Displaying publications 141 - 160 of 222 in total

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  1. Fulltext Schiff base metal derivatives enhance the expression of HSP70 and suppress BAX proteins in prevention of acute gastric lesion
    Golbabapour S, Gwaram NS, Al-Obaidi MM, Soleimani AF, Ali HM, Abdul Majid N
    Biomed Res Int, 2013;2013:703626.
    PMID: 24298554 DOI: 10.1155/2013/703626
    Schiff base complexes have appeared to be promising in the treatment of different diseases and disorders and have drawn a lot of attention to their biological activities. This study was conducted to evaluate the regulatory effect of Schiff base metal derivatives on the expression of heat shock proteins (HSP) 70 and BAX in protection against acute haemorrhagic gastric ulcer in rats. Rats were assigned to 6 groups of 6 rats: the normal control (Tween 20 5% v/v, 5 mL/kg), the positive control (Tween 20 5% v/v, 5 mL/kg), and four Schiff base derivative groups named Schiff_1, Schiff_2, Schiff_3, and Schiff_4 (25 mg/kg). After 1 h, all of the groups received ethanol 95% (5 mL/kg) but the normal control received Tween 20 (Tween 20 5% v/v, 5 mL/kg). The animals were euthanized after 60 min and the stomachs were dissected for histology (H&E), immunohistochemistry, and western blot analysis against HSP70 and BAX proteins. The results showed that the Schiff base metal derivatives enhanced the expression of HSP70 and suppressed the expression of BAX proteins during their gastroprotection against ethanol-induced gastric lesion in rats.
    Matched MeSH terms: HSP70 Heat-Shock Proteins/biosynthesis*
  2. Comparison of thermoregulatory responses to heat between Malaysian and Japanese males during leg immersion
    Wijayanto T, Wakabayashi H, Lee JY, Hashiguchi N, Saat M, Tochihara Y
    Int J Biometeorol, 2011 Jul;55(4):491-500.
    PMID: 20824480 DOI: 10.1007/s00484-010-0358-5
    The objective of this study was to investigate thermoregulatory responses to heat in tropical (Malaysian) and temperate (Japanese) natives, during 60 min of passive heating. Ten Japanese (mean ages: 20.8 ± 0.9 years) and ten Malaysian males (mean ages: 22.3 ± 1.6 years) with matched morphological characteristics and physical fitness participated in this study. Passive heating was induced through leg immersion in hot water (42°C) for 60 min under conditions of 28°C air temperature and 50% RH. Local sweat rate on the forehead and thigh were significantly lower in Malaysians during leg immersion, but no significant differences in total sweat rate were observed between Malaysians (86.3 ± 11.8 g m(-2) h(-1)) and Japanese (83.2 ± 6.4 g m(-2) h(-1)) after leg immersion. In addition, Malaysians displayed a smaller rise in rectal temperature (0.3 ± 0.1°C) than Japanese (0.7 ± 0.1°C) during leg immersion, with a greater increase in hand skin temperature. Skin blood flow was significantly lower on the forehead and forearm in Malaysians during leg immersion. No significant different in mean skin temperature during leg immersion was observed between the two groups. These findings indicated that regional differences in body sweating distribution might exist between Malaysians and Japanese during heat exposure, with more uniform distribution of local sweat rate over the whole body among tropical Malaysians. Altogether, Malaysians appear to display enhanced efficiency of thermal sweating and thermoregulatory responses in dissipating heat loss during heat loading. Thermoregulatory differences between tropical and temperate natives in this study can be interpreted as a result of heat adaptations to physiological function.
    Matched MeSH terms: Heat-Shock Response/physiology
  3. Pediatric melioidosis in Pahang, Malaysia
    How HS, Ng KH, Yeo HB, Tee HP, Shah A
    J Microbiol Immunol Infect, 2005 Oct;38(5):314-9.
