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Background: The increasing use of platelet-rich plasma (PRP) to treat muscle injuries raises concerns because transforming growth factor–beta (TGF-β) in PRP may promote fibrosis in the injured muscle and thus impair muscle regeneration. Purpose: To investigate whether suramin (a TGF-β inhibitor) can reduce muscle fibrosis to improve healing of the injured muscle after PRP treatment and identify the underlying molecular mechanism. Study Design: Controlled laboratory study. Methods: Myoblasts isolated from the gastrocnemius muscle of Sprague Dawley rats were treated with PRP or PRP plus suramin. MTT assays were performed to evaluate cell viability. The expression of fibrosis-associated proteins (such as type I collagen and fibronectin), Smad2, and phosphorylated Smad2 was determined using Western blot analysis and immunofluorescent staining. An anti–TGF-β antibody was employed to verify the role of TGF-β in fibronectin expression. Gastrocnemius muscles were injured through a partial transverse incision and then treated using PRP or PRP plus suramin. Hematoxylin and eosin staining was conducted to evaluate the healing process 7 days after the injury. Immunofluorescent staining was performed to evaluate fibronectin expression. Muscle contractile properties—fast-twitch and tetanic strength—were evaluated through electric stimulation. Results: PRP plus 25 μg/mL of suramin promoted myoblast proliferation. PRP induced fibronectin expression in myoblasts, but suramin reduced this upregulation. The anti–TGF-β antibody also reduced the upregulation of fibronectin expression in the presence of PRP. The upregulation of phosphorylated Smad2 by PRP was reduced by either the anti–TGF-β antibody or suramin. In the animal study, no significant difference was discovered in muscle healing between the PRP versus PRP plus suramin groups. However, the PRP plus suramin group had reduced fibronectin expression at the injury site. Fast-twitch strength and tetanic strength were significantly higher in the injured muscle treated using PRP or PRP plus suramin. Conclusion: Simultaneous PRP and suramin use reduced fibrosis in the injured muscle and promoted healing without negatively affecting the muscle’s contractile properties. The underlying molecular mechanism may be associated with the phosphorylated Smad2 pathway. Clinical Relevance: Simultaneous PRP and suramin use may reduce muscle fibrosis without compromising muscle contractile properties and thus improve muscle healing.

Aims Diabetic cardiomyopathy is a multifactorial disease characterized by an early onset of diastolic dysfunction (DD) that precedes the development of systolic impairment. Mechanisms that can restore cardiac relaxation improving intracellular Ca2+ dynamics represent a promising therapeutic approach for cardiovascular diseases associated to DD. Istaroxime has the dual properties to accelerate Ca2+ uptake into sarcoplasmic reticulum (SR) through the SR Ca2+ pump (SERCA2a) stimulation and to inhibit Na+/K+ ATPase (NKA). This project aims to characterize istaroxime effects at a concentration (100 nmol/L) marginally affecting NKA, in order to highlight its effects dependent on the stimulation of SERCA2a in an animal model of mild diabetes. Methods and results Streptozotocin (STZ) treated diabetic rats were studied at 9 weeks after STZ injection in comparison to controls (CTR). Istaroxime effects were evaluated in vivo and in left ventricular (LV) preparations. STZ animals showed 1) marked DD not associated to cardiac fibrosis, 2) LV mass reduction associated to reduced LV cell dimension and T-tubules loss, 3) reduced LV SERCA2 protein level and activity and 4) slower SR Ca2+ uptake rate, 5) LV action potential (AP) prolongation and increased short-term variability (STV) of AP duration, 6) increased diastolic Ca2+, and 7) unaltered SR Ca2+ content and stability in intact cells. Acute istaroxime infusion (0.11 mg/kg/min for 15 min) reduced DD in STZ rats. Accordingly, in STZ myocytes istaroxime (100 nmol/L) stimulated SERCA2a activity and blunted STZ-induced abnormalities in LV Ca2+ dynamics. In CTR myocytes, istaroxime increased diastolic Ca2+ level due to NKA blockade albeit minimal, while its effects on SERCA2a were almost absent. Conclusions SERCA2a stimulation by istaroxime improved STZ-induced DD and intracellular Ca2+ handling anomalies. Thus, SERCA2a stimulation can be considered a promising therapeutic approach for DD treatment. Translational perspective Deficient sarcoplasmic reticulum (SR) Ca2+ uptake has been identified in cardiomyocytes from failing human hearts with impaired diastolic relaxation (e.g. diabetic hearts) and has been associated with a decreased SERCA2a expression and activity and/or with a higher SERCA2a inhibition by phospholamban. Thus, SERCA2a may represent a pharmacological target for interventions aimed at improving cytosolic Ca2+ compartmentalization into the SR to limit diastolic dysfunction pathologies. In this context, istaroxime is the first-in-class luso-inotropic agent targeting SERCA2a that has already demonstrated its efficacy in clinical trials and may be useful to clarify the relevance of SERCA2a stimulation in controlling cytosolic Ca2+ level.

BackgroundHeart failure (HF) therapeutic toolkit would strongly benefit from the availability of ino-lusitropic agents with a favorable pharmacodynamics and safety profile. Istaroxime is a promising agent, which combines Na+/K+ pump inhibition with SERCA2a stimulation; however, it has a very short half-life and extensive metabolism to a molecule, named PST3093. The present work aims to investigate whether PST3093, still retains the pharmacodynamic and pharmacokinetic properties of its parent compound.MethodsWe studied PST3093 for its effects on SERCA2a and Na+/K+ ATPase activities, Ca2+ dynamics in isolated myocytes and hemodynamic effects in an in-vivo rat model of diabetic (streptozotocin (STZ)-induced) cardiomyopathy.ResultsIstaroxime infusion in HF patients led to accumulation of PST3093 in the plasma; clearance was substantially slower for PST3093 than for istaroxime. In cardiac rat preparations PST3093 did not inhibit the Na+/K+ ATPase activity, but retained SERCA2a stimulatory activity. In in-vivo echocardiographic assessment, PST3093 improved overall cardiac performance and reversed most STZ-induced abnormalities. PST3093 i.v. toxicity was considerably lower than that of istaroxime and it failed to significantly interact with 50 off-targets.ConclusionsOverall, PST3093 is a “selective” SERCA2a activator, the prototype of a novel pharmacodynamic category with a potential in the ino-lusitropic approach to HF with prevailing diastolic dysfunction. Its pharmacodynamics are peculiar and its pharmacokinetics are suitable to prolong the cardiac beneficial effect of istaroxime infusion.Graphical abstract

