bluuebunny/crossref_metadata_2025 huggingface dataset:
Korean probiotic kimchi prevented Helicobacter pylori‐associated gastric cancer in mice and human
Authors: Han Young‐Min , Park Jong‐Min , Lee Dongyun , Oh Ji Young , Hahm Ki Baik
Published: November 2023

As dietary, non‐microbial intervention whether Korean probiotic kimchi can prevent Helicobacter pylori‐induced atrophic gastritis as well as gastric cancer, we have tried either in vitro/in vivo experimental model of chronic H. pylori‐initiated, high salt diet‐promoted, gastric tumorigenesis in mice model and clinical trial to explore the real impact of kimchi administration on to the changes of fecal microbiota. H. pylori‐infected C57BL/6 mice were administered with cancer preventive kimchi (cpKimchi) mixed in drinking water up to 36 weeks and cancer preventive actions of anti‐inflammation and anti‐mutagenesis were compared between standard recipe kimchi (sKimchi) and special recipe cpKimchi. As results, the erythematous and nodular changes, mucosal ulcerative and erosive lesions in the stomach were noted at 24th weeks, but cpKimchi administration significantly ameliorated these gastric pathologies and after 36th weeks, scattered nodular masses, some ulcers, and thin nodular gastric mucosa were noted in H. pylori‐infected mice, whereas these gross lesions were significantly attenuated in cpKimchi group. Significant expressions of COX‐2 and IL‐6, activated NF‐κB and STAT3, increased apoptosis, and marked oxidative stresses were noted in H. pylori‐infected group relevant to tumorigenesis, but these were all significantly attenuated in cpKimchi group. cpKimchi administration afforded significant changes in fecal microbiota, implicated in cancer preventive actions. In conclusion, daily dietary intake of cpKimchi can be an effective way either to rejuvenate H. pylori‐atrophic gastritis or to prevent tumorigenesis supported with the concerted actions of anti‐oxidative, anti‐inflammatory, and anti‐mutagenic mechanisms.
Vitamin D and Its Therapeutic Targets in Gastric Cancer
Authors: Cho Chi Hin , Li Ming Xing , Hu Wei
Published: November 2023

Backgrounds and objectives

Vitamin D3 has been widely used for bone health in humans. Epidemiological studies indicated that vitamin D3 deficiency was correlated with cancer risk. Previous studies also demonstrated that vitamin D3 could potentiate the antitumor effect in a variety of cancer types. Our research focuses on studying the therapeutic effects of vitamin D3 in gastric cancer and its relationship with cathelicidin, an inducible host defense and antimicrobial and anticancer peptide by the vitamin both in vitro and in vivo.

Methods

MTT assay was used to detect the gastric cancer cell viability. Flow cytometry was used to detect the cell cycle distribution of gastric cancer cell. An animal model of orthotopic gastric cancer was established in nude mice to evaluate the anticancer actions of vitamin D3 for in vivo study.

Results

1α,25(OH)2 vitamin D3 (1α,25(OH)2D3), the active form of vitamin D3, could significantly inhibit the proliferation and induce cell cycle arrest through stimulating the expression of p21 in gastric cancer cells (TMK1) but not in the normal gastric epithelial cells (HFE145). CDK2 and cyclin E expressions were decreased by 1α,25(OH)2D3 in TMK1 cells. This vitamin analogue also successfully induced the expression of cathelicidin (LL37) and provoked autophagy in these cancer cells. Knockdown of VDR by siRNA abolished the anti‐proliferative effect of 1α,25(OH)2D3. Decrease the expression of LL37 by siRNA abolished the autophagic effect of 1α,25(OH)2D3 but not the anti‐proliferative effect on cells. These findings indicate that the antitumor effect of vitamin D3 in TMK1 cells is independent of LL37 and autophagy. We also found that daily oral administration with vitamin D3 significantly inhibited tumor growth in mouse stomachs. Such treatment also increased VDR and p21 expressions and induced LCB3 II level in the gastric tumor tissues.

Conclusion

Our results suggest that vitamin D3 inhibits gastric cancer in a VDR‐dependent manner followed by the increased expression of p21 in gastric cancer cells. As this vitamin is currently used as a dietary supplement mainly for bone diseases in humans, it could also function as a novel therapeutic agent or prophylactic treatment for gastric cancer in the future.

Support or Funding Information

This study was partly supported by the General Research Fund from the Hong Kong Research Grant Council (CUHK 463613) and the Health and Medical Research Fund from the Food and Health Bureau (13120062) in Hong Kong and the National Natural Science Foundation of China (No. 81473269).
Rbfox1 Regulates Calcium Signaling to Prevent Pressure Overload Induced Cardiac Dysfunction
Authors: Umar Sadiq , Zhu Wuqiang , Bender Ingrid , Van Berlo Jop
Published: November 2023

RNA splicing and processing provide important means of genetic control to diversify gene function, and fine‐tune protein production. RNA regulation is a critical step in the expression of most genes, and its misregulation often results in human disease. Rbfox1 is a RNA binding protein that regulates alternative splicing and RNA stability, and plays an important role in regulating alternative splicing (AS) in neurons, skeletal muscle, and the heart. Recently, Rbfox1 was identified as a critical regulator of Mef2 splicing to protect the heart from failure. However, its role in protecting the heart from failing is likely not limited to Mef2 splicing. To begin to study the role of Rbfox1 in heart failure, we generated cardiomyocyte specific Rbfox1 gene‐deletion mice (cRbfox1−/−). Cardiomyocyte specific deletion of Rbfox1 was confirmed by Western blotting and immunohistochemistry. cRbfox1−/− mice showed mild hypertrophy and depressed cardiac function under homeostatic conditions, which did not deteriorate with age. Pressure overload by trans‐aortic constriction (TAC) caused exaggerated cardiac hypertrophy and accelerated heart failure in cRbfox1−/− compared to wildtype mice. Since Rbfox1 is a known RNA binding protein, we performed RNA sequencing and found significant changes in calcium regulated genes. We measured calcium dynamics and noted a significantly delayed Calcium reuptake into the Sarcoplasmic Reticulum, which is likely caused by decreased SERCA2a expression on Western blot. In conclusion, Rbfox1 is important to maintain cardiac function by regulating calcium signaling. We are currently unraveling the mechanisms via which Rbfox1 regulates Serca2a function.

