BACKGROUND: Perturbations in bone marrow mesenchymal stem cell (BMSC) differentiation play an important role in steroid-induced osteonecrosis of the femoral head (SONFH). At present, studies on SONFH concentrate upon the balance within BMSC osteogenic and adipogenic differentiation. However, BMSC apoptosis as well as proliferation are important prerequisites in their differentiation. The hedgehog (HH) signaling pathway regulates bone cell apoptosis. Baicalin (BA), a well-known compound in traditional Chinese medicine, can affect the proliferation and apoptosis of numerous cell types via HH signaling. However, the potential role and mechanisms of BA on BMSCs are unclear. Thus, we aimed to explore the role of BA in dexamethasone (Dex)-induced BMSC apoptosis in this study. METHODS: Primary BMSCs were treated with 10 -6 mol/L Dex alone or with 5.0 μmol/L, 10.0 μmol/L, or 50.0 μmol/L BA for 24 hours followed by co-treatment with 5.0 μmol/L, 10.0 μmol/L, or 50.0 μmol/L BA and 10 -6 mol/L Dex. Cell viability was assayed through the Cell Counting Kit-8 (CCK-8). Cell apoptosis was evaluated using Annexin V-fluorescein isothiocyanate/propidium iodide (PI) staining followed by flow cytometry. The imaging and counting, respectively, of Hochest 33342/PI-stained cells were used to assess the morphological characteristics and proportion of apoptotic cells. To quantify the apoptosis-related proteins (e.g., apoptosis regulator BAX [Bax], B-cell lymphoma 2 [Bcl-2], caspase-3, and cleaved caspase-3) and HH signaling pathway proteins, western blotting was used. A HH-signaling pathway inhibitor was used to demonstrate that BA exerts its anti-apoptotic effects via the HH signaling pathway. RESULTS: The results of CCK-8, Hoechst 33342/PI-staining, and flow cytometry showed that BA did not significantly promote cell proliferation (CCK-8: 0 μmol/L, 100%; 2.5 μmol/L, 98.58%; 5.0 μmol/L, 95.18%; 10.0 μmol/L, 98.11%; 50.0 μmol/L, 99.38%, F   =  2.33, P   >  0.05), but it did attenuate the effect of Dex on apoptosis (Hoechst 33342/PI-staining: Dex+ 50.0 μmol/L BA, 12.27% vs. Dex, 39.27%, t  = 20.62; flow cytometry: Dex + 50.0 μmol/L BA, 12.68% vs. Dex, 37.43%, t  = 11.56; Both P  < 0.05). The results of western blotting analysis showed that BA reversed Dex-induced apoptosis by activating the HH signaling pathway, which down-regulated the expression of Bax, cleaved-caspase 3, and suppressor of fused (SUFU) while up-regulating Bcl-2, sonic hedgehog (SHH), and zinc finger protein GLI-1 (GLI-1) expression (Bax/Bcl-2: Dex+ 50.0 μmol/L BA, 1.09 vs. Dex, 2.76, t  = 35.12; cleaved caspase-3/caspase-3: Dex + 50.0 μmol/L BA, 0.38 vs . Dex, 0.73, t  = 10.62; SHH: Dex + 50.0 μmol/L BA, 0.50 vs . Dex, 0.12, t  = 34.01; SUFU: Dex+ 50.0 μmol/L BA, 0.75 vs . Dex, 1.19, t  = 10.78; GLI-1: Dex+ 50.0 μmol/L BA, 0.40 vs . Dex, 0.11, t  = 30.68. All P  < 0.05). CONCLUSIONS BA antagonizes Dex-induced apoptosis of human BMSCs by activating the HH signaling pathway. It is a potential candidate for preventing SONFH.
Humans ; Hedgehog Proteins/metabolism* ; bcl-2-Associated X Protein ; Caspase 3/metabolism* ; Signal Transduction/physiology* ; Apoptosis ; Apoptosis Regulatory Proteins/pharmacology* ; Dexamethasone/pharmacology* ; Mesenchymal Stem Cells/metabolism* ; Bone Marrow Cells