The stimulation of sarcoplasmic reticulum calcium ATPase SERCA2a emerged as a novel therapeutic strategy to efficiently improve overall cardiac function in heart failure (HF) with reduced arrhythmogenic risk. Istaroxime is a clinical-phase IIb compound with a double mechanism of action, Na+/K+ ATPase inhibition and SERCA2a stimulation. Starting from the observation that istaroxime metabolite PST3093 does not inhibit Na+/K+ ATPase while stimulates SERCA2a, we synthesized a series of bioisosteric PST3093 analogues devoid of Na+/K+ ATPase inhibitory activity. Most of them retained SERCA2a stimulatory action with nanomolar potency in cardiac preparations from healthy guinea pigs and streptozotocin (STZ)-treated rats. One compound was further characterized in isolated cardiomyocytes, confirming SERCA2a stimulation and in vivo showing a safety profile and improvement of cardiac performance following acute infusion in STZ rats. We identified a new class of selective SERCA2a activators as first-in-class drug candidates for HF treatment.

BPC 157-activated endothelial nitric oxide synthase (eNOS) is associated with tissue repair and angiogenesis as reported in previous studies. However, how BPC 157 regulates the vasomotor tone and intracellular Src-Caveolin-1 (Cav-1)-eNOS signaling is not yet clear. The present study demonstrated a concentration-dependent vasodilation effect of BPC 157 in isolated rat aorta. Attenuation of this vasodilation effect in the absence of endothelium suggested an endothelium-dependent vasodilation effect of BPC 157. Although slightly increased vasorelaxation in aorta without endothelium was noticed at high concentration of BPC 157, there was no direct relaxation effect on three-dimensional model made of vascular smooth muscle cells. The vasodilation effect of BPC 157 was nitric oxide mediated because the addition of L-NAME or hemoglobin inhibited the vasodilation of aorta. Nitric oxide generation was induced by BPC 157 as detected by intracellular DFA-FM DA labeling which was capable of promoting the migration of vascular endothelial cells. BPC 157 enhanced the phosphorylation of Src, Cav-1 and eNOS which was abolished by pretreatment with Src inhibitor, confirming the upstream role of Src in this signal pathway. Activation of eNOS required the released binding with Cav-1 in advance. Co-immunoprecipitation analysis revealed that BPC 157 could reduce the binding between Cav-1 and eNOS. Together, the present study demonstrates that BPC 157 can modulate the vasomotor tone of an isolated aorta in a concentration- and nitric oxide-dependent manner. BPC 157 can induce nitric oxide generation likely through the activation of Src-Cav-1-eNOS pathway.

Pleomorphic mantle cell lymphoma (PMCL) can closely mimic diffuse large B-cell lymphoma (DLBCL) morphologically, and expression of CD5 and cyclin D1 is helpful for differential diagnosis. To date, no cases of CD5/cyclin D1 double-negative PMCL have been reported. Four cases of B-cell lymphoma with an immunophenotype of CD5(-) cyclin D1(-) SOX11(+) and morphologic features compatible with DLBCL were included. Two were previously identified, and the other 2 were screened from 500 cases of B-cell lymphoma. We analyzed their clinicopathologic, immunophenotypic, genetic, and gene expression features. Cases of cyclin D1-positive PMCL, cyclin D1-negative PMCL, germinal center B-cell (GCB) DLBCL, and activated B cell (ABC) DLBCL were also studied for comparison. Similar to other PMCL cases, these 4 patients were mainly elderly male individuals with an aggressive clinical course. None of these tumors had detectable translocations involving CCND1, CCND2, CCND3, CCNE1, CCNE2, MYC, BCL2, or BCL6. The genome-wide copy number profile of these 4 cases was similar to that of cyclin D1-negative PMCL. None of these tumors had high expression of cyclin D1, cyclin D2, or cyclin D3. Similar to cyclin D1-negative PMCL, these cases had higher expression of cyclin E1 and cyclin E2 compared with cyclin D1-positive PMCL. The gene expression pattern of these tumors was also similar to that of cyclin D1-negative PMCL. Here we report for the first time 4 cases of CD5/cyclin D1 double-negative PMCL. SOX11 positivity is useful to identify these rare tumors, and further genetic and gene expression analysis can be used to confirm the diagnosis.

Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by CVie Therapeutics Limited (Taipei, Taiwan) and Windtree Therapeutics (Warrington, USA) Diabetic cardiomyopathy is a multifactorial disease characterized by an early onset of diastolic dysfunction (DD) that precedes the development of systolic impairment. Mechanisms that can restore cardiac relaxation improving intracellular Ca2+ dynamics represent a promising therapeutic approach for cardiovascular diseases associated to DD. Istaroxime has the double property to accelerate Ca2+ uptake into sarcoplasmic reticulum (SR) through the SR Ca2+ pump (SERCA2a) stimulation and to inhibit Na+/K+ ATPase (NKA). The project aims to characterize istaroxime effects at a concentration (100 nM) marginally affecting NKA, in order to highlight its effects dependent on the stimulation of SERCA2a in a model of mild diabetes. Streptozotocin (STZ) treated diabetic rats were studied at 9 weeks after STZ injection in comparison to controls (CTR). Istaroxime effects were evaluated in vivo and in left ventricular (LV) preparations. STZ animals showed 1) marked DD not associated to cardiac fibrosis, 2) LV mass reduction associated to reduced LV cell dimension and T-tubules loss, 3) reduced LV SERCA2 protein level and activity and 4) slower SR Ca2+ uptake rate, 5) LV action potential (AP) prolongation and increased short-term variability (STV) of AP duration, 6) increased diastolic Ca2+, 7) unaltered SR Ca2+ content and stability in intact cells. Acute istaroxime infusion (0.11 mg/kg/min for 15 min) reduced DD in STZ rats. Accordingly, in STZ myocytes istaroxime (100 nM) stimulated SERCA2a activity and blunted STZ-induced abnormalities in LV Ca2+ dynamics. In CTR myocytes, istaroxime increased diastolic Ca2+ level due to NKA blockade albeit minimal, while its effects on SERCA2a were almost absent. SERCA2a stimulation by istaroxime improved STZ-induced DD and intracellular Ca2+ handling anomalies. Thus, SERCA2a stimulation can be considered a promising therapeutic approach for DD treatment. Abstract Figure.

Background: Studies have demonstrated that db/db mice have increased susceptibility to myocardial ischemia-reperfusion (IR) injury and ventricular tachyarrhythmias (VA). We aimed to investigate the antiarrhythmic and molecular mechanisms of ranolazine in db/db mouse hearts with acute IR injury.Methods: Ranolazine was administered for 1 week before coronary artery ligation. Diabetic db/db and control db/+ mice were divided into ranolazine-given and -nongiven groups. IR model was created by 15-min left coronary artery ligation and 10-min reperfusion. In vivo electrophysiological studies and optical mapping to simultaneously record intracellular Ca2+ (Cai) and membrane voltage in Langendorff-perfused hearts were performed. Western blotting and whole-cell patch clamp study were performed to evaluate the effect of ranolazine in the non-IR and IR zones. Results: The severity of VA inducibility by burst pacing was higher in db/db mice than db/+ mice with acute IR injury. Ranolazine suppressed VA inducibility and severity in db/db and db/+ mice. Optical mapping studies showed that ranolazine significantly shortened action potential duration (APD80), Cai transient duration (CaiTD80), Cai decay time, ameliorated conduction inhomogeneity, and suppressed arrhythmogenic alternans induction. The expression of pThr17-phospholamban, calsequestrin 2 and SCN5A in the IR zone was significantly downregulated in db/db mice, which was ameliorated by ranolazine. Conclusions: Ranolazine pretreatment shortens APD80 and CaiTD80, reduces Cai decay time, and ameliorates conduction velocity inhomogeneity to suppress induction of arrhythmogenic alternans and VA; and amelioration of downregulation of pThr17-phospholamban, calsequestrin 2 and SCN5A may partly underlie the anti-arrhythmic molecular mechanisms of ranolazine in db/db mouse hearts with IR injury.

Aldehyde dehydrogenase 2 (ALDH2) is an enzyme that detoxifies reactive oxygen species (ROS)-generated aldehyde adducts such as 4-hydroxy-trans-2-nonenal (4-HNE). Previous meta-analyses have shown an increase in the risk of atrial fibrillation (AF) in patients with chronic alcohol consumption. ALDH2*2, a common dysfunctional polymorphism in the ALDH2 gene, has been linked to an increased risk of cancer and heart disease. We tested the effect of ALDH2 deficiency on alcohol-induced AF in a murine model of chronic-binge ethanol feeding, with ALDH2*2 knock-in (KI) mice generated by a CRISPR/CAS9 system. In addition, right atrial appendages were obtained from eight patients with AF undergoing open heart surgery. The results showed that burst atrial pacing induced a greater susceptibility to AF in ALDH2*2 KI mice exposed to chronic ethanol intoxication than in wild-type mice, resulting from a higher degree of 4-HNE accumulation and collagen deposition in their atria. Alda-1 attenuated transforming growth factor beta 1 (TGF-&beta, 1) expression and collagen deposition in the atria and reduced AF inducibility. Patients with AF and the ALDH2*2 allele exhibited greater oxidative stress and substrate remodeling in their atria than non-carriers. In conclusion, ALDH2 deficiency may increase the risk of chronic alcohol and tachypacing-induced AF through the accumulation of 4-HNE and increased ROS production.

Paraquat (PQ) is a highly lethal herbicide. Ingestion of large quantities of PQ usually results in cardiovascular collapse and eventually death. However, the mechanism of acute PQ poisoning induced cardiotoxicity is poorly understood. Therefore, the purpose of the present study was to aim to investigate the mechanisms of PQ induced cardiotoxicity by examining the effects of PQ on hemodynamics in vivo, as well as in vitro on isolated hearts and ventricular myocytes in rats. Intravenous administration of PQ (100 or 180 mg/kg) in anesthetized rats induced dose-dependent decreases in heart rate, blood pressure, and cardiac contractility (left ventricular [LV] dP/dtmax). Furthermore, it prolonged the rate-corrected QT (QTc) interval. In Langendorff-perfused isolated hearts, PQ (33 or 60 μM) decreased LV pressure and contractility (LV dP/dtmax in isolated ventricular myocytes), PQ (10–60 μM) decreased the amplitude of Ca2+ transients and cell shortening in a concentration-dependent manner. Patch-clamp experiments demonstrated that PQ decreased the amplitude and availability of the transient outward K+ channel (Ito) and altered its gating kinetics. These results suggest that PQ-induced cardiotoxicity results mainly from diminished Ca2+ transients and inhibited K+ channels, which lead to the suppression of LV contractile force and prolongation of the QTc interval.

