The gene and protein expression levels of pro-inflammatory cytokines IL-1β and IL-18 were detected by qPCR and Western blot. Macrophage typing was detected by flow cytometry. The expression levels of NLRP3 and Caspase-1 were detected by Western blot. RESULTS: Inflammatory cell infiltration in the bone marrow cavity was significantly reduced in the BMT+MMI-0100 group. Western blot results showed that the protein expression levels of IL-1β and IL-18 in the BMT+MMI-0100 group were decreased compared to the BMT+NaCl group on day 7 and day 14 (all P <0.01). The qPCR results showed that compared to the BMT+NaCl group, the IL-18 gene expression levels in the BMT+MMI-0100 group were significantly reduced on day 7 and day 14 (both P <0.01). In the BMT+MMI-0100 group, the expression level of IL-1β gene decreased on day 7 (P <0.05), but increased and was higher than that in the BMT+NaCl group on day 14 (P <0.05). Flow cytometry results showed that the expression of M1 macrophages and M1/M2 ratio decreased in the BMT+MMI-0100 group compared to BMT+NaCl group (all P <0.05). Western blot results showed that the protein expression levels of NLRP3 and Caspase-1 in the BMT+MMI-0100 group were lower than those in the BMT+NaCl group (all P <0.05). CONCLUSION MMI-0100 can ameliorate bone marrow inflammatory injury after allo-HSCT and may act by reducing NLRP3 expression to promote M2 polarization.
Animals ; Interleukin-1beta/metabolism* ; Rats ; Interleukin-18/metabolism* ; Hematopoietic Stem Cell Transplantation/adverse effects* ; Mice ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Inflammation ; Bone Marrow/pathology* ; Protein Serine-Threonine Kinases/metabolism* ; Intracellular Signaling Peptides and Proteins/antagonists & inhibitors* ; Caspase 1/metabolism* ; Macrophages ; Transplantation, Homologous

OBJECTIVE: To investigate the mechanism of electroacupuncture (EA) in treating diabetic gastroparesis (DGP) by inhibiting the activation of Nod-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome and pyroptosis mediated via NLRP3/cysteinyl aspartate specific proteinase-1 (caspase-1)/gasdermin D (GSDMD) signaling pathway. METHODS: Forty Sprague-Dawley rats were randomly divided into 4 groups including the control, DGP model, EA, and MCC950 groups. The DGP model was established by a one-time high-dose intraperitoneal injection of 2% streptozotocin and a high-glucose and high-fat diet for 8 weeks. EA intervention was conducted at Zusanli (ST 36), Liangmen (ST 21) and Sanyinjiao (SP 6) with sparse-dense wave for 15 min, and was administered for 3 courses of 5 days. After intervention, the blood glucose, urine glucose, gastric emptying, and intestinal propulsive rate were observed. Besides, HE staining was used to observe histopathological changes in gastric antrum tissues, and TUNEL staining was utilized to detect DNA damage. Protein expression levels of NLRP3, apoptosis-associated speck-like protein containing CARD (ASC), pro-caspase-1, caspase-1 and GSDMD were measured by Western blot. Immunofluorescence staining was employed to assess the activity of GSDMD-N. Lactate dehydrogenase (LDH) levels were detected by using a biochemical kit. RESULTS: DGP rats showed persistent hyperglycemia and a significant decrease in gastrointestinal motility (P<0.05 or P<0.01), accompanied by pathological damage in their gastric antrum tissues. Cellular DNA was obviously damaged, and the expressions of NLRP3, ASC, pro-caspase-1, caspase-1 and GSDMD proteins were significantly elevated, along with enhanced fluorescence signals of GSDMD-N and increased LDH release (P<0.01). EA mitigated hyperglycemia, improved gastrointestinal motility in DGP rats and alleviated their pathological injury (P<0.05). Furthermore, EA reduced cellular DNA damage, lowered the protein levels of NLRP3, ASC, pro-caspase-1, caspase-1 and GSDMD, suppressed GSDMD-N activity, and decreased LDH release (P<0.05 or P<0.01), demonstrating effects comparable to MCC950. CONCLUSION EA promotes gastrointestinal motility and repairs the pathological damage in DGP rats, and its mechanism may be related to the inhibition of NLRP3 inflammasome and pyroptosis mediated by NLRP3/caspase-1/GSDMD pathway.
Animals ; Electroacupuncture ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Pyroptosis ; Rats, Sprague-Dawley ; Caspase 1/metabolism* ; Gastroparesis/physiopathology* ; Signal Transduction ; Male ; Diabetes Mellitus, Experimental/physiopathology* ; Phosphate-Binding Proteins/metabolism* ; Gastrointestinal Motility ; Rats ; Intracellular Signaling Peptides and Proteins/metabolism* ; Diabetes Complications/physiopathology* ; Gasdermins

