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Papers by Eduardo Fricovsky

International Journal of Pharmaceutical Investigation

The L-ascorbate (AA), L-ascorbyl dibutyrate (AADB), L-ascorbyl dipalmitate (AADP), L-ascorbyl pal... more The L-ascorbate (AA), L-ascorbyl dibutyrate (AADB), L-ascorbyl dipalmitate (AADP), L-ascorbyl palmitate (AAP), and L-ascorbyl stearate (AS) are shown in Figure 1 and were obtained from TCI and Alfa Aesar. Enzymes and materials given below were from Sigma (catalog numbers) unless stated otherwise. Methods Unless otherwise stated, all enzymes come from rabbit and all experimental temperatures were 25°C, pH 8.0. Compared to the main enzyme activity, it was determined that enzyme enolase (E0379) contained activities ≥ 0.05% by LDH or by PFK-1; LDH contained ≥ 0.01% enolase activity; and aldolase (A8811) contained ≥ 0.05% PFK-1. AA-fatty acid derivatives were dissolved in ethanol or dimethyl sulfoxide (DMSO, D8418). It can be shown that neither 15% ethanol nor 15% DMSO inhibited any enzymes used in these studies, more than the upper limit of the solvents used. Minimum six experiemnts were performed. Less than ± 10% standard deviation from the mean (SEM) than Data were acceptable. ± 10% error bars represent the SEM.

International Journal of Pharmaceutical Investigation

Journal of Pharmaceutical Research International

Background: Pharmacy students in Mexico are exposed to United States’ pharmacy community services... more Background: Pharmacy students in Mexico are exposed to United States’ pharmacy community services in hopes to adopt the services for their own pharmacy program. Objectives: This study aims to assess the effectiveness of a strictly online-based teaching method to improve student knowledge on the role of pharmacists and the pharmacy curriculum in Mexico and the United States. Methods: This was a prospective study of pharmacy students attending the University of California, San Diego Skaggs School of Pharmacy and Pharmaceutical Sciences (UCSD SSPPS) and Facultad de Quimic-Pharmaco-Biologia de la Universidad Michoacana San Nicolas de Hidalgo (UMSNH) during the 2015-2016 academic year who enrolled in the E-Learning Collaborative and Educational Experience Independent Study. Results: The e-learning course had 25 students total from both the United States and Mexico enrolled. Out of the 25 students, 4 students from the United States and 11 students from Mexico agreed to participate in the ...

Medical Education, 2022

At our university hospital, we recently developed and implemented a multidisciplinary curriculum ... more At our university hospital, we recently developed and implemented a multidisciplinary curriculum that integrates ultrasound as a compulsory part into medical education directly from start to finish. The curriculum follows a spiral course with four levels of training in which learning activities are repeated with continuously growing complexity. Competency-centred “probe-in-the-hand” courses are held in small groups of maximum six learners. Students start to practice ultrasonography by scanning each other, attending training in skills labs and, finally, deepen experience in clinical settings. Students should prepare self-determinedly for courses using learning videos available on the university's in-house network and on publicly available e-learning platforms. On the first training level, during preclinical education, ultrasonography is closely linked to anatomy dissectionand physiology courses. With this vertical integration, basic sciences are put into context and vice versa, clinical aspects are introduced into early medical training. At the same time, specific psychomotor skills are introduced. On the second level, in the third year of medical education, students apply point-of-care ultrasound in peers, skills lab simulations and ultrasound phantoms. The skills lab will be available during semester breaks to provide the opportunity to practice outside scheduled courses. On the third level, during advanced clinical education, students select a compulsory elective ultrasound course in a specialty of their choice, held at five consecutive dates following the concept of work-based learning. This allows students to direct their own learning and to focus on their preferred specialty. From then on, they conduct ultrasound examinations in patients. During the final year, students successively adapt skills and knowledge to growing medical experience. Now they are expected to use ultrasound with a large degree of independence and confidence. Entrustable professional activities are specified and assessed concomitantly.