Background: Skeletal muscle injuries are very common in sports medicine. Conventional therapies have limited clinical efficacy. New treatment methods should be developed to allow athletes to return to play with better function. Purpose: To evaluate the in vitro differentiation potential of bone marrow–derived mesenchymal stem cells and the in vivo histologic and physiologic effects of mesenchymal stem cell therapy on muscle healing after contusion injury. Study Design: Controlled laboratory study. Methods: Bone marrow cells were flushed from both femurs of 5-week-old C57BL/6 mice to establish immortalized mesenchymal stem cell lines. A total of 36 mice aged 8 to 10 weeks were used to develop a muscle contusion model and were divided into 6 groups (6 mice/group) on the basis of the different dosages of IM2 cells to be injected (0, 1.25 × 105, and 2.5 × 105 cells with/without F-127 in 100 μL of phosphate-buffered saline). Histological analysis of muscle regeneration was performed, and the fast-twitch and tetanus strength of the muscle contractions was measured 28 days after muscle contusion injury, after injections of different doses of mesenchymal stem cells with or without the F-127 scaffold beginning 14 days after contusion injury. Results: The mesenchymal stem cell–treated muscles exhibited numerous regenerating myofibers. All the groups treated with mesenchymal stem cells (1.25 × 105 cells, 2.5 × 105 cells, 1.25 × 105 cells plus F-127, and 2.5 × 105 cells plus F-127) exhibited a significantly higher number of regenerating myofibers (mean ± SD: 111.6 ± 14.77, 133.4 ± 21.44, 221.89 ± 32.65, and 241.5 ± 25.95, respectively) as compared with the control group and the control with F-127 (69 ± 18.79 and 63.2 ± 18.98). The physiologic evaluation of fast-twitch and tetanus strength did not reveal differences between the age-matched uninjured group and the groups treated with various doses of mesenchymal stem cells 28 days after contusion. Significant differences were found between the control group and the groups treated with various doses of mesenchymal stem cells after muscle contusion. Conclusion: Mesenchymal stem cell therapy increased the number of regenerating myofibers and improved fast-twitch and tetanus muscle strength in a mouse model of muscle contusion. However, the rapid decay of transplanted mesenchymal stem cells suggests a paracrine effect of this action. Treatment with mesenchymal stem cells at various doses combined with the F-127 scaffold is a potential therapy for a muscle contusion. Clinical Relevance: Mesenchymal stem cell therapy has an effect on sports medicine because of its effects on myofiber regeneration and muscle strength after contusion injury.

Supplemental material, DS_10.1177_0363546520905853 for Application of Bone Marrow–Derived Mesenchymal Stem Cells for Muscle Healing After Contusion Injury in Mice by Chih-Hao Chiu, Tsan-Hsuan Chang, Shih-Sheng Chang, Gwo-Jyh Chang, Alvin Chao-Yu Chen, Chun-Ying Cheng, Su-Ching Chen, Jen-Fen Fu, Chih-Jen Wen and Yi-Sheng Chan in The American Journal of Sports Medicine

Inherited cardiac conduction disease (CCD) is rare, it is caused by a large number of mutations in genes encoding cardiac ion channels and cytoskeletal proteins. Recently, whole-exome sequencing has been successfully used to identify causal mutations for rare monogenic Mendelian diseases. We used trio-based whole-exome sequencing to study a Chinese family with multiple family members affected by CCD, and identified a heterozygous missense mutation (c.343C&gt, T, p.Leu115Phe) in the desmin (DES) gene as the most likely candidate causal mutation for the development of CCD in this family. The mutation is novel and is predicted to affect the conformation of the coiled-coil rod domain of DES according to structural model prediction. Its pathogenicity in desmin protein aggregation was further confirmed by expressing the mutation, both in a cellular model and a CRISPR/CAS9 knock-in mouse model. In conclusion, our results suggest that whole-exome sequencing is a feasible approach to identify candidate genes underlying inherited conduction diseases.

Background. The Auto Manipulation Device for Acupuncture (AMDA) is designed for providing stable, quantified effects and higher frequency when doing lifting and thrusting manipulation. The purpose of this study is to investigate the safety of manipulation by AMDA in different frequency and duration in healthy rats. Methods. The study was divided into two parts: single intervention and once a day for a week. 12 rats and 15 rats were randomly allocated to different groups: Control (needle insertion only), AMDA (2Hz/10Mins), AMDA (2Hz/20Mins), AMDA (20Hz/10Mins), and AMDA (20Hz/20Mins) for single and repeated interventions. Real-time physiological functions, laboratory data, and the bilateral muscle tissue of acupoint (ST 36) were obtained after the intervention. Results. We found neither real-time physiological functions nor laboratory data differences between control group and AMDA groups in both parts. In the muscle tissue samples, the slight damage had been observed in the AMDA group with a frequency of 2 Hz for 20 minutes after once intervention, and the repeated session groups noted more obvious tissue damage with fibrotic change. Although the period was shorter, higher frequency manipulation caused more damage that fibroblast nuclei became more slender and obvious. However, no significant adverse effect was noted such as crippled and molting in the whole process. Conclusion. Our study suggested that the safety issue of AMDA operation in rats is feasible because there was no difference between control group and AMDA groups among real-time physiological functions and laboratory data. However, manipulation with higher frequency should be more preserved.

Inherited cardiac conduction disease (CCD) is rare; it is caused by a large number of mutations in genes encoding cardiac ion channels and cytoskeletal proteins. Recently, whole-exome sequencing has been successfully used to identify causal mutations for rare monogenic Mendelian diseases. We used trio-based whole-exome sequencing to study a Chinese family with multiple family members affected by CCD, and identified a heterozygous missense mutation (c.343C>T, p.Leu115Phe) in the desmin (DES) gene as the most likely candidate causal mutation for the development of CCD in this family. The mutation is novel and is predicted to affect the conformation of the coiled-coil rod domain of DES according to structural model prediction. Its pathogenicity in desmin protein aggregation was further confirmed by expressing the mutation, both in a cellular model and a CRISPR/CAS9 knock-in mouse model. In conclusion, our results suggest that whole-exome sequencing is a feasible approach to identify candidate genes underlying inherited conduction diseases.