Sympathetic cues via the adrenergic signaling critically regulate bone homeostasis and contribute to neurostress-induced bone loss, but the mechanisms and therapeutics remain incompletely elucidated. Here, we reveal an osteoclastogenesis-centered functionally important osteopenic pathogenesis under sympatho-adrenergic activation with characterized microRNA response and efficient therapeutics. We discovered that osteoclastic miR-21 was tightly regulated by sympatho-adrenergic cues downstream the β2-adrenergic receptor (β₂AR) signaling, critically modulated osteoclastogenesis in vivo by inhibiting programmed cell death 4 (Pdcd4), and mediated detrimental effects of both isoproterenol (ISO) and chronic variable stress (CVS) on bone. Intriguingly, without affecting osteoblastic bone formation, bone protection against ISO and CVS was sufficiently achieved by a (D-Asp₈)-lipid nanoparticle-mediated targeted inhibition of osteoclastic miR-21 or by clinically relevant drugs to suppress osteoclastogenesis. Collectively, these results unravel a previously underdetermined molecular and functional paradigm that osteoclastogenesis crucially contributes to sympatho-adrenergic regulation of bone and establish multiple targeted therapeutic strategies to counteract osteopenias under stresses.
Adrenergic Agents/pharmacology* ; Apoptosis Regulatory Proteins/pharmacology* ; Bone Diseases, Metabolic/metabolism* ; Humans ; Liposomes ; MicroRNAs/genetics* ; Nanoparticles ; Osteoclasts ; Osteogenesis/physiology* ; RNA-Binding Proteins/pharmacology*

Apoptosis plays important roles in maintaining normal development and homeostasis and in the pathophysiological processes of various diseases.Previous studies have shown that cardiomyocyte apoptosis is involved in the development of various cardiovascular diseases.The apoptosis repressor with caspase recruitment domain(ARC)is abundantly expressed in heart,which makes ARC a unique and central cardioprotective factor via anti-apoptotic pathway.This article reviews the structure and characteristics of ARC as well as the roles and mechanisms of ARC in cardiovascular diseases.
Apoptosis ; Apoptosis Regulatory Proteins ; physiology ; Cardiovascular Diseases ; Caspase Activation and Recruitment Domain ; Humans

Hepatocellular carcinoma (HCC) is one of the most common types of liver cancer and is the second leading cause of cancer mortality with an estimated 745 500 deaths annually (Jemal et al., 2011). Although new therapeutic modalities including novel chemotherapeutic interventions and targeted therapy have been applied, the prognosis of HCC patients remains unsatisfactory due to the high incidence of intrahepatic and distal metastases (Siegel et al., 2018).
Apoptosis Regulatory Proteins/physiology* ; Biomarkers ; Carcinoma, Hepatocellular/pathology* ; Female ; Genome ; Humans ; Hypoxia ; Liver Neoplasms/pathology* ; Male ; MicroRNAs/analysis* ; Neoplasm Staging ; Prognosis ; Repressor Proteins/physiology*

