Expression of heat shock proteins (Hsps) 27 and 70 in kidney in cases of fatal hemorrhage.

The expression levels of intracellular heat shock proteins (Hsps), specialized chaperone proteins, increase in cases of cellular stress with protein misfolding and aggregation. In a previous study, we demonstrated that there is an extensive increase in intracellular Hsp27 and 70 expression levels in renal tissues in fire fatality cases. Hsp expression can be induced by not only heat, but also by tissue hypoxia. In cases of fatal hemorrhage, the individual suffers hypoxemia and consequently tissue hypoxia. Here, we examined 43 cases of fatal hemorrhage and a control group of 85 deaths not related to blood loss or temperature exposure. We evaluated Hsp27 and 70 protein expression levels in renal tissue using immunohistochemistry. The results revealed that no extensive Hsp27 or 70 expression is induced in the fatal hemorrhage cases. The renal Hsp levels were similar to those of the control group. Fatal blood loss does not cause relevant cell stress.

HMGN5 promotes IL-6-induced epithelial-mesenchymal transition of bladder cancer by interacting with Hsp27.

Bladder cancer (BC) is one of the most common cancers worldwide, with a high rate of recurrence and poor outcomes. High-mobility group nucleosome-binding domain 5 (HMGN5) is overexpressed in many cancers and could cause carcinogenesis in BC. By protein-protein-interaction (PPI) analysis, we found that heat shock protein 27 (Hsp27), also a crucial functional factor in BC carcinogenesis, is significantly related to HMGN5. Hsp27 is required for IL-6-mediated EMT via STAT3/Twist signaling in prostate cancer. Here, we hypothesize that HMGN5 may interact with Hsp27 to affect IL-6-induced EMT and invasion in BC via STAT3 signaling. In the present study, we found that HMGN5 and Hsp27 are highly expressed in BC tissues and positively correlated with each other. HMGN5 interacts with Hsp27 in vitro, to modulate the cell invasion and EMT in BC. Moreover, HMGN5 could modulate IL-6-Hsp27-induced EMT and invasion in BC cells by regulating STAT3 phosphorylation and STAT3 targeting of the Twist promoter. HMGN5 interacts with Hsp27 to promote tumor growth in a human BC xenograft model in nude mice. In summary, HMGN5 interacts with Hsp27 to promote IL-6-induced EMT, therefore promoting invasion in BC and contributing to the progression of BC.

Cytoprotective effect of eupatilin against indomethacin-induced damage in feline esophageal epithelial cells: relevance of HSP27 and HSP70.

Indomethacin is a non-steroidal anti-inflammatory drug with clearly known side effects on the gastrointestinal tract. The purpose of the present study was to investigate whether eupatilin inhibit cell injury induced by indomethacin in cultured feline esophageal epithelial cells (EECs). EECs were used to investigate the ability of eupatilin to induce the expression of heat shock proteins (HSP27 and HSP70) and analyze its cytoprotective effect against indomethacin-induced damage. The treatment of EECs with indomethacin for 8 h decreased cell viability. Western blot analysis showed that the levels of HSPs gradually decreased in cells treated with indomethacin, while eupatilin treatment increased the levels of HSPs. When treated with both indomethacin and eupatilin, the levels of HSPs increased rapidly, and were maintained at 130-140%. In addition, treatment with the specific inhibitors of PTK, PKC, PLC, p38 MAPK, JNKs, and PI3K attenuated the eupatilin-induced expression of HSPs. Pretreatment of EECs with the inhibitors of protein synthesis, actinomycin D or cycloheximide, attenuated the cytoprotective effect of eupatilin on indomethacin-induced cell damage. Reactive oxygen species production was upregulated by indomethacin, but downregulated by eupatilin. Taken together, it was suggested that HSPs were partly responsible for the eupatilin-mediated cytoprotective activity against the indomethacin-induced damage in EECs.

Sustained cell body reactivity and loss of NeuN in a subset of axotomized bulbospinal neurons after a chronic high cervical spinal cord injury.