BACKGROUND Piceatannol, a grape-derived polyphenol, has been linked to proarrhythmic properties by aggravating inhomogeneous conduction delay in the ischemia-reperfusion (IR) zone to enhance arrhythmogenic alternans in heart failure (HF) rabbits. The underlying molecular mechanisms of piceatannol-induced conduction disturbance were unclear in this model. METHODS HF was induced by 4 weeks' rapid ventricular pacing. IR injury was induced in vivo using a protocol of left coronary artery ligation and release. Left ventricular cardiomyocytes were isolated enzymatically for whole-cell patch-clamp studies. Piceatannol (10 μM) was administrated to test its inhibitory effect on sodium current (INa ). Immunoblots studies and immunoenzymological staining were conducted in tissues sampled from the IR and remote zones. RESULTS Peak INa density was less in failing cardiomyocytes than control cardiomyocytes. IR injury further reduces peak INa density in both groups. Piceatannol showed a greater INa inhibitory effect in HF than control cardiomyocytes. Western blots showed reduced NaV 1.5 protein expression in the HF group compared to the control group but no significant difference between remote and IR zones. Immunostaining showed that IR led to cytosolic redistribution of NaV 1.5, especially in failing hearts. CONCLUSIONS Downregulation of NaV 1.5 protein expression and reduced peak INa density are found in the failing hearts. Piceatannol exerts a greater inhibitory effect on peak INa in the failing cardiomyocytes than in the controls. IR injury further decreases peak INa density, which is more prominent in the failing hearts than in the control hearts.

Prostacyclin agonists that bind the prostacyclin receptor (IP) to stimulate cAMP synthesis are effective vasodilators for the treatment of idiopathic pulmonary arterial hypertension (IPAH), but this signaling may occur through nuclear peroxisome proliferator-activated receptor-γ (PPARγ). There is evidence of scant IP and PPARγ expression but stable prostanoid EP4 receptor (EP4) expression in IPAH patients. Both IP and EP4 functionally couple with stimulatory G protein (Gs), which activates signal transduction. We investigated the effect of an EP4-specific agonist on pulmonary arterial remodeling and its regulatory mechanisms in pulmonary arterial smooth muscle cells (PASMCs). Immunoblotting evealed IP, EP4, and PPARγ expression in human pulmonary arterial hypertension (PAH) and monocrotaline (MCT)-induced PAH rat lung tissue. Isolated PASMCs from MCT-induced PAH rats (MCT-PASMCs) were treated with L-902,688, a selective EP4 agonist, to investigate the anti-vascular remodeling effect. Scant expression of IP and PPARγ but stable expression of EP4 was observed in IPAH patient lung tissues and MCT-PASMCs. L-902,688 inhibited IP-insufficient MCT-PASMC proliferation and migration by activating PPARγ in a time- and dose-dependent manner, but these effects were reversed by AH-23848 (an EP4 antagonist) and H-89 [a protein kinase A (PKA) inhibitor], highlighting the crucial role of PPARγ in the activity of this EP4 agonist. L-902,688 attenuated pulmonary arterial remodeling in hypoxic PAH mice and MCT-induced PAH rats; therefore, we conclude that the selective EP4 agonist L-902,688 reverses vascular remodeling by activating PPARγ. This study identified a novel EP4-PKA-PPARγ pathway, and we propose EP4 as a potential therapeutic target for PAH.

Background: There is an urgency to develop robust prognostic biomarkers for metastatic colorectal cancer (mCRC) patients receiving chemotherapy. The current study aimed to examine the prognostic significance of circulating tumour cells (CTCs) and to develop a prognostic model incorporating CTCs in predicting the outcomes of mCRC patients treated with chemotherapy. Methods: Our study prospectively enrolled 55 mCRC patients who had undergone palliative chemotherapy between 2011 and 2014. Baseline CTCs and clinicopathological variables predictive of survival outcome were identified using univariate analysis. Negative selection-based protocol plus flow cytometry was used for CTC identification. Results: The median overall survival (OS) and progression-free survival (PFS) were 24.2 months and 8.7 months, respectively. CTCs were detected in all the patients, and the median number of CTCs was 30.8/mL (range: 5.8-431.3/mL). The median OS and PFS were 37.1 and 13.3 months, respectively, for patients with CTC number ≤30/mL, while the median OS and PFS were 14.9 months and 5.1 months, respectively, for patients with CTC number >30/mL (both P

Cysteine cathepsin proteases play critical roles in cardiovascular disease progression and are implicated in extracellular matrix (ECM) degradation. Patients with pulmonary arterial hypertension (PAH) exhibit increased elastase production by pulmonary arterial smooth muscle cells (PASMCs), which is related to the degradation of elastic fibers and pulmonary vascular remodeling. However, the mechanism by which cathepsins regulate the ECM and PASMC proliferation in PAH remains unclear. We hypothesized that cathepsin proteases in PASMCs promote the development of PAH. Here, we show overexpression of cathepsin S (Cat S) and degradation of elastic laminae in the lungs of patients with idiopathic PAH and in the PASMCs of monocrotaline-induced PAH model (MCT-PAH) rats. In addition, pulmonary hypertension can be treated in MCT-PAH rats by administering a selective Cat S inhibitor, Millipore-219393, which stimulates peroxisome proliferator-activated receptor-γ (PPARγ) to inhibit the expression of Cat S, thus suppressing the proliferation and migration of MCT-PAH PASMCs. We then reduced Cat S or PPARγ expression by using small interfering RNA in human PASMCs to demonstrate a mechanistic link between Cat S signaling and PPARγ protein, and the results suggest that PPARγ is upstream of Cat S signaling. In conclusion, the activity of Cat S in pulmonary vascular remodeling and degradation of elastin fibers through the disruption of PPARγ is pathophysiologically significant in PAH.

