Hypertension is accompanied by structural and mechanical abnormalities in resistance arteries. The effects of resveratrol, a phenolic phytoalexin found naturally in various foods, on systolic blood pressure and resistance artery structure and stiffness were assessed in spontaneously hypertensive rats (SHRs). Vascular geometry and mechanical properties of pressurized mesenteric resistance arteries were calculated from media and lumen dimensions measured using pressure myography. Compared to normotensive Wistar-Kyoto (WKY) rats, resistance arteries from SHRs displayed remodeling with narrowed lumen diameters (246.2±21.0 vs. 308.1±14.3 μm, p<0.05), thickened media widths (39.8±4.6 vs. 28.5±2.7 μm, p<0.05) and augmented media-to-lumen ratios (17.7±2.6 vs. 9.3±1.0, p<0.05). Calculations of remodeling and growth indices revealed that SHR vessels underwent mostly eutrophic remodeling. Systolic blood pressure was elevated in 20-week-old SHR versus WKY rats (219±6 vs. 155±6 mmHg, p<0.01) and was unaffected by resveratrol (2.5 mg/Kg/d). In SHRs, resveratrol treatment attenuated eutrophic remodeling and normalized increased vessel compliance (p<0.01) as determined by a restorative leftward shift in the stress-strain curve of SHR arteries (p<0.01). Resveratrol treatment restored stiffness in SHRs (4.2±0.4 vs. 6.6±0.5, p<0.05) through the normalization of vessel geometry. Immunoblotting revealed that resveratrol negated typical pronounced ERK1/2 signaling in SHR arteries. Thus, the results of this study suggest that resveratrol restores vascular mechanical properties in SHRs and attenuates remodeling. Furthermore the attenuation of remodeling in SHR arteries with resveratrol treatment is associated with the inhibition of ERK1/2 activity.

Myocardial infarction (MI) is a leading cause of congestive heart failure (CHF), and its course of cardiac remodeling is of paramount importance in prevention and treatment of cardiac dysfunction. Activation of the sympathetic nervous system (SNS), and the renin angiotensin system (RAS), is critical in cardiac subcellular remodeling post MI. Although blockade has prevented remodeling, little is known regarding the beneficial effects in reversing subcelllular changes in failing hearts. Upon rat coronary artery occlusion - losartan, metoprolol, and prazosin were initiated 12 weeks post MI for 8 weeks, to evaluate their reversal effects at the molecular and cellular levels. As the sarcoplasmic reticulum (SR) primary regulates intracellular Ca2+ in cardiac contraction/relaxation, we hypothesized that abnormalities in its function and regulation contribute to contractile dysfunction. We examined cardiac performance, SR function, SR molecular expression and plasma catecholamine levels 20 weeks post MI. The fibrinous myocardium, cardiac hypertrophy and pulmonary edema all portrayed CHF, in addition to elevated LVEDP and depressed dP/dt. Ejection fraction, fractional shortening, and cardiac output were all significantly reduced, as were IVSs, LVIDd, LVPWs, and LVPWd. SR preparations showed altered phospholamban (PLB) and sarcoplasmic reticulum Ca2+ ATPase (SERCA2a) mRNA, which appropriately matched their protein expression. These modifications correlated to decreased cardiac SR Ca2+-uptake, providing further disruptions in Ca2+ homeostasis. Therefore, these modifications in the mRNA of PLB and SERCA2a are postulated to play a critical role in SR protein remodeling. Supplementary studies addressed remodeling of mRNA myofibrils, which revealed a decreased α-MHC isozyme with an increased β-MHC isozyme, and reduced myofibrillar Ca2+-stimulated ATPase post MI. Finally, circulating plasma catecholamine levels of norepinephrine, epinephrine and dopamine were significantly elevated. Losartan, metoprolol, and prazosin corrected lung edema, myocardial hypertrophy, cardiac contractile dysfunction, and attenuated PLB and SERCA2a proteins, whereas α- and β- MHC mRNA were only attenuated by losartan; and metoprolol only attenuated β-MHC mRNA. SR Ca2+-uptake activities and plasma catecholamines of norepinephrine were partially reversed, yet dopamine was only affected by losartan. Early work previously focused on prevention, but this study is one of the first to attempt reversal of cardiac subcellular remodeling in CHF due to MI.