    PMID: 16211138
    Melioidosis is much less common in children than in adults. This study investigated the incidence, demographic characteristics, presenting symptoms and outcome of pediatric melioidosis in Pahang, Malaysia. This retrospective study included patients < or =18 years old with positive body fluid cultures for Burkholderia pseudomallei from January 2000 to June 2003. Data on culture results were obtained from 2 referral hospitals. The incidence of pediatric melioidosis was 0.68/100,000 population per year. Of the 13 patients identified during the study period, 10 were male; 9 were Malays, 2 were Indians and 2 were aborigines. The mean age of these patients was 9.5 +/- 5.4 years. None of the patients had a previous history of confirmed melioidosis or predisposing factors for infection. Localized melioidosis was the most common presentation (46.2%) followed by melioidosis with septic shock (38.4%). Among patients with localized melioidosis, head and neck involvement (83.3%) was the most common presentation (2 patients with cervical abscesses, 1 with submandibular abscesses and 2 with acute suppurative parotitis) and another patient had right axillary abscess. All of the patients with septic shock had pneumonia and 2 of them had multi-organ involvement. The mortality among patients with septic shock was 80% and death occurred within 24 h of admission in all cases. In contrast, no complications or death occurred among patients with localized melioidosis. Melioidosis with septic shock is less common than localized melioidosis in pediatric patients, but is associated with very high mortality.
    Matched MeSH terms: Shock, Septic/mortality
  4. The effect of different degrees of feed restriction on heat shock protein 70, acute phase proteins, and other blood parameters in female broiler breeders
    Najafi P, Zulkifli I, Soleimani AF, Kashiani P
    Poult Sci, 2015 Oct;94(10):2322-9.
    PMID: 26316343 DOI: 10.3382/ps/pev246
    The aim of the current study was to determine the physiological response to feed restriction in female broiler breeders using a range of conventional and novel indicators. One hundred female breeders were subjected to one of five feeding regimens from d 28 to 42 as follows (i) ad libitum feeding (AL), (ii-v) 75, 60, 45, and 30% of ad libitum feed intake. Blood heterophil to lymphocyte ratio (HLR), and plasma circulating corticosterone (CORT), ghrelin (GHR), serotonin (5-HT), and dopamine (DA) and serum acute phase proteins (APP) concentrations together with brain heat shock protein (HSP) 70 level were measured. The results showed a significant effect of feed restriction on blood HLR and plasma CORT, GHR, 5-HT, DA, and brain HSP 70 levels. However, feed restriction had no effect on serum levels of APP of alpha-1 acid glycoprotein, ovotransferin, and ceruloplasmin. Serum levels of 5-HT and GHR varied curvilinearly with the feed restriction level. The relationship between brain HSP 70 and level of feed restriction was negligible. However, significant linear relationships between HLR, CORT, DA, and the level of feed restriction were noted. Thus, these 3 parameters appear to represent a straight forward relation with severity of feed restriction.
    Matched MeSH terms: HSP70 Heat-Shock Proteins/metabolism
  5. Fulltext Nucleotide and encoded amino acid sequences of the membrane protein precursor and the membrane protein genes of three dengue-2 viruses isolated in Malaysia from patients with dengue haemorrhagic fever, dengue shock syndrome or dengue fever
    Samuel S, Koh CL, Pang T, Lam SK
    Nucleic Acids Res, 1990 Apr 11;18(7):1905.
    PMID: 2336374 DOI: 10.1093/nar/18.7.1905
    Matched MeSH terms: Shock, Septic/microbiology
  6. TCR-like domain antibody against Mycobacterium tuberculosis (Mtb) heat shock protein antigen presented by HLA-A*11 and HLA-A*24
    Dass SA, Norazmi MN, Acosta A, Sarmiento ME, Tye GJ
    Int J Biol Macromol, 2020 Jul 15;155:305-314.
    PMID: 32240734 DOI: 10.1016/j.ijbiomac.2020.03.229
    T cell receptor (TCR)-like antibodies, obtained with the use of phage display technology, sandwich the best of the both arms of the adaptive immune system. In this study, in vitro selections against the latency associated Mycobacterium tuberculosis (Mtb) heat shock protein 16 kDa antigen (16 kDa) presented by HLA-A*011 and HLA-A*24 were carried out with the use of a human domain phage antibody library. TCR-like domain antibodies (A11Ab and A24Ab) were successfully generated recognizing 16 kDa epitopes presented by HLA-A*011 and HLA-A*24 molecules respectively. Both antibodies were found to be functional in soluble form and exhibited strong binding capacity against its targets. The results obtained support the future evaluation of these ligands for the development of diagnostic and therapeutic tools for tuberculosis infection.
    Matched MeSH terms: Heat-Shock Proteins/immunology*
  7. Epigenetic modification: possible approach to reduce Salmonella enterica serovar enteritidis susceptibility under stress conditions
    Soleimani AF, Zulkifli I, Hair-Bejo M, Ebrahimi M, Jazayeri SD, Hashemi SR, et al.
