Percentage Of Early Apoptosis Research Articles

The effect of pDNA-Buforin II on the expression changes of lncRNAs PCA3, PCAT1, PRNCR1, GAS5 in prostate cancer

BackgroundThis work aims to analyze the alterations in the levels of PCA3, PCAT1, PRNCR1, and GAS5 long non-coding RNAs (lncRNAs) after the activation of pDNA-buforin II in PC3 cancer cells. Materials and methodsThe synthetic nucleic acid sequence of buforin II was included in the pcDNA3.1(+) Mammalian Expression Plasmid. The accuracy of cloning was assessed by using PCR and enzyme digestion techniques. The vectors were transfected into cells utilizing LipofectamineTM2000. The PC3 cancer cells were evaluated using flow cytometry and wound healing analysis. The expression levels of lncRNAs and apoptotic genes were assessed utilizing real-time PCR, with a significance threshold of P < 0.05. ResultsThe recombinant plasmid containing the pDNA-buforin II vector was successfully generated, and the gene sequence demonstrated complete uniformity (100 % similarity) with the buforin II gene. The transfection efficiency of PC3 cells was 79 %. The results are quantified utilizing the growth inhibition 50 % (GI50) parameter, representing the concentration of pDNA-buforin II required to halt 50 % of cell growth. The percentages of early apoptosis, late apoptosis, necrosis, and viable PC3 cells in the pDNA-buforin II group were 23.30 %, 12.70 %, 3.9 %, and 60.10 %, respectively. The RT-PCR study demonstrated that the presence of pDNA-buforin II in PC3 cells decreased the transcription of PCA3, PCAT1, and PRNCR1 lncRNAs compared to the control group treated with PBS. Furthermore, it enhanced the transcription of GAS5 lncRNA. The findings demonstrated a significant upregulation of transcription factors in programmed cell death after treatment with pDNA-buforin II (∗∗P < 0.01). ConclusionsAccording to the results of this study, it can be inferred that pDNA-buforin II can modify the transcription of genes in PC3 cancer cells, specifically about lncRNAs involved in cell apoptotic pathways. The pDNA-buforin II molecule has promising anticancer capabilities and can trigger apoptosis in cells.

The Investigation of Quercus Infectoria Gall Aqueous Extract Effect on the Cell Proliferation, Apoptosis and Expression of CCND1, TP53, BCL2 and BAX Genes in Cell Line of Lung, Gastric and Esophageal Cancers.

The therapeutic potential of Quercus infectoria (QI) gall, including its anti-inflammatory, antioxidant, and anticancer properties, is well-known. However, its impact on lung, gastric, and esophageal cancer cells remain unclear. This study aims to explore the effects of QI gall aqueous extract on cell viability, apoptosis, and gene expression in A549, BGC823, and KYSE-30 cell lines. A549, BGC823, and KYSE-30 cells were seeded in complete medium and incubated with different concentrations of QI gall extract for 24 hours. Cell viability was measured by an MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay. The induction of apoptosis was assessed through flow cytometric analysis after the adding FITC-conjugated Annexin V (Annexin V-FITC) and propidium iodide (PI). The mRNA expression levels of CCND1, TP53, BCL2 and BAX genes were determined using Real-time Quantitative Polymerase Chain Reaction analysis. The MTT assay demonstrated that treatment with QI gall extract significantly reduced the number of viable cells in the A549, BGC823, and KYSE-30 cell lines at IC50 concentrations of 440.1, 437.1, and 465.2 mg/ml, respectively. Additionally, compared to untreated cell population, the percentages of early apoptosis, late apoptosis, and necrosis in the A549, BGC823, and KYSE-30 cells significantly increased following treatment with QI gall extract (P< 0.05). Also, the treatment with QI gall extract influenced the expression of CCND1, TP53, BCL2 and BAX genes. The present findings indicated that the gall extract of QI can inhibit the growth of A549, BGC823, and KYSE-30 cells by inducing apoptosis, which may be mediated via mitochondria-dependent pathway.

