Bone Marrow Stromal Cells Promote Neuronal Restoration in Rats with Traumatic Brain Injury: Involvement of GDNF Regulating BAD and BAX Signaling.

BACKGROUND/AIMS: To investigate the effects of bone marrow stromal cells (BMSCs) and underlying mechanisms in traumatic brain injury (TBI). METHODS: Cultured BMSCs from green fluorescent protein-transgenic mice were isolated and confirmed. Cultured BMSCs were immediately transplanted into the regions surrounding the injured-brain site to test their function in rat models of TBI. Neurological function was evaluated by a modified neurological severity score on the day before, and on days 7 and 14 after transplantation. After 2 weeks of BMSC transplantation, the brain tissue was harvested and analyzed by microarray assay. And the coronal brain sections were determined by immunohistochemistry with mouse anti-growth-associated protein-43 kDa (anti-GAP-43) and anti-synaptophysin to test the effects of transplanted cells on the axonal regeneration in the host brain. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and Western blot were used to detect the apoptosis and expression of BAX and BAD. RESULTS: Microarray analysis showed that BMSCs expressed growth factors such as glial cell-line derived neurotrophic factor (GDNF). The cells migrated around the injury sites in rats with TBI. BMSC grafts resulted in an increased number of GAP-43-immunopositive fibers and synaptophysin-positive varicosity, with suppressed apoptosis. Furthermore, BMSC transplantation significantly downregulated the expression of BAX and BAD signaling. Moreover, cultured BMSC transplantation significantly improved rat neurological function and survival. CONCLUSION: Transplanted BMSCs could survive and improve neuronal behavior in rats with TBI. Mechanisms of neuroprotection and regeneration were involved, which could be associated with the GDNF regulating the apoptosis signals through BAX and BAD.

Protein microarray for complex apoptosis monitoring of dysplastic oral keratinocytes in experimental photodynamic therapy.

BACKGROUND: Photodynamic therapy is an alternative treatment of muco-cutaneous tumors that uses a light source able to photoactivate a chemical compound that acts as a photosensitizer. The phthalocyanines append to a wide chemical class that encompasses a large range of compounds; out of them aluminium-substituted disulphonated phthalocyanine possesses a good photosensitizing potential. RESULTS: The destructive effects of PDT with aluminium-substituted disulphonated phthalocyanine are achieved by induction of apoptosis in tumoral cells as assessed by flow cytometry analysis. Using protein microarray we evaluate the possible molecular pathways by which photodynamic therapy activates apoptosis in dysplastic oral keratinocytes cells, leading to the tumoral cells destruction. Among assessed analytes, Bcl-2, P70S6K kinase, Raf-1 and Bad proteins represent the apoptosis related biomolecules that showed expression variations with the greatest amplitude. CONCLUSIONS: Up to date, the intimate molecular apoptotic mechanisms activated by photodynamic therapy with this type of phthalocyanine in dysplastic human oral keratinocytes are not completely elucidated. With protein microarray as high-throughput proteomic approach a better understanding of the manner in which photodynamic therapy leads to tumoral cell destruction can be obtained, by depicting apoptotic molecules that can be potentially triggered in future anti-tumoral therapies.

Radiofrequency ablation does not induce apoptosis in the rat myocardium.