Non-alcoholic fatty liver disease (NAFLD), including non-alcoholic fatty liver (NAFL), non-alcoholic steatohepatitis (NASH), and advanced fibrosis, is a leading cause of chronic liver disease worldwide, progressing to cirrhosis and ultimately hepatocellular carcinoma (HCC). Excessive accumulation of fatty acids in the liver triggers multiple forms of hepatocyte death and exacerbates NAFLD progression, with pyroptosis and apoptosis considered key events. Recent studies show that cysteine aspartic acid specific protease-3 (caspase-3) is a central regulator of both pyroptosis and apoptosis in NAFLD. Activated caspase-3 not only directly induces apoptosis but also cleaves the N-terminal domain of gasdermin E (GSDME), disrupts cell membranes, releases inflammatory factors, and thereby mediates pyroptosis. Inhibiting caspase-3 expression in NAFLD can alleviate hepatocyte injury (such as ballooning degeneration), dampen pro-inflammatory signaling, and reduce apoptosis. Caspase-3 acts as a key node coordinating pyroptosis and apoptosis and may serve as a novel therapeutic target for the prevention and treatment of NAFLD.
Non-alcoholic Fatty Liver Disease/metabolism* ; Humans ; Pyroptosis/physiology* ; Apoptosis/physiology* ; Caspase 3/physiology* ; Animals ; Gasdermins

OBJECTIVES: To explore the mechanism by which histone deacetylase 1 (HDAC1) regulates steroid-induced apoptosis of mouse osteocyte-like MLO-Y4 cells. METHODS: MLY-O4 cells were treated with 400 nmol/L trichostatin A (TSA) or 1 mmol/L dexamethasone for 24 h or transfected with a HDAC1-overexpressing vector prior to TSA or dexamethasone treatment. The changes in the expressions of HDAC1, SP1, cleaved caspase-3 and Bax, SP1 acetylation level, cell proliferation, and cell apoptosis were examined. The interaction between HDAC1 and SP1 was determined with immunoprecipitation assay and Western blotting. RESULTS: Treatment with dexamethasone significantly increased cell apoptosis, enhanced the expressions of cleaved caspase-3 and Bax, reduced HDAC1 expression, and suppressed proliferation of MLO-Y4 cells. Both TSA and dexamethasone obviously increased SP1 acetylation level and the expression of SP1 in MLO-Y4 cells. HDAC1 overexpression in the cells significantly attenuated the effect of TSA and dexamethasone, promoted cell proliferation, lowered the expressions of SP1, cleaved caspase-3 and Bax, and inhibited dexamethasone-induced cell apoptosis. Immunoprecipitation assay and Western blotting demonstrated the interaction between HDAC1 and SP1 in the cells. CONCLUSIONS HDAC1 inhibits dexamethasone-induced apoptosis and promotes proliferation of cultured mouse osteocytes by suppressing SP1 expression via promoting its deacetylation.
Animals ; Apoptosis/drug effects* ; Mice ; Histone Deacetylase 1/genetics* ; Osteocytes/drug effects* ; Sp1 Transcription Factor/metabolism* ; Acetylation ; Dexamethasone/pharmacology* ; Cell Proliferation/drug effects* ; Caspase 3/metabolism* ; Cell Line ; Hydroxamic Acids/pharmacology* ; bcl-2-Associated X Protein/metabolism*