Support or Funding Information

Acknowledgement: This work was supported by National Institutes of Health grants and Lillehei Scholar Award (to JVB).
Kolaviron quenches ischaemic‐reperfusion injury (IRI) in isolated rat heart via activation of Akt/PKB and suppression of p38MAPK/PARP/Caspase 3 signalling pathways
Authors: Oyagbemi Ademola Adetokunbo , Bester Dirk , Esterhuyse Johan , Farombi Olatunde
Published: November 2023

The study was designed to investigate the ameliorative effect of Kolaviron (KV) on ischaemic‐reperfusion injury in experimental rat models. Twenty male Wistar rats were randomly divided into 2 groups: Group one received corn oil as a vehicle and rats in group two were orally administered KV at 200 mg/kg for four weeks. After four weeks of KV pre‐treatment, hearts were excised and mounted on the Working heart perfusion system. Western blot analysis was carried out on frozen heart samples. From this study, there was a significant (p<0.05) reduction in the activity of catalase, superoxide dismutase and glutathione peroxidase with concomitant reduction in oxygen radical absorbance capacity (ORAC) in ischaemic rat heart of animals that received corn oil without KV pre‐treatment. Similarly, pre‐treatment of rats with KV led to a significant (p<0.05) decline in intracellular reactive oxygen species (ROS) and malondialdehyde. Western blots analyses revealed that KV significantly increased the expressions of total Akt/PKB, phosphorylated Akt/PKB at serine 473 and also caused a significant reduction in p38 MAPK, Caspase 3, and cleaved PARP. Combining all, we propose that KV offered notable cardioprotection via quenching of ROS and up‐regulation of pro‐survival sinalling pathways. KV may therefore offer a novel therepeutic window for cardiovascular and other heart related conditions.
β‐Arrestin‐Biased β2‐Adrenergic Receptor Signaling Provides Cardioprotection in Ischemia/Reperfusion Injury
Authors: Grisanti Laurel A , de Lucia Claudio , Gao Erhe A , Koch Walter J , Benovic Jeffrey L , Tilley Douglas G
Published: November 2023

β‐Adrenergic receptors (βAR) are important regulators of cardiac function in the normal and failing heart. Activation of the β1AR subtype increases contractility and cardiomyocyte death whereas the β2AR can promote survival. In response to cardiac injury, increased catecholamines activate and downregulate β1AR thus, β‐adrenergic receptor antagonists or β‐blockers are commonly prescribed in to restore β1AR expression and preserve contractility. However, promoting the pro‐survival effects of β2AR, which are known to occur in part through β‐arrestin (ARR)‐dependent signaling, may be a beneficial therapeutic strategy. Pepducins have been developed based on the intracellular loop (ICL) domains of β2AR to activate either Gαs‐ or βARR‐dependent β2AR signaling pathways. We hypothesized that pepducin‐mediated engagement of βARR‐dependent β2AR signaling in the heart would be therapeutically advantageous following ischemia/reperfusion (I/R) injury. To test this, wild‐type (WT) C57BL/6 mice received three intracardiac injections of either a βARR‐biased pepducin (ICL1‐9) or a scrambled control pepducin at the time of ischemia (30 min) followed by reperfusion. Assessment of cardiomyocyte death 24h post‐I/R using TUNEL staining showed a decrease in cell death in animals treated with ICL1‐9 when compared to scrambled pepducin, correlating with decreased infarct size and improved cardiac function as measured by echocardiography. Assessment of cardiac function at later time points showed that the cardioprotective effects of ICL1‐9 were preserved over time and resulted in decreased cardiac remodeling. Although βARR1KO mice displayed similar cell death, infarct size, and contractility changes following I/R as their WT counterparts, they did not manifest a cardioprotective response from ICL1‐9 treatment, indicating that βARR signaling is essential in relaying ICL1‐9‐dependent cardioprotection. These results demonstrate that pharmacologically‐mediated activation of βARR‐biased β2AR signaling provides a therapeutic benefit in the context of I/R‐induced injury and may provide an improved strategy for the treatment of acute cardiac injury.