Oligodendrocytes (OLs) are myelinating glial cells that form myelin sheaths around axons to ensure rapid and focal conduction of action potentials. Here, we found that an axonal outgrowth regulatory molecule, AATYK (apoptosis-associated tyrosine kinase), was up-regulated with OL differentiation and remyelination. We therefore studied its role in OL differentiation. The results showed that AATYK knockdown inhibited OL differentiation and the expression of myelin genes in vitro. Moreover, AATYK-deficiency maintained the proliferation status of OLs but did not affect their survival. Thus, AATYK is essential for the differentiation of OLs.
Animals ; Animals, Newborn ; Apoptosis Regulatory Proteins ; genetics ; metabolism ; Cell Differentiation ; drug effects ; physiology ; Cell Proliferation ; drug effects ; genetics ; Cells, Cultured ; Cuprizone ; toxicity ; Demyelinating Diseases ; chemically induced ; metabolism ; pathology ; Embryo, Mammalian ; Gene Expression Regulation, Developmental ; genetics ; Ki-67 Antigen ; metabolism ; Mice ; Mice, Inbred C57BL ; Myelin Basic Protein ; metabolism ; Myelin Proteolipid Protein ; metabolism ; Myelin Sheath ; drug effects ; metabolism ; Oligodendroglia ; drug effects ; metabolism ; Protein-Tyrosine Kinases ; genetics ; metabolism ; RNA, Small Interfering ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF super family found in recent years, which widely exists in the body tissues and participates in the immune regulation, immune stability, and immune surveillance of the human body. The TRAIL receptor is expressed in the surface of a variety of cells. Recent studies show that TRAIL induces the apoptosis of tumor cells and has no significant toxic effect on normal cells. Its anti-tumor activity and safety have been widely recognized. The development of prostate cancer is regulated by the mechanisms of cell apoptosis. TRAIL can induce the apoptosis of prostate cancer cells, and therefore has a great application value in the treatment of prostate cancer.
Antineoplastic Agents ; therapeutic use ; Apoptosis ; Apoptosis Regulatory Proteins ; Humans ; Male ; Membrane Glycoproteins ; Prostatic Neoplasms ; drug therapy ; pathology ; Receptors, TNF-Related Apoptosis-Inducing Ligand ; physiology ; therapeutic use ; TNF-Related Apoptosis-Inducing Ligand ; Tumor Necrosis Factor-alpha

OBJECTIVE To explore downstream regulatory pathway of microRNA-21 (miR-21) in colon cancer cells (RKO) through detecting miR-21 and its target PDCD4, and the influence of miR-21 regulation on the sensitivity of RKO cells to 5-fluorouracil (5-FU). METHODS 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the effect of 5-FU on the viability of RKO cells with knockout of miR-21 or high expression of PDCD4. Real-time was used to determine the expression of PDCD4, ABCC5 and CD44 in RKO cell after knockout of miR-21. RESULTS MTT assay reveals that the IC50 of 5-FU in RKO-WT cells (52.82 ± 0.06 umol/L) was about 67% higher than in miR-21 knockout cells (32.23 ± 0.05 umol/L) (P < 0.05), and the apoptosis ratio elevated after knockout of miR-21. High expression of PDCD4, a target gene of miR-21, can negatively regulate the expression of ABC transporter ABCC5 and the stem cell marker CD44. CONCLUSION MiR-21 can mediate the drug resistance to 5-FU by inhibiting its target PDCD4, which can regulate the expression of ABCC5 and CD44 genes.
ATP Binding Cassette Transporter, Sub-Family G, Member 5 ; ATP-Binding Cassette Transporters ; genetics ; Antimetabolites, Antineoplastic ; pharmacology ; Apoptosis Regulatory Proteins ; physiology ; Cell Line, Tumor ; Colonic Neoplasms ; drug therapy ; pathology ; Drug Resistance, Neoplasm ; Fluorouracil ; pharmacology ; Humans ; Hyaluronan Receptors ; genetics ; Lipoproteins ; genetics ; MicroRNAs ; physiology ; RNA-Binding Proteins ; physiology

OBJECTIVETo study the changes in the levels of authophagy-related proteins ATG4A and p-ATG4A in nervous tissue after treated with tri-ortho-cresyl phosphate and explore the possible pathogenesis of OPIDN.