Hypertension is accompanied by structural and mechanical abnormalities in resistance arteries. The effects of resveratrol, a phenolic phytoalexin found naturally in various foods, on systolic blood pressure and resistance artery structure and stiffness were assessed in spontaneously hypertensive rats (SHRs). Vascular geometry and mechanical properties of pressurized mesenteric resistance arteries were calculated from media and lumen dimensions measured using pressure myography. Compared to normotensive Wistar-Kyoto (WKY) rats, resistance arteries from SHRs displayed remodeling with narrowed lumen diameters (246.2±21.0 vs. 308.1±14.3 μm, p<0.05), thickened media widths (39.8±4.6 vs. 28.5±2.7 μm, p<0.05) and augmented media-to-lumen ratios (17.7±2.6 vs. 9.3±1.0, p<0.05). Calculations of remodeling and growth indices revealed that SHR vessels underwent mostly eutrophic remodeling. Systolic blood pressure was elevated in 20-week-old SHR versus WKY rats (219±6 vs. 155±6 mmHg, p<0.01) and was unaffected by resveratrol (2.5 mg/Kg/d). In SHRs, resveratrol treatment attenuated eutrophic remodeling and normalized increased vessel compliance (p<0.01) as determined by a restorative leftward shift in the stress-strain curve of SHR arteries (p<0.01). Resveratrol treatment restored stiffness in SHRs (4.2±0.4 vs. 6.6±0.5, p<0.05) through the normalization of vessel geometry. Immunoblotting revealed that resveratrol negated typical pronounced ERK1/2 signaling in SHR arteries. Thus, the results of this study suggest that resveratrol restores vascular mechanical properties in SHRs and attenuates remodeling. Furthermore the attenuation of remodeling in SHR arteries with resveratrol treatment is associated with the inhibition of ERK1/2 activity.

Myocardial infarction (MI) is a leading cause of congestive heart failure (CHF), and its course of cardiac remodeling is of paramount importance in prevention and treatment of cardiac dysfunction. Activation of the sympathetic nervous system (SNS), and the renin angiotensin system (RAS), is critical in cardiac subcellular remodeling post MI. Although blockade has prevented remodeling, little is known regarding the beneficial effects in reversing subcelllular changes in failing hearts. Upon rat coronary artery occlusion - losartan, metoprolol, and prazosin were initiated 12 weeks post MI for 8 weeks, to evaluate their reversal effects at the molecular and cellular levels. As the sarcoplasmic reticulum (SR) primary regulates intracellular Ca2+ in cardiac contraction/relaxation, we hypothesized that abnormalities in its function and regulation contribute to contractile dysfunction. We examined cardiac performance, SR function, SR molecular expression and plasma catecholamine levels 20 weeks post MI. The fibrinous myocardium, cardiac hypertrophy and pulmonary edema all portrayed CHF, in addition to elevated LVEDP and depressed dP/dt. Ejection fraction, fractional shortening, and cardiac output were all significantly reduced, as were IVSs, LVIDd, LVPWs, and LVPWd. SR preparations showed altered phospholamban (PLB) and sarcoplasmic reticulum Ca2+ ATPase (SERCA2a) mRNA, which appropriately matched their protein expression. These modifications correlated to decreased cardiac SR Ca2+-uptake, providing further disruptions in Ca2+ homeostasis. Therefore, these modifications in the mRNA of PLB and SERCA2a are postulated to play a critical role in SR protein remodeling. Supplementary studies addressed remodeling of mRNA myofibrils, which revealed a decreased α-MHC isozyme with an increased β-MHC isozyme, and reduced myofibrillar Ca2+-stimulated ATPase post MI. Finally, circulating plasma catecholamine levels of norepinephrine, epinephrine and dopamine were significantly elevated. Losartan, metoprolol, and prazosin corrected lung edema, myocardial hypertrophy, cardiac contractile dysfunction, and attenuated PLB and SERCA2a proteins, whereas α- and β- MHC mRNA were only attenuated by losartan; and metoprolol only attenuated β-MHC mRNA. SR Ca2+-uptake activities and plasma catecholamines of norepinephrine were partially reversed, yet dopamine was only affected by losartan. Early work previously focused on prevention, but this study is one of the first to attempt reversal of cardiac subcellular remodeling in CHF due to MI.