    Avian Pathol, 2012;41(4):351-4.
    PMID: 22834548 DOI: 10.1080/03079457.2012.691155
    Stressors may influence chicken susceptibility to pathogens such as Salmonella enterica. Feed withdrawal stress can cause changes in normal intestinal epithelial structure and may lead to increased attachment and colonization of Salmonella. This study aimed to investigate modulatory effects of epigenetic modification by feed restriction on S. enterica serovar Enteritidis colonization in broiler chickens subjected to feed withdrawal stress. Chicks were divided into four groups: ad libitum feeding; ad libitum feeding with 24-h feed withdrawal on day 42; 60% feed restriction on days 4, 5, and 6; and 60% feed restriction on days 4, 5, and 6 with 24-h feed withdrawal on day 42. Attachment of S. Enteritidis to ileal tissue was determined using an ex vivo ileal loop assay, and heat shock protein 70 (Hsp70) expression was evaluated using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and western blotting. Feed withdrawal stress increased S. Enteritidis attachment to ileal tissue. However, following feed withdrawal the epigenetically modified chickens had significantly lower attachment of S. Enteritidis than their control counterparts. A similar trend with a very positive correlation was observed for Hsp70 expression. It appears that epigenetic modification can enhance resistance to S. Enteritidis colonization later in life in chickens under stress conditions. The underlying mechanism could be associated with the lower Hsp70 expression in the epigenetically modified chickens.
    Matched MeSH terms: HSP70 Heat-Shock Proteins/metabolism
  8. Thymoquinone induces apoptosis and increase ROS in ovarian cancer cell line
    Taha MM, Sheikh BY, Salim LZ, Mohan S, Khan A, Kamalidehghan B, et al.
    Cell Mol Biol (Noisy-le-grand), 2016 May 30;62(6):97-101.
    PMID: 27262811
    Nigella sativa is also known for its properties as a traditional herbal healing for many ailments. In this study, the anticancer properties of thyomquinone (TQ), the active ingredient of N. sativa, were studied using ovarian cancer cell line (Caov-3 cells). The anti-proliferative activity of TQ was determined using MTT and the apoptosis was investigated using Flowcytometry and Annexin-V Assays. Multiparameteric cytotoxicity bioassays were used to quantify the changes in cell permeability and mitochondrial membrane potential. Reactive oxygen species (ROS) and apoptosis-involved cell markers were examined to verify cell death mechanism. The MTT-assay showed that TQ induces anti-proliferative activity on Caov-3 with an IC50 of 6.0±0.03 μg/mL, without any cytotoxic activity towards WRL-68 normal hepatocytes. A significant induction of early phase of apoptosis was shown by annexin-V analysis. Treatment of Caov-3 cells with TQ induces decreases in plasma membrane permeability and mitochondrial membrane potential. Visible decrease in the nuclear area was also observed. A significant decrease is observed in Bcl-2 while Bax is down-regulated. TQ-triggered ROS-mediated has found to be associated with Hsp70 dysregulation, an indicator of oxidative injury. We found that TQ induced anti-cancer effect involves intrinsic pathway of apoptosis and cellular oxidative stress. Our results considered collectively indicated that thyomquinone may be a potential agent for ovarian cancer drug development.
    Matched MeSH terms: HSP70 Heat-Shock Proteins/metabolism
  9. Pandanus tectorius fruit extract promotes Hsp70 accumulation, immune-related genes expression and Vibrio parahaemolyticus tolerance in the white-leg shrimp Penaeus vannamei
    Anirudhan A, Okomoda VT, Mimi Iryani MT, Andriani Y, Abd Wahid ME, Tan MP, et al.
    Fish Shellfish Immunol, 2021 Feb;109:97-105.