Synthesis and Characterization of Novel 4-aryl-4H-chromene Derivatives Using Borax and Evaluation of their Anticancer Effects.

4-aryl-4H-chromenes have attracted attention as potential anticancer agents. In an effort to discover effective compounds, we designed a new series of these chromenes with methoxy substitution at 2, 3, 4, 5, and 6 positions. The synthesized compounds were tested for anticancer properties against two human cancer cell lines (MCF-7 and PC3) as well as a normal cell line. The MTT assay showed that the 5g derivative, with methoxy groups at ortho and meta positions, exhibited the highest potency (IC50 = 40 µM) against the PC3 cell line. Furthermore, induction of apoptosis was explored through various methods, such as flow cytometry analysis, morphological changes, activation of caspase 3, ROS, and MMP. Our findings revealed that compound 5g induced apoptosis in the PC3 cell line, which was demonstrated by activation of caspase 3, an increase in ROS levels, and early apoptosis percentage. These results suggest that compound 5g holds promise as a potential therapeutic approach to cancer treatment.

Effects of vitamin D supplementation in extender on sperm kinematics and apoptosis following the freeze-thaw process in normozoospermic and asthenozoospermic Holstein bulls

BackgroundAsthenozoospermia is a usual male infertility factor, characterized by decreased semen quality. It has been revealed that antioxidants improve sperm function, enhance endogenous antioxidant activities, and protect spermatozoa against oxidative damage during cryopreservation. This aimed to evaluate the effects of vitamin D on sperm kinematics and apoptosis in the semen of bulls with normozoospermia and asthenozoospermia after the freeze-thaw process. For this purpose, 32 semen samples of four Holstein bulls (normozoospermic, progressive motility > 70 %) and 32 semen samples of four bull (asthenozoospermic progressive motility < 40 %) were collected and pooled separately (normozoospermic and asthenozoospermic). Samples were then diluted into four equal aliquots of extender containing different vitamin D concentrations (0, 5, 10, and 50 ng/mL) and aspirated into a 0.5 mL straw.ResultsThe percentages of sperm progressive motility and viability were significantly higher (P < 0.05) in 50 ng/mL of vitamin D in normozoospermic group. Sperm kinematics parameters including curvilinear velocity (VCL), straight-line velocity (VSL), and average path velocity (VAP) were significantly higher in the high dose (50 ng/mL) vitamin D-treated group compared to the low dose vitamin D-treated group (5ng/mL) in normozoospermic bull semen samples. The supplementation of the semen extender with different concentrations of vitamin D could not increase the rate of acrosome integrity in normozoospermic bulls compared to the control group (P < 0.05). In the asthenozoospermic group, 10 ng/mL vitamin D-treated group could increase the rate of plasma membrane integrity compared to 5 ng/mL vitamin D-treated group (P < 0.05). The percentages of early-apoptosis (P = 0.049) and late-apoptosis (P = 0.005) were significantly higher in the asthenozoospermic than the normozoospermic group.ConclusionsThe present study revealed that a high dose (50 ng/mL) of vitamin D protected normozoospermic bulls’ sperms from the freezing procedure and lead to higher quality of frozen-thawed bull sperm.

The Effect of Vitamin C on Apoptosis and Bax/Bcl-2 Proteins Ratio in Peripheral Blood Lymphocytes of Patients during Cardiac Interventional Procedures.