Following central nervous system lesion, the ability of injured axons to regrowth may depend on the level and duration of the injured cell body response (CBR). Therefore, to investigate whether axotomized brainstem neurons maintain a durable growth-competent state after spinal cord injury, we studied the effect of a chronic C2 hemisection in rats on the expression of various CBR markers involved in axon regeneration, such as c-Jun, ATF-3, HSP27, NO synthase (NOS), and also of the neural mature phenotype marker NeuN, in the bulbospinal respiratory neurons as compared to the gigantocellularis nucleus. Both at 7 and 30 days post-lesion (DPL), c-Jun and HSP27 were present in, respectively, ~60 and ~20% of the axotomized respiratory neurons, whereas the apoptotic factor caspase 3 was not detected in these cells. NOS appeared belatedly, and it was detected in ~20% of the axotomized respiratory neurons at 30DPL. At 30DPL, these different CBR markers were strongly colocalized in a sub-population of axotomized respiratory neurons and also in a sub-population of injured neurons within the gigantocellularis nucleus. Such CBR was also accompanied by a sustained alteration of the neural mature phenotype, as indicated by a loss of NeuN immunoreactivity selectively in HSP27+ bulbospinal neurons at 7DPL and 30DPL. Altogether, this study shows that a subset of axotomized medullary respiratory neurons remains in a growth-competent state after a chronic injury, suggesting that they may play a preferential role in long-lasting respiratory neuroplasticity processes.

Proteomic Profiling and Differential Messenger RNA Expression Correlate HSP27 and Serpin Family B Member 1 to Apical Periodontitis Outcomes.

INTRODUCTION: Understanding protein expression profiles of apical periodontitis may contribute to the discovery of novel diagnostic or therapeutic molecular targets. METHODS: Periapical tissue samples (n = 5) of patients with lesions characterized as nonhealing were submitted for proteomic analysis. Two differentially expressed proteins (heat shock protein 27 [HSP27] and serpin family B member 1 [SERPINB1]) were selected for characterization, localization by immunofluorescence, and association with known biomarkers of acute inflammatory response in human apical periodontitis (n = 110) and healthy periodontal ligaments (n = 26). Apical periodontitis samples were categorized as stable/inactive (n = 70) or progressive/active (n = 40) based on the ratio of expression of receptor activator of nuclear factor kappa-B ligand (RANKL)/osteoprotegerin (OPG). Next, the expression of HSP27, SERPINB1, C-X-C motif Chemokine Receptor 1 (CXCR1), matrix metalloproteinase 8 (MMP8), myeloperoxidase (MPO), and cathepsin G (CTSG) messenger RNA was evaluated using real-time polymerase chain reaction. Data analysis was performed using the Shapiro-Wilk test, analysis of variance, and the Pearson test. P values <.05 were considered statistically significant. RESULTS: Proteomic analysis revealed 48 proteins as differentially expressed in apical periodontitis compared with a healthy periodontium, with 30 of these proteins found to be expressed in all 4 lesions. The expression of HSP27 and SERPINB1 was ∼2-fold higher in apical periodontitis. Next, an increased expression of HSP27 was detected in epithelial cells, whereas SERPINB1 expression was noted in neutrophils and epithelial cells. HSP27 and SERPINB1 transcripts were highly expressed in stable/inactive lesions (P < .05). Significant negative correlations were found between the expression of HSP27 and SERPINB1 with biomarkers of acute inflammation including CXCR1, MPO, and CTSG. CONCLUSIONS: Our data suggest HSP27 and SERPINB1 as potential regulators of the inflammatory response in apical periodontitis. Additional functional studies should be performed to further characterize the role of these molecules during the development/progression of apical periodontitis.

Suppression of HSP27 Restores Retinal Function and Protects Photoreceptors From Apoptosis in a Light-Induced Retinal Degeneration Animal Model.

