Isometric exercise promotes arteriogenesis in rats after myocardial infarction

Sevoflurane Preconditioning Protects Against Myocardial Ischemia Reperfusion Injury in Mice via PI3K/AKT/GSK3β-mediated Upregulation of Syntaxin1a

Preconditioning with volatile anesthetics, such as isoflurane and sevoflurane, can protect the myocardium against ischemia/reperfusion injury (IRI). Syntaxin1A (Stx1A) is cardioprotective and regulated by volatile anesthetics. However, is the mechanism by which sevoflurane preconditioning (SPC) induces Stx1A to exert myocardial protection remains unclear. The study investigates whether SPC induces upregulation of Stx1A through the thymoma viral proto-oncogene (AKT)/Glycogen synthase kinase 3 β (GSK3β) signaling pathway. Myocardial IRI model in mice was established by surgically ligating the left anterior descending coronary followed by loosening of the occlusion. Regulation of signaling pathway by intraperitoneal administration of the phosphatidylinositol 3-kinase (PI3K) inhibitor, Ly294002 (30 mg/kg), and GSK3β inhibitor, TWS119 (30 mg/kg). The triphenyl tetrazolium chloride (TTC) staining method was used to measure the myocardial infarction area. Serum creatine kinase MB (CK-MB) and lactic dehydrogenase (LDH) concentration were measured by enzyme-linked immunosorbent assay (ELISA). Western blot was employed to examine AKT/GSK3β pathway activity, as well as expressions of Stx1A, small ubiquitin-like modifier 1 (SUMO1), growth hormone-releasing hormone (GHRH), or calcitonin gene-related peptide (CGRP), and brain natriuretic peptide (BNP). Both IRI and SPC induced upregulation of Stx1A in mice. However, the upregulation was abolished by treatment with Ly294002, while TWS119 further increased its expression (p < 0.05). Myocardial infarct area, serum CK-MB, and LDH were elevated in the IRI group but were inhibited by SPC-induced (p < 0.05); however, this inhibition by SPC was eliminated by Ly294002 (p < 0.05). TWS119 causes the opposite effect (p < 0.05). These findings demonstrated that SPC activated the AKT/GSK3β signaling pathway to upregulate Stx1A expression and provide protection to the myocardium.

Phosphoproteomic and proteomic profiling in post-infarction chronic heart failure

Background: Post-infarction chronic heart failure is the most common type of heart failure. Patients with chronic heart failure show elevated morbidity and mortality with limited evidence-based therapies. Phosphoproteomic and proteomic analysis can provide insights regarding molecular mechanisms underlying post-infarction chronic heart failure and explore new therapeutic approaches. Methods and results: Global quantitative phosphoproteomic and proteomic analysis of left ventricular tissues from post-infarction chronic heart failure rats were performed. A total of 33 differentially expressed phosphorylated proteins (DPPs) and 129 differentially expressed proteins were identified. Bioinformatic analysis indicated that DPPs were enriched mostly in nucleocytoplasmic transport and mRNA surveillance pathway. Bclaf1 Ser658 was identified after construction of Protein-Protein Interaction Network and intersection with Thanatos Apoptosis Database. Predicted Upstream Kinases of DPPs based on kinase-substrate enrichment analysis (KSEA) app showed 13 kinases enhanced in heart failure. Proteomic analysis showed marked changes in protein expression related to cardiac contractility and metabolism. Conclusion: The present study marked phosphoproteomics and proteomics changes in post-infarction chronic heart failure. Bclaf1 Ser658 might play a critical role in apoptosis in heart failure. PRKAA1, PRKACA, and PAK1 might serve as potential therapeutic targets for post-infarction chronic heart failure.

Comparison of time-dependent resistance isometric exercise and active range of motion exercise in alleviating the sensitization of postoperative axial pain after cervical laminoplasty

BACKGROUND

Postoperative axial pain (PAP) is a significant complication after cervical laminoplasty.

OBJECTIVE

To investigate pain sensitization in PAP patients and effects of time-dependent resistance isometric exercise compared to active range-of-motion exercise on PAP.

STUDY DESIGN

Retrospective cohort analysis.

METHODS

211 patients undergoing postoperative 12-week exercises were evaluated for pressure pain threshold (PPT), temporal summation (TS) and both cross-sectional area and fatty infiltration of paraspinal muscles preoperatively and 3 months postoperatively. There patients underwent Numeric rating pain scale (NRS) and neck disability index (NDI) 3 and 6 months postoperatively.

RESULTS

At postoperative 3-month assessments, fewer patients undergoing isometric exercise showed PAP compared to range-of-motion exercise group (14/98 vs. 34/113; P = 0.006), and pain-related assessments in the former were lower than the latter (NRS at rest: 0.3 ± 0.8 vs. 0.7 ± 1.4, P = 0.014; NRS with movements: 0.4 ± 1.0 vs. 1.0 ± 1.7, P = 0.015; NDI: 2.4 ± 6.3 vs. 6.7 ± 10.9, P = 0.002). Postoperative cross-sectional area was smaller in isometric exercise group (603.5 ± 190.2) than in range-of-motion exercise group (678.7 ± 215.5) (P = 0.033), and the former showed higher local-area PPT and lower TS than the latter (PPT: 3.9 ± 1.8 vs. 3.1 ± 1.6, P = 0.002; TS: 1.8 ± 0.9 vs. 2.2 ± 1.0, P = 0.003). PAP patients showed lower local-area PPT and greater TS than those without PAP in both isometric (PPT: 2.8 ± 0.7 vs. 4.0 ± 1.9, P = 0.019; TS: 2.4 ± 0.6 vs. 1.7 ± 0.9, P = 0.011) and range-of-motion (PPT: 2.2 ± 0.9 vs. 3.6 ± 1.7, P < 0.001; TS: 2.8 ± 0.8 vs. 1.9 ± 0.9, P < 0.001) exercise groups.

CONCLUSIONS

Both peripheral and central sensitization are involved in PAP. Time-dependent isometric exercise has more positive effects on PAP than range-of-motion exercise because of its advantages in improving pain sensitization.

Roles of isometric contraction training in promoting neuroprotection and angiogenesis after stroke in adult rats

100 rats were randomly divided into a sham-operated group and middle cerebral artery occlusion (MCAO) modeling groups. The sham group after surgery was observed for 14 days. After MCAO, some rats received isometric contraction training (ICT) which was as follows: an atraumatic tourniquet was placed around left or right hind limb to achieve hind limb ischemia for 5 min, followed by 5 min of reperfusion, 4 cycles for one time, once a day, and five days per week. The MCAO modeling groups included the following four groups: i) a group only received MCAO, and was observed for seven days (MCAO-7d), ii) a group only received MCAO, and was observed for 14 days (MCAO-14d), iii) a group, after MCAO, received ICT for seven days (ICT-7d), and iv) a group, after MCAO, received ICT for 14 days (ICT-14d). Brain infarct area, behavioral outcomes, the number of neurons, apoptosis, cerebral edema and cerebral water content were assessed, respectively. The mRNA expression of vascular endothelial growth factor (VEGF) was assayed with RT-PCR, and protein expression of VEGF was quantified with western blot. compared with MCAO controls, cerebral infarction, neurological deficits and neuronal apoptosis were reduced significantly in the ICT groups, while the number of neurons was increased. Moreover, the mRNA expression of VEGF and protein expression of VEGF were enhanced after 1 and 2 weeks of ICT. ICT may promote angiogenesis and neuroprotection after ischemic stroke and this new remodeling method provide a novel strategy for rehabilitation of stroke patients.