Background: There is a close relationship between the effects of free radicals and apoptosis, and vitamin C is known as a potent scavenger of free radicals.Objective: The aim of this study was to evaluate the effect of vitamin C against the radiation-induced apoptosis and the ratio of Bax/Bcl-2 proteins in peripheral blood lymphocytes in patients undergoing cardiac procedures in vivo condition.Material and Methods: In this clinical intervention study, blood samples from 6 patients in the first group were taken to assess the effect of radiation on the apoptosis and Bax/Bcl-2 proteins ratio, and 5 patients as the second group to evaluate the effect of vitamin C on the apoptosis and Bax/Bcl-2 proteins ratio before and 24 hours after the examination. Flow cytometry was used to analyze the apoptosis and ELISA method to assess Bax and Bcl-2 proteins amount. Results: In the second group receiving 25 mg/kg vitamin C and a mean skin dose of 1001 mGy in the chest area, there was no significant difference (P <0.05) in the percentage of early apoptosis in 24 hours after the examination than before it. This significant increase in the percentage of apoptosis in the first group (385.6 mGy) was associated with a significant increase in the Bax/Bcl-2 ratio (P <0.05), while in the second group, it was not associated with a significant decrease in the Bax/Bcl-2 ratio in 24 hours after the examination than before it.Conclusion: Our results suggest that vitamin C may modulate Bax and Bcl-2 proteins expression, in maintaining peripheral blood lymphocytes in patients undergoing cardiology in radiation-induced apoptosis.

Evaluation of the Potential Anticancer Activity of Zamzam Water in Human Colon Cancer Cell Line

Zamzam water (ZW) is a naturally hard alkaline type of water with unique physical and chemical properties that are different from any other water. The aim of the current work is to evaluate the potential anticancer activity of ZW against colon cancer. Human colon cancer HCT-116 and human skin fibroblast HSF cell lines were treated with two treatment conditions of ZW, Z1 with adjusted pH to 7.4 and Z2 without pH adjustment (pH 8). Cell viability was assessed using MTT and trypan blue dye exclusion assays. Cell cycle alterations and the type of cell death were investigated using flow cytometry technique. Cellular and mitochondrial reactive oxygen species (ROS) levels were quantified by H2DCFDA and MitoSOX assays, respectively. The results of the current study showed that both ZW treatments reduced cell viability of cancer cells. MTT assay showed a significant reduction in cell viability to 87% and 66%, respectively, after treatment with Z1 and Z2 (p≤0.0001). Cell death has occurred via apoptotic pathway under the two treatment conditions. The percentage of early apoptosis was 3%, 3.5% and 2.8% in control, Z1 and Z2 respectively. In the late apoptotic stage, there was a significant increase (4.2%) only for Z2 treatment in comparison to the control (p≤0.001). The cells were arrested in the G2/M phase of the cell cycle, and decreased in G1 phase after 24 hours of treatment with ZW. Only Z2 treatment, showed an increase in the production of both cytoplasmic and mitochondrial ROS. In conclusion, our results indicate, for the first time, that ZW induces apoptosis of human colon cancer HCT-116 cells, suggesting the potential anticancer effect of ZW against colon cancer.

Effect of metformin on inflammatory cytokine and apoptosis induced by lipopolysaccharide in THP-1 cells

Objective To investigate the direct anti-inflammatory effects of metformin by observing its dosedependent effect on the secretion of inflammatory factors and apoptosis induced by lipopolysaccharide (LPS) in THP-1cells.Methods THP-1 cells were cultured in vitro and incubated with 1 μg/ml LPS and various concentrations of metformin for 6,24,and 48 h.The cytotoxicity of metformin was assessed by lactate dehydrogenase (LDH) release assay.The contents of interleukin (IL)-1 β,IL-6,IL-8,and tumor necrosis factor α (TNF-α) in the culture medium were measured by ELISA,and FACS flow cytometer was used to detect the percentage of early apoptosis in THP-1cells.Results Metformin dose-dependently decreased the secretion of IL-1β,IL-6,IL-8,and TNF-α in THP-1cells,especially at 48 h.1 and 5 mmol/L metformin significantly inhibited the release of IL-1β,IL-6,IL-8,and TNF-α as stimulated by LPS (P＜0.05 or P＜0.01).Metformin also dose-dependently inhibited early apoptosis of THP-1 cells induced by LPS (F =4.695,P =0.036).The percentage of early apoptosis in 1 and 5 mmol/L metformin groups were lower than that of LPS group (37.47％,33.35％ vs 49.90％,P＜0.05 or P＜0.01).Conclusion Metformin dose-dependently inhibits early apoptosis and decreases the secretion of inflammatory factors induced by LPS in THP-1 cells,suggesting that it possesses anti-inflammatory effect. Key words: Metformin ; Lipopolysaccharide ; THP-1 cells ; Inflammatory fators; Apoptosis