The FASEB Journal, 2014

Protein O-GlcNAcylation has been shown to play a major role in the development of type 2 diabetes... more Protein O-GlcNAcylation has been shown to play a major role in the development of type 2 diabetes and diabetic complications. This study is investigating differences of gene expression of proteins ...

American journal of pharmaceutical education, Jan 25, 2017

Objective. To implement and evaluate the effectiveness of an interactive health literacy program ... more Objective. To implement and evaluate the effectiveness of an interactive health literacy program by measuring pharmacy students' knowledge and confidence. Design. A health literacy module consisting of a lecture and workshop was incorporated into a self-care course for first-year pharmacy students. Active-learning activities included practicing health literacy tools, discussing faculty-created video vignettes, and improving readability of patient education monographs. A non-validated survey assessed knowledge and confidence before and after training. Assessment. Fifty-three students (88%) completed a pre-training survey, and 60 (100%) completed a post-training survey. Students' confidence improved in six of seven areas (p<.001). Students' knowledge significantly improved in three of 14 areas (p<.01) pertaining to the average American reading level, high-risk age groups, and correlation of late prescription refills to low health literacy. Although knowledge increase...

Journal of Biological Chemistry, 2008

Increased nuclear protein O-linked ␤-N-acetylglucosamine glycosylation (O-GlcNAcylation) mediated... more Increased nuclear protein O-linked ␤-N-acetylglucosamine glycosylation (O-GlcNAcylation) mediated by high glucose treatment or the hyperglycemia of diabetes mellitus contributes to cardiac myocyte dysfunction. However, whether mitochondrial proteins in cardiac myocytes are also submitted to O-Glc-NAcylation or excessive O-GlcNAcylation alters mitochondrial function is unknown. In this study, we determined if mitochondrial proteins are O-GlcNAcylated and explored if increased O-GlcNAcylation is linked to high glucose-induced mitochondrial dysfunction in neonatal rat cardiomyocytes. By immunoprecipitation, we found that several mitochondrial proteins, which are members of complexes of the respiratory chain, like subunit NDUFA9 of complex I, subunits core 1 and core 2 of complex III, and the mitochondrial DNA-encoded subunit I of complex IV (COX I) are O-GlcNAcylated. By mass spectrometry, we identified that serine 156 on NDUFA9 is O-GlcNAcylated. High glucose treatment (30 mM glucose) increases mitochondrial protein O-GlcNAcylation, including those of COX I and NDUFA9 which are reduced by expression of O-GlcNAcase (GCA). Increased mitochondrial O-GlcNAcylation is associated with impaired activity of complex I, III, and IV in addition to lower mitochondrial calcium and cellular ATP content. When the excessive O-GlcNAc modification is reduced by GCA expression, mitochondrial function improves; the activity of complex I, III, and IV increases to normal and mitochondrial calcium and cellular ATP content are returned to control levels. From these results we conclude that specific mitochondrial proteins of cardiac myocytes are O-GlcNAcylated and that exposure to high glucose increases mitochondrial protein O-GlcNAcylation, which in turn contributes to impaired mitochondrial function.

American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 2012

We examined the role that enzymatic protein O-GlcNAcylation plays in the development of diabetic ... more We examined the role that enzymatic protein O-GlcNAcylation plays in the development of diabetic cardiomyopathy in a mouse model of Type 2 diabetes mellitus (DM2). Mice injected with low-dose streptozotocin and fed a high-fat diet developed mild hyperglycemia and obesity consistent with DM2. Studies were performed from 1 to 6 mo after initiating the DM2 protocol. After 1 mo, DM2 mice showed increased body weight, impaired fasting blood glucose, and hyperinsulinemia. Echocardiographic evaluation revealed left ventricular diastolic dysfunction by 2 mo and O-GlcNAcylation of several cardiac proteins and of nuclear transcription factor Sp1. By 4 mo, systolic dysfunction was observed and sarcoplasmic reticulum Ca2+ ATPase expression decreased by 50%. Fibrosis was not observed at any timepoint in DM2 mice. Levels of the rate-limiting enzyme of the hexosamine biosynthetic pathway, glutamine:fructose-6-phosphate amidotransferase (GFAT) were increased as early as 2 mo. Fatty acids, which are...