Support or Funding Information

NIH‐HL‐105414‐DGT
adrenergic Receptor‐Stimulated Cardiac Myocyte Apoptosis: Role of Cytochrome P450 ω‐Hydroxylase Cytochrome P450 ω‐Hydroxylase
Authors: Guo Lirong , Zhong Tiecheng , O'Rourke Stephen T. , Sun Chengwen
Published: November 2023

Prolonged or excessive β‐adrenergic activation leads to cardiomyocyte loss and heart dysfunction. However, the underlying cellular mechanisms are still unclear. Therefore, we first confirmed the effect of isoproterenol (ISO), a β‐adrenergic receptor agonist, on cardiac toxicity using TUNEL and Caspase activity assays in cultured rat cardiomyocytes. ISO treatment significantly increased cardiomyocyte apoptosis. Persistent ISO stimulation of cardiomyocytes also increased the expression of CYP4A3, a major CYP450 ω‐hydroxylase that produces 20‐Hydroxyeicosatetraenoic acid (20‐HETE), in a time‐dependent manner. Next, we examined the effect of ISO and 20‐HETE on cardiomyocyte apoptosis using annexin V and propidium iodide staining. Treatment with either 20‐HETE or ISO significantly increased cardiomyocyte apoptosis, and inhibition of 20‐HETE production using 17‐ODYA, a CYP450 ω‐hydroxylase inhibitor, dramatically attenuated ISO‐induced cardiomyocyte apoptosis. To determine the apoptotic pathway involved, the mitochondrial membrane potential (ΔΨm) was measured by detecting the ratio of JC‐1 green/red emission intensity. The results demonstrated that 17‐ODYA significantly abolished ISO‐induced disruption in ΔΨm and that 20‐HETE alone induced a marked disruptive effect on ΔΨm in cardiomyocytes. 20‐HETE‐induced ΔΨm disruption and apoptosis were attenuated by KN93, a CaMKII blocker, suggesting that this action of 20‐HETE is mediated by a CaMKII‐dependent mechanism. Taken together, these results demonstrate that 20‐HETE treatment induces significant apoptosis via mitochondrial‐dependent pathways, and that inhibition of 20‐HETE production using 17‐ODYA attenuates ISO‐induced cardiomyocyte apoptosis. Thus, CYP450 ω‐hydroxylase could be a novel target to protect against cardiac damage induced by excessive β‐adrenergic activation or hypersympathoexcitability.

Support or Funding Information

This work was supported by Grants from the National Institute of Neurological Disorders and Stroke, National Institutes of Health (NIH, NS55008), American Heart Association (10GRNT3170012), Norman Bethune Program of Jilin University (2015221), and Education Department of Jilin Province (2015498).
Activation of GPER (G protein‐coupled estrogen receptor) increases Gs activity via forming a plasma membrane complex with AKAP/SAP97
Authors: Yu Xuan , Stallone John N. , Heaps Cristine L. , Han Guichun
Published: November 2023

Evidence suggest that G protein‐coupled estrogen receptor (GPER) is emerging as a therapeutic target in cardiovascular diseases. Activation of GPER elicits many cardiovascular protective effects, including lowering blood pressure, reducing ischemia/reperfusion‐induced cardiac infarct size and decreasing the process of atherosclerosis in animal models. However, the understanding of the mechanisms underlying GPER‐mediated actions is still limited. The objective of this study is to test the hypothesis that activation of GPER by selective agonist G‐1 increases Gs activation by forming a plasma membrane complex with AKAP/SAP97. Isometric tension studies, Gs activity assays, immunoprecipitation studies and Western blots were performed by using porcine coronary arteries, primary cultured porcine coronary artery smooth muscle cells (PCASMCs) and HA‐tagged GPER gene stably transfected HEK293 cells (GPER‐HEK293). First, we measured the Gs activity in both GPER‐HEK293 cells and PCASMCs with selective GPER agonist G‐1 (1 μM); and observed that treatment with G‐1 significantly elevated the Gs‐GTP level. Next, we explored the association of GPER with Gs in immunoprecipitation studies of both GPER‐HEK293 cells and PCASMCs. Similar to Gs activity assays, activation of GPER with G‐1 promoted the association of activated GPER with Gs, and it was in a concentration dependent manner in PCASMCs. We further observed effects of GPER activation on cAMP production in PCASMCs and demonstrated that G‐1 significantly stimulated cAMP production. Last, we investigated the interaction of both Protein Kinase A‐anchoring Protein (AKAP5) and membrane‐associated guanylate kinase SAP97 to GPER by applying FMP‐API‐1 (100 μM) in isometric tension studies to disrupt the interaction between AKAPs and PKA, and detecting AKAP and SAP97 in immunoprecipitation studies in PCASMCs. Pretreatment with FMP‐API‐1 attenuated G‐1‐induced relaxation (10 – 3,000 nM) of endothelium‐denuded coronary arteries preconstricted with PGF2α (1 μM). In immunoprecipitation studies, G‐1 clearly enhanced the interaction of both AKAP5 and SAP97 to GPER. Therefore, we conclude that activation of GPER with G‐1 stimulates the production of cAMP, which is due to GPER coupling to Gs via forming a plasma membrane signaling complex with AKAP/SAP97.

Support or Funding Information

AHA, Diversity of G Protein
Altered regulation of cardiac sympathetic nerve activity during hypertension
Authors: Ramchandra Rohit , McBryde Fiona , George Bindu , Paton Julian F , Mahesh Darvina
Published: November 2023

Hypertension remains one of the strongest predictors of premature death and an increase in sympathetic nerve activity has been implicated in the pathogenesis of hypertension. In this context, increased sympathetic drive to the heart promotes arrhythmias and sudden death in patients, but the level of cardiac sympathetic nerve activity (CSNA) in hypertension has been assessed only by indirect methods. We tested the hypothesis that directly recorded CSNA is increased in renovascular hypertension.