The recommended treatment varies depending on the severity of muscle injuries. The aim of this study was to evaluate the in vitro myoblast proliferation and the in vivo histologic and physiologic effects of hyperbaric oxygen treatment on muscle healing after contusion. Cells from the C2C12 myoblast cell line were exposed to 100% O2 for 25 min then to air for 5 min at 2.5 atmospheres absolute in a hyperbaric chamber for a total treatment duration of 90 min per 48 h at intervals of 2, 4, 6 and 8 days. Cell growth measurements and western blot analysis of myogenin and actin were performed. Then, 18 mice aged 8-10 weeks were used in the muscle contusion model. The histologic and physiologic effects and muscle regeneration after hyperbaric oxygen treatment were evaluated. The myoblast growth rate was significantly higher (p < 0.05) after hyperbaric oxygen treatment. Densitometric evaluation demonstrated a 39% (p < 0.05) and 25% (p < 0.05) increase in myogenin and actin protein levels, respectively, in the cells treated with 1 dose of hyperbaric oxygen. Similarly, the myogenin and actin protein levels increased for samples receiving multiple hyperbaric oxygen treatments when compared with the control. Physiologic evaluation of fast twitch and tetanus strength revealed a significant difference between the control group and the 14-day hyperbaric oxygen group. In conclusion, hyperbaric oxygen treatment increases the myoblast growth rate and myogenin and actin production. Better histologic and physiologic performance were found after hyperbaric oxygen treatment in animal contusion model. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:329-335, 2020.

Atrial fibrillation (AF) is associated with oxidative stress and Ca2+-handling abnormalities in atrial myocytes. Our prior study has demonstrated the involvement of CD44, a membrane receptor for hyaluronan (HA), in the pathogenesis of AF. This study further evaluated whether CD44 and its related signaling mediate atrial tachycardia-induced oxidative stress and Ca2+-handling abnormalities. Tachypacing in atrium-derived myocytes (HL-1 cell line) induced the activation of CD44-related signaling, including HA and HA synthase (HAS) expression. Blocking HAS/HA/CD44 signaling attenuated tachypacing-induced oxidative stress (NADPH oxidase [NOX] 2/4 expression) and Ca2+-handling abnormalities (oxidized Ca2+/calmodulin-dependent protein kinase II [ox-CaMKII] and phospho-ryanodine receptor type 2 [p-RyR2] expression) in HL-1 myocytes. Furthermore, a direct association between CD44 and NOX4 was documented in tachy-paced HL-1 myocytes and atrial tissues from AF patients. In vitro, Ca2+ spark frequencies in atrial myocytes isolated from CD44-/- mice were lower than those from wild-type mice. Furthermore, administration of an anti-CD44 blocking antibody in atrial myocytes isolated from wild-type mice diminished the frequency of Ca2+ spark. Ex vivo tachypacing models of CD44-/- mice exhibited a lower degree of oxidative stress and expression of ox-CaMKII/p-RyR2 in their atria than those of wild-type mice. In vivo, burst atrial pacing stimulated a less inducibility of AF in CD44-/-mice than in wild-type mice. In conclusion, atrial tachypacing-induced Ca2+-handling abnormalities are mediated via CD44/NOX4 signaling, which provides a possible explanation for the development of AF.

Mechanical ventilation (MV) can save the lives of patients with sepsis. However, MV in both animal and human studies has resulted in ventilator‐induced diaphragm dysfunction (VIDD). Sepsis may promote skeletal muscle atrophy in critically ill patients. Elevated high‐mobility group box‐1 (HMGB1) levels are associated with patients requiring long‐term MV. Ethyl pyruvate (EP) has been demonstrated to lengthen survival in patients with severe sepsis. We hypothesized that the administration of HMGB1 inhibitor EP or anti‐HMGB1 antibody could attenuate sepsis‐exacerbated VIDD by repressing HMGB1 signalling. Male C57BL/6 mice with or without endotoxaemia were exposed to MV (10 mL/kg) for 8 hours after administrating either 100 mg/kg of EP or 100 mg/kg of anti‐HMGB1 antibody. Mice exposed to MV with endotoxaemia experienced augmented VIDD, as indicated by elevated proteolytic, apoptotic and autophagic parameters. Additionally, disarrayed myofibrils and disrupted mitochondrial ultrastructures, as well as increased HMGB1 mRNA and protein expression, and plasminogen activator inhibitor‐1 protein, oxidative stress, autophagosomes and myonuclear apoptosis were also observed. However, MV suppressed mitochondrial cytochrome C and diaphragm contractility in mice with endotoxaemia (P

Additional file 2: Table S1. Cellular electrophysiology in HFa and HFr rats.

The molecular mechanism for worsening left ventricular (LV) function after mitral valve (MV) repair for chronic mitral regurgitation remains unknown. We wished to assess the LV transcriptome and identify determinants associated with worsening LV function post-MV repair. A total of 13 patients who underwent MV repair for chronic primary mitral regurgitation were divided into two groups, preserved LV function (N = 8) and worsening LV function (N = 5), for the study. Specimens of LV from the patients taken during surgery were used for the gene microarray study. Cardiomyocyte cell line HL-1 cells were transfected with gene-containing plasmids and further evaluated for mRNA and protein expression, apoptosis, and contractile protein degradation. Of 67,258 expressed sequence tags, microarrays identified 718 genes to be differentially expressed between preserved-LVF and worsening-LVF, including genes related to the protein ubiquitination pathway, bone morphogenetic protein (BMP) receptors, and regulation of eIF4 and p70S6K signaling. In addition, worsening-LVF was associated with altered expressions of genes pathologically relevant to heart failure, such asdownregulated apelin receptors and upregulated peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A). HL-1 cardiomyocyte cells transfected with ubiquitination-related genes demonstrated activation of the protein ubiquitination pathwaywith an increase in the ubiquitin activating enzyme E1 (UAE-E1). It also led to increased apoptosis, downregulated and ubiquitinated X-linked inhibitor of apoptosis protein (XIAP), and reduced cell viability. Overexpression of ubiquitination-related genes also resulted in degradation and increased ubiquitination of &alpha, smooth muscle actin (SMA). In conclusion, worsening-LVF presented differential gene expression profiles from preserved-LVF after MV repair. Upregulation of protein ubiquitination-related genes associated with worsening-LVF after MV repair may exert adverse effects on LV through increased apoptosis and contractile protein degradation.