    PMID: 33352338 DOI: 10.1016/j.fsi.2020.12.011
    Plants and herbal extracts are indispensable for controlling the spread of disease-causing bacteria, including those that infect aquatic organisms used in aquaculture. The use of plant or herbal extract is expected to be safe for aquatic animals and less harmful to the environment, as opposed to conventional therapeutic alternatives such as antibiotics that promote the occurrence of potential antibiotic-resistant bacteria when used improperly. The efficacy of Pandanus tectorius fruit extract in the regulation of Hsp70 expression, pro-phenoloxidase (ProPO), peroxinectin, penaeidin, crustin and transglutaminase, all immune peptides essential for Vibrio tolerance in white leg shrimp, Penaeus vannamei, was investigated in this study, which included the determination of the safety levels of the extract. Tolerance of shrimp against Vibrio parahaemolyticus, a pathogenic bacteria that causes Acute Hepatopancreas Necrosis Disease (AHPND), was assessed on the basis of median lethal dose challenge survival (LD50 = 106 cells/ml). Mortality was not observed 24 h after exposure of 0.5-6 g/L of the fruit extract, indicating that P. tectorius was not toxic to shrimp at these concentrations. A 24-h incubation of 2-6 g/L of the fruit extract increased shrimp tolerance to V. parahaemolyticus, with survival doubled when the maximum dose tested in this study was used. Concomitant with a rise in survival was the increase in immune-related proteins, with Hsp70, ProPO, peroxinectin, penaeidin, crustin and transglutaminase increased 10, 11, 11, 0.4, 8 and 13-fold respectively. Histological examination of the hepatopancreas and muscle tissues of Vibrio-infected shrimp primed with P. tectorius extract revealed reduced signs of histopathological degeneration, possibly due to the accumulation of Hsp70, a molecular chaperone crucial to cellular protein folding, tissue repair and immune response of living organisms, including Penaeid shrimp.
    Matched MeSH terms: HSP70 Heat-Shock Proteins/immunology*
  10. Establishment of lung auscultation scoring method and responses of acute phase proteins and heat shock proteins in vaccinated and non-vaccinated goats
    Jesse FFA, Chung ELT, Abba Y, Muniandy KV, Tan AHAR, Maslamany D, et al.
    Trop Anim Health Prod, 2019 Feb;51(2):289-295.
    PMID: 30088124 DOI: 10.1007/s11250-018-1683-7
    Pneumonic pasteurellosis is an economically important infectious disease in the small ruminant industry which causes sudden death and loss for farmers. Nonetheless, this disease is still a common sight in sheep and goats in Malaysia, probably due to the unpopular usage of pasteurellosis vaccine or inappropriate vaccination practices. The aim of this study was designed to classify the severity of pneumonia via the establishment of auscultation scoring method and to quantify the acute phase proteins and heat shock proteins responses from vaccinated and non-vaccinated goats. Goat farms, consist of vaccinated and non-vaccinated farms, were selected in this study: where 15 clinically normal healthy goats and 9 pneumonic goats were selected from vaccinated farms whereas 15 clinically normal healthy goats and 31 pneumonic goats from non-vaccinated farms were selected for this study. Crackle lung sounds were not detected in both vaccinated and non-vaccinated normal goats. However, vaccinated pneumonic goats showed mild crackle lung sound while non-vaccinated pneumonic goats exhibited moderate crackle lung sound. There were significant increases (p shock proteins concentrations for the non-vaccinated pneumonic goats group. In this study, conclusion can be made that the vaccinated goats exhibited very mild clinical responses of pneumonia and non-significant biomarker responses compared to the non-vaccinated goats. Thus, vaccination is an effective preventive measure to control pneumonic pasteurellosis and acute phase proteins and heat shock proteins can be considered as future biomarkers in screening and rapid diagnostic method for this particular disease.
    Matched MeSH terms: Heat-Shock Proteins/blood*
  11. Inhibition of corticosterone synthesis and its effect on acute phase proteins, heat shock protein 70, and interleukin-6 in broiler chickens subjected to feed restriction
    Najafi P, Zulkifli I, Soleimani AF
    Poult Sci, 2018 Apr 01;97(4):1441-1447.
    PMID: 29462352 DOI: 10.3382/ps/pex364
    The aim of the current study was to elucidate whether inhibition of corticosterone (CORT) synthesis could modify stress response to feed deprivation and its possible interactions with feed restriction in the neonatal period in broiler chickens. Equal numbers of broiler chicks were subjected to either 60% feed restriction (60FR) or ad libitum (AL) on d 4, 5, and 6. On day 7, blood CORT, acute phase proteins (APP), interleukin-6 (IL-6) levels, and brain heat shock protein 70 (HSP70) expression were determined. On d 35, chickens in each early age feeding regimen were subjected to one of the following treatments: (i) ad libitum feeding (ALF), (ii) 24 h feed deprivation (SFR), or (iii) 24 h feed deprivation with intramuscular injection of 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) at 100 mg/kg BW (SFR+DDT). The effect of SFR on CORT, APP, IL-6, and HSP 70 were determined on d 36. The results showed that subjecting chicks to 60FR significantly elevated CORT and brain HSP70 concentration compared to the AL group on d 7. The early feeding regimen had no significant effect on CORT, alpha-1 acid glycoprotein (AGP), ovotransferrin (OVT), ceruoplasmin (CP), IL-6, or brain HSP70 on d 36. The CORT, AGP, OVT, CP, IL-6, and brain HSP70 expression of SFR birds following 24 h of feed deprivation (d 36) were significantly higher than their ALF and SFR+DDT counterparts. Both ALF and SFR+DDT birds had similar values. Stress attributed to feed deprivation without concurrent increase in CORT had a negligible effect on serum levels of APP and IL-6 and brain HSP70 expression.