Renovascular hypertension was induced by surgical clipping of one renal artery. Following three weeks post‐clip, electrodes were surgically implanted into cardiac sympathetic nerve fascicles of adult sheep. Following recovery from surgery, resting levels of mean arterial pressure, heart rate and cardiac sympathetic nerve activity were recorded. In conscious sheep, the renal clipping procedure induced hypertension relative to sham operated controls (106 ± 4 vs. 86 ± 6 mmHg, p<0.05, n=6 per group). However, no significant change in heart rate was observed between the two groups. Direct cardiac sympathetic nerve activity recording in conscious sheep showed that burst frequency of cardiac sympathetic nerves was higher in renovascular hypertensive sheep compared to sham control ewes (39 ± 2.6 vs. 28 ± 1.8 bursts per minute, p < 0.05). In addition, our data suggest that baroreflex control of CSNA at lower pressures was impaired (upper plateau of 226 ± 23 vs 386 ± 64 % of control).

Our data includes the first ever recordings of cardiac sympathetic nerve activity in hypertension and suggest a potential role for CSNA in mediating the chronic elevation in arterial pressure in hypertensive animals.

Support or Funding Information

The University of Auckland Faculty Research Development Fund
A novel actor in mechanotransduction: transient receptor potential cation channel vanilloid (TRPV) 1 in ventilator‐induced lung injury (VILI)
Authors: Michalick Laura , Liedtke Wolfgang , Kuebler Wolfgang M.
Published: November 2023

Study objective

Mechanical ventilation can damage the lung by causing endothelial barrier failure, edema formation and lung injury. Yet, the exact mechanisms underlying the mechanotransduction at the microvascular barrier are still unclear. In previous work, we had identified a critical role of the endothelial Ca2+ channel transient receptor potential vanilloid 4 (TRPV4) in endothelial barrier failure subsequent to mechanical overventilation. Here, we assessed the relevance of TRPV1 as novel regulator in VILI in vivo, and probed for its contribution to TRPV4‐induced Ca2+ signalling in vivo, ex vivo and in vitro.

Methods

Wild type, TRPV4‐ or TRPV1‐deficient mice were ventilated for 2 h with low (7 mL/kg) and high (20 mL/kg) tidal volumes (LVT/HVT) in vivo. Endothelial [Ca2+]i in isolated‐perfused lungs, inflated with 5 or 15 cmH2O, and in human pulmonary microvascular endothelial cells (HPMVECs) was quantified by real‐time imaging with or without pharmacological inhibition of TRPV1 and TRPV4, or after activation of TRPV1 and/or TRPV4 by capsaicin and/or GSK1016790A, respectively.

Results

TRPV1 or TRPV4 deficiency or inhibition by either SB366791 or HC‐067047, respectively, attenuated VILI, and reduced the endothelial [Ca2+]i response to high pressure inflation ex vivo, with exception of SB366791 treatment, which only diminished the sustained [Ca2+]i response, but not the initial Ca2+ influx. In vitro Ca2+ measurements from HPMVECs showed a characteristic increase in endothelial [Ca2+]i that in response to selective TRPV4, yet activation of TRPV1 alone had no effect. Dual activation of both TRPV channels, however, amplified and prolong the TRPV4‐mediated Ca2+ influx into HPMVECs.

Conclusions

Here, we demonstrate a critical role of TRPV1 as amplifier of TRPV4‐mediated [Ca2+]i response and barrier failure for VILI in vivo, ex vivo and in vitro, and identify a novel signalling axis that may present putative pharmacological targets for the prevention or treatment of ventilator‐associated lung disease.
High‐Fat‐Diet Induced Non‐Alcoholic Fatty Liver Disease and Cardiac Physiology in Mice
Authors: McCarthy Alanna , Luckey Stephen
Published: November 2023

Non‐alcoholic fatty liver disease (NAFLD) is a serious consequence of high‐fat diet intake and currently affects approximately one third of the world's entire population. Recent evidence suggests that patients with NAFLD have a higher incidence of cardiovascular disease compared to the general population. However, little is known about the link between NAFLD and pathological cardiac remodeling leading to heart disease. Therefore, the objective of this study is to investigate the morphometric and molecular changes associated with the cardiac phenotype resulting from NAFLD induced by a high‐fat diet. In addition, since the Chromosome 18 Chromosome Substitution Strain (CSS‐18) mice have reduced liver disease on a high‐fat diet as compared to the C57BL6 mice, this study aims to determine if CSS‐18 mice are resistant to pathological cardiac remodeling in comparison to C57BL6 mice. Both CSS‐18 and C57BL6 male mice were divided into normal chow diet and high‐fat, low‐sucrose diet groups at 5 weeks of age and administered a diet for 14 days. Morphometric measurements determined that there were no statistically significant differences in heart sizes as measured by heart weight‐to‐tibia length ratio (HW/TL) in either the CSS‐18 and C57Bl6 mice. In order to investigate the molecular changes in the left ventricle following 14 days of diet administration, quantitative PCR was conducted to evaluate the relative gene expression of the sarcoplasmic reticulum Ca2+‐ATPase (SERCA) gene. Expression levels of SERCA were slightly increased by 16% in C57Bl6 mice on a high fat diet whereas SERCA gene expression was not altered in CSS‐18 mice. These investigations suggest although no changes at the morphometric level were determined following 14 days of diet administration, molecular changes at this time are observable. Moreover, these data suggest that there may be differences in gene expression between the CSS‐18 and C57Bl6 mouse strains following diet administration. We are currently conducting additional quantitative PCR analysis of other hypertrophic markers to better understand the molecular changes that may be occurring as a result of NAFLD induced by a high‐fat diet as well as any potential differences between the two mouse strains.