BACKGROUND: The mechanisms implicated in the genesis of delayed radiofrequency (RF) effects remain unclear, but may be related to extension of the lesion beyond the region of coagulative necrosis. The role of apoptosis in this process has not been previously reported. We assessed whether RF promotes apoptosis in the region surrounding acute ablation lesions in a rat model. METHODS: Wistar rats (n=30; weight 300 g) were anesthesized, the chest was opened, and the heart was exposed. A modified unipolar RF ablation (custom catheter 4.5-mm-tip diameter, 12 Watts, 10 seconds) was undertaken on the left ventricular anterolateral epicardial surface and the chest was closed. After 2 hours, animals were killed for histological (hematoxylin and eosin, TdT-mediated dUTP Nick End-Labeling [TUNEL] assay) and immunohistochemical (anti-BAD and anti-caspase 3 antibodies) analysis (n=18). Additional animals (n=12) were sacrificed at 2 (n=3), 24 (n=3), 48 (n=3), and 72 hours (n=3) after ablation exclusively for anti-BAD Western Blotting analysis. RESULTS: Lesions were characterized by well-defined regions of coagulative necrosis. In 18/18 (100%) animals, TUNEL assay revealed positive luminescent reaction cells in the region surrounding the lesion, extending up to 2 mm from the border zone. However, microscopic evaluation of the nuclei and immunohistochemical and anti-BAD Western Blotting analysis were negative in all (100%) rats. Thus, positive TUNEL reaction in the periphery of the ablation lesion likely reflects nonspecific DNA damage. CONCLUSION: RF ablation does not promote apoptosis in the periphery of the myocardial lesion. This finding may have implications for the elucidation of late lesion extension following RF ablation.

Interfering with interferon-γ signalling in intestinal epithelial cells: selective inhibition of apoptosis-maintained secretion of anti-inflammatory interleukin-18 binding protein.

The intestinal epithelial barrier represents an important component in the pathogenesis of inflammatory bowel diseases. Interferon (IFN)-γ, a T helper type 1 (Th1) cytokine, regulated by the interleukin (IL)-18/IL-18 binding protein (bp) system, modulates the integrity of this barrier. The aim of this work was to study functionally the consequences of IFN-γ on intestinal epithelial cells (IEC) and to interfere selectively with identified adverse IFN-γ effects. IEC lines were stimulated with IFN-γ. IL-18 and IL-18bp were assessed by enzyme-linked immunosorbent assay. Staining of phosphatidylserine, DNA laddering, lactate dehydrogenase (LDH) release, cleavage of poly-adenosine diphosphate-ribose-polymerase (PARP) and activation of caspase-3 were analysed to determine cell death. Inhibitors of tyrosine kinase, caspase-3 or p38 mitogen-activated kinase ((MAP) activity were used. Cytokines were measured in supernatants of colonic biopsies of healthy controls and inflammatory bowel disease (IBD) patients. In IEC lines, IFN-γ up-regulated IL-18bp selectively. Ex vivo, IFN-γ was present in supernatants from cultured biopsies and up-regulated with inflammation. Contrary to previous reports, IFN-γ alone induced apoptosis in IEC lines, as demonstrated by phosphatidylserin staining, DNA cleavage and LDH release. Further, activation of caspase-3, PARP cleavage and expression of pro-apoptotic Bad were induced. Partial inhibition of caspase-3 and of p38 but not JAK tyrosine kinase, preserved up-regulation of IL-18bp expression. Selective inhibition of IFN-γ mediated apoptosis, while preserving its beneficial consequences on the ratio of IL-18/IL-18bp, could contribute to the integrity of the mucosal barrier in intestinal inflammation.

Expression of apoptotic factors in vaginal tissues from women with urogenital prolapse.

AIMS: Increased apoptotic activity in pelvic tissues may contribute to development of pelvic floor disorders. We evaluated expression of apoptotic factors (Bcl-2 family) in vaginal tissues from women with pelvic organ prolapse (POP) and how these factors correlate with severity of prolapse. METHODS: mRNA and protein expression of anti-apoptotic and pro-apoptotic factors in vaginal tissues from subjects and controls were determined by real-time PCR and Western blot. Severity of prolapse was staged using POP-Q criteria. RESULTS: Differential expression of Bcl-2 family factors was observed in protein rather than in gene expression. During the secretory phase, the anti-apoptotic (Bcl-2, Bcl-xl) and pro-apoptotic protein (Bax) were upregulated in controls compared to cases (P < 0.05). The ratios of Bcl-2/Bax and Bcl-2/Bad, which determine cellular sensitivity to induction of apoptosis, were higher in controls versus cases. Higher ratios indicate reduced cellular sensitivity to apoptosis. Protein expression of Bax and Bad was higher in women with severe compared to mild prolapse (P < 0.05). CONCLUSION: Increased expression of Bad, Bax, and decreased ratios of Bcl-2/Bax, Bcl-2/Bad suggest increased apoptotic activity or sensitivity to induction of apoptosis in vaginal tissues of women with POP.