Purpose: We used a light-induced retinal degeneration animal model to investigate possible roles of heat shock protein 27 (HSP27) in retinal/photoreceptor protection. Methods: Sprague-Dawley rats were used for the light-induced retinal degeneration animal model. The histology of eye sections was observed for morphologic changes in the retina. Cell apoptosis was examined in each group using the terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, and electroretinography was used to evaluate retinal function. Protein and mRNA expression levels of different retinal cell markers were also detected through immunofluorescence staining, Western blotting, and real-time PCR. Results: The thickness of the outer nuclear layer significantly decreased after 7-day light exposure. Moreover, we injected a viral vector for silencing HSP27 expression into the eyes and observed that photoreceptors were better preserved in the HSP27-suppressed (sHSP27) retina 2 weeks after injection. HSP27 suppression also reduced retinal cell apoptosis caused by light exposure. In addition, the loss of retinal function caused by light exposure was reversed on suppressing HSP27 expression. We subsequently found that the expression of the Rho gene and immunofluorescence staining of rhodopsin and arrestin (cell markers for photoreceptors) increased in sHSP27-treated retinas. HSP27 suppression did not affect the survival of ganglion and amacrine cells. Conclusions: Retinal cell apoptosis and functional loss were observed after 7-day light exposure. However, in the following 2 weeks after light exposure, HSP27 suppression may initiate a protective effect for retinal cells, particularly photoreceptors, from light-induced retinal degeneration.

Effect of HSP27 and Cofilin in the injury of hypoxia/reoxygenation on hepatocyte membrane F-actin microfilaments.

Hypoxia-reoxygenation (H/R) injury hepatocyte models were established to simulate the ischemia/reperfusion injury of transplanted organ. Through the study of the molecular mechanism of H/R on the F-actin damage of the liver cytomembrane, the mechanism of F-actin damage induced by ischemia and reperfusion was studied from the level of cell and molecule.The hypoxic environment of cells in vitro was simulated by chemical hypoxia agent CoCl2. Liver cells were detected by MTT, H/R group was subdivided into 3 subgroups: H/R 2, 4, and 6 h. Changes of cell shape and the growth state, apoptosis, ultrastructural changes, and the changes in F-actin microfilament content were observed. Heat shock protein 27 (HSP27), Cofilin, and F-actin gene and protein levels were determined by real-time polymerase chain reaction and western blot assay, respectively.Cells showed circular adherence growth under normal circumstances, while the spindle cells and shedding cells were significantly increased in H/R groups. Apoptosis cells in H/R group were increased significantly with the extension of hypoxia time. The number of endoplasmic reticulum was decreased significantly in the H/R group, the mitochondrion hydropic was degenerated and the glycogen was disappeared. The F-actin fibers in the H/R group were disordered, the morphology of the fibers was obviously decreased, and the fluorescence staining decreased obviously (P < .05). The transcription and expression levels of HSP27, Cofilin, and F-actin were significantly lower than those in the control group (P < .05).These results demonstrate that H/R can affect the correct assembly of F-actin microfilaments and weakens the normal cycle of F-actin microfilaments through inhibiting the protein expression and gene transcription of HSP27 and Cofilin in hepatocytes, thereby changing the skeleton of F-actin microfilaments.

Ayurvedic Amalaki Rasayana promotes improved stress tolerance and thus has anti-aging effects in Drosophila melanogaster.

Amalaki Rasayana (AR) is a common Ayurvedic herbal formulation of Phyllanthus emblica fruits and some other ingredients, and is used for general good health and healthy aging. We reported it to improve life history traits and to suppress neurodegeneration as well as induced apoptosis in Drosophila. The present study examines responses of Drosophila reared on AR-supplemented food to crowding, thermal or oxidative stresses. Wild-type larvae/flies reared on AR-supplemented food survived the various cell stresses much better than those reared on control food. AR-fed mutant park13 or DJ-1 beta Delta93 (Parkinson's disease model) larvae/flies, however, showed only partial or no protection, respectively, against paraquat-induced oxidative stress, indicating essentiality of DJ-1 beta for AR-mediated oxidative stress tolerance. AR feeding reduced the accumulation of reactive oxygen species (ROS) and lipid peroxidation even in aged (35-day-old) wild-type flies while enhancing superoxide dismutase (SOD) activity. We show that while Hsp70 or Hsp83 expression under normal or stress conditions was not affected by AR feeding, Hsp27 levels were elevated in AR-fed wild-type control as well as heat-shocked larvae. Therefore, besides the known anti-oxidant activity of Phyllanthus emblica fruits, dietary AR also enhances cellular levels of Hsp27. Our in vivo study on a model organism shows that AR feeding significantly improves tolerance to a variety of cell stresses through reduced ROS and lipid peroxidation on the one hand, and enhanced SOD activity and Hsp27 on the other. The resulting better homeostasis improves life span and quality of organism's life.

Drug-induced Modulation of Heat Shock Protein HSPB1 in an Ovarian Cancer Cell Model.