American Journal of Physiology-Cell Physiology, 2014

Excess enzyme-mediated protein O-GlcNAcylation is known to occur with diabetes mellitus. A charac... more Excess enzyme-mediated protein O-GlcNAcylation is known to occur with diabetes mellitus. A characteristic of diabetic cardiomyopathy is the development of myocardial fibrosis. The role that enhanced protein O-GlcNAcylation plays in modulating the phenotype of cardiac fibroblasts (CF) is unknown. To address this issue, rat CF were cultured in normal glucose (NG; 5 mM glucose) or high-glucose (HG; 25 mM) media for 48 h. Results demonstrate that CF cultured in HG have higher levels (∼50%) of overall protein O-GlcNAcylation vs. NG cells. Key regulators of collagen synthesis such as transforming-growth factor-β1 (TGF-β1), SMADs 2/3, and SMAD 7 protein levels, including those of arginase I and II, were altered, leading to increases in collagen levels. The nuclear transcription factor Sp1 and arginase II evidence excess O-GlcNAcylation in HG cells. Expression in CF of an adenovirus coding for the enzyme N-acetylglucosaminidase, which removes O-GlcNAc moieties from proteins, decreased Sp1 a...

American Journal of Physiology-Cell Physiology, 2010

There must be something unique about a class of drugs (discovered and developed in the mid-1940s)... more There must be something unique about a class of drugs (discovered and developed in the mid-1940s) where there are more than 130 ongoing clinical trials currently listed. Tetracyclines were developed as a result of the screening of soil samples for antibiotic organisms. The first of these compounds chlortetracycline was introduced in 1948. Soon after their development tetracyclines were found to be highly effective against various pathogens including rickettsiae, Gram-positive, and Gram-negative bacteria, thus, becoming a class of broad-spectrum antibiotics. The mechanism of action of tetracyclines is thought to be related to the inhibition of protein synthesis by binding to the 30S bacterial ribosome. Tetracyclines are also an effective anti-malarial drug. Over time, many other “protective” actions have been described for tetracyclines. Minocycline, which can readily cross cell membranes, is known to be a potent anti-apoptotic agent. Its mechanism of action appears to relate to spec...

American Journal of Physiology-Cell Physiology, 2008

Mitochondrial transcription factor A (TFAM) is essential for mitochondrial DNA transcription and ... more Mitochondrial transcription factor A (TFAM) is essential for mitochondrial DNA transcription and replication. TFAM transcriptional activity is decreased in diabetic cardiomyopathy; however, the functional implications are unknown. We hypothesized that a reduced TFAM activity may be responsible for some of the alterations caused by hyperglycemia. Therefore, we investigated the effect of TFAM overexpression on hyperglycemia-induced cytosolic calcium handling and mitochondrial abnormalities. Neonatal rat cardiomyocytes were exposed to high glucose (30 mM) for 48 h, and we examined whether TFAM overexpression, by protecting mitochondrial DNA, could reestablish calcium fluxes and mitochondrial alterations toward normal. Our results shown that TFAM overexpression increased to more than twofold mitochondria copy number in cells treated either with normal (5.5 mM) or high glucose. ATP content was reduced by 30% and mitochondrial calcium decreased by 40% after high glucose. TFAM overexpressi...

American Journal of Physiology-Cell Physiology, 2012

Sorcin localizes in cellular membranes and has been demonstrated to modulate cytosolic Ca2+ handl... more Sorcin localizes in cellular membranes and has been demonstrated to modulate cytosolic Ca2+ handling in cardiac myocytes. Sorcin also localizes in mitochondria; however, the effect of sorcin on mitochondrial Ca2+ handling is unknown. Using mitochondrial pericam, we measured mitochondrial Ca2+ concentration and fluxes in intact neonatal cardiac myocytes overexpressing sorcin. Our results showed that sorcin increases basal and caffeine-stimulated mitochondrial Ca2+ concentration. This effect was associated with faster Ca2+ uptake and release. The effect of sorcin was specific for mitochondria, since similar results were obtained with digitonin-permeabilized cells, where cytosolic Ca2+ flux was disrupted. Furthermore, mitochondria of cardiac myocytes in which sorcin was overexpressed were more Ca2+-tolerant. Experiments analyzing apoptotic signaling demonstrated that sorcin prevented 2-deoxyglucose-induced cytochrome c release. Furthermore, sorcin prevented hyperglycemia-induced cytoch...