[Morphological and histochemical analysis of mucous membrane transformation of the artificial urinary bladder].

The performed morphologic study of transformation mechanisms of the intestinal reservoir mucous membrane using modern immunochemical and histochemical methods revealed three morphologic phases of enteric epithelium adaptation; reactive-inflammatory, compensatory-protective and atrophic. Enteric urinary reservoir preserves the cambial apparatus typical for the enteric phenotype with an inherent apoptosis activity and proliferation which confirms a low level of tumor transformation risk.

Vascular endothelial growth factor is an autocrine survival factor for breast tumour cells under hypoxia.

Vascular endothelial growth factor (VEGF) is produced by most tumour types and stimulates the growth of new blood vessels in the tumour. The expansion of a solid tumour ultimately leads to the development of hypoxic regions, which increases VEGF production and further angiogenesis. In this study, we examined the role of VEGF in the survival of breast tumour cells under hypoxia. Murine 4T1 and human MDA-MB-231 tumour cells were cultured under normoxic and hypoxic growth conditions in the presence or absence of VEGF neutralising antibodies. Apoptosis was assessed in addition to changes in expression of the anti- and pro-apoptotic proteins, Bcl-2 and Bad, respectively. The effect of hypoxia on the novel VEGF receptor, NP1 (neuropilin-1) and the role of the PI3K (phosphatidylinositol-3-kinase) signalling pathway in response to VEGF were examined. VEGF blockade resulted in direct tumour cell apoptosis of both tumour cell lines under normoxia and hypoxia. While blocking VEGF resulted in a downregulation of hypoxia-induced Bcl-2 expression, there was a significant increase in the pro-apoptotic protein Bad relative to cells cultured under hypoxia alone. Both hypoxia and VEGF phosphorylated Akt. Neutralising antibodies to VEGF abrogated this effect, implicating the PI3K pathway in VEGF-mediated cell survival of mammary adenocarcinoma cells. This study demonstrates that VEGF acts as a survival factor not only for endothelial cells as previously thought, but also for some breast tumour cells, protecting them from apoptosis, particularly under hypoxic stress. The data presented provide an additional rationale for combining anti-VEGF strategies with conventional anti-cancer therapies such as chemotherapy and radiotherapy.

Leptin and leptin receptor in pig spermatozoa: evidence of their involvement in sperm capacitation and survival.

Several studies have recently investigated the role of leptin, the adipocyte-secreted hormone, in the growth and reproduction of rodents, humans, and domestic animals. The present study was designed to explore the expression of leptin and its receptor in pig spermatozoa. Successful Western blot evidenced a 16 kDa band for leptin and six isoforms, ranging from 120 to 40 kDa, for the leptin receptor. Both leptin and leptin receptor were interestingly located at sperm acrosomal level, suggesting their involvement in the oocyte fertilization events. In fact, both capacitation indexes and acrosin activity were enhanced by leptin, and these effects were reduced by the anti-leptin receptor antibody. Afterwards, we investigated the main transduction pathways regulated by the hormone. Our results showed that, in pig sperm, leptin can trigger the signal transducer and activator of transcription 3, a classical component of cytokine signal transduction pathways, whose expression has not been previously reported in male gamete; in addition it was found constitutively activated. Besides, leptin was able to induce the activation of phosphatidylinositol phosphate kinase 3 and MAP kinase pathways as well as of BCL2, a known antiapoptotic protein. These data address to a role of leptin and its receptor on pig sperm survival. The presence of leptin and its receptor in pig sperm suggests that they, through an autocrine short loop, may induce signal transduction and molecular changes associated with sperm capacitation and survival.

Overexpression of phospho-Akt correlates with phosphorylation of EGF receptor, FKHR and BAD in nasopharyngeal carcinoma.

The Akt pathway is one of the most common molecular alterations in various human malignancies. However, its involvement in nasopharyngeal carcinoma (NPC) tumorigenesis has not been well established. In this study, the status of Akt activation and expression of its upstream and downstream molecules was investigated in 64 NPC and 38 non-malignant nasopharyngeal tissues by immunohistochemistry. The hotspot mutations of PIK3CA, encoding the p110alpha catalytic subunit of phosphatidylinositol 3-kinase (PI3K), were also determined in 25 of these NPC tissues. No hotspot mutations were found in any of the samples tested. Akt was activated in 27 (42.2%) and 23 (35.9%) NPCs, as indicated by p-Akt (Thr308) and p-Akt (Ser473) immunoreactivity, respectively. PTEN loss did not correlate statistically with activated Akt. However, a positive correlation was observed between activated Akt and phospho-epidermal growth factor receptor (p-EGFR), suggesting that the EGFR signaling might be one of the upstream regulators of the Akt pathway. The phosphorylation of forkhead (FKHR) and Bcl-2 associated death domain (BAD), but not mammalian target of rapamycin and glycogen synthase kinase-3beta, was significantly correlated with Akt activation. This implies that Akt promotes cell proliferation (as estimated by Ki-67) and survival, at least, through the inactivation of FKHR and BAD in NPC. Our data revealed that the EGFR/PI3K/Akt signaling pathway is important in NPC pathogenesis and that PIK3CA hotspot mutations are rare in NPC.

Immunohistochemical detection of BH3-only proteins in ameloblastic tumors.

OBJECTIVE: To evaluate expression of BH3-only proteins in odontogenic tumors, expression of Bid, Bim, Bad, Noxa, and Puma was analyzed in ameloblastic tumors as well as in tooth germs. METHODS: Nine tooth germs, 37 ameloblastomas, and five malignant ameloblastic tumors were examined immunohistochemically with antibodies against Bid, Bim, Bad, Noxa, and Puma. RESULTS: Immunohistochemical reactivity for Bid, Bim, Bad, Noxa, and Puma was detected in the cytoplasm of cellular components in normal and neoplastic odontogenic tissues. Expression of these BH3-only proteins was evident in odontogenic epithelial cells near the basement membrane in tooth germs and ameloblastic tumors. Acanthomatous ameloblastomas showed no reactivity for Bid, Bim, Bad, Noxa, or Puma in keratinizing cells, whereas granular cells in granular cell ameloblastomas reacted with these BH3-only proteins. Basal and desmoplastic ameloblastomas and ameloblastic carcinomas showed immunoreactivity for the BH3-only proteins in most neoplastic cells. CONCLUSION: Expression of Bid, Bim, Bad, Noxa, and Puma in tooth germs and ameloblastic tumors suggests that the BH3-only proteins have a role in apoptotic cell death of normal and neoplastic odontogenic epithelium. Distinctive expression patterns of these BH3-only proteins in ameloblastoma variants suggest that the BH3-only proteins might be involved in tumor cell differentiation of ameloblastomas.

Indices of apoptosis activation after blood cardioplegia and cardiopulmonary bypass.

BACKGROUND: Cardioplegic arrest (CA) using cold blood cardioplegia (CBC) has been reported to reduce ischemia-reperfusion (IR)-induced myocardial injury via apoptosis. We studied key apoptotic mediators via the caspase-dependent and intrinsic pathways as well as poly(ADP)-ribosylating protein (PARP) activity in myocardial and peripheral tissues after CA and cardiopulmonary bypass (CBP). METHODS AND RESULTS: Right atrial (RA) and skeletal muscle(SM) was harvested from cardiac surgical patients with similar baseline characteristics (N =6) before and after CPB and CBC. Total and modified caspase-3, Bcl-2, Bad, apoptosis-inducing factor (AIF), and PARP were quantified by immunoblotting. Terminal caspase-3 activity was assessed and immunohistochemistry was performed for PARP and AIF. TUNEL staining was used for identification of apoptotic cells. Microarray gene expression analysis was performed using Affymetrix U95 GeneChip. In RA tissue, CA with CBC significantly increased phosphorylation of Bcl-2 (Ser70), Bad (Ser112) (2.63+/-0.4 and 1.77+/-0.3-fold respectively; P<0.05), and cleavage of the downstream caspase 3 (1.45+/-0.1-fold; P<0.05). There was no significant change in total protein levels. Also, there was an increase in mature AIF (57 kDa) levels (1.22+/-0.01-fold; P<0.05) and a trend toward nuclear translocation on histological staining. Caspase 3 activity was increased 1.5+/-0.14-fold (P<0.05). The number of apoptotic cells in atrial tissue increased after compared with before CPB/CA using TUNEL staining (1.55+/-0.66 versus 0.325+/-0.05%, respectively; P=0.03). In contrast, SM samples did not show any of the changes observed in RA tissue after CPB. CONCLUSIONS: Despite optimal current surgical myocardial protection, we found that CA with CBC induced both programmed cell death and survival signaling in myocardial tissue.

Expression of bcl2 family proteins and active caspase 3 in classical Hodgkin's lymphomas.

The expression of various bcl2 family proteins has been reported in Hodgkin and Reed-Sternberg cells, but the proteins bad, bid, and bim have not been analyzed in classical Hodgkin's lymphomas (HLs). This study aimed to investigate the expression of the proteins bcl2, bcl-xl, mcl1, bax, bak, bad, bid, bim, and active caspase 3, and the TUNEL (terminal deoxynucleotidyl transferase-mediated in situ labeling) index to gain further insight into the apoptosis profile of classical HLs. A high expression of the proteins bcl2, bcl-xl, mcl1, bax, bak, bad, bid, and bim in HRS cells was found in 27 of 101 (27%), 95 of 101 (94%), 27 of 97 (29%), 73 of 95 (77%), 37 of 102 (36%), 85 of 94 (90%), 19 of 109 (17%), and 43 of 91 (47%) cases, respectively. The high expression of bcl-xl, bax, and bad in HRS cells in most classical HLs indicates that these proteins may play predominant roles in the regulation of apoptosis in classical HLs. Active caspase 3-positive and TUNEL-positive Reed-Sternberg cells were detected in 47 of 70 (67%; range, 0%-12%) and 60 of 71 (85%; range, 0%-19%) cases, respectively. Significant positive correlations were found between bax/bcl2 (P = .002), bad/bcl2 (P = .020), bad/bcl-xl (P = .003), and bim/mcl1 (P = .036). Based on these findings, it could be hypothesized that the antiapoptotic proteins bcl2, bcl-xl, and mcl1 may counteract the expression of the proapoptotic proteins bax, bad, and bim, thereby contributing to the survival of Reed-Sternberg cells.

Etanercept attenuates the development of cerulein-induced acute pancreatitis in mice: a comparison with TNF-alpha genetic deletion.

TNF-alpha plays a pivotal role in the pathogenesis of acute pancreatitis. Recent studies have shown that TNF-alpha inhibition significantly ameliorates the course of experimental acute pancreatitis, but in this context, the effects of Etanercept, a novel anti-TNF-alpha agent, have not been investigated so far. The aims of the present study are (i) to assess the effects of pharmacological inhibition of TNF-alpha by means of Etanercept on the inflammatory response and apoptosis in a murine model of necrotizing acute pancreatitis and (ii) to compare the results to those observed in TNF-alpha receptor 1 knockout (TNFR1-KO) mice. Necrotizing acute pancreatitis was induced in TNF-alpha wild type for TNFR1 (WT) and TNFR1-KO mice by intraperitoneal injection of cerulein (hourly x5, 50 microg/kg). In another group of WT mice, Etanercept was administered (5 or 10 mg/kg, s.c.) at 1 h after first cerulein injection. Control groups received saline treatment. After 24 h, biochemical, histological, and immunohistochemical evidences of acute pancreatitis developed in all cerulein-treated mice; apoptosis was also present in the pancreas. Contrarily, pancreatitis histological features, amylase and lipase levels, pancreas water content, and myeloperoxidase activity were reduced in a similar degree in Etanercept-treated and TNFR1-KO mice. Likewise, in these two groups, immunohistochemical stainings and terminal deoxynucleotidyltransferase-mediated UTP nick-end labeling assay were found negative. TNF-alpha receptor 1 gene deletion and Etanercept administration ameliorate the course of experimental acute pancreatitis in a similar degree. Future studies on clinical applications of Etanercept in pancreatitis seem promising.

Immunohistochemical analysis of phospho-BAD protein and mutational analysis of BAD gene in gastric carcinomas.

Mounting evidence indicates that deregulation of apoptosis contributes to the development of human cancers. BAD, a proapoptotic Bcl-2 family protein, regulates the intrinsic apoptosis pathway. The aim of this study was to explore whether alterations of phospho-BAD (p-BAD) protein that antagonizes apoptosis function of BAD and mutation of BAD gene are characteristics of human gastric cancers. We analyzed expression of p-BAD in 60 gastric adenocarcinomas by immunohistochemistry. Also, we analyzed BAD gene for detection of somatic mutations by single-strand conformation polymorphism (SSCP) assay. p-BAD expression was detected well in normal gastric mucosal epithelial cells, whereas it was detected in only 51% (31 of the 60) of the cancers. There was no somatic mutation of BAD gene in the 60 gastric cancer samples. The decreased expression of p-BAD in malignant gastric epithelial cells compared to normal mucosal epithelial cells suggested that loss of p-BAD expression may play a role in gastric tumorigenesis. The data also suggest that BAD mutation may not be a direct target of inactivation in gastric tumorigenesis.

Gene expression and development of mouse zygotes following droplet vitrification.

The concept of ultra-rapid vitrification has emerged in recent years; the accelerated cooling rate reduced injury attributed to cryopreservation and improved post-freezing developmental competence of vitrified oocytes and embryos. The objectives of the present study were to develop a simple and effective ultra-rapid vitrification method (droplet vitrification) and evaluate its effects on post-thaw development and apoptosis-related gene expression in mouse zygotes. Presumptive zygotes were equilibrated for 3 min in equilibration medium and washed 3 times in vitrification solution. A drop (5 microL) of vitrification solution containing 10-12 embryos was placed directly onto surface of liquid nitrogen, with additional liquid nitrogen poured over the drop. For thawing and cryoprotectant removal, vitrified drops were put into dilution medium for 3 min, followed by M2 medium for 5 min. Although cleavage rate did not differ significantly among the control (90.8+/-2.8%; mean+/-S.E.M.), toxicity control (83.5+/-3.2%), and vitrified (86.2+/-3.1%) zygotes, rates of blastocyst and hatched blastocyst formation were lower (P<0.01) in vitrified zygotes (49.7+/-4.7% and 36.0+/-4.7%) and toxicity controls (47.3+/-4.6% and 40.3+/-4.6%) compared with controls (65.5+/-4.1% and 54.2+/-4.3%). Exposure of zygotes to vitrification solution, as well as the vitrification process, down-regulated the expression of Bax, Bcl2, and p53 genes in blastocysts. Although droplet vitrification was efficient and easy, it altered the transcriptional activities of Bax, Bcl2, and p53 genes in vitrified embryos, indicating a strong relationship between reduced developmental competence and the altered transcriptional activities of these genes.

Molecular indices of apoptosis after intermittent blood and crystalloid cardioplegia.

BACKGROUND: We investigated whether intermittent blood and crystalloid cardioplegia differentially affect myocardial apoptosis and apoptosis gene-related proteins. METHODS AND RESULTS: Rabbit hearts were perfused with Krebs-Henseleit buffer on a Langendorff apparatus. Control hearts (n=6) were perfused for 120 minutes without cardioplegic ischemia. Hearts were arrested for 60 minutes with warm (37 degrees C) crystalloid cardioplegia (iW-CCP) (n=8) or with warm blood cardioplegia (iW-BCP) (n=8) administered intermittently. In cold (0 to 4 degrees C) groups, hearts were arrested for 60 minutes with cold crystalloid cardioplegia (iC-CCP; n=8) or with cold blood cardioplegia (iC-BCP; n=6) administered intermittently. The hearts were reperfused for 30 minutes with Krebs-Henseleit buffer. iC-BCP significantly preserved the recovery of left ventricular and microvascular function compared with the other 3 experimental groups. There were no significant differences in total protein levels of caspase 3, Bcl-2, Bad, and Bax among the groups. iC-BCP significantly induced greater phosphorylation of Bad (5.6+/-0.8-fold) as compared with the other 3 groups (3.4+/-0.6-fold in iC-CCP, P<0.05; 2.5+/-0.3 in iW-BCP, P<0.05; and 1.4+/-0.2 in iW-CCP, P<0.01). iC-BCP induced less caspase 3 activation and apoptosis than the other 3 groups. CONCLUSIONS: iC-BCP is superior to the other cardioplegic solutions in increasing the phosphorylation of Bad, inhibiting the activation of caspase 3, and preventing apoptosis. These effects of iC-BCP were associated with preserved left ventricular function and endothelium-dependent relaxation of coronary microvessels.

Bradykinin preconditioning improves the profile of cell survival proteins and limits apoptosis after cardioplegic arrest.

BACKGROUND: We hypothesized that preconditioning the heart with bradykinin (BK) would improve the profile of antiapoptotic proteins and inhibit myocardial apoptosis. METHODS AND RESULTS: Eighteen rabbit hearts were retrogradely perfused with Krebs-Henseleit buffer (KHB). Six control hearts were perfused with KHB for 90 minutes without cardioplegia ischemia. Six hearts were arrested for 30 minutes (37 degrees C) with crystalloid cardioplegia (CCP). Six BK preconditioning (BKPC) hearts received a 10-minute coronary infusion of 10(-8) M BK-enriched KHB followed by a 5-minute recovery period and were then arrested for 30 minutes with CCP. The hearts were reperfused for 30 minutes with KHB. BKPC significantly improved the recovery of left ventricular pressure (73+/-5 versus 51+/-4 mm Hg; P<0.05) and reduced the percentage of myocardial apoptosis (3.4+/-0.3% versus 1.2+/-0.2%; P<0.05) as compared with CCP. There were no significant differences in total protein levels of caspase 3, Bcl-2, Bad, and Bax, among the groups. Both BKPC and CCP induced phosphorylation of Bad at Ser112, but the BKPC group had higher phosphorylated Bad than CCP (4.4+/-0.5 versus 2.0+/-0.3; P<0.05). Both BKPC and CCP alone increased caspase 3 cleavage and activity as compared with controls (P<0.05 and P<0.01, respectively), but BKPC caused less cleavage and activation of caspase 3 than CCP alone (P<0.05). CONCLUSIONS: BKPC increased Bad phosphorylation, inhibited caspase 3 activation, and limited myocardial apoptosis, which were associated with improvement of left-ventricular performance. These results identify novel molecular mechanisms underlying the protective effects of BKPC during cardiac surgery.

Immunohistochemical detection of apoptotic markers in gastric cancer.