BACKGROUND: Heat-shock protein HSPB1 (alternative name HSP27) plays a pivotal role in cell survival pathways, apoptosis, metastasis and has been frequently linked to treatment resistance in ovarian cancer (OC) and other malignancies. Characteristic HSPB1 induction in different solid tumors is often caused by cytotoxic agents. MATERIALS AND METHODS: An in vitro OC cell model system was established to characterize resistance mechanisms during chemotherapy. Human OC cell lines OVCAR-3, SK-OV-3 and TOV-21G were treated with paclitaxel or carboplatin. Cellular growth was analyzed by cell counting. Intra- and extracellular HSPB1 concentrations were assessed by western blot and enzyme-linked immunosorbent assays. RESULTS: Incubation with paclitaxel, and with carboplatin significantly reduced cell growth without a definitive increase of intracellular HSPB1 expression. HSPB1 demonstrated drug-inducible secretion into the extracellular compartment. CONCLUSION: Despite its current lack of analysis in patient samples, serum soluble HSPB1 may function as a specific biomarker for monitoring response to chemotherapy in patients with OC.

Heat Shock Protein Beta-1 Modifies Anterior to Posterior Purkinje Cell Vulnerability in a Mouse Model of Niemann-Pick Type C Disease.

Selective neuronal vulnerability is characteristic of most degenerative disorders of the CNS, yet mechanisms underlying this phenomenon remain poorly characterized. Many forms of cerebellar degeneration exhibit an anterior-to-posterior gradient of Purkinje cell loss including Niemann-Pick type C1 (NPC) disease, a lysosomal storage disorder characterized by progressive neurological deficits that often begin in childhood. Here, we sought to identify candidate genes underlying vulnerability of Purkinje cells in anterior cerebellar lobules using data freely available in the Allen Brain Atlas. This approach led to the identification of 16 candidate neuroprotective or susceptibility genes. We demonstrate that one candidate gene, heat shock protein beta-1 (HSPB1), promoted neuronal survival in cellular models of NPC disease through a mechanism that involved inhibition of apoptosis. Additionally, we show that over-expression of wild type HSPB1 or a phosphomimetic mutant in NPC mice slowed the progression of motor impairment and diminished cerebellar Purkinje cell loss. We confirmed the modulatory effect of Hspb1 on Purkinje cell degeneration in vivo, as knockdown by Hspb1 shRNA significantly enhanced neuron loss. These results suggest that strategies to promote HSPB1 activity may slow the rate of cerebellar degeneration in NPC disease and highlight the use of bioinformatics tools to uncover pathways leading to neuronal protection in neurodegenerative disorders.

Phosphorylated Heat Shock Protein 20 (HSPB6) Regulates Transforming Growth Factor-α-Induced Migration and Invasion of Hepatocellular Carcinoma Cells.

Human hepatocellular carcinoma (HCC) is one of the major malignancies in the world. Small heat shock proteins (HSPs) are reported to play an important role in the regulation of a variety of cancer cell functions, and the functions of small HSPs are regulated by post-translational modifications such as phosphorylation. We previously reported that protein levels of a small HSP, HSP20 (HSPB6), decrease in vascular invasion positive HCC compared with those in the negative vascular invasion. Therefore, in the present study, we investigated whether HSP20 is implicated in HCC cell migration and the invasion using human HCC-derived HuH7 cells. The transforming growth factor (TGF)-α-induced migration and invasion were suppressed in the wild-type-HSP20 overexpressed cells in which phosphorylated HSP20 was detected. Phospho-mimic-HSP20 overexpression reduced the migration and invasion compared with unphosphorylated HSP20 overexpression. Dibutyryl cAMP, which enhanced the phosphorylation of wild-type-HSP20, significantly reduced the TGF-α-induced cell migration of wild-type HSP20 overexpressed cells. The TGF-α-induced cell migration was inhibited by SP600125, a c-Jun N-terminal kinases (JNK) inhibitor. In phospho-mimic-HSP20 overexpressed HuH7 cells, TGF-α-stimulated JNK phosphorylation was suppressed compared with the unphosphorylated HSP20 overexpressed cells. Moreover, the level of phospho-HSP20 protein in human HCC tissues was significantly correlated with tumor invasion. Taken together, our findings strongly suggest that phosphorylated HSP20 inhibits TGF-α-induced HCC cell migration and invasion via suppression of the JNK signaling pathway.