Diabetic patients with cardiomyopathy show a higher incidence of arrhythmias and sudden death. Chronic hyperglycemia induces the formation of advanced glycation end products (AGEs), which contribute to the pathogenesis of diabetic cardiomyopathy. This study investigated whether inhibition of AGEs formation by aminoguanidine (AG) could prevent cardiac electromechanical and arrhythmogenic remodeling in diabetes mellitus. Streptozotocin-induced diabetic rats received AG (100 mg/kg daily, i.p.) or vehicle (normal saline, i.p.) for 5 weeks. The rats underwent hemodynamic recording to evaluate cardiac function, and heart preparations were used to determine the electrical, mechanical, and biochemical functions. In vitro high glucose-induced AGEs formation, reactive oxygen species (ROS) generation, and action potential changes were examined in HL-1 atrial cells. AG treatment improved the diabetes-induced depression in left ventricular pressure and the relaxation rate, and normalized the prolongation of QTc intervals in anesthetized rats. AG reduced the vulnerabilities to atrial and ventricular tachyarrhythmias in perfused diabetic hearts. AG normalized the prolonged action potential duration in diabetic atrial and ventricular muscles, which was correlated with the restoration of both transient outward (Ito) and steady-state outward (ISS) K+ current densities in cardiomyocytes. The abnormal kinetics of Ca2+ transients and contraction were reversed in cardiomyocytes from AG-treated diabetic rats, along with parallel preservation of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA2a) expression. Furthermore, ex vivo and in vitro studies showed AG attenuated AGEs and ROS formation. Thus, long-term administration of AG ameliorated cardiac electromechanical remodeling and arrhythmogenicity in diabetic rats and may present an effective strategy for the prevention of diabetes-associated arrhythmias.

Piceatannol, a grape-derived polyphenol, has been linked to proarrhythmic properties by aggravating inhomogeneous conduction delay in the ischemia-reperfusion (IR) zone to enhance arrhythmogenic alternans in heart failure (HF) rabbits. The underlying molecular mechanisms of piceatannol-induced conduction disturbance were unclear in this model.HF was induced by 4 weeks' rapid ventricular pacing. IR injury was induced in vivo using a protocol of left coronary artery ligation and release. Left ventricular cardiomyocytes were isolated enzymatically for whole-cell patch-clamp studies. Piceatannol (10 μM) was administrated to test its inhibitory effect on sodium current (IPeak IDownregulation of NaV 1.5 protein expression and reduced peak I

Background: Platelet-rich plasma (PRP) contains various cytokines and growth factors that may be beneficial to the healing process of injured muscle. Based on the authors’ previous study, PRP releasate can promote proliferation and migration of skeletal muscle cells in vitro, so animal studies are performed to support the use of PRP to treat muscle injury in vivo. Purpose: To investigate the effect of PRP releasate on regeneration of injured muscle, as well as its effect on inflammatory reaction and cell apoptosis, in the early stages of the muscle-healing process. Study Design: Controlled laboratory study. Methods: The gastrocnemius muscles of Sprague-Dawley rats were injured by partial transverse incision and then treated with PRP releasate. Hematoxylin and eosin stain was used to evaluate the healing process of injured muscle at 2, 5, and 10 days after injury. TUNEL assay was used to evaluate the cell apoptosis of injured muscle after PRP releasate treatment. Immunohistochemistry was used to stain the CD68-positive cells during the healing process. Muscle contractile properties, including fast-twitch and tetanic strength, were evaluated by electric stimulation. Results: The results revealed that PRP releasate treatment could enhance the muscle-healing process and decrease CD68-positive cells and apoptotic cells. Furthermore, the tetanic strength was significantly higher in injured muscle treated with PRP releasate. Conclusion: In conclusion, PRP releasate could enhance the healing process of injured muscle and decrease inflammatory cell infiltration as well as cell apoptosis. Clinical Relevance: PRP promotes skeletal muscle healing in association with decreasing inflammation and apoptosis of injured skeletal muscle. These findings provide in vivo evidence to support the use of PRP to treat muscle injury.

Prostacyclin agonists that bind the prostacyclin receptor (IP) to stimulate cAMP synthesis are effective vasodilators for the treatment of idiopathic pulmonary arterial hypertension (IPAH), but this signaling may occur through nuclear peroxisome proliferator-activated receptor-γ (PPARγ). There is evidence of scant IP and PPARγ expression but stable prostanoid EP

Background and Purpose This study was designed to examine the antiarrhythmic efficacy and the underlying mechanisms of the benzyl-furoquinoline vasodilator, CIJ-3-2F, in rat cardiac preparations. Experimental Approach Conduction electrograms and left ventricular pressure were determined in Langendorff-perfused hearts. Action potentials were assessed with microelectrode techniques, calcium transients by fura-2 fluorescence and ionic currents by whole-cell patch-clamp techniques. Key Results In isolated hearts, CIJ-3-2F prolonged sinus cycle length, QT interval, Wenckebach cycle length, atrio-His bundle and His bundle-ventricular conduction intervals, refractory periods in atrium, AV node, His-Purkinje system and ventricle, and also increased left ventricular pressure. CIJ-3-2F reduced the incidences of both ischaemic and reperfusion-induced ventricular arrhythmias and prevented the induction of atrial tachyarrhythmias. In both atrial and papillary muscles, CIJ-3-2F decreased upstroke velocity and prolonged duration of the action potential. In ventricular myocytes, CIJ-3-2F moderately increased the amplitude of [Ca2+]i transients and cell shortening. CIJ-3-2F inhibited the transient outward K+ current (Ito) (IC50 = 4.4 μM) with accelerated inactivation, a slower rate of recovery from inactivation and use-dependency. CIJ-3-2F also suppressed the steady-state outward K+ current (Iss, IC50 = 3.6 μM, maximum inhibition = 65.7%) and both the inward Na+ current (INa, IC50 = 2.8 μM) and L-type Ca2+ current (ICa,L, IC50 = 4.9 μM, maximum inhibition = 69.4%). Conclusions and Implications CIJ-3-2F blocked Na+ and Ito channels and, to some extent, also blocked Ca2+ and Iss channels, modifying cardiac electromechanical function. These effects are likely to underlie its antiarrhythmic properties.