    Matched MeSH terms: HSP70 Heat-Shock Proteins/metabolism*
  12. Postoperative death in a patient with unrecognized arrhythmogenic right ventricular dysplasia syndrome
    Toh KW, Nadesan K, Sie MY, Vijeyasingam R, Tan PS
    Anesth Analg, 2004 Aug;99(2):350-2, table of contents.
    PMID: 15271703
    Arrhythmogenic right ventricular dysplasia is an inherited disease causing fatty replacement of heart tissue. This disease often presents as T-wave inversion in the anterior leads of the electrocardiogram (ECG) with life-threatening ventricular arrhythmias. In older patients, progressive right and left ventricular failure can develop. This is a case report of postoperative death occurring in a 59-yr-old woman with undiagnosed arrhythmogenic right ventricular dysplasia after hepatic cystectomy. The patient had T-wave inversion in the inferior ECG leads and no history of arrhythmias. During general anesthesia, cardiovascular collapse occurred in the absence of arrhythmias that was unresponsive to resuscitation.
    Matched MeSH terms: Shock, Cardiogenic/etiology
  13. Influenza A virus neuraminidase protein interacts with Hsp90, to stabilize itself and enhance cell survival
    Kumar P, Gaur P, Kumari R, Lal SK
    J Cell Biochem, 2019 04;120(4):6449-6458.
    PMID: 30335904 DOI: 10.1002/jcb.27935
    Neuraminidase protein (NA) of influenza A virus (IAV) is popularly known for its sialidase function to assist in the release of progeny virus. However, involvement of NA in other stages of the IAV life cycle also indicates its multifunctional nature and necessity to interact with other host proteins. Here, we report a host protein-heat shock protein 90 (Hsp90), as a novel interacting partner of IAV NA. A classical yeast two-hybrid screen was conducted to identify a new host interacting partner for NA and the interaction was further validated by coimmunoprecipitation from cells, transiently expressing both proteins and also from IAV-infected cells. Confocal imaging showed that both proteins colocalized in the cytoplasm in transfected host cells. Interestingly, increased levels of NA in the presence of Hsp90 was observed, which tends to decrease if adenosine triphosphatase activity of Hsp90 is inhibited using 17-N-allylamino-17-demethoxygeldanamycin (17AAG). This establishes viral NA as a client protein of host chaperone Hsp90 contributing toward NA's stability via the NA-Hsp90 interaction. This is the first report showing the interaction of NA with Hsp90 and its role in stabilizing viral NA thus preventing it from degradation. Enhanced cell survival in the presence of this interaction was also observed, thus suggesting the requirement of stable viral NA, post-IAV infection, for efficient virus production in infected mammalian cells.
    Matched MeSH terms: HSP90 Heat-Shock Proteins/metabolism*
  14. Fulltext Augmented inflammatory cytokines in primary dengue infection progressing to shock
    Iyngkaran N, Yadav M, Sinniah M
    Singapore Med J, 1995 Apr;36(2):218-21.
    PMID: 7676273
    Dengue fever (DF) which is caused by four serotypes of dengue virus may in some cases progress into a life threatening situation of dengue haemorrhage fever (DHF) and dengue shock syndrome (DSS). It has been suggested that sequential infection with different dengue virus serotypes predisposes the patient towards DHF/DSS. We report here a primary dengue infection in a 10-year-old boy progressing from DF to DSS while under clinical observation. The report provides unequivocal evidence for the development of DSS in primary dengue infection caused by virus serotype 4. The close relationship between sequential changes in the levels of tumour necrosis factor (TNF), Interleukin 1 and 6 (IL-1 and IL-6) in the serum, to the clinical progression of the disease from DF to DHF/DSS and then to full recovery implicates a pathogenetic role for the inflammatory cytokines. The child also manifested clinical features consistent with Reye's syndrome and this suggests a common pathogenetic origin for DSS and the Reye-like syndrome induced by dengue virus.