Journal of the American College of Cardiology, 2008

The ability of minocycline to be transported into cardiac cells, concentrate in normal and ischem... more The ability of minocycline to be transported into cardiac cells, concentrate in normal and ischemic myocardium, and act as a cardioprotector in vivo was examined. We also determined minocycline's capacity to act as a reducer of myocardial oxidative stress and matrix metalloproteinase (MMP) activity. Background: The identification of compounds with the potential to reduce myocardial ischemic injury is of great interest. Tetracyclines are antibiotics with pleiotropic cytoprotective properties that accumulate in normal and diseased tissues. Minocycline is highly lipophilic and has shown promise as a possible cardioprotector. However, minocycline's potential as an in vivo cardioprotector as well as the means by which this action is attained are not well understood. Methods: Rats were subjected to 45 min of ischemia and 48 h of reperfusion. Animals were treated 48 h before and 48 h after thoracotomy with either vehicle or 50 mg/kg/day minocycline. Tissue samples were used for biochemical assays and cultured cardiac cells for minocycline uptake experiments. Results: Minocycline significantly reduced infarct size (ϳ33%), tissue MMP-9 activity, and oxidative stress. Minocycline was concentrated ϳ24-fold in normal (0.5 mmol/l) and ϳ50-fold in ischemic regions (1.1 mmol/l) versus blood. Neonatal rat cardiac fibroblasts, myocytes, and adult fibroblasts demonstrated a time-and temperaturedependent uptake of minocycline to levels that approximate those of normal myocardium. Conclusions: Given the high intracellular levels observed and results from the assessment of in vitro antioxidant and MMP inhibitor capacities, it is likely that minocycline acts to limit myocardial ischemic injury via mass action effects.

International Journal of Pharmaceutical Investigation

The L-ascorbate (AA), L-ascorbyl dibutyrate (AADB), L-ascorbyl dipalmitate (AADP), L-ascorbyl pal... more The L-ascorbate (AA), L-ascorbyl dibutyrate (AADB), L-ascorbyl dipalmitate (AADP), L-ascorbyl palmitate (AAP), and L-ascorbyl stearate (AS) are shown in Figure 1 and were obtained from TCI and Alfa Aesar. Enzymes and materials given below were from Sigma (catalog numbers) unless stated otherwise. Methods Unless otherwise stated, all enzymes come from rabbit and all experimental temperatures were 25°C, pH 8.0. Compared to the main enzyme activity, it was determined that enzyme enolase (E0379) contained activities ≥ 0.05% by LDH or by PFK-1; LDH contained ≥ 0.01% enolase activity; and aldolase (A8811) contained ≥ 0.05% PFK-1. AA-fatty acid derivatives were dissolved in ethanol or dimethyl sulfoxide (DMSO, D8418). It can be shown that neither 15% ethanol nor 15% DMSO inhibited any enzymes used in these studies, more than the upper limit of the solvents used. Minimum six experiemnts were performed. Less than ± 10% standard deviation from the mean (SEM) than Data were acceptable. ± 10% error bars represent the SEM.

International Journal of Pharmaceutical Investigation

Journal of Pharmaceutical Research International

Background: Pharmacy students in Mexico are exposed to United States’ pharmacy community services... more Background: Pharmacy students in Mexico are exposed to United States’ pharmacy community services in hopes to adopt the services for their own pharmacy program. Objectives: This study aims to assess the effectiveness of a strictly online-based teaching method to improve student knowledge on the role of pharmacists and the pharmacy curriculum in Mexico and the United States. Methods: This was a prospective study of pharmacy students attending the University of California, San Diego Skaggs School of Pharmacy and Pharmaceutical Sciences (UCSD SSPPS) and Facultad de Quimic-Pharmaco-Biologia de la Universidad Michoacana San Nicolas de Hidalgo (UMSNH) during the 2015-2016 academic year who enrolled in the E-Learning Collaborative and Educational Experience Independent Study. Results: The e-learning course had 25 students total from both the United States and Mexico enrolled. Out of the 25 students, 4 students from the United States and 11 students from Mexico agreed to participate in the ...