METHODSIn the first experiment, thirty hens were randomly divided into control group and 1 d, 5 d, 10 d and 21d treated groups, hens in treated groups were treated with TOCP by gavage at a single dosage of 600 mg/kg. In the second experiment, other thirty hens were also randomly divided into control group and 1 d, 5 d, 10 d and 21 d treated groups, hens in treated group were pretreated with PMSF by subcutaneous at a single dosage of 90 mg/kg. 24 h later, hens in intervention group was treated with TOCP by gavage at a single dosage of 600 mg/kg. The hens were killed at the corresponding time points, and collected their tibial nerves. The levels of ATG4A and p-ATG4A were measured by immunoblotting.

RESULTScompared with the control group, the levels of ATG4A decreased by36%, 43.7% and 41% at 1d, 5d and 10d in the intoxication groups (P < 0.05), the levels of p-ATG4A decreased by 22.5%, 25%and 21%at 1d, 5d and 10d in the intoxication group (P < 0.05). However, compared with the control group, there is no significant change in the levels of ATG4A and p-ATG4A in PMSF-pretreated groups.

CONCLUSIONThe intoxication of TOCP influence the levels of autophagy-related proteins ATG4A and p-ATG4A, which might be associated with the inhibition of autophagy activity in neurons of OPIDN.

Animals ; Apoptosis Regulatory Proteins ; metabolism ; Autophagy ; drug effects ; Chickens ; Female ; Nerve Tissue ; physiology ; Phosphorylation ; drug effects ; Tibial Nerve ; Tritolyl Phosphates ; toxicity

OBJECTIVE: Background: We detect the effects of Beclinl on paclitaxel-sensitivity in laryngeal carcinoma cell. METHOD: This study used Hep-2, Hep-2-pcDNA3. 1, Hep-2-Beclinl as invitro model. The effect of paclitaxel on the proliferation and cell apoptosis of laryngeal cancer cell lines was evaluated by MTT assay and flow cytometry. The protein expression level of Akt and p-Akt was detected by Western blot. Result: After treated by paclitaxel, the inhibition rate was significantly higher in Hep-2-Beclin cells than in Hep-2-pcDNA3. 1 cells and Hep-2 cells (P<. 05). After dealing with 10 tg/L paclitaxel, the apoptosis rate in Hep-2, Hep-2-pcDNA3. 1, Hep-2-Beclinl were (23. 75 ± 2 3. 77) %, (21. 25 ± 4. 92) %, (32. 50 ± 5. 97) %, respectively. After dealing with 20µg/L paclitaxel, the apoptosis rate in Hep-2, Hep-2-pcDNA3. 1, Hep-2-Beclinl were (38. 75 ± 4. 79) %, (38. 75±6. 55) %, (50. 00±7. 26) %, respectively. Paclitaxel-induced apoptosis was higher in Hep-2-Beclin cells than in Hep-2-pcDNA3. 1 cells and Hep-2 cells (P<. 05). The result of western blot showed that the protein expression level of p-Akt in Hep-2-Beclin cells was lower than in Hep-2-pcDNA3. 1 cells and Hep-2 cells (P<0. 05) and the protein expression level of Akt was similar in three cell lines (P>0. 05). CONCLUSION Beclinl enhances paclitaxel-sensitivity by inhibition of PI3K/Akt pathway.
Apoptosis ; Apoptosis Regulatory Proteins ; physiology ; Beclin-1 ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Laryngeal Neoplasms ; pathology ; Larynx ; Membrane Proteins ; physiology ; Paclitaxel ; pharmacology ; Phosphatidylinositol 3-Kinases

OBJECTIVETo explore the effects of microRNA-21 on apoptosis of myocardial cell of rats as induced by ischemia and hypoxia, and to analyze the underlying mechanisms.

