The heat shock/stress response of motor neurons : a potential therapeutic target in amyotrophic lateral sclerosis

Heat shock proteins (HSPs) play important roles in the maintenance and preservation of cellular homeostasis. Since previous findings demonstrated a neuroprotective role of the stress-inducible Hsp70 in an in vitro model of the neurodegenerative disease, amyotrophic lateral sclerosis (ALS) (Bruening et al., 1999), the objectives of this research was to study the endogenous heat shock response of motor neurons exposed to various stresses and to determine if known pharmacological inducers of HSPs can enhance the stress response of these cells. Neither heat shock nor glutamate excitotoxicity induced Hsp70 in motor neurons. In primary spinal cord cultures, expression of Cu/Zn superoxide dismutase (SOD-1) with mutations responsible for familial ALS also failed to result in Hsp70 induction, nor was Hsp70 expressed in spinal motor neurons of mutant SOD-1 (mSOD) transgenic mice or patients with sporadic or familial ALS. The lack of a strong heat shock response was associated with an inability to activate the main stress-sensing transcription factor, heat shock transcription factor-1 (HSF1). Overexpression of an activated form of HSF1, but not wildtype HSF1, in cultured motor neurons resulted in significant protection from mutant SOD-1 toxicity, which was accompanied by increased expression of Hsp70, Hsp40, and to a lesser degree, Hsp25. The effects of two nonsteroidal anti-inflammatory drugs, sodium salicylate, shown in cell lines to increase HSF1 binding to promoters of HSP genes (Jurivich et al., 1992), and niflumic acid, a preferential COX-2 inhibitor, on the heat shock response of motor neurons were assessed. Both drugs lowered the temperature threshold for induction of Hsp70 in glia and non-neuronal cells, but not in motor neurons. Concomitantly, neither drug prevented mSOD-mediated motor neuron death. Pyrrolidine dithiocarbamate (PDTC), previously shown to upregulate Hsp70 in cell lines through increased DNA binding and activation of HSF1 (D

Prophylactic salpingo-oophorectomy & surgical menopause for inherited risks of cancer: the need to identify biomarkers to assess the theoretical risk of premature coronary artery disease

Abstract Background Some women with genetic risk of breast and/or ovarian cancer (e.g., BRCA1/2) opt to undergo prophylactic salpingo-oophorectomy (PSO, or surgical removal of the ovaries & fallopian tubes) in order to reduce their risk of cancer. As a consequence, these women experience “surgical menopause” – accompanied by more severe climacteric symptoms that occur in a much shorter time frame. While the risk of coronary artery disease (CAD) rises with menopause, little is known about how the sudden loss of ovarian function from PSO alters the whole-body physiology, and whether it predisposes women to premature CAD. Methods/Design To manage CAD risk there is a prerequisite for reliable biomarkers that can help guide risk assessment and therapeutic interventions. To address these needs, this prospective, observational cohort study will evaluate surrogate markers reflective of CAD health in women experiencing surgical menopause after PSO. Twenty women representing each of the following groups will be enrolled over 3 years (total participants = 240): (i) pre-menopausal PSO, (ii) post-menopausal PSO, (iii) pre-menopausal women undergoing other pelvic surgery, and (iv) pre-menopausal controls (no surgery). All participants will provide blood plasma samples pre- and 1, 3, 6, & 12 months post-operatively, with serial samples collectively assessed for measurements of the study’s primary endpoints of interest. These include a hormone profile (estradiol, follicle stimulating hormone (FSH), luteinizing hormone (LH), and progesterone) and both conventional (lipid profile) and novel biomarkers (Heat Shock Protein 27 (HSP27), HSP27-antibodies (HSP27 Ab), proprotein convertase subtilisin/kexin 9 (PCSK9), inflammatory cytokines) of CAD. Another aspect of this study is the measurement and analysis of retinal vessel diameters – an emerging physiological parameter reflective of CAD risk. Finally, a patient engagement exercise will result in the drafting of patient-generated questionnaires that address the well-being and health concerns of these women as they transition through premature menopause and work with our research team to identify and discuss their health priorities. Discussion The protocol of our planned study investigating the effects of PSO on CAD is described herein. Characterization of novel CAD markers in women experiencing surgical menopause will yield new insights into the role of the functional ovary in modulating lipid parameters and other CAD risk factors such as HSP27 and HSP27 Ab