Support or Funding Information

Murdock Charitable Trust Start‐Up funding

Nadeau Lab at Pacific Northwest Diabetes Research Institute
CXCL4 Aggravates Cardiac Dilation and Mortality after Myocardial Infarction by Inducing Pro‐inflammatory M1 Macrophages and Inhibiting Macrophage Phagocytosis
Authors: Lindsey Merry L. , Jung Mira , Yabluchanskiy Andriy , Cannon‐Stewart Presley L. , Iyer Rugmani Padmanabhan , Flynn Elizabeth R. , DeLeon‐Pennell Kristine Y. , Ma Yonggang
Published: November 2023

CXCL4 (platelet factor 4) is a pro‐inflammatory chemokine whose deletion attenuates mesenteric ischemia/reperfusion injury in mice. We hypothesized that CXCL4 would exacerbate post‐myocardial infarction (MI) cardiac remodeling and dysfunction. Male C57BL/6J mice (3 to 6 month old) were subjected to permanent coronary artery ligation. CXCL4 gene expression in the infarct region significantly increased from day 3 to day 7 post‐MI, peaking at day 5 (all p<0.05 vs day 0). To investigate the impact of enhancing early CXCL4 levels on post‐MI cardiac remodeling, mice were treated with CXCL4 (25 μg/kg/day) or saline beginning at 24 h post‐MI through osmotic mini‐pump infusion. Saline treated mice showed 47% survival at day 7 post‐MI (7 out of 15), while CXCL4 treatment dramatically reduced survival to 10% (1 out of 10, p<0.05). Because most of the deaths occurred between days 5 to 7 post‐MI, we evaluated day 5 post‐MI. CXCL4 infusion resulted in a 64% increase in CXCL4 protein levels within the infarct region at day 5 post‐MI. Compared to the saline group, CXCL4 treated mice showed significantly higher end‐systolic and end‐diastolic volumes at day 5 post‐MI (both p<0.05), indicating that CXCL4 infusion exacerbated cardiac dilation. Macrophage infiltration into the infarct was similar in both groups at day 5 post‐MI. In vitro, CXCL4 (5 μg/mL, 4 hour stimulation) polarized peritoneal macrophages to a pro‐inflammatory M1 phenotype, evidenced by the upregulation of M1 markers (Ccl3, Ccl5, Il1β, Il6, and Tnfα, all p<0.05) without effect on M2 markers (Arg1, Cd163, Cd206, Tgfβ1, and Ym1). CXCL4 stimulated peritoneal macrophages showed reduced phagocytic potential, as evidenced by fewer uptake of fluorescent E. coli bioparticles compared to control (p<0.05). Impaired phagocytosis after CXCL4 treatment in vivo would inhibit removal of apoptotic cells and debris and impede cardiac wound healing and repair. In conclusion, CXCL4 infusion increased cardiac dilation and mortality post‐MI by inducing pro‐inflammatory M1 macrophages and inhibiting macrophage phagocytosis.

Support or Funding Information

This work was supported by the National Institutes of Health [HL075360, HL129823, and GM114833 to M.L.L., and P01HL051971 and P20GM104357]; the Biomedical Laboratory Research and Development Service of the Veterans Affairs Office of Research and Development Award [5I01BX000505 to M.L.L.]; and American Heart Association [15SDG22930009 to Y.M.].
Coronary Artery Disease Associated Correlation with Decreased Electron Transport Chain Complex Activity
Authors: Blaszak Scott , Ait‐Aissa Karima , Gutterman David D. , Beyer Andreas M.
Published: November 2023

Rational

Heart disease is the leading cause of death worldwide and abnormalities in mitochondrial function are increasingly recognized in association with cardiomyopathy, heart failure, and coronary artery disease (CAD). However, the direct contribution and mechanism of mitochondrial dysfunction on the development of CAD is not fully determined. It has been known for some time that the failing heart relies mostly on glycolysis for ATP production rather than mitochondrial oxidative phosphorylation. Metabolic defects associated with mitochondria are associated with poor cardiovascular outcomes. Currently, the mechanism and role of mitochondrial dysfunction with the development of CAD is not fully understood. We have previously found that mitochondrial DNA damage is significantly elevated in subjects with CAD. However, the functional consequences of these results have not been explored. We hypothesize that in the heart from subjects with CAD, mitochondrial respiration is decreased resulting in decreased mitochondrial ATP production due to defects in the electron transport chain (ETC).

Methods

Mitochondria from frozen tissue samples of discarded heart tissue from subjects with and without CAD were isolated. Electron transport chain complexes were separated via 5% acrylamide native‐PAGE and stained for specific complex activity (complex II, III, and IV) and total protein level; complex activity measured by substrate conversion was normalized to total protein levels.

Results

Our findings indicate a significant decrease in steady state ATP and NAD+ levels in CAD subjects compared to non‐CAD subjects (Figure 1 A and B). Detailed analysis of complex activity revealed decreased activity in subjects with CAD in complexes I, II, and III (Figure 2). Secondly, analysis of complex IV showed an increase in activity in CAD subjects (Figure 2).

Conclusions

Our results suggest a direct correlation between defects in the electron transport chain and coronary artery disease. However, the mechanism of mitochondria dysfunction leading to the development of CAD is currently not understood.