    Matched MeSH terms: Shock/etiology*
  15. Mechanism of the induction of endoplasmic reticulum stress by the anti-cancer agent, di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT): Activation of PERK/eIF2α, IRE1α, ATF6 and calmodulin kinase
    Merlot AM, Shafie NH, Yu Y, Richardson V, Jansson PJ, Sahni S, et al.
    Biochem Pharmacol, 2016 06 01;109:27-47.
    PMID: 27059255 DOI: 10.1016/j.bcp.2016.04.001
    The endoplasmic reticulum (ER) plays a major role in the synthesis, maturation and folding of proteins and is a critical calcium (Ca(2+)) reservoir. Cellular stresses lead to an overwhelming accumulation of misfolded proteins in the ER, leading to ER stress and the activation of the unfolded protein response (UPR). In the stressful tumor microenvironment, the UPR maintains ER homeostasis and enables tumor survival. Thus, a novel strategy for cancer therapeutics is to overcome chronically activated ER stress by triggering pro-apoptotic pathways of the UPR. Considering this, the mechanisms by which the novel anti-cancer agent, Dp44mT, can target the ER stress response pathways were investigated in multiple cell-types. Our results demonstrate that the cytotoxic chelator, Dp44mT, which forms redox-active metal complexes, significantly: (1) increased ER stress-associated pro-apoptotic signaling molecules (i.e., p-eIF2α, ATF4, CHOP); (2) increased IRE1α phosphorylation (p-IRE1α) and XBP1 mRNA splicing; (3) reduced expression of ER stress-associated cell survival signaling molecules (e.g., XBP1s and p58(IPK)); (4) increased cleavage of the transcription factor, ATF6, which enhances expression of its downstream targets (i.e., CHOP and BiP); and (5) increased phosphorylation of CaMKII that induces apoptosis. In contrast to Dp44mT, the iron chelator, DFO, which forms redox-inactive iron complexes, did not affect BiP, p-IRE1α, XBP1 or p58(IPK) levels. This study highlights the ability of a novel cancer therapeutic (i.e., Dp44mT) to target the pro-apoptotic functions of the UPR via cellular metal sequestration and redox stress. Assessment of ER stress-mediated apoptosis is fundamental to the understanding of the pharmacology of chelation for cancer treatment.
    Matched MeSH terms: Heat-Shock Proteins/genetics; Heat-Shock Proteins/metabolism; HSP40 Heat-Shock Proteins/genetics; HSP40 Heat-Shock Proteins/metabolism
  16. Fulltext Transcription Factor CREB3L1 Regulates Endoplasmic Reticulum Stress Response Genes in the Osmotically Challenged Rat Hypothalamus
    Greenwood M, Greenwood MP, Paton JF, Murphy D
    PLoS One, 2015;10(4):e0124956.
    PMID: 25915053 DOI: 10.1371/journal.pone.0124956
    Arginine vasopressin (AVP) is synthesised in magnocellular neurons (MCNs) of supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus. In response to the hyperosmotic stressors of dehydration (complete fluid deprivation, DH) or salt loading (drinking 2% salt solution, SL), AVP synthesis increases in MCNs, which over-burdens the protein folding machinery in the endoplasmic reticulum (ER). ER stress and the unfolded protein response (UPR) are signaling pathways that improve ER function in response to the accumulation of misfold/unfold protein. We asked whether an ER stress response was activated in the SON and PVN of DH and SL rats. We observed increased mRNA expression for the immunoglobulin heavy chain binding protein (BiP), activating transcription factor 4 (Atf4), C/EBP-homologous protein (Chop), and cAMP responsive element binding protein 3 like 1 (Creb3l1) in both SON and PVN of DH and SL rats. Although we found no changes in the splicing pattern of X box-binding protein 1 (Xbp1), an increase in the level of the unspliced form of Xbp1 (Xbp1U) was observed in DH and SL rats. CREB3L1, a novel ER stress inducer, has been shown to be activated by ER stress to regulate the expression of target genes. We have previously shown that CREB3L1 is a transcriptional regulator of the AVP gene; however, a role for CREB3L1 in the response to ER stress has yet to be investigated in MCNs. Here, we used lentiviral vectors to introduce a dominant negative form of CREB3L1 (CREB3L1DN) in the rat SON. Expression of CREB3L1DN in the SON decreased Chop and Xbp1U mRNA levels, but not BiP and Atf4 transcript expression. CREB3L1 is thus implicated as a transcriptional mediator of the ER stress response in the osmotically stimulated SON.
