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At least 991 records · Page 55Linked to original sources

PubMed2005

[The isolation and culture of Sertoli cells from adult testis and their immune privilege mechanism].

AIM: To set up a method of isolation and culture of Sertoli cells from adult testis and to investigate their immune privilege mechanism. METHODS: Adult testis Sertoli cells were prepared successfully by digestion with trypsin, collagenase, hyaluronidase and DNase, and then the expression of Fas-L and TGF-beta1 was examined by SABC staining. The Sertoli cells were cocultured with adult splenocytes to detect the inhibitory effect of Sertoli cells on splenocyte proliferation by MTT colorimetry. RESULTS: In cultured cells, Sertoli cells accounted for more than 80% of total cells. The activity of Sertoli cells reached 90%. Sertoli cells expressed Fas-L and TGF-beta1 and could inhibit the proliferation of cocultured splenocytes in vitro. CONCLUSION: A method of isolation and culture of Sertoli cells from adult testis has been established. The immune privilege mechanism of Sertoli cells may be related to the expression of Fas-L and TGF-beta1.

Adult↗

PubMed2005

[Investigation of immunological mechanism of the in vivo anti-tumor effect of K8 (C6H11N3O2)2[SiW9Ti3O40]] (WT)].

AIM: To investigate the in vivo anti-tumor effect of K(8)(C(6)H(11)N(3)O(2))(2)[SiW(9)Ti(3)O(40)] (WT) and the immunological mechanism. METHODS: WT was administrated intragastrically to mice bearing H22 hepatocarcinoma for 10 days and then the tumors were isolated and weighed. MTT colorimetry was used to detect lymphocyte transformation function and cytotoxicity of NK cells. The morphology of apoptotic tumor cells was observed under phase contrast microscope and light microscope after HE staining. The apoptosis rate of BEL-7402 cells treated with WT was detected by flow cytometry. RESULTS: Compared to the control group, WT obviously inhibited the growth of H22 tumor in tumor bearing mice (P<0.05). It enhanced significantly lymphocyte transformation function and cytotoxicity of NK cells (P<0.05). Apoptotic tumor cells were observed under microscope and detected by flow cytometry. CONCLUSION: WT inhibits significantly the growth of tumor by up-regulating the activity of immunocytes and inducing apoptosis of tumor cells.

Animals↗

PubMed2005

[Cytotoxicity study of heparin coated polyvinyl chloride material].

In this study, heparin ionically coated polyvinyl chloride (PVC) material was prepared by heparin-benzalkonium chloride complex (Group A), heparin-benzalkonium bromide complex (Group B) and heparin-polyethyleneimine compound (Group C). Cytotoxicity evaluation was conducted by direct cell contact evaluation and MTT colorimetry method. The results showed Group A and Group B caused L-929 cells to die out while Group C showed good compatibility with cells. The OD levels of Group A and B were lower than that of the Group C in MTT test. Method A and method B of heparin coating had remarkable cytotoxicity, while method C had little cytotoxicity and could be further studied for clinical use.

Animals↗

PubMed2005

[The effects of pronuciferine on NO and NOS production in cultured human umbilical vein endothelium cells].

OBJECTIVE: To investigate the effects of Pronuciferine on nitric oxide (NO), total nitric oxide synthase (tNOS) and inducible nitric oxide synthase (iNOS) production in cultured Human Umbilical Vein Endothelium Cells (HUVECs). METHODS: Pronuciferine was extracted from plumula nelumbinis. The experiments were performed in HUVECs in vitro. Cell-morphology was observed by light microscope. Cells viability was assessed by MTT assay. NO, tNOS and iNOS were measured by Colorimetry. RESULTS: Cell- morphology and viability weren't affected by Pronuciferine. Pronuciferine significantly increased the level of NO and the activity of tNOS, but had no effect on the activity of iNOS. CONCLUSION: Pronuciferine increases the level of NO by the enhancement of the activity of tNOS. It may have the protection on endothelial function.

Alkaloids↗

PubMed2005

[Effects of rhein on activity of caspase-3 in kidney and cell apoptosis on the progression of renal injury in glomerulosclerosis].

OBJECTIVE: To investigate the effects of rhein on the progression of renal injury and cell apoptosis in glomerulosclerosis, and further explore the protective mechanism of rhein on glomerulosclerosis. METHODS: Glomerulosclerosis models were made for SD rats by unilateral nephrectomy and being injected with Adriamycin into caudal vein, and randomly divided into control group, renal disease group, Rhein treatment group and Benazepril treatment group, and 6 rats in each group were killed at the 6th, 8th, 10th, 12th week respectively. The apoptosis protease-3 (caspase-3) in renal cortex was determined by immunohistochemistry stain method, and the activity of caspase-3 was measured by colorimetry, and the activity of nuclear factor-kappa B (NF-kappaB) was analyzed by gel electrophoretic mobility shift assay (EMSA), and renal tissue cell apoptosis was tested by terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) in order to observe expressions of caspase-3 and NF-kappaB and cell apoptosis of renal tissue. RESULTS: Renal disease group presented with distinct proteinuria, decreasing of blood albumin content and increasing of cholesterol concentration. Glomerulosclerosis index, apoptosis index, activity of NF-kappaB and expression of caspase-3 in renal disease group were more significantly higher than those in control group (P < 0.05 or P < 0.01) as time passed. Compared with the other time points in renal disease group, there were a great number of TUNEL-positive cells observed at the 10th week, slightly higher than that at the 12th week (9.3 +/- 2.3 vs 8.4 +/- 1.2, P > 0.05), the expression of Caspase-3 was also most obvious at the 10th week, significantly higher than that at the 12th week (11.4 +/- 2.5 vs 8.2 +/- 1.7, P < 0.05), which mainly located around capillary vessel in renal cortex, tending to be consistent with apoptosis cells expression. After the 8 weeks treatment of rhein or Benazepril, the number of TUNEL-positive cells significantly decreased and maintained at a certain level, and the activity of NF-kappaB and expression of caspase-3 decreased (P < 0.05), and renal pathological changes and biochemical changes improved magnificently, moreover, the expression of caspase-3 showed positive correlation with apoptosis index (r = 0.836, P < 0.01). CONCLUSION: Rhein could have significant protective effects on the progression of renal injury, and might regulate pathological changes by influencing the activities of NF-kappaB and caspase-3 in the early phase of glomerulosclerosis. Therefore, down-regulating caspase-3 expression in kidney might be one of the molecular mechanisms in the way that rhein could alleviate renal tissue cell apoptosis in glomerulosclerosis.

Animals↗

PubMed2005

[Cloning and expression of human interleukin 24 gene and study on its activity of inducing tumor cells apoptosis in vitro].

AIM: To clone and express IL-24 gene in E.coli and to study its antitumor activity to induce apoptosis of tumor cells after purification and refolding. METHODS: The total RNA was extracted from peripheral blood mononuclear cells (PBMC) and induced by ConA. The human IL-24 gene was amplified by RT-PCR before subcloned into expression vector pET32a(+) and expressed in E. coli. The fusion protein was identified by Edman and purified in chelating sepharose fast flow chromatography and refolding. The activity of inducing tumor cells apoptosis was observed by MTT colorimetry and morphological study in vitro. RESULTS: The obtained human IL-24 gene was identical with that included in GenBank. The recombinant IL-24 could be expressed in E. coli by IPTG induction as inclusion body (35 kD) with purity over 95%. The apoptosis of MCF-7 cells was induced by Trx-IL-24 protein. CONCLUSION: The fusion protein can be highly expressed in E. coli and the obtained protein with high purity can induce tumor cells apoptosis.

Apoptosis↗

PubMed2005

[The effect of hIL-4 on the expression of E-selectin and ICAM-1 on bovine aortic endothelial cells].

AIM: To investigate the effect of human interleukin-4 (hIL-4) on the expression of E-selectin and ICAM-1 on bovine aortic endothelial cells(BAEC) activated with TNF-alpha. METHODS: BAEC were cultured in different concentrations of hIL-4 for 2 h followed by treatment with 4 microg/L TNF-alpha for 6 h or 18 h. The expression of E-selectin and ICAM-1 on BAEC was detected by cell-ELISA. The effect of hIL-4 on viability of BAEC was detected by MTT colorimetry. RESULTS: Pretreatment of BAEC with hIL-4 inhibited the expression of E-selectin and ICAM-1 on BAEC activated by TNF-alpha in a dose-dependent manner (P<0.01). Both TNF-alpha and hIL-4 had no effect on the viability of BAEC. CONCLUSION: hIL-4 can suppress the expression of E-selectin and ICAM-1 on BAEC activated by TNF-alpha, which may contribute to the xenotransplant immune tolerance associated with hIL-4.

Adjuvants, Immunologic↗

PubMed2005

[Influence of IL-2 on proliferation of cultured human pituitary adenoma cells and its mechanism].

AIM: To investigate the effects of IL-2 on the proliferation, cell cycle, protein kinase C(PKC) and cAMP/cGMP of cultured human pituitary adenoma cells. METHODS: MTT colorimetry, (3)H-TdR and flow cytometry were used to detect the proliferation and radioimmunoassay was used to observe the effect of IL-2 on PKC activity and cAMP/cGMP levels of cultured human pituitary adenoma cells. RESULTS: (1) IL-2 (1 x 10(4), 1 x 10(5) and 5 x 10(5) U/L) stimulated the proliferation and DNA synthesis of cultured human pituitary adenoma cells in a dose-dependent manner. (2) IL-2 (1 x 10(4), 1 x 10(5) and 5 x 10(5) U/L) decreased the ratio of pituitary adenoma cells in G(1) phase and increased the ratio in S and G(2) phase markedly. (3) Compared with control, PMA, a PKC activator, increased the activity of membrane and total PKC in human pituitary adenoma cells. However, after treatment with IL-2 (1 x 10(5) U/L), a significant increase of the activity of cytoplasmic, membrane and total PKC in human pituitary adenoma cells was observed. (4) IL-2 (5 x 10(4), 1 x 10(5) U/L) decreased the amount of cAMP in the cytoplasm of human pituitary adenoma cells, but had no effect on that of cGMP. CONCLUSION: IL-2 can stimulate the proliferation of pituitary adenoma cells through PKC and cAMP/cGMP signaling pathways.

Antineoplastic Agents↗

PubMed2005

Isolation and culture of adult Sertoli cells and their effects on the function of co-cultured allogeneic islets in vitro.

BACKGROUND: Globally, 180 million people suffer from diabetes mellitus. Islet transplantation is believed to be an almost ideal therapy for insulin-dependent patients. How to maintain the viability and the function of isolated human islets is a challenge in clinical practice. Sertoli cells are considered 'nurse cells' in the seminiferous tubules and have been used in cell graft protocols for neurodegenerative diseases and diabetes in many studies. Many researchers have used immature murine testes as the primarily source of Sertoli cells in islet transplantation because they are easily purified. Mature human Sertoli cells have been seldom investigated. In the present study, we developed a method for the isolation and culture of Sertoli cells derived from adult human testes, and investigated their effects on the function of allogeneic islets when they were cultured together in vitro. METHODS: Adult Sertoli cells were prepared successfully by two-step enzyme digestion with trypsin, collagenase and hyaluronidase. They were identified by morphological characteristics and their activity was determined by MTT colorimetry over a 28-day culture time in vitro. A glucose-stimulated insulin secretion test was performed to detect the effects of Sertoli cells on allogeneic islets' function when they were co-cultured for 21 days in vitro. RESULTS: In cultured cells, mature human Sertoli cells accounted for more than 90% of total cells. The activity of Sertoli cells reached 95% and they remained highly cytoactive for a long time in vitro (P > 0.05). Compared with the islets cultured alone, the co-cultured islets with allogeneic Sertoli cells maintained higher sensitivity to glucose stimulation for the duration of the experiment (P < 0.01). CONCLUSIONS: A method of isolation and culture of Sertoli cells from adult testes has been established. Sertoli cells could enhance allogeneic islets' function when they were co-cultured in vitro. They could be a helper cell in islet transplantation.

Adult↗

PubMed2006

[Construction of recombinant adenovirus vector of hNRAGE gene and its effect on cell cycle of 293 cells].

AIM: To construct the recombinant adenovirus vector of hNRAGE gene and study its effect on the cell cycle of 293 cells. METHODS: hNRAGE gene was amplified by PCR and subcloned into the shuttle vector pAdTrack-CMV to construct a shuttle plasmid pAdTrack-CMV/hNRAGE. After sequencing, it was linearized with Pme I and cotransformed into E.coli BJ5183 cells with adenovirus genomic plasmid pAdEasy-1 by electroporation to achieve homologous recombination. After being digested with Pac I, the DNA of identified recombinant plasmid was transfected into QBI-293A cells by calcium phosphate transfection to package adenovirus. With the use of GFP gene expression in pAdTrack-CMV, the appearance of Ad-hNRAGE was observed and its concentration was measured. The expression of the target gene was detected by Western blot and its effect on cell cycle of 293 cells was examined by MTT colorimetry and FCM. RESULTS: The Ad-hNRAGE was successfully constructed and the expression of hNRAGE gene in 293 cells was proved by Western blot. After harvesting the virus particles, the concentration of Ad-hNRAGE was about 6.5x10(9) Ad/microL. The transfection of Ad-hNRAGE resulted in significantly lower proliferative rate of 293 cells compared with untransfected ones, with cell number of G0-G1 and G2-M phase increasing and that of S phase decreasing. CONCLUSION: hNRAGE gene can inhibit the growth of 293 cells.

Adenoviridae↗

PubMed2006

[Construction of pMSCV recombinant retroviral vector containing polo-like kinase 3(plk3) cDNA and its effects on cell proliferation].

AIM: To construct pMSCV retroviral vector (RV) containing Polo-like kinase 3(plk3) cDNA, a new member of Ser/Thr protein kinase family, and to study the function of plk3 gene by introducing it into human K562 and HL60 cells. METHODS: plk3 cDNA was sub-cloned into retroviral vector pMSCV-puroR to generate pMSCV-plk3-puroR, pMSCV-puroR being used as the control. RVs were generated by introducing RV vectors into 293T-Amphotropic packaging cells. Titers of RV were measured by NIH3T3 cells with Large-scale-real-time titration method (LaSRT). K562 and HL60 cells were infected with pMSCV-plk3-puroR or pMSCV-puroR viral supernatant by flow-through transduction method, respectively. Following 3-day selection with 3 mg/L puromycin, K562-plk3-puroR, HL60-plk3-puroR, K562-puroR and HL60-puroR cells were obtained. PCR was used to identify the integration of plk3 gene in K562-plk3-puroR and HL60-plk3-puroR cells. Transduction rates were determined by clone-forming ability against puromycin in semi-solid culture medium. Cell growth curve was measured by MTT colorimetry, the cell cycle and apoptotic analysis were detected by flow cytometry, etc. RESULTS: Virus titers generated was (1.31+/-0.65)x10(9)TU/L. The K562 and HL60 transfection efficiency reached 82.3%+/-3.70% and 62.9%+/-4.94%, respectively (n=3). After 3 d puromycin selection, purified K562-plk3-puroR and HL60-plk3-puroR cell were obtained. The proliferation of K562 and HL60 cells was slowed down by plk3 gene transduction. Compared with wild type K562 cells: (1) when cultured in complete DMEM medium, more K562-plk3-puroR cells were observed in G(0)-G(1), 49.7%+/-3.38% vs 43.9%+/-2.34% (P=0.03); (2) when cultured in serum-free DMEM medium for 10 h, fewer K562-plk3-puroR cells were observed in S phase, 43.6%+/-3.74% vs 54.5%+/-1.52% (P=0.02) with lower apoptosis rate, 3.4%+/-0.37% vs 1.3%+/-0.31% (P=0.01). CONCLUSION: Introduction of plk3 gene into tumor cells with RV vectors can slow down cell proliferation, prevent cells into cell cycle and protect cells from apoptosis in serum-free culture.