Medical Education, 2022

At our university hospital, we recently developed and implemented a multidisciplinary curriculum ... more At our university hospital, we recently developed and implemented a multidisciplinary curriculum that integrates ultrasound as a compulsory part into medical education directly from start to finish. The curriculum follows a spiral course with four levels of training in which learning activities are repeated with continuously growing complexity. Competency-centred “probe-in-the-hand” courses are held in small groups of maximum six learners. Students start to practice ultrasonography by scanning each other, attending training in skills labs and, finally, deepen experience in clinical settings. Students should prepare self-determinedly for courses using learning videos available on the university's in-house network and on publicly available e-learning platforms. On the first training level, during preclinical education, ultrasonography is closely linked to anatomy dissectionand physiology courses. With this vertical integration, basic sciences are put into context and vice versa, clinical aspects are introduced into early medical training. At the same time, specific psychomotor skills are introduced. On the second level, in the third year of medical education, students apply point-of-care ultrasound in peers, skills lab simulations and ultrasound phantoms. The skills lab will be available during semester breaks to provide the opportunity to practice outside scheduled courses. On the third level, during advanced clinical education, students select a compulsory elective ultrasound course in a specialty of their choice, held at five consecutive dates following the concept of work-based learning. This allows students to direct their own learning and to focus on their preferred specialty. From then on, they conduct ultrasound examinations in patients. During the final year, students successively adapt skills and knowledge to growing medical experience. Now they are expected to use ultrasound with a large degree of independence and confidence. Entrustable professional activities are specified and assessed concomitantly.

The FASEB Journal, 2014

Protein O-GlcNAcylation has been shown to play a major role in the development of type 2 diabetes... more Protein O-GlcNAcylation has been shown to play a major role in the development of type 2 diabetes and diabetic complications. This study is investigating differences of gene expression of proteins ...

American journal of pharmaceutical education, Jan 25, 2017

Objective. To implement and evaluate the effectiveness of an interactive health literacy program ... more Objective. To implement and evaluate the effectiveness of an interactive health literacy program by measuring pharmacy students' knowledge and confidence. Design. A health literacy module consisting of a lecture and workshop was incorporated into a self-care course for first-year pharmacy students. Active-learning activities included practicing health literacy tools, discussing faculty-created video vignettes, and improving readability of patient education monographs. A non-validated survey assessed knowledge and confidence before and after training. Assessment. Fifty-three students (88%) completed a pre-training survey, and 60 (100%) completed a post-training survey. Students' confidence improved in six of seven areas (p<.001). Students' knowledge significantly improved in three of 14 areas (p<.01) pertaining to the average American reading level, high-risk age groups, and correlation of late prescription refills to low health literacy. Although knowledge increase...

Journal of Biological Chemistry, 2008

Increased nuclear protein O-linked ␤-N-acetylglucosamine glycosylation (O-GlcNAcylation) mediated... more Increased nuclear protein O-linked ␤-N-acetylglucosamine glycosylation (O-GlcNAcylation) mediated by high glucose treatment or the hyperglycemia of diabetes mellitus contributes to cardiac myocyte dysfunction. However, whether mitochondrial proteins in cardiac myocytes are also submitted to O-Glc-NAcylation or excessive O-GlcNAcylation alters mitochondrial function is unknown. In this study, we determined if mitochondrial proteins are O-GlcNAcylated and explored if increased O-GlcNAcylation is linked to high glucose-induced mitochondrial dysfunction in neonatal rat cardiomyocytes. By immunoprecipitation, we found that several mitochondrial proteins, which are members of complexes of the respiratory chain, like subunit NDUFA9 of complex I, subunits core 1 and core 2 of complex III, and the mitochondrial DNA-encoded subunit I of complex IV (COX I) are O-GlcNAcylated. By mass spectrometry, we identified that serine 156 on NDUFA9 is O-GlcNAcylated. High glucose treatment (30 mM glucose) increases mitochondrial protein O-GlcNAcylation, including those of COX I and NDUFA9 which are reduced by expression of O-GlcNAcase (GCA). Increased mitochondrial O-GlcNAcylation is associated with impaired activity of complex I, III, and IV in addition to lower mitochondrial calcium and cellular ATP content. When the excessive O-GlcNAc modification is reduced by GCA expression, mitochondrial function improves; the activity of complex I, III, and IV increases to normal and mitochondrial calcium and cellular ATP content are returned to control levels. From these results we conclude that specific mitochondrial proteins of cardiac myocytes are O-GlcNAcylated and that exposure to high glucose increases mitochondrial protein O-GlcNAcylation, which in turn contributes to impaired mitochondrial function.