Funding Source: National Heart, Lung Blood Institute Training Grant T35 HL072483 (Harder)
Malignant hyperthermia‐associated mutation of RyR1 induces mitochondrial Ca2+ overload in the cardiomyocytes
Authors: O‐Uchi Jin , Mishra Jyotsna , Jhun Bong Sook , Sheu Shey‐Shing
Published: November 2023

Although human pedigrees carrying the ryanodine receptor type 1 (RyR1) mutations mainly show skeletal muscle disorders including malignant hyperthermia (MH), sudden cardiac death (SCD) in these MH families in the conscious condition without anesthesia are also frequently found in the clinical case studies. However, the molecular mechanism underlying cardiac phenotypes in human MH family is completely unknown. Our group previously reported that a low level of RyR1 is expressed in the mitochondria, but not in the sarcoplasmic reticulum (SR) in the rat and mouse hearts, which serves as an important mitochondrial Ca2+ influx pathway in addition to the mitochondrial Ca2+ uniporter in cardiomyocytes. We also showed, using knock‐in mice carrying a MH‐related RyR1 mutation Y522S (YS) that YS hearts exhibit disrupted mitochondrial morphology as well as compromised mitochondrial functions with a high cellular oxidative state. Moreover, ex‐vivo YS heart developed significantly higher number of multiple ventricular extrasystoles by β‐adrenergic stimulation compared those observed in the wild‐type (WT) hearts. Therefore, our main hypothesis is that YS‐RyR1s form “leaky channel” at mitochondria and induce mitochondrial Ca2+ overload, which alters the cellular Ca2+ handing in cardiomyocyte. Using isolated mitochondria loaded with Ca2+ or membrane‐potential sensitive dyes under the confocal microscope, we found that YS mitochondria have higher basal mitochondrial Ca2+ concentration, depolarized mitochondrial membrane potential. In addition, YS cardiomyocytes exhibit higher basal cytosolic Ca2+ concentration as well as slower cytosolic Ca2+ clearance compared to WT. Finally, pretreatment of RyR1 blocker dantrolene cancelled these changes in YS mitochondria and cardiomyocyes and normalized their Ca2+ handing profiles similar to those in WT. In summary, these results indicate that chronic mitochondrial Ca2+ overload via leaky mutant mRyR1 damages cardiac mitochondrial functions/structures, which may alter cytosolic Ca2+ handling, induce cellular oxidation, and increase the arrhythmogenic events in MH.

Support or Funding Information

16SDG27260248 AHA Scientist Development Grant
Normal Myogenic Programming of Skeletal Muscle Satellite Cells from Spinal Cord Injured Subjects
Authors: Savikj Mladen , Kostovski Emil , Ruby Maxwell Alexander , Iversen Per Ole , Zierath Juleen , Krook Anna , Widegren Ulrika
Published: November 2023

Spinal cord injury (SCI) leads to changes in the skeletal muscle below the level of injury, e.g. atrophy and fiber composition change, followed by metabolic changes at both local and systemic level. Satellite cells grown in vitro have been shown to reflect the changes in the skeletal muscle in response to type 2 diabetes, obesity, exercise and neurological diseases. In this study, we have assessed the myogenic programming in satellite cells from skeletal muscle after SCI. We hypothesized that the injury would affect the ability to produce a normal muscle phenotype. Satellite cells were isolated from vastus lateralis biopsies of six able bodied (AB) and eight individuals with a longstanding (>1year) SCI. Primary skeletal muscle cultures were grown and differentiated into myotubes. The expression of myogenic regulatory factors (MRFs) was determined by quantitative PCR. The amount of skeletal muscle specific structural proteins, as well as regulators of protein synthesis, protein degradation and fatty acid oxidation, were determined by Western blot. Immunohistochemistry was performed for structural and proliferation markers. The capacity for protein synthesis and fatty acid oxidation was determined by radioactive tracer‐based metabolic assays. Fluorescent microscopy has shown that both AB and SCI groups were able to form multinucleated myotubes with an abundance of Desmin. The nuclear localization of Ki67, a proliferation marker, was high in myoblasts, and decreased through differentiation in myotubes. The expression pattern of MRFs was mainly unaffected by SCI. Both groups expressed equal levels of Pax7, Myf5, Myf6 and Myogenin, while myoblasts from SCI subjects had increased Myod1. The protein amounts of skeletal muscle specific structural proteins (Desmin, Myh 1/2 and Myh7) increased through differentiation in both study groups. The myotubes from spinal cord injured contained more both fast and slow type myosin heavy chain. The rate of incorporation of radiolabelled phenylalanine into protein was equal between both study groups of myotubes. The protein content of the members of Akt‐mTOR signalling axis was unchanged. The same was true for FoxO transcription factors and their targets, involved in protein degradation. Oxidative capacity of the myotubes was equal among the two groups, determined by radiolabelled water production from palmitic acid, as well as the protein content of phosphorylated and total ACC. Our results indicate that the myogenic programming of satellite cells is unchanged in spinal cord injured individuals. This may have implications for targeted interventions for satellite cell activation in an attempt to combat skeletal muscle atrophy in the spinal cord injured.
Expression of neuromuscular junction genes in simian immunodeficiency virus infection: impact of chronic binge alcohol and antiretroviral therapy
Authors: Simon Liz , Ray Ishan Basu , Song Kejing , Molina Patricia E
Published: November 2023