HSP27 Knockdown Increases Cytoplasmic p21 and Cisplatin Sensitivity in Ovarian Carcinoma Cells.

Drug resistance is the leading cause of chemotherapy failure in the treatment of ovarian cancer. So far, little is known about the mechanism of chemoresistance in ovarian cancer. In this study, we explored the mechanism that HSP27 was involved in cisplatin resistance of ovarian cancer both in vitro and clinically. HSP27 protein was found to be upregulated and expressed in cisplatin-resistant ovarian cancer cell line C13*, and HSP27 siRNA transfection reversed the chemoresistance of C13*. We found that HSP27 exerted its chemoresistant role by inhibiting p21 transferring from the nucleus to the plasma through the activation of phosphorylated-Akt pathway. These findings have implications for clinical trials aimed at a potential therapeutic target for ovarian tumors that are refractory to conventional treatment.

Heat Shock Protein 27 is down-regulated in Ballooned Hepatocytes of Patients with Nonalcoholic Steatohepatitis (NASH).

Ballooning degeneration (BD) of hepatocytes is a distinguishing histological feature associated with the progression of nonalcoholic fatty liver disease (NAFLD). Under the assumption that NAFLD severity is associated with metabolic-stress we explored the hypothesis that heat shock 27 kDa protein 1 (HSP27), a protein chaperone involved in stress resistance and cytoskeletal-remodeling, might be deregulated in ballooned hepatocytes. We observed that fasting plasma glucose (fpG) (p = 0.00002), total cholesterol (p = 0.02) and triglycerides (p = 0.01) levels, and female sex (p = 0.01) were significantly associated with the presence of BD. A logistic regression model showed that BD was independently associated with fpG (p = 0.002); OR per unit of glucose concentration 1.05, 95% confidence interval 1.02-1.09. Furthermore, BD was associated with a significant 2.24-fold decrease in the expression level of HSP27-mRNA in comparison with absence of ballooning, p = 0.002. Ballooned hepatocytes showed very low HSP27 immunoreactivity compared with hepatocyes without ballooning (p = 0.009); HSP27 immunoreactivity was inversely correlated with fpG levels (R: -0.49, p = 0.01). In conclusion, BD is associated with down-regulation of liver HSP27 gene and protein expression, suggesting that ballooned hepatocytes fail to ensure a robust physiological response to metabolic-induced stress.

Melatonin reverses morphine tolerance by inhibiting microglia activation and HSP27 expression.

AIMS: Melatonin has been reported to attenuate opioid tolerance. In this study, we explored the possible mechanism of melatonin in diminishing morphine tolerance. MAIN METHODS: Two intrathecal (i.t.) catheters were implanted in male Wistar rats for drug delivery. One was linked to a mini-osmotic pump for morphine or saline infusion. On the seventh day, 50µg of melatonin or vehicle was injected through the other catheter instantly after discontinuation of morphine or saline infusion; 3h later, 15µg of morphine or saline was injected. The antinociceptive response was then measured using the tail-flick test every 30min for 120min. KEY FINDINGS: The results showed that chronic morphine infusion elicited antinociceptive tolerance and upregulated heat shock protein 27 (HSP27) expression in the dorsal horn of the rat spinal cord. Melatonin pretreatment partially restored morphine's antinociceptive effect in morphine-tolerant rats and reversed morphine-induced HSP27 upregulation. In addition, chronic morphine infusion induced microglial cell activation and was reversed by melatonin treatment. SIGNIFICANCE: The present study provides evidence that melatonin, acting via inhibiting morphine-induced neuroinflammation, can be useful as a therapeutic adjuvant for patients under long-term opioid treatment for pain relief.

Cytochrome P450 17A1 Inhibitor Abiraterone Acetate Counteracts the Heat Shock Protein 27's Cell Survival Properties in Prostate Cancer Cells.