American Journal of Physiology-Regulatory, Integrative and Comparative Physiology, 2012

We examined the role that enzymatic protein O-GlcNAcylation plays in the development of diabetic ... more We examined the role that enzymatic protein O-GlcNAcylation plays in the development of diabetic cardiomyopathy in a mouse model of Type 2 diabetes mellitus (DM2). Mice injected with low-dose streptozotocin and fed a high-fat diet developed mild hyperglycemia and obesity consistent with DM2. Studies were performed from 1 to 6 mo after initiating the DM2 protocol. After 1 mo, DM2 mice showed increased body weight, impaired fasting blood glucose, and hyperinsulinemia. Echocardiographic evaluation revealed left ventricular diastolic dysfunction by 2 mo and O-GlcNAcylation of several cardiac proteins and of nuclear transcription factor Sp1. By 4 mo, systolic dysfunction was observed and sarcoplasmic reticulum Ca2+ ATPase expression decreased by 50%. Fibrosis was not observed at any timepoint in DM2 mice. Levels of the rate-limiting enzyme of the hexosamine biosynthetic pathway, glutamine:fructose-6-phosphate amidotransferase (GFAT) were increased as early as 2 mo. Fatty acids, which are...

American Journal of Physiology-Cell Physiology, 2014

Excess enzyme-mediated protein O-GlcNAcylation is known to occur with diabetes mellitus. A charac... more Excess enzyme-mediated protein O-GlcNAcylation is known to occur with diabetes mellitus. A characteristic of diabetic cardiomyopathy is the development of myocardial fibrosis. The role that enhanced protein O-GlcNAcylation plays in modulating the phenotype of cardiac fibroblasts (CF) is unknown. To address this issue, rat CF were cultured in normal glucose (NG; 5 mM glucose) or high-glucose (HG; 25 mM) media for 48 h. Results demonstrate that CF cultured in HG have higher levels (∼50%) of overall protein O-GlcNAcylation vs. NG cells. Key regulators of collagen synthesis such as transforming-growth factor-β1 (TGF-β1), SMADs 2/3, and SMAD 7 protein levels, including those of arginase I and II, were altered, leading to increases in collagen levels. The nuclear transcription factor Sp1 and arginase II evidence excess O-GlcNAcylation in HG cells. Expression in CF of an adenovirus coding for the enzyme N-acetylglucosaminidase, which removes O-GlcNAc moieties from proteins, decreased Sp1 a...

American Journal of Physiology-Cell Physiology, 2010

There must be something unique about a class of drugs (discovered and developed in the mid-1940s)... more There must be something unique about a class of drugs (discovered and developed in the mid-1940s) where there are more than 130 ongoing clinical trials currently listed. Tetracyclines were developed as a result of the screening of soil samples for antibiotic organisms. The first of these compounds chlortetracycline was introduced in 1948. Soon after their development tetracyclines were found to be highly effective against various pathogens including rickettsiae, Gram-positive, and Gram-negative bacteria, thus, becoming a class of broad-spectrum antibiotics. The mechanism of action of tetracyclines is thought to be related to the inhibition of protein synthesis by binding to the 30S bacterial ribosome. Tetracyclines are also an effective anti-malarial drug. Over time, many other “protective” actions have been described for tetracyclines. Minocycline, which can readily cross cell membranes, is known to be a potent anti-apoptotic agent. Its mechanism of action appears to relate to spec...

