P5374Genetic deletion of IL-22 increased cardiac rupture after myocardial infarction in mice

Background

Interleukin-22 (IL-22) is a member of the IL-10 cytokine family, which mainly targets epithelial cells and does not target immune cells. Recently, it has been reported that IL-22 play roles in tissue repair in the skin and the liver; however, role of IL-22 in the process of tissue repair after myocardial infarction (MI) is unknown. Here, we investigated the role of IL-22 in tissue repair process after MI.

Methods and results

First, we examined the expression of IL-22 and its receptor IL-22RA1 in the wild type (WT) mice by real-time PCR. The expression of IL-22 and IL-22RA1 in the hearts were significantly increased 3 days after MI (p<0.05). To clarify the role of IL-22 in the heart after MI, we produced MI model in the WT mice and IL-22 knockout (KO) mice. We found that the IL-22 KO mice had significantly higher mortality than the WT mice after MI (p<0.05). Approximately 80% of the IL-22 KO mice died with cardiac rupture after MI. The infarct size which was estimated by evans blue dye and triphenyltetrazolium chloride staining at 3 days after MI was comparable between the IL-22 KO mice and the WT mice. Next, we performed real time PCR and PCR array analysis for tissue fibrosis and repair genes. We found that alpha-smooth muscle actin (aSMA), NF-kB, TNF-a and MMP13 (also known as collagenase-3) were significantly increased in the infarct area of IL-22 KO mice compared to WT mice. Immunostaining showed that the myofibroblast marker aSMA positive cells in the border area after MI were markedly higher in the IL-22 KO mice compared with the WT mice (p<0.05). Approximately 70% of cardiac rupture after MI in the IL-22 KO mice were occurred in the infarct area adjacent to the border area. Furthermore, we found aSMA positive cells and MMP13 positive cells around the ruptured site of the heart.

Conclusion

Thus, IL-22 KO mice exhibit high mortality and increased cardiac rupture after MI. And expression of aSMA and MMP13 were highly expressed in the ruptured site after MI in the IL-22 KO mice. These results suggest that IL-22 may play an important role in the tissue repair process after MI.

Effectiveness of Cardiac Rehabilitation for Prevention and Treatment of Sarcopenia in Patients with Cardiovascular Disease - A Retrospective Cross-Sectional Analysis

OBJECTIVE

Sarcopenia is a syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength, with the risk of frailty and poor quality of life. This study aimed to clarify the clinical characteristics of sarcopenia and to investigate the effects of comprehensive cardiac rehabilitation (CCR), including nutrition, physical exercise and medication, in patients with cardiovascular disease (CVD).

METHODS

We retrospectively studied 322 inpatients with CVD (age 72±12 years). Muscle mass, muscle strength and physical performance were assessed before and after exercise training in patients with and without sarcopenia, which was defined as either a gait speed of <0.8 m/s or reduced handgrip strength (<26 kg in males and <18 kg in females), together with lower skeletal muscle index (SMI) (<7.0 kg/m2 in males and <5.7 kg/m2 in females). The actual daily total calorie and nutrient intake was also calculated.

RESULTS

Sarcopenia was identified in 28% of patients with CVD, these patients having a higher prevalence of symptomatic chronic heart failure and chronic kidney disease. SMI was significantly associated with protein intake and statin treatment. The ratio of peak VO2 and SMI was significantly higher in the statin treatment group. Handgrip strength, gait speed, leg weight bearing index, and nutritional intake improved after exercise training in patients both with and without sarcopenia.

CONCLUSIONS

The present findings suggest that CCR is a promising strategy for prevention and treatment of sarcopenia in patients with CVD.

Functional performance of female patients more than 6 months after total hip arthroplasty shows greater improvement with weight-bearing exercise than with non-weight-bearing exercise. Randomized controlled trial

BACKGROUND

Impaired functional performance and decreased muscle strength and muscle atrophy generally persist for a long period after total hip arthroplasty (THA).

AIM

To investigate the effects of weight-bearing (WB) and non-weight-bearing (NWB) exercises on functional performance, Harris hip score (HHS), muscle strength and muscle thickness in women after THA.

DESIGN

A randomised, controlled trial.

SETTING

Community.

POPULATION

Sixty-five women who had undergone unilateral or bilateral THA at least 6 months before enrolment in the study.

METHODS

Participants were randomly allocated to the following groups: WB (n = 22), NWB (n = 21) and control (n = 22) groups. Participants in the WB and NWB groups performed daily home exercise programs for 8 weeks. Functional performance (timed up and go, sit-to-stand, stair climbing, walking speed and 3-min walk test), HHS, isometric muscle strength of the hip and knee muscle and gluteus and quadriceps muscle thickness were measured at baseline and after 8 weeks.

RESULTS

An intention-to-treat analysis revealed that both the intervention groups exhibited significant improvements in almost all functional performance measures compared with the control group. Furthermore, the WB group showed significantly greater pre-post changes in the sit-to-stand and 3-min walk test compared with the NWB group. In terms of HHS, only the WB group showed significantly greater improvement compared with the control group. Relative to the control group, improvements in all isometric strength measures were observed in both the intervention groups. Significant improvement in quadriceps muscle thickness was observed in the WB group compared with the control group. However, no significant difference was observed among the three groups in pre-post changes in gluteus muscle thickness.

CONCLUSION

WB and NWB home exercise programs were both effective for improving functional performance and muscle strength in women after THA. However, the WB exercise was more effective than the NWB exercise for improving sit-to-stand ability and walking endurance.

CLINICAL REHABILITATION IMPACT

In this study, we demonstrated that the WB exercise was more effective than the NWB exercise for improving functional performance in patients after THA.

Phosphoenolpyruvate, a glycolytic intermediate, as a cytoprotectant and antioxidant in ex-vivo cold-preserved mouse liver: a potential application for organ preservation

OBJECTIVES

The aim of this study was to examine the effect of phosphoenolpyruvate (PEP), a glycolytic intermediate, on organ damage during cold preservation of liver.

METHODS

An ex-vivo mouse liver cold-preservation model and an in-vitro liver injury model induced by hydrogen peroxide in HepG2 cells were leveraged.

KEY FINDINGS

PEP attenuated the elevation of aminotransferases and lactate dehydrogenase leakage during organ preservation, histological changes and changes in oxidative stress parameters (measured as thiobarbituric acid reactive substance and glutathione content) induced by 72 h of cold preservation of the liver. The effects were comparable with the University of Wisconsin solution, a gold standard organ preservation agent. The decrease in ATP content in liver during the cold preservation was attenuated by PEP treatment. PEP prevented the cellular injury and increases in intracellular reactive oxygen species in HepG2 cells. In addition, PEP scavenged hydroxyl radicals, but had no effect on superoxide anion as evaluated by an electron paramagnetic resonance spin-trapping technique.

CONCLUSIONS

PEP significantly attenuated the injury, oxidative stress and ATP depletion in liver during cold preservation. The antioxidative potential of PEP was confirmed by in-vitro examination. We suggest that PEP acts as a glycolytic intermediate and antioxidant, and is particularly useful as an organ preservation agent in clinical transplantation.