INTRODUCTION: Inhibition of androgen synthesis by abiraterone acetate (AA) entails enhanced overall survival rates and clinical benefit for patients with locally advanced and metastasized prostate cancer (PC). The expression of heat shock protein 27 (HSP27) is generally associated with cytoprotection and was demonstrated to mediate chemoresistance under cytostatic therapy, for instance, docetaxel treatment. In this study, we investigated the impact of AA treatment on HSP27 expression and PC cell growth. MATERIALS AND METHODS: HSP27 expression levels in docetaxel and AA-treated PC cell lines LNCaP and PC-3 were determined by SDS PAGE and Western blot analysis. Proliferation assays were performed using a CASY Cell Counter and Analyzer Model TT (Roche Applied Science). RESULTS: Despite significantly increased HSP27 expression in PC cells incubated with docetaxel, Western blot analysis implicated a significant reduction of the cytoprotective HSP27 in AA-treated PC cells. Notably, HSP27 stably overexpressed in PC-3-HSP27 cells did not appear as an HSP27-mediated proliferation benefit in the presence of AA as shown in docetaxel incubation studies. CONCLUSION: In contrast to repeatedly demonstrated HSP27-driven chemoresistance related to chemotherapeutics, our results may constitute a broader molecular mode of action of AA chemotherapy. AA efficacy may exert an HSP27 suppressive role that goes beyond the primarily assumed inhibition of androgen biosynthesis.

GaAlAs laser-induced pulp mineralization involves dentin matrix protein 1 and osteopontin expression.

OBJECTIVES: GaAlAs lasers induce pulp mineralization by promoting reparative dentinogenesis. This study analyzed the expression of dentin matrix protein 1 (DMP1) and osteopontin in GaAlAs laser-irradiated rat molars, to examine the hypothesis that these proteins play a role in the laser-induced reparative dentinogenic process. MATERIALS AND METHODS: The mesial surfaces of the upper first molars of 8-week-old Wistar rats were irradiated with a pulsed GaAlAs laser. After 1-14 days, mRNA expression of DMP1 and osteopontin in the coronal pulp was analyzed using real-time PCR. DMP1, osteopontin, and heat shock protein 25 (HSP25) were immunolocalized at 1-21 days. RESULTS: The pulp exhibited a degenerative zone in its mesial portion on days 1-3, and progressive formation of reparative dentin lined with HSP25-immunoreactive odontoblast-like cells, from day 7 onwards. DMP1 and osteopontin mRNA expression were significantly upregulated on days 1-7 and 3-7, respectively. From day 7 onwards, DMP1 and osteopontin immunoreactivity colocalized along the boundary between the primary and reparative dentin. CONCLUSION: GaAlAs laser irradiation of rat molars induced upregulated DMP1 and osteopontin mRNA expression in the coronal pulp, followed by the formation of reparative dentin and the colocalization of DMP1 and osteopontin immunoreactivity at the site at which this tissue first appeared.

In vitro evaluation of aspirin-induced HspB1 against heat stress damage in chicken myocardial cells.

To understand the potential association of heat stress resistance with HspB1 induction by aspirin (ASA) in chicken myocardial cells, variations of HspB1 expression and heat stressed-induced damage of myocardial cells after ASA administration were studied in primary cultured myocardial cells. Cytopathological lesions as well as damage-related enzymes, such as creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH), indicated the considerable protective ability of ASA pre-treatment against acute heat stress. Immunostaining assays showed that heat stress caused HspB1 to relocate into the nucleus, while ASA did not. ELISA analysis, revealed that HspB1 expression induced by ASA averaged 45.62-fold higher than that of the control. These results indicated that the acute heat-stressed injuries were accompanied by comparatively lower HspB1 expression caused by heat stress in vitro. ASA pre-treatment induced a level of HspB1 presumed to be sufficient to protect myocardial cells from acute heat stress in the extracorporal model, although more detailed mechanisms will require further investigation.

Human Cytomegalovirus Stimulates the Synthesis of Select Akt-Dependent Antiapoptotic Proteins during Viral Entry To Promote Survival of Infected Monocytes.