American Journal of Physiology-Cell Physiology, 2008

Mitochondrial transcription factor A (TFAM) is essential for mitochondrial DNA transcription and ... more Mitochondrial transcription factor A (TFAM) is essential for mitochondrial DNA transcription and replication. TFAM transcriptional activity is decreased in diabetic cardiomyopathy; however, the functional implications are unknown. We hypothesized that a reduced TFAM activity may be responsible for some of the alterations caused by hyperglycemia. Therefore, we investigated the effect of TFAM overexpression on hyperglycemia-induced cytosolic calcium handling and mitochondrial abnormalities. Neonatal rat cardiomyocytes were exposed to high glucose (30 mM) for 48 h, and we examined whether TFAM overexpression, by protecting mitochondrial DNA, could reestablish calcium fluxes and mitochondrial alterations toward normal. Our results shown that TFAM overexpression increased to more than twofold mitochondria copy number in cells treated either with normal (5.5 mM) or high glucose. ATP content was reduced by 30% and mitochondrial calcium decreased by 40% after high glucose. TFAM overexpressi...

American Journal of Physiology-Cell Physiology, 2012

Sorcin localizes in cellular membranes and has been demonstrated to modulate cytosolic Ca2+ handl... more Sorcin localizes in cellular membranes and has been demonstrated to modulate cytosolic Ca2+ handling in cardiac myocytes. Sorcin also localizes in mitochondria; however, the effect of sorcin on mitochondrial Ca2+ handling is unknown. Using mitochondrial pericam, we measured mitochondrial Ca2+ concentration and fluxes in intact neonatal cardiac myocytes overexpressing sorcin. Our results showed that sorcin increases basal and caffeine-stimulated mitochondrial Ca2+ concentration. This effect was associated with faster Ca2+ uptake and release. The effect of sorcin was specific for mitochondria, since similar results were obtained with digitonin-permeabilized cells, where cytosolic Ca2+ flux was disrupted. Furthermore, mitochondria of cardiac myocytes in which sorcin was overexpressed were more Ca2+-tolerant. Experiments analyzing apoptotic signaling demonstrated that sorcin prevented 2-deoxyglucose-induced cytochrome c release. Furthermore, sorcin prevented hyperglycemia-induced cytoch...

Journal of the American College of Cardiology, 2008

The ability of minocycline to be transported into cardiac cells, concentrate in normal and ischem... more The ability of minocycline to be transported into cardiac cells, concentrate in normal and ischemic myocardium, and act as a cardioprotector in vivo was examined. We also determined minocycline's capacity to act as a reducer of myocardial oxidative stress and matrix metalloproteinase (MMP) activity. Background: The identification of compounds with the potential to reduce myocardial ischemic injury is of great interest. Tetracyclines are antibiotics with pleiotropic cytoprotective properties that accumulate in normal and diseased tissues. Minocycline is highly lipophilic and has shown promise as a possible cardioprotector. However, minocycline's potential as an in vivo cardioprotector as well as the means by which this action is attained are not well understood. Methods: Rats were subjected to 45 min of ischemia and 48 h of reperfusion. Animals were treated 48 h before and 48 h after thoracotomy with either vehicle or 50 mg/kg/day minocycline. Tissue samples were used for biochemical assays and cultured cardiac cells for minocycline uptake experiments. Results: Minocycline significantly reduced infarct size (ϳ33%), tissue MMP-9 activity, and oxidative stress. Minocycline was concentrated ϳ24-fold in normal (0.5 mmol/l) and ϳ50-fold in ischemic regions (1.1 mmol/l) versus blood. Neonatal rat cardiac fibroblasts, myocytes, and adult fibroblasts demonstrated a time-and temperaturedependent uptake of minocycline to levels that approximate those of normal myocardium. Conclusions: Given the high intracellular levels observed and results from the assessment of in vitro antioxidant and MMP inhibitor capacities, it is likely that minocycline acts to limit myocardial ischemic injury via mass action effects.