Chow, Dick Ho Kiu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 93-103). / Abstracts in English and Chinese. / Abstract --- p.ii / Publications --- p.vii / Acknowledgement --- p.viii / Table of Contents --- p.x / List of Figures --- p.xiv / List of Tables --- p.xv / List of Abbreviations --- p.xvii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Bone and its Cellular Components --- p.1 / Chapter 1.1.1 --- Cellular Components of Bone --- p.1 / Chapter 1.1.2 --- Macroscopic Structure --- p.4 / Chapter 1.1.3 --- Microscopic Structure --- p.4 / Chapter 1.2 --- Fracture Healing --- p.5 / Chapter 1.2.1 --- Inflammation --- p.6 / Chapter 1.2.2 --- Soft Callus Formation --- p.6 / Chapter 1.2.3 --- Hard Callus Formation --- p.7 / Chapter 1.2.4 --- Bone Remodeling --- p.7 / Chapter 1.3 --- Low Magnitude High Frequency Vibration (LMHFV) Stimulation --- p.7 / Chapter 1.3.1 --- Mechanical Stimulation --- p.10 / Chapter 1.3.2 --- Effect of LMHFV on Bone --- p.12 / Chapter 1.4 --- Osteoporosis and Osteoporotic Fractures --- p.16 / Chapter 1.4.1 --- Epidemiology of Osteoporotic Fracture --- p.17 / Chapter 1.4.2 --- Pathophysiology --- p.17 / Chapter 1.4.3 --- Osteoporotic Fracture Healing --- p.20 / Chapter 1.5 --- Bisphosphonate --- p.23 / Chapter 1.5.1 --- Background --- p.23 / Chapter 1.5.2 --- Mechanism of Action --- p.24 / Chapter 1.5.3 --- U sage of Bisphosphonate --- p.25 / Chapter 1.5.4 --- Bisphosphonate Effects on Fracture Healing --- p.27 / Chapter 1.6 --- Hypothesis --- p.27 / Chapter 1.7 --- Study Plan --- p.28 / Chapter 1.7.1 --- Objectives --- p.28 / Chapter 2 --- Method --- p.29 / Chapter 2.1 --- Ovariectomized Rat Femoral Fracture Model --- p.29 / Chapter 2.1.1 --- Ovariectomized Rat Model. --- p.29 / Chapter 2.1.2 --- Closed Femoral Fracture --- p.31 / Chapter 2.2 --- Study Design --- p.32 / Chapter 2.3 --- LMHFV Treatment Protocol --- p.32 / Chapter 2.4 --- Bisphosphonate Treatment Protocol --- p.35 / Chapter 2.4.1 --- Pharmacological Parameters --- p.35 / Chapter 2.4.2 --- Ibandronate Injection Solution Preparation --- p.37 / Chapter 2.4.3 --- Injection --- p.37 / Chapter 2.5 --- Fluorochrome Labeling --- p.38 / Chapter 2.5.1 --- Fluorochrome Preparation --- p.38 / Chapter 2.5.2 --- Injection --- p.38 / Chapter 2.6 --- Assessments --- p.39 / Chapter 2.6.1 --- Radiographic Analysis --- p.39 / Chapter 2.6.2 --- uCT Analysis --- p.40 / Chapter 2.6.3 --- Undecalcified Histology --- p.43 / Chapter 2.6.4 --- ELISA Analysis on Bone Markers --- p.47 / Chapter 2.7 --- Statistical Analysis --- p.50 / Chapter 3 --- Results --- p.51 / Chapter 3.1 --- Radiographic Analysis --- p.52 / Chapter 3.1.1 --- Callus Bridging Rate --- p.52 / Chapter 3.1.2 --- Callus Width and Area --- p.52 / Chapter 3.2 --- uCT Analysis --- p.55 / Chapter 3.3 --- Histomorphometric Analysis --- p.61 / Chapter 3.3.1 --- Bone Mineralization Rate --- p.61 / Chapter 3.4 --- Bone Markers Analysis --- p.64 / Chapter 3.4.1 --- Osteocalcin --- p.64 / Chapter 3.4.2 --- TRAP5b --- p.64 / Chapter 3.4.3 --- Summary --- p.67 / Chapter 4 --- Discussion --- p.69 / Chapter 4.1 --- LMHFV Enhanced Bone Remodeling --- p.69 / Chapter 4.1.1 --- LMHFV Reversed Bis Inhibition on Bone Remodeling --- p.70 / Chapter 4.1.2 --- LMHFV Effect on Osteoclastic Resorption During Bone Re-modeling --- p.71 / Chapter 4.2 --- Enhanced Fracture Healing by LMHFV --- p.72 / Chapter 4.2.1 --- Acceleration of Fracture Healing by LMHFV --- p.72 / Chapter 4.2.2 --- LMHFV Inhibits Osteoclast Activity in the Early Phase of Healing --- p.73 / Chapter 4.2.3 --- LMHFV Stimulates Osteoblast Activity in the Early Phase of Healing --- p.74 / Chapter 4.3 --- Bis Delays Fracture Healing --- p.75 / Chapter 4.4 --- Experimental Design --- p.78 / Chapter 4.4.1 --- Inhibition Study --- p.78 / Chapter 4.4.2 --- Bisphosphonate Injection Protocol --- p.79 / Chapter 4.4.3 --- Individual Analysis of Bone Formation and Resorption . --- p.81 / Chapter 4.5 --- Clinical Implications --- p.84 / Chapter 4.5.1 --- LMHFV Enhanced Remodeling --- p.84 / Chapter 4.5.2 --- Bisphosphonate Delayed Remodeling --- p.85 / Chapter 4.6 --- Limitations --- p.85 / Chapter 4.6.1 --- Measurement of Bone Resorption --- p.85 / Chapter 4.6.2 --- Osteoporotic Fracture Model --- p.86 / Chapter 4.6.3 --- Inhibition of Bone Remodeling --- p.87 / Chapter 4.7 --- Future Studies --- p.88 / Chapter 4.7.1 --- LMHFV Effect on Osteoclast in vitro --- p.88 / Chapter 4.7.2 --- Biomechanics of Fracture Callus --- p.89 / Chapter 4.7.3 --- LMHFV Effect on Leptin- Adrenergic Pathway --- p.89 / Chapter 5 --- Conclusion --- p.91 / Bibliography --- p.93