Immunotoxicity of atrazine in Balb/c mice

The present study was designed to investigate the immunotoxicity of atrazine (ATZ) in male Balb/c mice. ATZ (175, 87.5, and 43.75 mg/kg bw/day) was administered by gavage method for 28 days. The following indexes were determined in various groups of mice: body and organ weight; antibody aggregation of serum hemolysin; proliferative response of splenocytes to ConA; delayed-type hypersensitivity (DTH); natural killer cell activity; clearance of neutral red and nitric oxide (NO) release from peritoneal macrophages; apostosis and necrosis of splenocytes and thymocytes; cytokine production; and serum lysozyme. Results showed that cell-mediated, humoral immunity, and non-specific immune function in the high-dose ATZ group were suppressed; NO release and interferon-γ(IFN-γ)/interleukin-4 (IL-4) were also significantly decreased in the high-dose group. In the medium-dose group, the proliferation response and IFN-γ production was significantly decreased. In the low-dose group, the proliferation response was significantly decreased. Serum lysozyme was decreased in the ATZ-treated groups. The percentage of early apoptosis in thymocytes was increased significantly in high- and medium-dose ATZ groups. In conclusion, ATZ elicited an inhibitory effect on cell-mediated immunity, humoral immunity, and non-specific immune function of mice.

AB0217 Dendritic cells and apoptosis in peripheral blood of patients with systemic lupus erythematosus

BackgroundSystemic lupus erythematosus (SLE) persists as a chronic inflammatory autoimmune disease. It is characterized by the production of autoantibodies and immune complexes that affect multiple organs (Seitz, 2010). The etiology...

Multifunctional up-converting nanocomposites with multimodal imaging and photosensitization at near-infrared excitation

Here we report the synthesis of silica coated NaYF4:Yb/Tm nanocomposites, with a covalent coating of 1,8-dihydroxy-3-methylanthraquinone (DHMA), which has high ability to produce reactive oxygen species (ROS) and fluorescein isothiocyanate (FITC) for downconverting imaging. Upon excitation by near-infrared light, the nanocomposites convert lower-energy light to higher-energy light, which will trigger DHMA to generate ROS and consequently kill the folate receptor (FR) (+) tumor cells. The apoptosis effect of tumor cells induced by the as-prepared nanocomposites [UCNP@(DHMA/FITC)@SiO2–FA] was proven by fluorescence microscope imaging after staining with Annexin V-FITC/PI, Caspase-3 Western blotting, flow cytometry assay and cell viability assay. The results indicated that the as-prepared nanocomposites can effectively induce apoptosis in HeLa and HepG2 cells and the percentage of early apoptosis in tumor cells is as high as 42.75%. In addition, the photosensitive efficiency of DHMA covalent coating nanocomposites [UCNP@(DHMA/FITC)@SiO2–FA] is higher than that of DHMA simply deposited nanocomposites [UCNP@SiO2(DHMA/FITC)–FA]. As a result, high photosensitivity and selectivity are achieved in tumor cells upon incubation with the nanocomposites and exposure to an NIR laser. Furthermore, multimodal fluorescence labelling is also achieved with good photostability and no background noise. Therefore, they will potentially be useful either as PDT drugs or multimodal luminescent probes in bioimaging.