Animals↗

PubMed2006

[The properties of exosomes secreted by human umbilical cord blood dendritic cells and its enhancement of CTL cytotoxicity].

AIM: To investigate the properties of exosomes secreted by dendritic cells(DCs) derived from human umbilical cord blood mononuclear cells(HUBMCs) and its enhancement of CTL cytotoxicity. METHODS: The HUBMCs were separated from human umbilical cord blood(HUCB). The generation of DCs were induced for 12 days in medium containing SCF, IL-4 and GM-CSF. Tumor antigen extracted by repeated freeze-thawing were added to culture medium and cultured successively for 2 days. The DCs were collected and exosomes were separated from culture supernatant through centrifugation at 100,000 g. The exosomes-associated properties were analyzed by FCM, SDS-PAGE, transmission electron microscope(TEM) and MTT colorimetry. RESULTS: After being induced for 12 days with SCF, IL-4 and GM-CSF the number of DCs had a 10-fold increase and displayed typically morphological characteristics of DCs. FCM analysis showed that the DCs loaded with tumor antigen expressed highly MHC-I, MHC-II, CD40, CD80, CD86, CD11c and CD54. Exosomes could be separated from culture supernatant of DCs by ultracentrifugation. Mixed lymphocyte reation(MLR) and cytotoxicity assay showed that exosomes secreted by DCs could effectively stimulate T cell proliferation and enhance their cytotoxicity. CONCLUSION: A large number of DCs are obtained from UBMCs and the exosomes are secreted from them in vitro. The exosomes can present tumor antigen to T cells and enhance the cytotoxicity of CTLs.

B7-1 Antigen↗

PubMed2006

[The inhibitory effects of dumb-bell decoy oligodeoxynucleotides targeting NF-kappaB on the growth of multiple myeloma cells and IL-6 expression].

AIM: To investigate the inhibitory effects of dumb-bell decoy oligodeoxynucleotides(ODNs) targeting NF-kappaB on the transcriptional activity of NF-kappaB binding to its cis-elements, growth of multiple myeloma cells 8266 and the expression of IL-6 in 8266 cells. METHODS: The inhibitory effects of dumbbell decoy ODNs targeting NF-kappaB on the transcriptional activity of NF-kappaB was detected by electrophoretic mobility shift assay(EMSA). 8266 cells were randomly divided into 8266 cells of passage (control), dumb-bell decoy ODNs treatment, and cationic liposome treatment groups. Dumb-bell decoy ODNs of 2, 4 and 8 mg/L were cultured respectively into 8266 cells via cationic liposome vector. Then, the transfected 8266 cells and their supernatant were collected at 8, 12 and 18 h. IL-6 expression was measured by ELISA. Effect of decoy ODNs on the growth of 8266 cells stimulated with IL-6 was measured by MTT Colorimetry assay. RESULTS: Dumbbell decoy ODNs effectively inhibited the binding of NF-kappaB to its cis-elements in vitro. Different doses of decoy ODNs (2, 4 and 8 mg/L) had different inhibitory effects on IL-6 expression in 8266 cells. After decoy ODNs had been transfected into 8266 cells stimulated by IL-6 via cationic liposome vector, both the growth of 8266 cells and activity of IL-6 were inhibited. CONCLUSION: Dumb-bell decoy ODNs can effectively inhibit the growth of 8266 cells and decrease the expression of IL-6 in myeloma cells through the inhibiting NF-kappaB activity.