Thesis (Ph. D.)--School of Dentistry. University of Missouri--Kansas City, 2003. / "A dissertation in oral biology and molecular biology and biochemistry." Advisor: Jian Q. Feng. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed July 16, 2008. Includes bibliographical references (leaves 109-121). Online version of the print edition.

Thesis (Ph. D.)--Rensselaer Polytechnic Institute, Troy, New York, 1992. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (p. 184-200).

Thesis (Ph. D.)--Rensselaer Polytechnic Institute, Troy, New York, 1992. / Includes bibliographical references (p. 184-200).

Background: The higher-order structure of chromatin changes in response to extracellular and environmental signals. We observed nuclear morphological changes in biopsied cancer tissue after chemotherapy. Since chromatin structure dictates gene expression, and therefore function, further investigation of this phenomenon may increase our understanding of therapeutic responses. I hypothesised that nuclear morphological changes in cancer in response to DNA-damage by chemotherapy are mediated by histone deacetylases (de Ruijter, van Gennip et al.). Methods: Ovarian cancer cell lines PEO1/PEO4 (platinum sensitive/resistant) were selected as in vitro models, and primary ovarian cancer xenografts OV1002 and HOX424 as in vivo models. Expression levels of HDACs, heterochromatin protein 1 (HP1), and DNA damage response (DDR) proteins were profiled by Western blot analysis after treatment with cisplatin. Immunofluorescence imaging was undertaken using confocal microscopy, and nuclear texture and γH2AX foci were measured in Image J. Cell cycle and apoptosis were detected by flow cytometry. Thirty eight different ovarian cancer biopsies and 175 xenograft samples were assessed for HDAC and HP1 expression in response to chemotherapy by quantitative immunofluorescence. HDAC2 expression was modulated by interfering RNAs (siRNA). Results: I demonstrated nuclear morphological changes in clinical tumours, xenografts, and cell lines in response to platinum chemotherapy by robust measurement of nuclear texture. Expression of HDAC2 increased in PEO1 cells treated with cisplatin at 24h, and this was accompanied by high expression of HP1s. Expression of components of both HDACs and DDR pathways (pBRCA1, γH2AX, pATM, pATR) showed time dependent changes after cisplatin treatment. Knockdown of HDAC2 reduced the expression of HP1, induced DNA double strand breaks (DSB) measured by γH2AX, and interfered with the activation of DDR induced by cisplatin. Furthermore, HDAC2 depletion affected γH2AX foci formation, cell cycle distribution, and apoptosis triggered by cisplatin, and was additive to the inhibitory effect of cisplatin in cell lines. By inhibiting expression of HDAC2, I observed reversible alteration of chromatin patterns during cisplatin treatment to some degree. In clinical ovarian cancer specimens, expression of HDAC4, HDAC8 and HP1γ significantly increased after chemotherapy in sensitive patients, with enhanced heterogeneity in chromatin pattern. HDAC2, HDAC8, and HP1 expression were also increased after carboplatin treatment in carboplatin-sensitive xenografts. Conclusion: These results demonstrate alterations in nuclear morphology after chemotherapy, and implicate HDACs in having a role in higher order chromatin changes and in cellular DNA damage responses in ovarian cancer both in vitro and in vivo.

Peripheral artery disease (PAD) and osteoporosis have recently been shown to be associated; with the parallel occurrence suggesting that PAD related ischemia may cause or enhance the onset of osteoporosis. In order to determine the mechanism linking osteoporosis and PAD this paper will examine the effects of ischemia and mechanical stimulation on bone remodeling. An immunohistochemistry protocol for vessel marking in bone was also developed. Ischemia was induced in a mouse model to determine vascular and mechanical property changes in bone in response to hypoxia, and mechanical loading-induced remodeling was analyzed for vascular changes. Both ischemia and mechanical loading increased bone vessel density, with ischemic bone increases seen at day 7 and 14. Bone stiffness increased after induced ischemia at day 28. These results point to resultant hypoxia from ischemia drives bone mechanical property changes, likely through stimulation of bone remodeling. We also conclude that an increase in vessel density is seen after induced mechanical loading of bone. Establishing the vascular contribution to the remodeling process may reveal treatment opportunities for remodeling-dependent pathologies such as osteoporosis.