Cinobufacini induced MDA-MB-231 cell apoptosis-associated cell cycle arrest and cytoskeleton function

Cinobufacini is a traditional Chinese anti-tumor drug and widely used in clinic experiences. But little is known about its effect on the cells. In this study, the effects of cinobufacini on breast cancer MDA-MB-231 cell were evaluated by CCK-8 assay, and the data showed cinobufacini could inhibit the MDA-MB-231 cells growth effectively in dose-dependent and time-dependent manners. Cell apoptosis and cell cycle were detected by flow cytometry analysis. After the cells being treated with 50 μg/mL cinobufacini for 48 h, the early apoptosis percentage (20.45 ± 1.46%) is much higher than the normal group (7.73 ± 1.21%). The cell cycle data indicated that cinobufacini caused a cell cycle arrest at S phase. What's more, cinobufacini can affect the disruption of cytoskeleton, and these alterations changed the cell-surface ultrastructure and the cell morphology which were detected by atomic force microscopy (AFM) at nanoscale level. It indicated that the cell membrane structure and cytoskeleton networks were destroyed and the cell tails were narrowed after the cell being treated with cinobufacini. The present study is to provide valuable new insights to understand the mechanism of the drug in anti-tumor process. Furthermore, the knowledge concerning the signaling of cell cycle is potentially important to clinical utility.

Expression changes and clinical significance of annexin V in maternal blood and placenta in patients with preeclampsia

To evaluate the expression of annexin V in maternal blood and placenta, and to explore the relationship between annexin V and preeclampsia (PE). 120 women with PE who delivered babies in the Second Hospital of Hebei Medical University from December 2007 to December 2009 were chosen as study groups. They were classified into four groups: early-onset mild group (n = 30), early-onset severe group (n = 30), late-onset mild group (n = 30) and late-onset severe group (n = 30). 30 women without perinatal complications who accepted elective term cesarean section were chosen as control group. Western blot and immunohistochemistry were used to detect the expression and localization of annexin V in placenta and maternal blood. Flow cytometry was employed to detect the apoptosis of cytotrophoblast. AnnexinVmRNA level was determined by reverse transcription (RT)PCR. Prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FiB), international normalized ratio (INR) were detected in each group. (1) The expression of annexin V in placenta and maternal blood were: 0.54 ± 0.12 and 0.62 ± 0.17 in early-onset mild group; 0.47 ± 0.15 and 0.56 ± 0.24 in early-onset severe group; 0.74 ± 0.23 and 1.08 ± 0.32 in late-onset mild group; 0.68 ± 0.28 and 0.72 ± 0.21 in late-onset severe group; 1.73 ± 0.35 and 1.55 ± 0.27 in control group. They were significantly lower in PE groups than in control group (P < 0.05). However, there was no significant difference among PE groups (P > 0.05). (2) The early apoptosis, late apoptosis percentage of trophoblast cells were: 3.21%, 0.86%, in early-onset mild group; 5.32%, 0.72%, in early-onset severe group; 2.43%, 0.63%, in late-onset mild group; 4.28%, 0.48% in late-onset severe group; 1.05%, 0.59%, in control group. Early apoptosis percentage in each group of PE was higher than that in control group (P < 0.05). However, there was no significant difference among PE groups (P > 0.05). (3) The annexin V mRNA levels in placenta were: 25.0 ± 3.0 in early-onset mild group; 24.8 ± 3.0 in early-onset severe group; 25.4 ± 3.9 in late-onset mild group; 25.1 ± 2.7 in late-onset severe group, respectively. All were significantly higher than that in control group (30.6 ± 3.0, P < 0.05), and no significant difference was found among PE groups (P > 0.05). (4) PT, APTT, FiB, INR levels were: (11.3 ± 2.4), (25.6 ± 2.9) s, (4.6 ± 0.9) g/L and 0.9 ± 0.2 in early-onset mild group; (12.1 ± 1.9), (27.2 ± 2.1) s, (5.0 ± 1.0) g/L and 0.9 ± 0.2 in early-onset severe group; (11.7 ± 2.3), (26.5 ± 2.3) s, (5.0 ± 0.7) g/L and 0.8 ± 0.3 in late-onset mild group; (11.4 ± 2.6), (27.3 ± 3.0) s, (4.3 ± 0.8) g/L and 0.8 ± 0.3 in late-onset severe group; (12.4 ± 2.7), (28.0 ± 1.9) s, (5.1 ± 1.2) g/L and 0.9 ± 0.2 in control group. There was no significant difference among PE groups and control group (P > 0.05). The expression changes of annexin V in placenta and maternal blood were observed in patients with PE. This indicated that annexin Vplayed an important role in the pathogenesis and progression of PE by affecting coagulation.

