ABSTRACT
AIM: Various components of metabolic syndrome associate with cardiac intracellular calcium (Cai 2+) mishandling, a precipitating factor in the development of heart failure. We aimed to provide a thorough description of early stage Cai 2+-cycling alterations in the fructose-fed rat, an experimental model of the disorder, where insulin resistance, hypertension and dyslipidaemia act cooperatively on the heart. METHOD: Rats were fed with fructose-rich chow. After 6 weeks, echocardiography was performed, which was followed by measurements of myocardial Cai 2+ transients recorded by Indo-1 surface fluorometry in isolated perfused hearts. Sarcoplasmic reticulum (SR) Ca(2+) -ATPase (SERCA2a) activity was assessed by administration of its inhibitor cyclopiazonic acid (CPA). Mathematical model analysis of Cai 2+ transients was used to estimate kinetic properties of SR Ca(2+) transporters. Protein levels of key Ca(2+) handling proteins were also measured. RESULTS: Echocardiography showed signs of cardiac hypertrophy, but in vivo and ex vivo haemodynamic performance of fructose-fed rat hearts were unaltered. However, a decline in Ca(2+) sequestration capacity (-dCai 2+/dt and decay time of Cai 2+ transients) was observed. Model estimation showed decreased affinity for Ca(2+) (higher K(m) ) and elevated V(max) for SERCA2a. Diseased hearts were more vulnerable to CPA application. Fructose feeding caused elevation in SERCA2a and phosphorylated phospholamban (PLB) expression, while total PLB level remained unchanged. CONCLUSION: In early stage, metabolic syndrome primarily disturbs SERCA2a function in the heart, but consequential haemodynamic dysfunction is prevented by upregulation of SERCA2a protein level and phosphorylation pathways regulating PLB. However, this compensated state is very vulnerable to a further decline in SERCA2a function.
Subject(s)
Heart/physiopathology , Metabolic Syndrome/metabolism , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism , Up-Regulation/physiology , Animals , Calcium/metabolism , Calcium-Binding Proteins/metabolism , Disease Models, Animal , Echocardiography , Insulin Resistance/physiology , Male , Models, Theoretical , Rats , Rats, Sprague-DawleyABSTRACT
BACKGROUND: Galanin is a trophic factor of the central and peripheral nervous system that shows widespread distribution in human skin. However, the exact localization and the role of galanin in the hair follicle (HF) remain to be clarified. OBJECTIVES: To characterize galanin expression in human scalp HFs and to examine the effects of galanin on normal human scalp HF growth in organ culture. METHODS: Immunohistochemistry was performed on cryosections of human female scalp skin. Anagen HFs were microdissected and cultured up to 9 days and treated with 100 nmol L(-1) galanin. Staining for Ki-67, TUNEL and Masson-Fontana were used to analyse proliferation, apoptosis and hair cycle staging of the HFs. Functional effects of galanin were tested in serum-free HF organ culture. RESULTS: Galanin-like immunoreactivity was detected in the outer root sheath (ORS) and inner root sheath. Additionally, galanin mRNA was detected in ORS keratinocytes and all HF samples tested. Galanin receptor transcripts (GalR2, GalR3) were also detected in selected samples. Galanin reduced proliferation of hair matrix keratinocytes in situ compared with vehicle-treated controls, shortened the hair growth phase (anagen) in vitro and reduced hair shaft elongation. This was accompanied by the premature development of a catagen-like morphology of galanin-treated HFs. CONCLUSIONS: We present the first evidence that human HFs are both a source and a functionally relevant target of galanin. Due to its hair growth-inhibitory properties in vitro, galanin application deserves further exploration as a potential new treatment strategy for unwanted hair growth (hirsutism, hypertrichosis).
Subject(s)
Galanin/physiology , Growth Inhibitors/physiology , Hair/growth & development , Cells, Cultured , Female , Galanin/pharmacology , Growth Inhibitors/pharmacology , Hair/drug effects , Hair Follicle/metabolism , Humans , Immunohistochemistry , Ki-67 Antigen/metabolism , Male , Middle Aged , Scalp/metabolismABSTRACT
The effects of proteosome inhibitor Bortezomib (BZ) were studied in vitro for 24 h on the protein kinase C (PKC) profiles, rates of proliferation and apoptosis in Jurkat cells and lymphocytes of 10 patients with systemic lupus erythematosus (SLE) and nine healthy subjects. The expressions of PKC proteins, the rates of proliferation and apoptosis were determined. The effects of BZ were different in the Jurkat and lupus T cells. Whereas BZ elevated the expression of PKC θ, δ and ξ isoenzymes in the Jurkat cells, it was unable to do that in the lupus T cells. BZ induced a dose-dependent increase in the apoptosis of Jurkat cells, while decreased the proliferation. The same effect of BZ was observed on the apoptosis of lymphocytes both in SLE and healthy subjects at concentrations higher than the therapeutic dose. We conclude that BZ treatment in vitro was not able to restore the SLE-specific defect (decrease) in the expression of PKC isoenzymes in the T cells as it was expected. This can be a limiting factor in the positive clinical effects of BZ in lupus.
Subject(s)
Boronic Acids/pharmacology , Isoenzymes/genetics , Lupus Erythematosus, Systemic/genetics , Proteasome Inhibitors/pharmacology , Protein Kinase C-delta/genetics , Protein Kinase C-epsilon/genetics , Protein Kinase C/genetics , Pyrazines/pharmacology , T-Lymphocytes/drug effects , Adult , Apoptosis/drug effects , Bortezomib , Case-Control Studies , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Female , Gene Expression/drug effects , Humans , Isoenzymes/immunology , Jurkat Cells , Lupus Erythematosus, Systemic/enzymology , Lupus Erythematosus, Systemic/immunology , Lupus Erythematosus, Systemic/pathology , Male , Middle Aged , Organ Specificity , Primary Cell Culture , Protein Kinase C/immunology , Protein Kinase C-delta/immunology , Protein Kinase C-epsilon/immunology , Protein Kinase C-theta , T-Lymphocytes/enzymology , T-Lymphocytes/immunology , T-Lymphocytes/pathologyABSTRACT
OBJECTIVES: Recent reports have unambiguously identified the presence and the growth-modulatory role of transient receptor potential vanilloid-1 (TRPV1), a central integrator of pain sensation, on numerous non-neuronal cell types and, of great importance, in certain malignancies. In this study, we have investigated the molecular expression of TRPV1 in the human tongue and its high-incidence malignant (squamous cell carcinoma, SCC) and premalignant (leukoplakia) conditions. METHODS: Immunohistochemistry, Western blotting and quantitative 'real-time' Q-PCR were performed to define the expression of TRPV1. RESULTS: A weak and sparse TRPV1-specific immunoreactivity was identified in the basal layers of the healthy human tongue epithelium. By contrast, we observed a dramatically elevated TRPV1-immunoreactivity in all layers of the epithelium both in precancerous and malignant samples. Furthermore, statistical analysis revealed that the marked overexpression of TRPV1 found in all grades of SCC showed no correlation with the degree of malignancy of the tumours. Finally, the molecular expression of TRPV1 was also identified in an SCC-derived cell line and was shown to be increased in parallel with the accelerated growth of the cells. CONCLUSION: Collectively, our findings identify TRPV1 as a novel, promising target molecule in the supportive treatment and diagnosis of human tongue SCC.