Apoptosis proteins may play a role in prognosis and therapy response; however, they have not been fully investigated in gastric cancer. We aimed to assess the expression of proteins in the Bcl-2 family. Immunohistochemistry was employed to examine the expression of the antiapoptotic proteins Bcl-2 and Bcl-XL and the proapoptotic proteins Bad, Bak, Bax, Bid, Bim, and p53 in 21 cases of gastric cancer. Immunopositivity was observed in 12/21 (57%) cases for p53, 16/21 (76%) cases for Bcl-XL, and 5/21 (23%) cases for Bcl-2. For the proapoptotic members of the Bcl family, loss of protein expression was observed: Bid (14/21 cases; 66%), Bad (13/21 cases; 61%), Bax (12/21 cases; 57%), Bak (9/21 cases; 42%), and Bim (4/21 cases; 19%). This study identified apoptosis proteins that exhibit heterogeneous expression between primary gastric carcinomas.

Systemic IGF-I treatment inhibits cell death in diabetic rat retina.

Diabetic retinopathy can result in apoptotic cell death of retinal neurons, as well as significant visual loss. It is further known that insulin-like growth factor (IGF) levels are reduced in diabetes and that IGF-I can prevent cell death in many cell types. In this study, we tested the hypothesis that systemic treatment with IGF-I could inhibit death of neuroretinal cells in diabetic rats by examining the expression of proapoptotic markers. In diabetic rat retina, the number of TUNEL-immunoreactive cells increased approximately sixfold in the photoreceptor layer (P<.001) and eightfold in the inner nuclear layer (INL; P<.001); phospho-Akt (p-Akt; Thr 308) immunoreactivity increased eightfold in the ganglion cell layer (GCL; P<.001) and threefold in the INL (P<.01). Subcutaneous IGF-I treatment significantly reduced the number of TUNEL (P<.001) and p-Akt immunoreactive retinal cells (P<.05) in diabetic rats approximately to the level of the nondiabetic group. Qualitative results showed that caspase-3 and BAD immunoreactivities were also elevated in diabetes and reduced in IGF-I-treated animals. Elevated TUNEL and p-Akt immunoreactivities were localized to distinct cell layers in the retina of diabetic rats. Early intervention with systemic IGF-I reduced the presence of proapoptotic markers indicative of neuroretinal cell death, despite ongoing hyperglycemia and weight loss. The eye is a special sensory organ, and these data show that cell loss in the nervous system, even in uncontrolled diabetes, can be prevented by IGF-I administration.

HSP90 inhibition leads to degradation of the TYK2 kinase and apoptotic cell death in T-cell acute lymphoblastic leukemia.

We previously found that tyrosine kinase 2 (TYK2) signaling through its downstream effector phospho-STAT1 acts to upregulate BCL2, which in turn mediates aberrant survival of T-cell acute lymphoblastic leukemia (T-ALL) cells. Here we show that pharmacologic inhibition of heat shock protein 90 (HSP90) with a small-molecule inhibitor, NVP-AUY922 (AUY922), leads to rapid degradation of TYK2 and apoptosis in T-ALL cells. STAT1 protein levels were not affected by AUY922 treatment, but phospho-STAT1 (Tyr-701) levels rapidly became undetectable, consistent with a block in signaling downstream of TYK2. BCL2 expression was downregulated after AUY922 treatment, and although this effect was necessary for AUY922-induced apoptosis, it was not sufficient because many T-ALL cell lines were resistant to ABT-199, a specific inhibitor of BCL2. Unlike ABT-199, AUY922 also upregulated the proapoptotic proteins BIM and BAD, whose increased expression was required for AUY922-induced apoptosis. Thus, the potent cytotoxicity of AUY922 involves the synergistic combination of BCL2 downregulation coupled with upregulation of the proapoptotic proteins BIM and BAD. This two-pronged assault on the mitochondrial apoptotic machinery identifies HSP90 inhibitors as promising drugs for targeting the TYK2-mediated prosurvival signaling axis in T-ALL cells.