    Matched MeSH terms: Heat-Shock Proteins/genetics; Heat-Shock Proteins/metabolism
  17. Effect of a carotene concentrate on the growth of human breast cancer cells and pS2 gene expression
    Nesaretnam K, Jin Lim E, Reimann K, Lai LC
    Toxicology, 2000 Oct 26;151(1-3):117-26.
    PMID: 11074306
    Breast cancer is the most common cancer in women worldwide. The growth of breast cancer cells is either hormone-dependent or hormone-independent. Both types are represented in vitro by the estrogen-receptor positive (ER+) MCF-7 and the estrogen-receptor negative (ER-) MDA-MB-231 cell lines, respectively. The pS2 gene is an estrogen-regulated gene and serves as a marker for the ER+ tumours. Carotenoids are pigments with anti-cancer properties besides having pro-vitamin A, antioxidant and free-radical quenching effects. This study was designed firstly, to compare the effect of palm oil carotene concentrate with retinoic acid on the growth of the ER+ MCF-7 and the ER- MDA-MB-231 cells; and secondly to evaluate the effect of the palm oil carotene concentrate on the regulation of pS2 mRNA. The growth experiments were performed with monolayer cells seeded in phenol red free RPMI 1640 culture media and subsequently treated with varying concentrations of either retinoic acid or palm oil carotenoids. The cell numbers were determined at the start of each experiment and then at successive time intervals. The results showed that the palm oil carotene concentrate caused dose-dependent inhibition of estradiol-stimulated growth of MCF-7 cells but did not affect the proliferation of MDA-MB-231 cells. Retinoic acid caused similar, albeit more potent effects, as significant inhibition was observed at lower concentrations than the palm oil carotenoids. In the pS2 gene expression experiment, cell monolayers were treated with the carotene concentrate (10(-6) M), either with or without supplemented estradiol (10(-8) M), and subsequently the RNA was extracted. Northern blotting was performed and the regulation of pS2 mRNA determined using a 32P-labelled pS2 cDNA probe. The results showed that the palm oil carotene concentrate did not affect the expression of pS2 mRNA and are therefore independent of the estrogen-regulated pathway.
    Matched MeSH terms: Heat-Shock Proteins/biosynthesis; Heat-Shock Proteins/genetics
  18. Palmatine Inhibits Up-Regulation of GRP78 and CALR Protein in an STZ-Induced Diabetic Rat Model
    Okechukwu PN, Ekeuku SO, Chan HK, Eluri K, Froemming GRA
    Curr Pharm Biotechnol, 2021;22(2):288-298.
    PMID: 32744968 DOI: 10.2174/1389201021666200730124208
    BACKGROUND: Diabetes Mellitus (DM) is characterized by hyperglycemia (high blood glucose levels) which is due to the destruction of insulin-producing β-cells in the islets of Langerhans in the pancreas. It is associated with oxidative and endoplasmic reticulum stress. The plant alkaloid Palmatine has been previously reported to possess antidiabetic and antioxidant properties as well as other protective properties against kidney and liver tissue damage.

    OBJECTIVE: Here, we investigated the ability of Palmatine to reduce the up-regulation of chaperone proteins Glucose Regulatory Protein 78 (GRP78), and Calreticulin (CALR) protein in a Streptozotocin (STZ)-induced diabetic rat model.

    METHODS: Streptozotocin (STZ) induced diabetes in Sprague Dawley rats treated with 2mg/kg of Palmatine for 12 weeks after the elevation of plasma glucose levels above 11mmol/L post-STZ administration. Proteins were extracted from the pancreas after treatment and Two-Dimensional gel electrophoresis (2-DE), PDQuest 2-D analysis software genomic solutions and mass spectrometer were used to analyze differentially expressed protein. Mass Spectrometry (MS/MS), Multidimensional Protein Identification Technology (MudPIT) was used for protein identification.

    RESULTS: There was an up-regulation of the expression of chaperone proteins CALR and GRP78 and down-regulation of the expression of antioxidant and protection proteins peroxidoxin 4 (Prdx4), protein disulfide isomerase (PDIA2/3), Glutathione-S-Transferase (GSTs), and Serum Albumin (ALB) in non-diabetic rats. Palmatine treatment down-regulated the expression of chaperone proteins CALR and GRP78 and up-regulated the expression of Prdx4, PDIA2/3, GST, and ALB.

    CONCLUSION: Palmatine may have activated antioxidant proteins, which protected the cells against reactive oxygen species and endoplasmic stress. The result is in consonance with our previous report on Palmatine.

    Matched MeSH terms: Heat-Shock Proteins/antagonists & inhibitors*; Heat-Shock Proteins/biosynthesis
  19. Fulltext Entamoeba histolytica: Quantitative Proteomics Analysis Reveals Putative Virulence-Associated Differentially Abundant Membrane Proteins
    Ng YL, Olivos-García A, Lim TK, Noordin R, Lin Q, Othman N
    Am J Trop Med Hyg, 2018 12;99(6):1518-1529.
    PMID: 30298805 DOI: 10.4269/ajtmh.18-0415
    Entamoeba histolytica is a protozoan parasite that causes amebiasis and poses a significant health risk for populations in endemic areas. The molecular mechanisms involved in the pathogenesis and regulation of the parasite are not well characterized. We aimed to identify and quantify the differentially abundant membrane proteins by comparing the membrane proteins of virulent and avirulent variants of E. histolytica HM-1:IMSS, and to investigate the potential associations among the differentially abundant membrane proteins. We performed quantitative proteomics analysis using isobaric tags for relative and absolute quantitation labeling, in combination with two mass spectrometry instruments, that is, nano-liquid chromatography (nanoLC)-matrix-assisted laser desorption/ionization-mass spectrometry/mass spectrometry and nanoLC-electrospray ionization tandem mass spectrometry. Overall, 37 membrane proteins were found to be differentially abundant, whereby 19 and 18 membrane proteins of the virulent variant of E. histolytica increased and decreased in abundance, respectively. Proteins that were differentially abundant include Rho family GTPase, calreticulin, a 70-kDa heat shock protein, and hypothetical proteins. Analysis by Protein ANalysis THrough Evolutionary Relationships database revealed that the differentially abundant membrane proteins were mainly involved in catalytic activities (29.7%) and metabolic processes (32.4%). Differentially abundant membrane proteins that were found to be involved mainly in the catalytic activities and the metabolic processes were highlighted together with their putative roles in relation to the virulence. Further investigations should be performed to elucidate the roles of these proteins in E. histolytica pathogenesis.
    Matched MeSH terms: HSP70 Heat-Shock Proteins/genetics; HSP70 Heat-Shock Proteins/metabolism
  20. Benchtop Isolation and Characterisation of Small Extracellular Vesicles from Human Mesenchymal Stem Cells
    Tan KL, Chia WC, How CW, Tor YS, Show PL, Looi QHD, et al.
    Mol Biotechnol, 2021 Sep;63(9):780-791.
    PMID: 34061307 DOI: 10.1007/s12033-021-00339-2
    The objective of this study is to develop a simple protocol to isolate and characterise small extracellular vesicles (sEVs) from human umbilical cord-derived MSCs (hUC-MSCs). hUC-MSCs were characterised through analysis of morphology, immunophenotyping and multidifferentiation ability. SEVs were successfully isolated by ultrafiltration from the conditioned medium of hUC-MSCs. The sEVs' size distribution, intensity within a specific surface marker population were measured with zetasizer or nanoparticle tracking analysis. The expression of surface and internal markers of sEVs was also assessed by western blotting. Morphology of hUC-MSCs displayed as spindle-shaped, fibroblast-like adherent cells. Phenotypic analysis by flow cytometry revealed that hUC-MSCs expressed MSC surface marker, including CD90, CD73, CD105, CD44 and exhibited the capacity for osteogenic, adipogenic and chondrogenic differentiation. Populations of sEVs with CD9, CD63 and CD81 positive were detected with size distribution in the diameter of 63.2 to 162.5 nm. Typical sEVs biomarkers such as CD9, CD63, CD81, HSP70 and TSG101 were also detected with western blotting. Our study showed that sEVs from hUC-MSCs conditioned medium were successfully isolated and characterised. Downstream application of hUC-MSCs-sEVs will be further explored.
    Matched MeSH terms: HSP70 Heat-Shock Proteins/genetics; HSP70 Heat-Shock Proteins/metabolism
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