METHODS(1) Rat myocardial cell line H9C2 was cultured in a serum-free and low glucose DMEM medium using a hypoxic incubator which was filled with 1% oxygen, 5% carbon dioxide, and 94% nitrogen to simulate ischemic environment. The expression of microRNA-21 in normal myocardial cells and cells treated with low oxygen exposure for 6 and 24 h were assessed by real-time fluorescent quantitative RT-PCR. (2) Another portion of myocardial cells were divided into 4 groups according to the random number table: normal control group (NC, ordinary culture without any treatment), ischemia/hypoxia group (IH, treated with ischemia and hypoxia for 24 h), negative transfection control+ischemia/hypoxia group (NC+IH, treated with ischemia and hypoxia for 24 h after the transfection of microRNA mimics control for 24 h), microRNA-21+ischemia/hypoxia group (M+IH, treated with ischemia and hypoxia for 24 h after the transfection of microRNA-21 mimics for 24 h). The cells in the latter three groups were examined immediately after treatment, and cells in group NC were collected and examined at the same time point. Apoptosis rate of myocardial cells was determined by flow cytometer. The mRNA and protein expression levels of programmed cell death 4 (PDCD4) in myocardial cells were determined by real-time fluorescent quantitative RT-PCR and Western blotting respectively. The sample numbers in this experiment were 6 or 3. Data were processed with one-way analysis of variance and LSD- t test.

RESULTS(1) The expression level of microRNA-21 in normal myocardial cells and cells treated with ischemia and hypoxia for 6 and 24 h were respectively 1.09 ± 0.17, 0.75 ± 0.08, and 0.67 ± 0.08 (F = 11.280, P = 0.009). Compared with expression level of microRNA-21 in normal myocardial cells, those of cells treated for 24 h (t = 4.461, P = 0.004) and 6 h (t = 3.642, P = 0.011) were both lower, and the former was more obvious. Therefore all the ischemia and hypoxia treatment time of cells in the following experiment was 24 h. (2) The apoptosis rate of myocardial cells in group NC was (3.5 ± 0.7)%. After being treated with ischemia and hypoxia for 24 h, the apoptosis rates of myocardial cells in groups IH, NC+IH, and M+IH were respectively (17.3 ± 3.2)%, (16.4 ± 3.0)%, and (7.6 ± 2.0)% (F = 15.176, P = 0.001). Compared with that of group NC, the apoptosis rate of myocardial cells of group IH was significantly increased (t = 5.641, P < 0.001), while it was significantly decreased in group M+IH as compared with group NC+IH (t = 3.588, P = 0.007). The mRNA expression level of PDCD4 in group NC was 1.06 ± 0.21. After being treated with ischemia and hypoxia for 24 h, the mRNA expression levels of PDCD4 in groups IH, NC+IH, and M+IH were respectively 3.01 ± 0.34, 3.05 ± 0.25, and 1.48 ± 0.24 (F = 44.952, P < 0.001). Compared with that of group NC, the mRNA expression level of PDCD4 in group IH was higher (t = 8.945, P < 0.001), while it was significantly lower in group M+IH as compared with group NC+IH (t = 7.253, P < 0.001). The protein expression level of PDCD4 in group NC was 0.44 ± 0.08. After being treated with ischemia and hypoxia for 24 h, the protein expression levels of PDCD4 in groups IH, NC+IH, and M+IH were respectively 0.96 ± 0.13, 1.05 ± 0.12, and 0.58 ± 0.12 (F = 18.804, P = 0.008). Compared with that of group NC, the protein expression level of PDCD4 in group IH was higher (t = 5.429, P = 0.006), while it was significantly reduced in group M+IH as compared with group NC+IH (t = 4.903, P = 0.008).

CONCLUSIONSIschemia and hypoxia reduce the expression of microRNA-21 in myocardial cells, while increasing the expression of microRNA-21 can alleviate the ischemia/hypoxia-induced apoptosis by lowering the expression of PDCD4.

Animals ; Apoptosis ; genetics ; physiology ; Apoptosis Regulatory Proteins ; genetics ; metabolism ; Blotting, Western ; Cell Line ; Flow Cytometry ; Hypoxia ; Ischemia ; MicroRNAs ; genetics ; Myocardium ; Myocytes, Cardiac ; RNA, Messenger ; genetics ; Rats ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection