Sex-Dependent Glial Signaling in Pathological Pain: Distinct Roles of Spinal Microglia and Astrocytes / 神经科学通报·英文版

Increasing evidence suggests that spinal microglia regulate pathological pain in males. In this study, we investigated the effects of several microglial and astroglial modulators on inflammatory and neuropathic pain following intrathecal injection in male and female mice. These modulators were the microglial inhibitors minocycline and ZVEID (a caspase-6 inhibitor) and the astroglial inhibitors L-α-aminoadipate (L-AA, an astroglial toxin) and carbenoxolone (a connexin 43 inhibitor), as well as U0126 (an ERK kinase inhibitor) and D-JNKI-1 (a c-Jun N-terminal kinase inhibitor). We found that spinal administration of minocycline or ZVEID, or Caspase6 deletion, reduced formalin-induced inflammatory and nerve injury-induced neuropathic pain primarily in male mice. In contrast, intrathecal L-AA reduced neuropathic pain but not inflammatory pain in both sexes. Intrathecal U0126 and D-JNKI-1 reduced neuropathic pain in both sexes. Nerve injury caused spinal upregulation of the astroglial markers GFAP and Connexin 43 in both sexes. Collectively, our data confirmed male-dominant microglial signaling but also revealed sex-independent astroglial signaling in the spinal cord in inflammatory and neuropathic pain.

Role of long non-coding RNA BC088414 in hypoxic-ischemic injury of neural cells / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the role of long non-coding RNA (lncRNA) BC088414 in hypoxic-ischemic injury of neural cells.</p><p><b>METHODS</b>Rat adrenal pheochromocytoma (PC12) cells were divided into four groups: normoxic, oxygen glucose deprivation (OGD), siRNA-normoxic (siRNA group) and siRNA-OGD (n=3 each). Cells were incubated in glucose-free and serum-free DMEM medium under the conditions of 37℃ and 1% O2+99% N2/CO2 for 6 hours to establish an in vitro hypoxic-ischemic model. Quantitative real-time PCR was used to measure mRNA expression of lncRNA BC088414, β2-adrenoceptor (Adrb2), and caspase-6 (CASP6). siRNAs were used to inhibit BC088414 expression in PC12 cells. The TUNEL method was used to measure cell apoptosis.</p><p><b>RESULTS</b>The OGD group had a significantly higher cell apoptotic index than the normoxic group (P<0.01). After inhibition of BC088414 expression, the OGD group had a significantly reduced apoptotic index (P<0.05). The OGD group had significantly higher mRNA expression levels of lncRNA BC088414, Adrb2, and CASP6 compared with the normoxic group (P<0.05). The siRNA -normoxic group had significantly lower mRNA expression levels of Adrb2 and CASP6 than the normoxic group (P<0.05), and the siRNA-OGD group also had significantly lower mRNA expression levels of Adrb2 and CASP6 than the OGD group (P<0.05).</p><p><b>CONCLUSIONS</b>LncRNA BC088414 may promote apoptosis through Adrb2 and CASP6 and aggravate neural cell injury induced by hypoxia-ischemia.</p>

Mechanism Underlying Curcumin-induced Apoptosis and Cell Cycle Arrest on SCC25 Human Tongue Squamous Cell Carcinoma Cell Line

Several studies have shown that curcumin, which is derived from the rhizomes of turmeric, possesses antimicrobial, antioxidant and anti-inflammatory properties. The antitumor properties of curcumin have also now been demonstrated more recently in different cancers. This study was undertaken to investigate the modulation of cell cycle-related proteins and the mechanisms underlying apoptosis induction by curcumin in the SCC25 human tongue squamous cell carcinoma cell line. Curcumin treatment of the SCC25 cells resulted in a time- and dose-dependent reduction in cell viability and cell growth, and onset of apoptotic cell death. The curcumin-treated SCC25 cells showed several types of apoptotic manifestations, such as nuclear condensation, DNA fragmentation, reduced MMP and proteasome activity, and a decreased DNA content. In addition, the treated SCC25 cells showed a release of cytochrome c into the cytosol, translocation of AIF and DFF40/CAD into the nuclei, a significant shift in the Bax/Bcl-2 ratio, and the activation of caspase-9, caspase-7, caspase-6, caspase-3, PARP, lamin A/C, and DFF45/ICAD. Furthermore, curcumin exposure resulted in a downregulation of G1 cell cycle-related proteins and upregulation of p27KIP1. Taken together, our findings demonstrate that curcumin strongly inhibits cell proliferation by modulating the expression of G1 cell cycle-related proteins and inducing apoptosis via proteasomal, mitochondrial, and caspase cascades in SCC25 cells.

Antioxidative and antiapoptotic effects of the Attractin gene on Sertoli cells in mice / 中华男科学杂志

<p><b>OBJECTIVE</b>To evaluate the effects of Attractin (Atrn) silence on the anti-oxidative and anti-apoptotic abilities of TM4 Sertoli cells and its influence on the expressions of superoxide dismutase (SOD) and caspase6 in the cells.</p><p><b>METHODS</b>We observed the apoptotic indexes of TM4 Sertoli cells with normal expression (control), partial deletion, and complete deletion of the Atrn gene (psiRNA-TM4, psiAtrn-TM4, and mu-SC). We determined the mRNA and protein expressions of SOD and caspase6 by Q-PCR and Western blot, measured the SOD activity and malondialdehyde (MDA) contentby spectrophotometry, and detected the apoptotic index of the cells by TUNEL.</p><p><b>RESULTS</b>Compared with psiRNA-TM4, after inhibition of the Atrn expression, the Sertoli cells in the psiAtrn-TM4 and mu-SCgroups showed significantly decreased expressions ofSOD mRNA (70.76% and 92.58%) and protein (65.11% and 71.0%) (both P < 0.05). The levels of caspase 6 mRNA and protein were increased 5.28 and 3.40 times in the psiAtrn-TM4 and 2.97 and 2.50 times in the mu-SCgroup as compared with the normal control (both P < 0.05). Atrn deletion markedly increased the apoptotic indexes of the cells in the psiAtrn-TM4 and mu-SC groups by 16.22% and 22.03% (P < 0.05) and reduced the activity of SOD by 23.00% and 39.37% (P < 0.05); it also elevated the level of MDA by 155.22% (P < 0.05).</p><p><b>CONCLUSION</b>The Atrn gene exerts influence on the function of Sertoli cells in multiple ways, in which antioxidative stress and apoptosis regulation may play an important role.</p>

Inhibition of Jumi extraction on growth of human cervical cancer cell line HeLa / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the inhibition of Jumi (traditional Chinese medicine) extraction on the growth of human cervical cancer cell line HeLa.</p><p><b>METHODS</b>Nude mouse model of human cervical cancer HeLa cell transplantation was established. The nude mice bearing cancer were randomly divided into control group and Jumi treated groups with different concentration (0.001, 0.002, 0.005, 0.01 mg/ml). The growth of cervical cancer cell in experimental mice were measured. Cultured HeLa cells were incubated in culture media with or without Jumi extract for 48 hours. Cell proliferation rate, cell apoptosis, caspase-3/7 and caspase-6 activity were determined by MTT colorimetric assay, flow cytometry analysis and spectrophotometric detection, respectively.</p><p><b>RESULTS</b>With the increase of the concentration of Jumi extract, tumor-bearing mice tumor inhibition rate gradually increased. The proliferation of cultured HeLa cells were significantly inhibited by Jumi extract in a dose-dependent manner. IC50 was 0.004 mg/ml. Apoptosis rates in the cells treated with Jumi extract were higher than those of the control group. Compared with the control group, except for lower Jumi treated group (0.001 mg/ml), caspase-3/7 and caspase-6 activity were significantly increased in the all Jumi treated groups.</p><p><b>CONCLUSION</b>Jumi extract can inhibit the proliferation of human cervical cancer cell line HeLa in vitro in a dose-dependent manner and promote cell apoptosis through caspase-3, caspase-7 and caspase-6 pathway.</p>

Mechanism Underlying NaF-induced Apoptosis and Cell Cycle Arrest on G361 Human Melanoma Cell Line / 체질인류학회지

Fluoride is widely used in dentistry to prevent dental caries, even though the safety of fluoride is a controversial issue. There are no known adverse effects of long-term fluoride ingestion for caries prevention, but an overdose can cause serious acute toxicity. Nevertheless it is accepted that fluoride is an important material for oral health. This study was undertaken to investigate the modulation of cell cycle-related proteins and apoptosis induction underlying mechanism by NaF treatment on G361 human melanoma cell line. The viability of G361 cells and the growth inhibition of G361 cells were assessed by MTT assay and clonogenic assay respectively. Hoechst staining, DNA electrophoresis and TUNEL staining were conducted to observe G361 cells undergoing apoptosis. G361 cells were treated with NaF, and Western blotting, immunocytochemistry, confocal microscopy, FACScan flow cytometry, MMP activity and proteasome activity were performed. NaF treatment in G361 cells resulted in a time- and does-dependent decrease of cell viability and a does-dependent inhibition of cell growth, and induced apoptotic cell death. And tested G361 cells showed several lines of apoptotic manifestation such as nuclear condensation, DNA fragmentation, the reduction of MMP and proteasome activity, the decrease of DNA contents, the release of cytochrome c into cytosol, the translocation of AIF and DFF40 (CAD) onto nuclei, a significant shift of Bax/Bcl-2 ratio, and the activation of caspase-9, caspase-7, caspase-6, caspase-3, PARP, Lamin A/C and DFF45 (ICAD). Furthermore, NaF resulted in down-regulation of the G1 cell cycle-related proteins, and up-regulation of p53. Taken collectively, our present findings demonstrate that NaF strongly inhibits cell proliferation by modulating the expression of the G1 cell cycle-related proteins and induces apoptosis via proteasome, mitochondria and caspase cascades in G361 cells.

Zinc: A promising agent in dietary chemoprevention of cancer.

Proper intake of dietary nutrients is considered crucial for preventing the initiation of events leading to the development of carcinoma. Many dietary compounds have been considered to contribute in cancer prevention including zinc, which plays a pivotal role in host defense against the initiation and promotion of several malignancies. Zinc is an essential element that is integral to many proteins and transcription factors which regulate key cellular functions such as the response to oxidative stress, DNA replication, DNA damage repair, cell cycle progression, and apoptosis. Zinc has been ascribed roles in the metabolism and interaction of malignant cells, particularly in apoptosis. Zinc is involved in structural stabilization and activation of the p53 that appears to be an important component of the apoptotic process and also in activation of certain members of the caspase family of proteases. Zinc exerts a positive beneficial effect against chemically induced preneoplastic progression in rats and provides an effective dietary chemopreventive approach to disease in vulnerable section of population with family history of carcinoma. The present review provides an insight into the research conducted on animals as well as on human subjects for providing the concept that zinc deficiency is an important factor in the development and progression of malignancy and that zinc could be efficacious in the prevention and treatment of several cancers viz., colon, pancreas, oesophageal and head and neck. However, it needs further exploration with regard to other definitive bioassays including protein expression and documentation of specific molecular markers to establish the exact mechanism for zinc-mediated cancer chemoprevention. Preclinical trials need to investigate the genetic and epigenetic pathways of chemoprevention by zinc.

Pro-apoptotic effect on osteosarcoma SOSP-9607 cells by human recombinant caspase-6 fusion protein / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the pro-apoptotic effect of Her-2 targeted recombinant caspase-6 fusion protein on osteosarcoma SOSP-9607 cells.</p><p><b>METHODS</b>Recombinant immunocasp-6 was generated by sequential fusion of the genes of a signal peptide, a single-chain Her-2 antibody (e23sFv), a PEA translocation domain (PEA aa253-364) and an active caspase-6. The immunocasp-6 gene was cloned into pCMV plasmid to construct a kind of eukaryotic expression vector, i.e. pCMV-e23sfv-PE II-caspase-6 (abbr. pCMV-6) and transfected into SOSP-9607 cells. Murine xenograft models were randomly divided into two groups that received i.m. injections of liposome encapsulated pCMV-6 or pCMV alone. The tumor volume and weight of the nude mice and the tumor weight of the cured mice were observed and statistically analyzed. The morphological changes of the tumors were examined with HE staining, apoptotic morphology of the tumor was observed by TUNEL staining and the gene expression was analyzed by immunohistochemical staining.</p><p><b>RESULTS</b>The tumor growth of the mice in the treatment group was significantly slower than that of the control group (P = 0.001). The weight of the nude mice in the treatment group was significantly higher than that of the control group (P = 0.0002). The tumor weight of the mice in the treatment group was significantly lower than that of the control group (P = 0.0006). HE and TUNEL staining of the tumor of nude mice in the treatment groups showed typical characteristics of apoptosis, while normal structure was found in the control group. Furthermore, caspase-6 was not found in the tumor and muscle tissues in the control group, but only in the treatment group by immunohistochemistry.</p><p><b>CONCLUSION</b>Immunocasp-6 can selectively recognize and bind to and kill HER-2 positive osteosarcoma cells, therefore, to offer some foundation for the clinical treatment of osteosarcoma.</p>

Streptomycin-induced apoptosis of rat cochlear hair cell cultured in vitro / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To evaluate if caspase pathway was involved in streptomycin-induced cell apoptosis in cochlear hair cells.</p><p><b>METHODS</b>F344 rats at postnatal day 3 or 4 were used for the study in cochlear organotypic cultures. The cochlear basilar membrane was micro-dissected out and cultured overnight, and then treated with 1 mmol/L streptomycin for 24 hours. Before the termination, the activity of caspase-8, 9 or 6 were detected with FAM-peptide-FMK labeled caspase-8, 9 or 6, respectively. The stereocilia and cuticular plate of hair cells were stained with TRITC conjugated phalloidin, and the nuclei were stained with Topro-3 DNA probe. The specimens were observed and photographed under confocal fluorescent microscope.</p><p><b>RESULTS</b>Streptomycin with 1 mmol/L causes about 80% cochlear hair cells missing in the basal turn and 10% hair cell loss in the apex. After streptomycin treatment, the nuclear shrinkage and fragmentation were found in most cochlear hair cells, and the caspase-8, caspase-9 and caspase-6 were greatly activated.</p><p><b>CONCLUSIONS</b>Apoptosis is involved in the cochlear hair cells death induced by Streptomycin in vitro. The caspase activities in upstream and downstream are maybe the major apoptotic pathway.</p>

Induction of Apoptosis by Genistein in Human Melanoma Cells / 대한해부학회지

Genistein is a naturally occurring isoflavone that has been identified predominantly in soybean. It has been found that genistein can inhibit the growth of various cancer cell lines. Melanoma continues to increase in incidence in many parts of the world and remains among the top six cancers as a cause of death and morbidity. Understanding and overcoming resistance mechanism(s) of melanoma to apoptosis would therefore facilitate identification of new therapeutic targets and development of new treatments. This study was undertaken to investigate whether genistein induced apoptosis on human melanoma cells (G361). Genistein had a significant dose- and time-dependent inhibitory effect on the viability of G361 cells. The death of cells was further demonstrated to be due to apoptosis characterized by chromatin condensation and apoptotic bodies by hoechst staining, and DNA electrophoresis. p53 levels were not altered by genistein treatment. Genistein treatment induced caspase-3 cleavage and activation. Poly (ADP-ribose)-polymerase (PARP) and DNA fragmentation factor 45 (DFF45), which are caspase-3 substrates, were cleaved during genistein-induced apoptosis. It was found that the caspase-6 substrate lamin A was cleaved, whose cleavage has been reported to be necessary for complete condensation of DNA during apoptosis. The expression level and phosphorylation of focal adhesion kinase (FAK) were reduced by genistein treatment. These results suggest that genistein may constitute a potential antitumor compound against melanoma occurring at oral mucosa and skin.

Phloretin induces apoptosis of BEL-7402 cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To examine the effect of phloretin on apoptosis of BEL-7402 cells.</p><p><b>METHODS</b>The viability changes of BEL- 7402 cells as a result of phloretin-induced toxicity were analyzed using MTT assay, and the cell morphology changes were observed with fluorescence microscope. Flow cytometry was used to analyze the cell cycle and mitochondrial membrane potential changes, and chromogenic substrate assay performed to detect caspase activity.</p><p><b>RESULTS</b>Phloretin induced obvious cytotoxicity against BEL-7402 cells with IC50 of 89.23 microg/mL. The growth curve demonstrated decreased growth of the cells as phloretin concentration increased. Cell apoptosis occurred 24 h after treatment with 40-160 microg/mL phloretin. Morphological, the cells exposed to phloretin exhibited nuclear chromatin condensation and increased fluorescence intensity. The activity of caspase-9 reached the peak level 12 h after phloretin exposure, and leak levels of caspase-6 and caspase-3 activities occurred 18 and 24 h after the exposure, respectively.</p><p><b>CONCLUSION</b>Phloretin can induce BEL-7402 cell apoptosis though the mitochondrial pathway.</p>

Induction of G2 /M phase arrest and apoptosis of MCF-7 cells by novel benzofuran lignan via suppressing cell cycle proteins / 药学学报

In the present study, a newly synthesized benzofuran lignan 4-formyl-2-(4-hydroxy-3methoxyphenyl)-5-(2-methoxycarbonyethyl)-7-methoxy-benzo [b] furan (ERJT-12) was tested for its antiproliferative activity on human tumor cells. The related mechanisms were also investigated. In vitro growth inhibitory effects of ERJT-12 on various cancer cell lines were determined by MTT assay. Cell cycle distribution and apoptosis were detected by flow cytometry. The integrity of DNA was assessed by agarose gel electrophoresis. Activation of Caspase-3/7 and Caspase-6 was measured by colorimetric assay. The expressions of cell cycle proteins cell divide cycle 25c (Cdc25c), cyclin dependent kinase 1 (CDK1), CyclinB1 and apoptosis-related proteins Bax and Bcl-2 were detected by Western blotting. MTT assay showed that ERJT-12 inhibited the proliferation of several cancer cell lines including multidrug resistant cells. MCF-7 cells were markedly arrested at gap2/mitosis (G2/M) phase after treatment with ERJT-12 and progressed into apoptosis. The increased activities of Caspase-3/7 and Caspase-6 in MCF-7 cells were observed. The expression of CyclinB1 was down-regulated. The activities of Cdc25c and CDK1 protein were suppressed and Bcl-2 protein was phosphorylated. ERJT-12 displays potent antiproliferative activity towards cancer cells through suppressing cell cycle proteins, arresting cell cycle at G2/M phase and inducing apoptosis. It might be a novel candidate for cancer therapy.

J774A.1 cell apoptosis induced by Leptospira interrogans and effects of caspase-3, -6 activation on apoptosis / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the apoptosis of J774A.1 cells induced by Leptospira interrogans and the effect of caspase-3, -6 activation on the apoptosis.</p><p><b>METHODS</b>Mouse monocyte-macrophage like cell line J774A.1 was infected by L.interrogans serogroup Icterohaemorrhagiae serovar icterohaemorrhagiae Lai strain 56601. The apoptosis or necrosis of infected cells was examined by flow cytometry using fluorescein labeling FITC-Annexin V/PI. The activity of caspase-3, -6, and their cleaved substrates PARP and Lamin A/C were measured by fluorometry and Western Blotting, respectively.</p><p><b>RESULT</b>L. interrogans strain Lai was able to induce apoptosis of J774A.1 cells and the maximal apoptotic rate was(48.81+/-5.95)% when microbe: cell ratio was 100: 1. The maximal activities of caspase-3 and -6 in the infected J774A.1 cells were (1453.41+/-36.07) and (618.65+/-39.82) FU, respectively, which were 16.38- and 9.98-fold of those uninfected cells. PARP and Lamin A/C in the infected cells were detected. Caspase-3 and -6 inhibitors remarkably blocked the L. interrogans-induced apoptosis in J774A.1 cells.</p><p><b>CONCLUSION</b>L. interrogans is able to induce the apoptosis of J774A.1 cells and intracellular caspase-3 and -6 are closely associated with the apoptosis.</p>

A study on the time-dependent expression of caspase-6 during repair of skin contusion in rats / 法医学杂志

OBJECTIVE@#To investigate the expression of caspase-6 in rat skin contusion and its surrounding areas during repairment.@*METHODS@#Immunohistochemical SP method and Western blot technique were used to study the expression and activation of caspase-6 in rat skin contusion and its surrounding areas.@*RESULTS@#Weak expression of caspase-6 was detected in cytoplasms of polymorphonuchear cells (PMNs) infiltrated in the injured area at 3 hours post-contusion. The ratio of the caspase-6 positive cells was low (25.78 +/- 1.38)%. The expression of caspase-6 was increased prominently (47.70 +/- 5.14)% at 12 hours post-contusion. Almost all of the PMNs, mononuclear cells (MNCs) and fibroblastic cells (FBCs) were caspase-6 positive with both cytoplasm and nucleus staining (54.58 +/- 5.64)% on post-contusion day 3. The expression of caspase-6 decreased gradually thereafter. The expression of the 34-kDa pro-caspase-6 was detected by Western blot in both control and the post-contusion groups with time dependent dynamics.@*CONCLUSION@#These results suggest that caspase-6 may play a major role in trauma-induced inflammatory response. Since caspase-6 shows a timely dependent expression in PMNs, MNCs and FBCs during skin injury repair in rat, it may be used as a marker for the contusion age determination,

zVAD-fmk, unlike BocD-fmk, does not inhibit caspase-6 acting on 14-3-3/Bad pathway in apoptosis of p815 mastocytoma cells

In a preliminary study, we found that benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone (zVAD- fmk), unlike Boc-aspartyl(OMe)-fluoromethylketone (BocD-fmk), at usual dosage could not prevent genistein-induced apoptosis of p815 mastocytoma cells. This study was undertaken to reveal the mechanism underlying the incapability of zVAD-fmk in preventing this type of apoptosis. We observed that 14-3-3 protein level was reduced in genistein-treated cells and that BocD-fmk but not zVAD-fmk prevented the reduction of 14-3-3 protein level and the release of Bad from 14-3-3. We also demonstrated that truncated Bad to Bcl-xL interaction in genistein- treated cells was prevented by BocD-fmk but not by zVAD-fmk treatment. Our data indicate that BocD- fmk, compared to zVAD-fmk, has a certain preference for inhibiting 14-3-3/Bad signalling pathway. We also elucidated that this differential efficacy of BocD-fmk and zVAD-fmk resulted from the different effect in inhibiting caspase-6 and that co-treatment of zVAD-fmk and caspase-6 specific inhibitor substantially prevented genistein-induced apoptosis. Our data shows that caspase-6 plays a role on Bad/14-3-3 pathway in genistein-induced apoptosis of p815 cells, and that the usual dose of zVAD-fmk, in contrast to BocD-fmk, did not prevent caspase-6 acting on 14-3-3/Bad-mediated event.

Induction of Apoptosis in Human Oral Squamous Carcinoma Cells by Extracellular Products from Pseudomonas aeruginosa / 대한해부학회지

It was reported that cancer in humans and animals infected with microbial pathogens was regressed about 100 years ago. Bacteria are able to trigger apoptosis by a variety of mechanisms including the secretion of protein synthesis inhibitors, pore forming proteins, molecules activating the endogenous death machinery in the infected cell. This study was conducted in order to investigate whether extracellular products of Psuedomonas aeruginosa (EPPA) induce apoptosis in human oral carcinoma cells (OSC9). The EPPA showed cytotoxic effect on OSC9 cells in dose and time-dependent manner. The cell death was demonstrated to be due to apoptosis characterized by chromatin condensation and nuclear fragment. EPPA treatment induced cleavage of caspase-3 and caspase-6. The caspase substrates, PARP, DFF45 and lamin A were cleaved during EPPA-induced apoptosis. Taken together, EPPA induces apoptosis on human oral squamous carcinoma cells in caspase-dependent manner. Our data therefore provide that EPPA contains a novel antitumor agent for human oral squamous carcinoma.

Role of p-38 MAP Kinase in apoptosis of hypoxia-induced osteoblasts / 대한치과교정학회지

Tooth movement by orthodontic force effects great tissue changes within the periodontium, especially by shifting the blood flow in the pressure side and resulting in a hypoxic state of low oxygen tension. The aim of this study is to elucidate the possible mechanism of apoptosis in response to hypoxia in MC3T3E1 osteoblasts, the main cells in bone remodeling during orthodontic tooth movement. MC3T3E1 osteoblasts under hypoxic conditions (2% oxygen) resulted in apoptosis in a time-dependent manner as estimated by DNA fragmentation assay and nuclear morphology stained with fluorescent dye, Hoechst 33258. Pretreatment with Z-VAD-FMK, a pan-caspase inhibitor, or Z-DEVD-CHO, a specific caspase-3 inhibitor, completely suppressed the DNA ladder in response to hypoxia. An increase in caspase-3-like protease (DEVDase) activity was observed during apoptosis, but no caspase-1 activity (YVADase) was detected. To confirm what caspases are involved in apoptosis, Western blot analysis was performed using anti-caspase-3 or -6 antibodies. The 10-kDa protein, corresponding to the active products of caspase-3, and the 10-kDa protein of the active protein of caspase-6 were generated in hypoxia-challenged cells in which the processing of the full length form of caspase-3 and -6 was evident. While a time course similar to this caspase-3 and -6 activation was evident, hypoxic stress caused the cleavage of lamin A, which was typical of caspase-6 activity. In addition, the stress elicited the release of cytochrome c into the cytosol during apoptosis. Furthermore, we observed that pre-treatment with SB203580, a selective p38 mitogen activated protein kinase inhibitor, attenuated the hypoxia-induced apoptosis. The addition of SB203580 suppressed caspase-3 and -6-like protease activity by hypoxia up to 50%. In contrast, PD98059 had no effect on the hypoxia-induced apoptosis. To confirm the involvement of MAP kinase, JNK/SAPK, ERK, or p38 kinase assay was performed. Although p38 MAPK was activated in response to hypoxic treatment, the other MAPK -JNK/SAPK or ERK- was either only modestly activated or not at all. These results suggest that p38 MAPK is involved in hypoxia-induced apoptosis in MC3T3E1 osteoblasts.

Effects of caspases on cerebromicrovascular endothelial cell apoptosis induced by hypoxia / 药学学报

<p><b>AIM</b>To study the effects of caspases on cerebromicrovascular endothelial cell apoptosis induced by hypoxia in vitro.</p><p><b>METHODS</b>The cultured bovine cerebromicrovascular endothelial cells were exposed to NaCN in glucose-free medium. Cell viability was determined by trypan blue staining. Cell apoptosis was defined by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) and flow cytometry. The expression of caspase-3 was detected by immunocytochemical method. Four caspase inhibitors were used to validate the effect of caspases on cell apoptosis.</p><p><b>RESULTS</b>NaCN in glucose-free medium initiated cerebromicrovascular endothelial cell injury markedly and typical apoptotic cells were found in this model. The expression of caspase-3 increased significantly. Four caspase inhibitors decreased the number of injured cells. Selective inhibitor of caspase-1 and -6 reduced expression of caspase-3 significantly.</p><p><b>CONCLUSION</b>The results suggest that caspases family plays an important role in cerebromicrovascular endothelial cell apoptosis induced by NaCN and caspase-3 acts on the downstream of caspase-1 and -6 in protease cascade action to induce apoptosis.</p>

Effect of Hypoxia on the Signal Transduction of Apoptosis in Osteoblasts / 대한치과교정학회지

Mammalian cell is critically dependent on a continuous supply of oxygen. Even brief periods of oxygen deprivation can result in profound cellular damage. The aim of this study was to examine the possible mechanism of apoptosis in response to hypoxia in MC3T3E1 osteoblasts. MC3T3E1 osteoblasts under hypoxic conditions (2% oxygen) resulted in apoptosis in a time-dependent manner, determined by DNA fragmentation assay and nuclear morphology, stained with fluorescent dye (Hoechst 33258) Pretreatment with Z-VAD-FMK, a pan-caspase inhibitor, or Z-DEVD-CHO, a specific caspase-3 inhibitor, suppressed the DNA ladder in response to hypoxia in a concentration-dependent manner. An increase in caspase-3-like protease (DEVDase) activity was observed during apoptosis, but no caspase-1 activity (YVADase) was detected. To confirm what caspases were involved in apoptosis, western blot analysis was performed using an anti-caspase-3 or 6 antibody. The 17-kDa protein, that corresponds to the active products of caspase-3 and the 20-kDa protein of the active protein of caspase-6 were generated in hypoxia-challenged lysates, in which the full length forms of caspase-3 and 6 were evident. With a time course similar to caspase-3 and 6 activation, hypoxic stress also caused the cleavage of Lamin A, typical of caspase-6 activity. In addition, the hypoxic stress elicited the release of cytochrome c into the cytosol during apoptosis. These findings suggested that the activation of caspases accompanied by a cytochrome c release in response to hypoxia was involved in apoptotic cell death in MC3T3E1 osteoblasts.

Role of p53 and p38 MAPK on Doxorubicin and Lovastatin-induced Apoptosis in Colon Cancer Cells

PURPOSE: Apoptosis plays a central role in tumor development and it has been hypothesized that lack or failure of apoptosis leads to the development of tumors, including colon cancers. Anticancer drugs do not invariably cytotoxic to all cancer cells. Some resistant cells against anticancer drugs are resuming to proliferate after initial damage, whereas others undergo permanent growth arrest or death. The resistance of advanced colorectal cancers to chemotherapy is often related to mutations in p53 tumor suppressor gene. METHODS: To understand the molecular mechanism of lovastatin-induced apoptosis, the relationship between p53 and p38 MAPK upon cytotoxicity by anticancer drug was investigated in colon cancer cell lines including HCT-116 (p53 wild type) and HT-29 (mutated p53). Doxorubicin (dox) or lovastatin (lova) increased the cytotoxicity of colon cancer cells in a dose- and time-dependent manner. RESULTS: Cytotoxic effects of dox and lova was more prominent in HCT-116 than HT-29. The combined treatment of dox and lova further increased the cytotoxic effect on both cells. The cytotoxicity of dox and lova was resulted from apoptotic cell death, which was determined by genomic DNA fragmentation, PARP cleavage and activation of caspase-3 and -9. The Combined treatment of dox and lova synergistically increased the catalytic activity of caspase-3 and -9 in colon cancer cells, but not caspase-6 and -8. Anticancer drugs also induced the cytosolic release of cytochrome c from mitochondria. Dox also induced the accumulation and activation of p53 protein (phosphorylation of p53, ser15), which was suppressed by lova. p38 MAPK inhibitor, SB203580, significantly increased the apoptotic death of lova-treated cells. Furthermore, Lova significantly induced apoptotic death of MKK6 D/D stable transfectant compared to pcDNA3.1 transfectant of HT-29 cells, which was determined by MTT assay, DNA fragmentation, and caspase activation. Similarly to MKK6 D/D transfectant, Exip (alternative splicing p38 gene) transfectant showed the apoptogenic effect of dox with lova. CONCLUSION: These results indicate that lova induces apoptosis in colon cancer cells via p38 MAPK-dependent and p53-independent mechanism.