Recombinant heat shock protein 27 (HSP27/HSPB1) protects against cadmium-induced oxidative stress and toxicity in human cervical cancer cells

Cadmium (Cd) is a carcinogen with several welldescribed toxicological effects in humans, but its molecular mechanisms are still not fully understood. Overexpression of heat shock protein 27 (HSP27/HSPB1)—a multifunctional protein chaperone—has been shown to protect cells from oxidative damage and apoptosis triggered by Cd exposure. The aims of this work were to investigate the potential use of extracellular recombinant HSP27 to prevent/counteract Cdinduced cellular toxicity and to evaluate if peroxynitrite was involved in the development of Cd-induced toxicity. Here, we report that the harmful effects of Cd correlatedwith changes in oxidative stress markers: upregulation of reactive oxygen species, reduction in nitric oxide (NO) bioavailability, increment in lipid peroxidation, peroxynitrite (PN), and protein nitration; intracellular HSP27 was reduced. Treatments with Cd (100 μM) for 24 h or with the peroxynitrite donor, SIN-1, decreased HSP27 levels (~50%), suggesting that PN formation is responsible for the reduction of HSP27. Pre-treatments of the cells either with Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) (a pharmacological inhibitor of NO synthase) or with recombinant HSP27 (rHSP27) attenuated the disruption of the cellular metabolism induced by Cd, increasing in a 55 and 52%, respectively, the cell viability measured by CCK-8. Cd induced necrotic cell death pathways, although apoptosis was also activated; pre-treatment with LNAME or rHSP27 mitigated cell death. Our findings show for the first time a direct relationship between Cd-induced toxicity and PN production and a role for rHSP27 as a potential therapeutic agent that may counteract Cd toxicity.Fil: Alvarez Olmedo, Daiana Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; Argentina. University of Calgary; CanadáFil: Biaggio, Veronica Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Koumbadinga, Geremy A.. University of Calgary; CanadáFil: Gomez, Nidia Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Shi, Chunhua. University of Calgary; CanadáFil: Ciocca, Daniel Ramon. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Batulan, Zarah. University of Calgary; CanadáFil: Fanelli, Mariel Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: O´Brien, Edward R.. University of Calgary; Canad

Nonsteroidal anti-inflammatory drugs differentially affect the heat shock response in cultured spinal cord cells

Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to amplify the heat shock response in cell lines by increasing the binding of heat shock transcription factor–1 to heat shock elements within heat shock gene promoters. Because overexpression of the inducible heat shock protein 70 (Hsp70) was neuroprotective in a culture model of motor neuron disease, this study investigated whether NSAIDs induce Hsp70 and confer cytoprotection in motor neurons of dissociated spinal cord cultures exposed to various stresses. Two NSAIDs, sodium salicylate and niflumic acid, lowered the temperature threshold for induction of Hsp70 in glia but failed to do so in motor neurons. At concentrations that increased Hsp70 in heat shocked glial cells, sodium salicylate failed to delay death of motor neurons exposed to hyperthermia, paraquat-mediated oxidative stress, and glutamate excitotoxicity. Neither sodium salicylate nor the cyclooxygenase-2 inhibitor, niflumic acid, protected motor neurons from the toxicity of mutated Cu/Zn-superoxide dismutase (SOD-1) linked to a familial form of the motor neuron disease, amyotrophic lateral sclerosis. Thus, treatment with 2 types of NSAIDs failed to overcome the high threshold for the activation of heat shock response in motor neurons