Protein, carbohydrate, lipid concentrations and HSP 70–HSP 90 (stress protein) expression over an annual cycle: useful tools to detect feeding constraints in a benthic suspension feeder

In this study we examined the mechanism of corpus luteum (CL) regression by measuring changes in expression of prostaglandin G/H synthase-1 (PGHS-1) and -2 (PGHS-2) in day 4 CL and inducible heat shock protein 70 (HSP-70) in day 4 and day 9 CL of immature superovulated rats. The rats were superovulated and treated with 500 µg of prostaglandin F2α (PGF2α) on day 4 or day 9 after CL formation. Ovaries and serial blood samples were removed during the 24-hour period following treatment. Plasma progesterone was determined by radioimmunoassay while mRNA abundance and protein expression were assessed by semiquantitative RT-PCR and immunoblot analysis, respectively. One hour after PGF2α, both day 4 and day 9 rats exhibited a significant decrease in progesterone secretion; however, there was a greater decrease in day 9 rats. In ovarian samples removed on day 4, there was a significant increase in mRNA for PGHS-2 at 1 hour after PGF2α. PGHS-1 mRNA content remained unchanged. Immunoblot analyses showed an increase in PGHS-2 protein expression only at 8 h. There were no changes in PGHS-1 protein expression. In day 9 rats, ovarian HSP-70 protein levels increased by 50% after PGF2α injection; however, on day 4 there was no change in expression of this protein over the sampling period. These results suggest that expression of PGHS-2 may be involved in inhibiting progesterone production and that expression of HSP-70 may be required for complete CL regression in the rat.Key words: rat, prostaglandin F2α, corpus luteum, prostaglandin G/H synthase, heat shock protein-70.

Download Full-text

STRESS PROTEIN EXPRESSION KINETICS

Annual Review of Biomedical Engineering ◽

10.1146/annurev.bioeng.7.060804.100449 ◽

2006 ◽

Vol 8 (1) ◽

pp. 403-424 ◽

Cited By ~ 56

Author(s):

Kenneth R. Diller

Keyword(s):

Protein Expression ◽

Stress Protein ◽

Expression Kinetics

Download Full-text

Tribulus terrestris protects rat myocardium against isoproterenol-induced ischemic injury: role of HSP 70 and cardiac endogenous antioxidants

Alternative Medicine Studies ◽

10.4081/ams.2011.e9 ◽

2011 ◽

Vol 1 (1) ◽

pp. 9

Author(s):

Ipseeta Ray Mohanty ◽

Ujjwala Maheswari ◽

Daniel Joseph ◽

Yeshwant Deshmukh

Keyword(s):

Myocardial Injury ◽

Stress Protein ◽

Myocardial Necrosis ◽

Thiobarbituric Acid ◽

Antioxidant Defense System ◽

Control Group ◽

Tribulus Terrestris ◽

Marker Enzyme ◽

Hsp 70 ◽

Endogenous Antioxidants

The present study was undertaken to evaluate the cardioprotective activity of Tribulus terrestris (Tt), a medicinal herb following isoproterenol (ISP)-induced myocardial injury. The contribution of heat shock protein (HSP) 70, key anti-stress protein, endogenous antioxidants and oxidant -antioxidant balance in attenuating myocardial injury was further studied. Hydroalcoholic extract of Tt {1, 2.5, 5 & 10 mg/kg} were orally fed once a daily to Wistar rats for 21 days. On the 20th and 21st day, both control (ISP control) and Tt fed rats were challenged with ISP (85 mg/ kg, s. c. two doses at 24h intervals) induced myocardial necrosis. Histopathological evaluation, cardiac marker enzyme: Creatinine phospho - kinase(CPK) and antioxidative parameters: Glutathione (GSH), Thiobarbituric acid reactive substances (TBARS), Catalase (CAT), Glutathione peroxidase (GSHPx) and Superoxide dismutase (SOD) levels were estimated. Tt (2.5 mg/kg) intake per se upregulated HSP 70; increased basal SOD, CAT activity (P<0.05) and caused a marked fall in basal TBARS levels (P<0.05) in comparison to sham. Following ISP challenge, significant oxidative stress with evidence of myocardial necrosis was observed in the ISP control group. ISPinduced changes in myocardial SOD, GSHPx and GSH were prevented by both the 2.5 and 10 mg/kg doses of Tt, though cellular injury was minimal with 2.5 mg/kg dose. The results emphasize that pre-treatment with Tt offered significant protection against ISP-induced myocardial necrosis through a unique property of enhancement of endogenous antioxidants, stabilization of cytoskeleton structure which in turn is attributed to HSP 70 expression along with fortified antioxidant defense system.

Download Full-text

Exercise training increases hepatic endoplasmic reticulum (er) stress protein expression in MTP-inhibited high-fat fed rats

Cell Biochemistry and Function ◽

10.1002/cbf.1643 ◽

2010 ◽

Vol 28 (3) ◽

pp. 202-210 ◽

Cited By ~ 19

Author(s):

Natalie Ann Chapados ◽

Jean-Marc Lavoie

Keyword(s):

Endoplasmic Reticulum ◽

Exercise Training ◽

Protein Expression ◽

Er Stress ◽

Stress Protein ◽

High Fat

Download Full-text

Differential activation of heat-shock and oxidation-specific stress genes in chemically induced oxidative stress

Biochemical Journal ◽

10.1042/bj3090453 ◽

1995 ◽

Vol 309 (2) ◽

pp. 453-459 ◽

Cited By ~ 38

Author(s):

L Tacchini ◽

G Pogliaghi ◽

L Radice ◽

E Anzon ◽

A Bernelli-Zazzera

Keyword(s):

Oxidative Stress ◽

Heat Shock ◽

Time Course ◽

Consensus Sequence ◽

Single Agent ◽

Stress Protein ◽

Hsp 70 ◽

Activator Protein ◽

Chemically Induced ◽

Haem Oxygenase

Post-ischaemic reperfusion increases the level of the major heat-shock (stress) protein hsp 70 and of its mRNA by transcriptional mechanisms, and activates the binding of the heat-shock factor HSF to the consensus sequence HSE. In common with CoCl2 treatment, post-ischaemic reperfusion increases the level of haem oxygenase mRNA, an indicator of oxidative stress, but CoCl2 does not seem to induce the expression of the hsp 70 gene [Tacchini, Schiaffonati, Pappalardo, Gatti and Bernelli-Zazzera (1993) Lab. Invest. 68, 465-471]. Starting from these observations, we have now studied the expression of two genes of the hsp 70 family and of other possibly related genes under conditions of oxidative stress. Three different chemicals, which cause oxidative stress by various mechanisms and induce haem oxygenase, enhance the expression of the cognate hsc 73 gene, but do not activate the inducible hsp 70 gene. Expression of the other genes that have been studied seems to vary in intensity and/or time course, in relation to the particular mechanism of action of any single agent. The pattern of induction of the early-immediate response genes c-fos and c-jun observed during oxidative stress differs from that found in post-ischaemic reperfused livers. Oxidative-stress-inducing agents do not promote the binding of HSF to its consensus sequence HSE, such as occurs in heat-shock and post-ischaemic reperfusion, and fail to activate AP-1 (activator protein 1). With the possible exception of Phorone, the oxidative stress chemically induced in rat liver activates NFkB (nuclear factor kB) and AP-2 (activator protein 2) transcription factors.

Download Full-text