Cell Line, Tumor↗

PubMed2006

[Effects of RNAi on hypoxia inducible factor-1alpha activity and proliferation of hypoxic pulmonary artery smooth muscle cells in rat].

Pulmonary vascular remodeling is one of the major characteristics of hypoxia-induced pulmonary hypertension, mainly represented by over-proliferation of pulmonary artery smooth muscle cells (PASMCs). Hypoxia inducible factor-1alpha (HIF-1alpha) is a transcription factor which is produced by the cells exposed to hypoxia. HIF-1alpha up-regulates the expression of many hypoxia response genes (HRGs) for the body to adapt to hypoxia and maintain homeostasis. The expression of HIF-1alpha in the PASMCs is remarkably elevated under hypoxic condition and it stimulates the proliferation of PASMCs. In this experiment, we used gene clone technology to design and synthesize two siRNAs based on the sequence of HIF-1alpha mRNA. They were separately subcloned into the plasmid of pGenesil-1 containing U6 promoter. The pGenesil-1 vector of the RNA interference eukaryotic expression vector specific to HIF-1alpha gene was constructed. DNA sequencing of the plasmid verified the successful construction of the HIF-1alpha RNAi. We isolated and cultured the PASMCs of rat. The pGenesil-1 vector was transferred into the PASMCs with METAFECTENE in vitro. The positive cell clones transfected with pGenesil-1 were obtained after being screened with 400 mug/ml G418. These PASMCs were cultured in normoxia and hypoxia. After 48 h, the effects of RNAi on the expression of HIF-1alpha mRNA were detected by RT-PCR. The cellular growth activities were assayed by MTT colorimetry and flow cytometry in vitro. The results showed that for the PASMCs cultured in hypoxia for 48 h, the cell proliferation of blank group and control group were remarkably increased and the HIF-1alpha mRNA expressions were up-regulated, while the cell proliferation of the treatment groups did not increase and the HIF-1alpha mRNA expressions were not up-regulated. In conclusion, we successfully constructed the recombinant plasmid of RNAi and transfected them into the PASMCs in vitro. The RNAi inhibited the expression of HIF-1alpha mRNA in the PASMCs, and subsequently it remarkably suppressed the proliferation of PASMCs in hypoxia. These results indicate that HIF-1alpha plays a pivotal role in PASMC proliferation.

Animals↗

PubMed2005

[Research of a new kind of biological response modifier to anti-laryngocarcinoma].

OBJECTIVE: To find a new kind of biological response modifier to anti-laryngocarcinoma through studying the efficiency of resveratrol. METHOD: To detect the growth inhibiting rate of Hep-2 exposed to resveratrol with MTT colorimetry and to analyze the apoptosis and cell cycle of Hep-2 with flow cytometry. As having formed the model of laryngocarcinoma, quite a few indicatrixes including the content changes of IL-2, IL-8,TGF-beta1 and VEGF were detected. RESULT: Resveratrol could induce apoptosis of Hep-2 in time-concentration-dependent manners showing obvious cell cycle blocking of G0/G1 and apoptotic peak. Furthermore, resveratrol improved remarkably the growth condition of mice planted with Hep-2 while enhancing their immunological function. CONCLUSION: As a kind of biological response modifier, resveratrol could strengthen anti-tumor immunoresponse, accommodating lymphocyte to secrete cytokine, through which it exerted the efficiency of anti-laryngocarcinoma.

Animals↗

PubMed2006

[Correlation between immunochemical level and patient with caries].

OBJECTIVE: To explore the relationship between immunochemical level of salivary and caries in children aged 4-6 years old. METHODS: Two groups were assorted as patients with caries and without caries. Every group included 45 people. Measurements of salivary secretory immunoglobulin A (SIgA)were performed by using radio-immunoassay and single agar diffusion assay. The levels of lysozyme (LZ), alkaline phosphatase (ALP) and lactic dehydrogenase (LDH) were studied with colorimetry and turbidimentry. RESULTS: The levels of LDH, SigA, ALP, LZ had significant difference between the two groups (P < 0.05). The level of LDH between patients and peoples without caries had little difference (P > 0.05). CONCLUSION: The incidence of caries is associated with age, and it may have association with immunochemical levels of salivary.