Of the 1.5 million people living with HIV/AIDS (PLWHA) in the United States, approximately 40% have a history of alcohol use disorders. Decreased skeletal muscle mass and function remains a strong and consistent predictor of mortality among PLWHA and occurs at an earlier age among PLWHA compared to the general population. We have previously demonstrated that chronic binge alcohol (CBA) alters gene and microRNA expression and DNA methylation of genes involved in neuromuscular junction function in skeletal muscle obtained at end‐stage of simian immunodeficiency virus (SIV) infection in male rhesus macaques. The aim of this study was to determine whether CBA and/or antiretroviral therapy (ART) altered skeletal muscle expression of genes involved in neuromuscular junction during earlier stages of SIV‐infection in male rhesus macaques. Daily CBA (blood alcohol levels ~50 mM) or sucrose (SUC) administration was initiated 3 months prior to intrarectal SIVmac251 inoculation and continued throughout the study period. Antiretroviral therapy (ART) or placebo was initiated 2.5 months after SIV infection and continued through the study period. Four treatment groups (SUC/SIV±ART and CBA/SIV±ART) were studied at endpoint (11 months post SIV‐infection). Our results demonstrate that CBA and ART decreased expression of brain derived neurotrophic factor (BDNF) in the muscle. SIV increased expression of Acetylcholine receptor gene (AChR) irrespective of CBA or SUC administration in non‐ART treated macaques. However, ART decreased AChR expression to levels similar to controls. No significant changes in the expression of Agrin, Muscle Associated Receptor Tyrosine Kinase (MuSK), Neuregulin, Low‐ Density Lipoprotein Receptor‐Related Protein 4 (LRP4) were detected. We have previously reported that CBA decreases miR‐206 and increases HDAC4 expression in the muscle, and that HDAC4 is a direct target of miR‐206. Expression of BDNF and AChR are reported to be regulated by miR‐206 and/or HDAC4. We hypothesize that the dysregulation of miR‐206‐HDAC4 axis due to CBA potentially plays a role in impairing genes involved in neuromuscular function. Future studies will determine the functional relevance of impaired neuromuscular gene expression and its potential role in compromised skeletal muscle function due to alcohol use in PLWHA.

Support or Funding Information

Research reported was supported by the National Institutes of Health under award numbers P60 AA009803, 1K01AA024494‐01A1
Deletion of claudin‐7 disrupts epithelial cell differentiation in mouse intestines
Authors: Xing Tiaosi , Ding Lei , Camacho Rolando , Chen Yan‐hua
Published: November 2023

The integrity of intestinal mucosa is vital for nutrition absorption and defense against pathogens. Disruption of intestinal epithelial homeostasis leads to a variety of intestinal disorders, such as chronic inflammation, mucosal ulceration, and cancer. Tight junctions are the physical barrier protecting the body from invasion of intestinal lumen pathogens. As one of the tight junction integral membrane proteins, Claudin‐7 plays an essential role in maintaining intestinal structure and mucosal architecture. To dissect the function of claudin‐7 in intestinal epithelial homeostasis, we used the global (gCldn7−/−) and intestinal‐specific (cCldn7−/−) claudin‐7 knockout mice generated recently as our model systems. Through genome‐wide gene‐expression microarray analysis, immunofluoresent light microscopy, immunohistochemistry, as well as Western blotting analysis, we found that epithelial cell differentiation was greatly altered in claudin‐7‐deficient intestines. For example, enterocytes were dramatically reduced in postnatal day 4 gCldn7−/− and 2–4 months old cCldn7−/− mouse intestines. Goblet cells, Paneth cells, enteroendocrine cells and tuft cells were all significantly decreased in cCldn7−/− mouse small intestines. More importantly, the epithelial cell proliferation in claudin‐7‐deficient intestines was no longer limited to the crypt region and low part of villi where epithelial stem cells and fate‐committed progenitor cells are located. We identified a list of gene expression changes related to cell proliferation and differentiation by microarray analysis between the wild type and claudin‐7‐deficient intestines. These findings suggest that claudin‐7 may have a novel, unidentified function regulating epithelial cell renewal in intestines and play a critical role in maintaining the balance of intestinal epithelial cell proliferation and differentiation.

Support or Funding Information

This study is supported by National Institute of Health grant DK103166.
Extracellular microRNA in age‐related bone loss
Authors: Hamrick Mark
Published: November 2023

Microvesicle‐ and exosome‐mediated transport of microRNAs (miRNAs) represents a novel cellular and molecular pathway for cell‐cell communication, and previous studies have indicated that specific circulating extracellular microRNAs are associated with osteoporosis and bone fracture. We have investigated the hypothesis that extracellular vesicles (EVs), including exosomes and microvesicles, may contribute to bone loss with aging by transporting specific miRNAs. EVs isolated from bone marrow of aged mice are readily endocytosed by bone marrow stromal (stem) mesenchymal stem cells (BMSCs). Moreover, EVs from aged mice suppress the osteogenic differentiation of BMSCs. We then examined age‐related changes in the miRNAs carried by bone‐derived EVs. These data indicate that the miR‐183 cluster (miR‐183/‐182/‐96) is elevated with age in bone‐derived EVs isolated from different strains of aged mice. In silico analysis reveals that miR‐183 targets Hmox1, and reduced Hmox1 with miR‐183 transfection has previously been shown to increase osteoclastogenesis. We found that miR‐183 can also induce senescence and suppress the osteogenic differentiation of BMSCs, and others have demonstrated that miR‐182 can inhibit the osteogenic differentiation of BMSCs and MC3T3 osteoprogenitor cells. Together these data indicate that aging can significantly alter the miRNA cargo of extracellular vesicles in the bone marrow microenvironment, which may in turn contribute to age‐related bone loss.