Aims To characterize the clinicopathologic and genetic features of pleomorphic mantle cell lymphoma (PMCL) which morphologically mimics diffuse large B-cell lymphoma (DLBCL). Methods and results We systematically screened 500 B-cell lymphomas morphologically compatible with DLBCL using an immunohistochemical algorithm of three markers (CD5, cyclin D1 and SOX11). Ten cases of PMCL were identified for further study, and surprisingly four (40%) of them were cyclin D1-negative. These ten patients were mostly elderly male with an advanced disease, and their median survival was only 11 months. All cyclin D1-positive PMCLs tested showed an IGH-CCND1 translocation, whereas one of the four cyclin D1-negative PMCLs had a translocation involving CCND2 and a high CCND2 mRNA level (P

Blood lactate increases during incremental exercise at high-intensity workloads, and limited exercise capacity is a characteristic of obese animals. This study examined whether blood lactate changes in response to incremental exercise is disrupted in obese animals. Muscular and hepatic proteins that are critical in lactate metabolism were also investigated. Rats were randomized to either standard chow (control) or high-fat diet (HFD) groups. All animals underwent an incremental treadmill test after 14 wk of diet intervention. Blood lactate levels were measured before and after the treadmill test. Activities of mitochondrial oxidative phosphorylation and glycolysis were examined in muscle tissues. Proteins in the liver and skeletal muscles that participate in the turnover of blood lactate were determined by Western blot. Running time in the incremental treadmill test decreased in the HFD group, and blood lactate accumulated faster in these animals than in the control group. Animals with HFD had a decreased level of hepatic monocarboxylate transporter 2, the protein responsible for blood lactate uptake in the liver. Skeletal muscles of animals with HFD showed greater glycolytic activity and decreased content of lactate dehydrogenase B, which converts lactate to pyruvate. We conclude that blood lactate accumulated faster during incremental exercise in obese animals and was associated with their decreased exercise performance. Changes in the metabolic pattern of muscles and changes of liver and muscle proteins associated with lactate utilization likely contribute to the abnormal response of blood lactate to incremental exercise in obese animals.

The depletion of cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) and phosphatase and tensin homolog (PTEN) is the critical mediator of pulmonary arterial hypertension (PAH). We hypothesized that the activation of phosphorylated CREB (pCREB) and PTEN could inhibit the AKT signaling pathway to attenuate pulmonary arterial remodeling in rats with monocrotaline-induced PAH. We observed decreased PTEN and pCREB in idiopathic PAH versus control tissue. We reduced PTEN using small interfering RNA in human control pulmonary arterial smooth muscle cells (PASMCs) and observed an increase in pAKT. Consistent with PTEN knockdown in PASMCs, prostaglandin E1 (PGE1) induced pCREB expression to stimulate PTEN protein expression and inhibited pAKT in a time- and dose-dependent manner. The enhanced proliferation and migration of PASMCs following PTEN knockdown were significantly inhibited by PGE1 treatment. The PGE1-induced elevation of PTEN expression in PTEN-depleted PASMCs was decreased by the application of a PKA inhibitor and a CBP-CREB interaction inhibitor. Supplementation with a novel emulsion composition comprising PGE1 in rats with monocrotaline-induced PAH prevented pulmonary arterial remodeling and improved hemodynamics via the induced expression of PTEN. We conclude that PGE1 recruits pCREB/PTEN to decrease the migration and proliferation of PASMCs associated with PAH. This finding elucidates a relevant underlying mechanism of the PGE1/CREB/PTEN signaling pathway to prevent progressive PAH.

Background Atrial fibrillation (AF) causes atrial remodeling, and the left atrium (LA) is the favored substrate for maintaining AF. It remains unclear if AF remodels both atria differently and contributes to LA arrhythmogenesis and thrombogenesis. Therefore, we wished to characterize the transcript profiles in the LA and right atrium (RA) in sinus rhythm (SR) and AF respectively. Methods Paired LA and RA appendages acquired from patients receiving cardiac surgery were used for ion-channel- and whole-exome-based transcriptome analysis. The ultrastructure was evaluated by immunohistochemistry. Results Twenty-two and twenty ion-channels and transporters were differentially expressed between the LA and RA in AF and SR, respectively. Among these, 15 genes were differentially expressed in parallel between AF and SR. AF was associated with increased LA/RA expression ratio in 9 ion channel-related genes, including genes related to calcium handling. In microarray, AF was associated with a differential LA/RA gene expression ratio in 309 genes, and was involved in atherosclerosis-related signaling. AF was associated with the upregulation of thrombogenesis-related genes in the LA appendage, including P2Y12, CD 36 and ApoE. Immunohistochemistry showed higher expressions of collagen-1, oxidative stress and TGF-β1 in the RA compared to the LA. Conclusions AF was associated with differential LA-to-RA gene expression related to specific ion channels and pathways as well as upregulation of thrombogenesis-related genes in the LA appendage. Targeting the molecular mechanisms underlying the LA-to-RA difference and AF-related remodeling in the LA appendage may help provide new therapeutic options in treating AF and preventing thromboembolism in AF.