Effects of prometryne on apoptosis and necrosis in thymus, lymph node and spleen in mice

Prometryne is a methylthio-s-triazine herbicide. Significant traces are documented in environment, mainly waters, soil and plants used for nutrition. The aim of this study was to estimate prometryne immunotoxic properties through induction of apoptotic and/or necrotic changes in thymocytes, splenocytes and lymph node cells after repeated subchronical exposure. Three different doses of prometryne (185, 375, 555 mg kg −1) were applied per os every 48 h, over 28 days. Flow cytometry assay (annexinV-FITC and PI) was conducted to record apoptotic and necrotic damage. In the spleen significant changes in the percentage of apoptotic cells were not detected between treated and control groups respectively. In thymus and lymph node, within the lowest dose group (185 mg kg −1), an increase in percentage of early apoptosis without any significant increase in necrosis was detected. Medium (375 mg kg −1) as well as high dose triggered increase in late apoptosis in lymph node while in thymus; late apoptosis was increased only in animals exposed to the highest dose (555 mg kg −1). The highest applied dose, in thymus and lymph node respectively, caused a general decrease in percentage of vital cells in favour of marked increase of percentages of all types of dying cells (apoptotic, late apoptotic/early necrotic and necrotic). Prometryne caused disbalance in major organs of immune system, markedly lymph nodes and thymus, by induction of early apoptotic changes in dose/time specific manner.

Low intensity ultrasound-induced apoptosis in human gastric carcinoma cells

To investigate the low intensity ultrasound (US)-induced apoptosis in human gastric carcinoma cells and its potential mechanism and to suggest a new therapeutic approach to gastric carcinoma. Human SGC-7901 gastric carcinoma cells were cultured in vitro and irradiated by low intensity US for 10 min at different intensities with different incubation times after irradiation. Morphologic changes were examined under microscope with trypan blue staining and then the percentage of early apoptotic cells was detected by flow cytometry (FCM) with double staining of fluorescein isothiocyanate (FITC)-Annexin V/propidium iodide (PI). Two-dimensional electrophoresis (2DE) was used to get the protein profile and some proteins differently expressed after US irradiation were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Functional analysis was performed to investigate the mechanism of US-induced cell apoptosis. The percentage of apoptotic cells increased about 10% after US irradiation (12.0 W/cm(2), 12 h culture). The percentage of early apoptosis and secondary necrosis in the US-irradiated cells increased with the increased US intensity. Moreover, apoptotic cells increased with the increased culture time after US irradiation and reached its maximum at about 12 h. Several new proteins appeared after US irradiation and were up or down regulated more than 2 times. Some heat shock proteins (HSPs) were found to be associated with the signal process simulating the apoptosis of cells. Low intensity US could induce apoptosis in human gastric carcinoma cells. US-induced apoptosis is related to US intensity/culture time. US-induced apoptosis may be caspases-dependent and endoplasmic reticulum (ER) stress-triggered apoptosis may also contribute to it. Proteomic experimental system is useful in finding the protein alteration in carcinoma cells after US irradiation, helping to develop a new cancer therapy.

The alteration of protein profile of Walker 256 carinosarcoma cells during the apoptotic process induced by ultrasound

The objective of this study was to investigate the alteration of the protein profile in cells after sonication and to identify the key proteins involved in the process of cell apoptosis. Walker 256 carinosarcoma cells were exposed to focused ultrasound (US) at the intensity of 2.0, 7.0, 10.2, 14.2 and 17.0 W/cm 2 (I spta) for 10 min in vitro and the morphologic and functional changes of the cells were detected by hematoxylin & eosin staining and flow cytometry, with double staining of fluorescein isothiocyanate (FITC)-labeled Annexin V/propidium iodide (PI). The protein compositions in the cells after sonication were detected by 2-D SDS polyacrylamide gel electrophoresis. Our results showed that apoptosis of Walker 256 carinosarcoma cells could be induced by US. The percentage of early apoptosis and secondary necrosis increased with increasing intensity of US irradiation. Comparing with the protein patterns of cells before sonication, it was found that around 420 new protein spots were present in the gel after sonication. Among them, Hsp60 and Bcl-2 like protein 13 were found to be involved in the process of cell apoptosis and US-induced apoptosis of the cells was probably performed through the pathway of promoting the activation of caspase-3. (E-mail: mxwan@mail.xjtu.edu.cn)

Heat Shock Treatment Enhances Graft Cell Survival in Skeletal Myoblast Transplantation to the Heart

Graft survival after skeletal myoblast transplantation is affected by various pathological processes caused by environmental stress. Heat shock is known to afford protection of several aspects of cell metabolism and function. We hypothesized that prior heat shock treatment of graft cells would improve their survival after cell transplantation. L6 rat skeletal myoblasts expressing ss-galactosidase (ss-gal) were subjected to heat shock (42 degrees C, 1 hour). Increased expression of heat shock protein 72 was detected 24 hours later in the heat-shocked cells. After hypoxia-reoxygenation in vitro, lactate dehydrogenase leakage was significantly attenuated in the heat-shocked cells; in addition, the percentage of early apoptosis was lower in this group measured by flow cytometry with annexin V staining. For the in vivo study, 1 x 10(6) heat-shocked (hsCTx) or normal-cultured (CTx) myoblasts were infused into the explanted rat hearts through the coronary artery followed by heterotopic heart transplantation. ss-gal activity was significantly higher in the hsCTx group after cell transplantation, with an estimated 8 x 10(6) surviving cells per heart in the hsCTx group and 5 x 10(6) cells in the CTx group on day 28. Discrete loci of grafted cells were globally observed in the myocardium of the hsCTx and CTx groups, with a higher frequency in the hsCTx group. Surviving myoblasts occasionally differentiated into myotubes and had integrated with the native cardiomyocytes. Heat-shocked skeletal myoblasts demonstrated improved tolerance to hypoxia-reoxygenation insult in vitro and enhanced survival when grafted into the heart. Heat shock treatment could be useful in improving graft cell survival in cell transplantation.

Heat Shock Treatment Enhances Graft Cell Survival in Skeletal Myoblast Transplantation to the Heart

Background —Graft survival after skeletal myoblast transplantation is affected by various pathological processes caused by environmental stress. Heat shock is known to afford protection of several aspects of cell metabolism and function. We hypothesized that prior heat shock treatment of graft cells would improve their survival after cell transplantation. Methods and Results —L6 rat skeletal myoblasts expressing β-galactosidase (β-gal) were subjected to heat shock (42°C, 1 hour). Increased expression of heat shock protein 72 was detected 24 hours later in the heat-shocked cells. After hypoxia-reoxygenation in vitro, lactate dehydrogenase leakage was significantly attenuated in the heat-shocked cells; in addition, the percentage of early apoptosis was lower in this group measured by flow cytometry with annexin V staining. For the in vivo study, 1×10 6 heat-shocked (hsCTx) or normal-cultured (CTx) myoblasts were infused into the explanted rat hearts through the coronary artery followed by heterotopic heart transplantation. β-gal activity was significantly higher in the hsCTx group after cell transplantation, with an estimated 8×10 6 surviving cells per heart in the hsCTx group and 5×10 6 cells in the CTx group on day 28. Discrete loci of grafted cells were globally observed in the myocardium of the hsCTx and CTx groups, with a higher frequency in the hsCTx group. Surviving myoblasts occasionally differentiated into myotubes and had integrated with the native cardiomyocytes. Conclusions —Heat-shocked skeletal myoblasts demonstrated improved tolerance to hypoxia-reoxygenation insult in vitro and enhanced survival when grafted into the heart. Heat shock treatment could be useful in improving graft cell survival in cell transplantation.