UNLABELLED: Primary peripheral blood monocytes are responsible for the hematogenous dissemination of human cytomegalovirus (HCMV) following a primary infection. To facilitate viral spread, we have previously shown HCMV to extend the short 48-h life span of monocytes. Mechanistically, HCMV upregulated two specific cellular antiapoptotic proteins, myeloid leukemia sequence 1 (Mcl-1) and heat shock protein 27 (HSP27), to block the two proteolytic cleavages necessary for the formation of fully active caspase 3 and the subsequent initiation of apoptosis. We now show that HCMV more robustly upregulated Mcl-1 than normal myeloid growth factors and that Mcl-1 was the only myeloid survival factor to rapidly induce HSP27 prior to the 48-h cell fate checkpoint. We determined that HCMV glycoproteins gB and gH signal through the cellular epidermal growth factor receptor (EGFR) and αvß3 integrin, respectively, during viral entry in order to drive the increase of Mcl-1 and HSP27 in an Akt-dependent manner. Although Akt is known to regulate protein stability and transcription, we found that gB- and gH-initiated signaling preferentially and cooperatively stimulated the synthesis of Mcl-1 and HSP27 through mTOR-mediated translation. Overall, these data suggest that the unique signaling network generated during the viral entry process stimulates the upregulation of select antiapoptotic proteins allowing for the differentiation of short-lived monocytes into long-lived macrophages, a key step in the viral dissemination strategy. IMPORTANCE: Human cytomegalovirus (HCMV) infection is endemic within the human population. Although primary infection is generally asymptomatic in immunocompetent individuals, HCMV is a significant cause of morbidity and mortality in the immunocompromised. The multiorgan inflammatory diseases associated with symptomatic HCMV infection are a direct consequence of the monocyte-mediated systemic spread of the virus. In order for peripheral blood monocytes to facilitate viral dissemination, HCMV subverts the short 48-h life span of monocytes by inducing the expression of cellular antiapoptotic proteins Mcl-1 and HSP27. Here, we demonstrate that the rapid and simultaneous upregulation of Mcl-1 and HSP27 is a distinctive feature of HCMV-induced monocyte survival. Moreover, we decipher the signaling pathways activated during viral entry needed for the robust synthesis of Mcl-1 and HSP27. Identifying the virus-specific mechanisms used to upregulate select cellular factors required for the survival of HCMV-infected monocytes is important to the development of new classes of anti-HCMV drugs.

Expression profiles of heat shock protein 27 and αB-crystallin and their effects on heat-stressed rat myocardial cells in vitro and in vivo.

The present study established a heat-stressed rat heart model, and used an H9c2 myocardial cell line to investigate the expression profiles of heat shock protein (Hsp)27 and αB-crystallin, both in vivo and in vitro. Rats and myocardial cells were subjected to 42 ˚C for 0, 20, 40, 60, 80 or 100 min, following which the mRNA and protein expression levels of Hsp27 and αB-crystallin were measured. Following heat shock, the protein expression levels of Hsp27 and αB-crystallin were significantly decreased in the rat heart cells in vivo, whereas their mRNA levels were significantly increased. The opposing association between the protein and mRNA expression levels of Hsp27 and αB-crystallin suggests that the progression from mRNA into proteins via translation may delayed, or proteins may exist as either oligomers or in the phosphorylated form under heat stress. In vitro, Hsp27 and αB-crystallin exhibited similar reductions in the protein levels at 40 and 60 min, then increased to normal values following 80 min of heat stress. However, the mRNA levels were not consistent with the protein levels. The mRNA levels of Hsp27 and αB-crystallin did however exhibit similar tendencies following 60 min of heat stress. The present study investigated these apparently conflicting results between the in vitro cell line and the in vivo body system. The results demonstrated that the protein and mRNA expression levels of Hsp27 and αB-crystallin exhibited similar trends in vivo and in vitro, respectively. These results were confirmed by analysis with STRING 9.1 software, which indicated that Hsp27 and αB-crystallin are co-expressed in rat myocardial cells. However, the individual cell lines and whole body system exhibited different trends in Hsp27 and αB-crystallin levels prior to and following heat stress, thus require further investigation.

Development of synovial membrane in the temporomandibular joint of the human fetus.

The development of the synovial membrane was analyzed in serial sections of 21 temporomandibular joints of human fetuses at 9 to 13 weeks of gestation. Sections of two fetuses at 12 weeks of development were used to perform immunohistochemical expression of the markers CD68 and Hsp27 on the synovial lining. Macrophage-like type A and fibroblast-like type B cells, which express CD68 and Hsp27, respectively, were observed at the twelfth week of development. Our results suggest that the development of the synovial membrane is related to the vascularization of the joint and the formation of the articular cavities.