Support or Funding Information

National Institute on Aging (NIA AG036675)
For Successful Weight Loss, Counting Calories Matters but Method Might Not
Authors: Foster Jaime Sarah , Gorin Amy , Mobley Amy
Published: November 2023

To date, many models of weight loss have been deemed successful; however, maintenance remains a challenge. It has been proposed that self‐monitoring is an important behavior in both weight loss and maintenance of weight loss. The purpose of this study was to determine if participant self‐selected form of monitoring calories, (i.e. electronic, paper, or no monitoring) predicted significant differences in weight loss. This study included adults (n=102) enrolled in a standard behavioral weight loss intervention with their partners. For each week a diet record was completed and submitted, participants were given one point, thus higher cumulative scores would indicate more prolonged self‐monitoring. Pearson's correlations were run between percent of weight lost and 1) type of record completed and 2) cumulative number of records submitted. No significant differences were observed between electronic versus paper monitoring. Regardless of calorie monitoring method, the more diet records completed by participants during the course of the intervention was significantly, positively associated with weight loss at week 12 (r= 0.319, p > .001), but there was no association at week 24 of the intervention. Interestingly, calorie monitoring compliance for the first 12 weeks of the program was associated with better weight loss outcomes at 24 weeks (r= 0.237, p <.05). These findings suggest self‐monitoring may be more important during initial behavior change and over time the benefits wane, and it seems that the method of self‐monitoring does not matter. Although this study did not find differences in method of self‐monitoring in weight loss outcomes, it is unknown if there is preferential self‐monitoring method for weight maintenance or if a partner's compliance with self‐monitoring might predict their own success, which will be analyzed upon study completion.

Support or Funding Information

The work was supported by funding from the NHLBI (R21 HL125157)
Dairy Consumption is Associated with Body Composition, Physical Function and Frailty in Community‐Dwelling Older Adults: The Quebec NuAge Longitudinal Study
Authors: Farsijani Samaneh , Payette Hélène , Morais José A. , Shatenstein Bryna , Gaudreau Pierrette , Chevalier Stéphanie
Published: November 2023

Background

Despite the potential contribution of dietary factors to healthy aging, the role of dairy products, as part of the diet, on body composition and physical performance in free‐living older adults has been scarcely studied in longitudinal studies.

Objectives

Our primary aim was to investigate the association between total dairy intake and body composition and physical performance of older adults from the NuAge longitudinal study on Nutrition and Aging. Our secondary objective was to examine the association between dairy intake and frailty at baseline (T0).

Design

Participants (n=1499; aged 67–84y,) were assessed for total dairy consumption (servings/d) (milk, cheese, yogurt and dairy‐based desserts) by 6 nonconsecutive 24‐h food recalls collected over 2 years. Body composition was measured by DXA in a subgroup of subjects (54%) at T0 and after 2‐y (T2). Functional composite scores were calculated for muscle strength (handgrip, arm and leg) and mobility (timed up‐&‐go, chair stand, normal and fast walking speed), measured at T0 and annually thereafter for 3 y. Frailty was defined according to Fried et al. 2001 criteria. Mixed‐model analysis was performed to assess trajectories of body composition and function across time per sex, as conditioned by total dairy intake, adjusted for potential covariates.

Results

Consumption of total and individual dairy products was similar in both sexes, except for high‐fat dairy products and yogurt which were consumed more by men and women, respectively. Higher dairy consumption was independently associated with a higher lean mass (LM) and mobility scores in both sexes, and a better strength score only in men throughout the follow‐up. Interestingly, total dairy intake was inversely associated with fat mass (FM) in women whereas the association was positive in men. Longitudinal declines in LM and functional scores were not associated with dairy consumption. In men, but not in women, the risk of pre‐frailty/frailty was less among high (≥2 servings/d) versus low (<0.6 servings/d) dairy consumers (odds ratio= 0.52; 95% CI=0.30–0.92).

Conclusions

Our results indicate that greater dairy consumption is associated with better body composition and function, i.e., two major predictors of frailty in aging. However, further research is required to explore the long‐term benefits of dairy product consumption and its potential causative association with healthy aging.

Support or Funding Information

Dairy Farmers of Canada.
Glucose, Insulin and Metabolic Response to Soy and Whey Protein among Normal Healthy Weight Indians
Authors: Sucharita S , Cope M , Selvam S , Thomas T , Mukherjea R , Kuriyan R , Kurpad AV
Published: November 2023

INTRODUCTION

High quality dietary protein intake has been linked to the healthy growth and development of lean tissue. Both milk and legumes are recognized as high quality protein sources. However, the acute effect of consumption of different sources and amounts of high quality protein on glucose homeostasis, particularly in South Asian Indians, is unknown. This is relevant in this population group, which has a greater risk of developing diabetes, and a habitually low intake of high quality protein.

METHODS

This study investigated the effect of milk (whey) and legume‐based (soy) protein on glucose homeostasis and energy metabolism, among healthy normal weight Indians. The study tested protein type (soy protein vs. whey protein) and dose (15% vs. 30% Energy). Healthy adult males between ages of 20–35 years (n=15) received four test meals in random order. Blood samples were collected at the following time points Basal (−10 and −5 min), and post meal (15, 30, 45, 60, 90, 120,180, 240 and 300 min) for glucose and insulin estimations. The incremental area under the curve was measured for plasma glucose and insulin. Energy expenditure and substrate oxidation were measured every 30 minutes for 300 minutes after the meal. Satiety was estimated using visual analogue scale at 0, 10, 40 min, and every half hour thereafter.

RESULTS

The incremental area under the curve for plasma insulin was significantly higher for 30% whey compared to 30% soy protein (p<0.01). There was no difference in the insulinogenic response between 15% whey and 15% soy protein (p=0.07). Within a specific protein, only whey protein demonstrated a higher insulin response with a higher dose (p<0.01). There were no differences in plasma glucose across protein source or doses. Satiety and energy expenditure did not differ between protein source and doses.

CONCLUSION

At lower doses, whey and soy protein do not elicit different insulinogenic responses. However, at higher doses whey protein has greater insulinogenic response compared to soy protein, making soy protein a better source for those at greater risk for developing diabetes.

Support or Funding Information

DuPont Nutrition & Health