Alkaline Phosphatase↗

PubMed2006

[The effects of EPHPH on acoustic brainstem response threshold and its relative factors of senile model rats].

OBJECTIVE: The effect of EPHPH on aged deafness and its mechanism was explored by observing the effects of EPHPH on acoustic brainstem response threshold (ABRT), malondialdehyde (MDA), superoxide dismutase (SOD), total-nitrogen monoxide (NOS) and typing-nitrogen monoxide (iNOS) in cochleae tissues of senile model rats. METHOD: ABRT value was measured by induced potentiometer, MDA was measured by TBA colorimetry, SOD was determined by nitrite method, NOS and iNOS was determined by spectrophotometry in cochleae tissues of senile model rats that separately administered by gavage the alcoholic extract from 2.16, 4.32 or 8.64 g x kg(-1) x d(-1) PHPH once a day for 6 months. RESULT: ABRT value and MDA content notably increased, activities) of SOD, NOS and iNOS notably decreased in cochlear tissues of senile model rats from control. It indicated on relative analysis that relativity between ABRT value ascent and MDA ascent showed positive, relaxivities between ABRT value ascent and activity descents of SOD, NOS and iNOS showed all negative. It differently resisted ABRT value ascent and MDA ascent in cochlear tissues that senile model rats separately administered the alcoholic extract from 2.16, 4.32 or 8.64 g x kg(-1) x d(-1) PHPH whose relaxivities between quantity and efficiency showed all negative. It differently inhibited activity descents of SOD, NOS and iNOS in cochlear tissues that senile model rats separately administered various doses of EPHPH whose relaxivities between quantity and efficiency showed all positive. CONCLUSION: EPHPH may relieve the degree of aged deafness and its mechanism may be connected with eliminating oxygen free radicals and increasing the activities of SOD, NOS and iNOS in cochleae of natural senile rats.

Aging↗

PubMed2005

[Effects of PLK1 gene silence on apoptosis of K562 cells].

OBJECTIVE: To investigate the effects of PLK1 gene silence by short hairpin RNA (shRNA) on PLK1 expression and apoptosis in K562 cells, and explore the role of PLK1 in the pathogenesis of leukemia. METHODS: The shRNA fragment targeting at 1416-1436 bp of PLK1 mRNA was synthesized and cloned into pEGFP-H1 vector, named as pEGFP-H1/PLK1. The empty control, pEGFP-H1 and pEGFP-H1/PLK1 were transfected into K562 cells respectively via electroporation. 24 h or 48 h after transfection, gene and protein expression of PLK1 in the cells were assayed by RT-PCR and Western blot analysis respectively, cells viability by MTT assay, caspase-3 activity by colorimetry, cell cycle and apoptosis by FACS. RESULTS: 24 and 48 h after transfection, PLK1 expression in K562 cells was 1.25 +/- 0.07 for control group, 0.52 +/- 0.04 and 0.25 +/- 0.02 for pEGFP-H1/PLK1 group, and 1.24 +/- 0.08 and 1.23 +/- 0.09 for pEGFP-H1 group respectively. The alteration status of PLK1 protein levels were similar to that of PLK mRNA levels. The apoptosis rate was (8.3 +/- 0.6)% in control group, (8.7 +/- 0.7)% in pEGFP-H1 group and (49.7 +/- 3.8)% and (82.3 +/- 6.9)% in pEGFP-H1/PKLK1 group at 24 and 48 h, respectively. In addition, cell fraction at G(2)/M phase was increased obviously compared with control and pEGFP-H1-transfected group. CONCLUSION: The constructed shRNA can remarkably inhibit PLK1 expression and transfected K562 cell proliferation, increase apoptosis and block cell-cycle, suggesting that PLK1 play important roles in apoptosis and cell-cycle control of leukemia cells.

Apoptosis↗