Protective function of tocilizumab in human cardiac myocytes ischemia reperfusion injury

Rivaroxaban down-regulates pyroptosis and the TLR4/NF-κB/NLRP3 signaling pathway to promote flap survival

BACKGROUND

Flap placement remains the primary method for wound repair, but postoperative ischemic flap necrosis is of major concern. This study explored whether rivaroxaban, a factor Xa inhibitor, enhanced flap survival.

METHODS

Thirty-six rats were randomly divided into control, low-dose rivaroxaban (3 mg/kg/day), and high-dose rivaroxaban (7 mg/kg/day) groups. On postoperative day 7, the flap survival rate was analyzed and the average survival area calculated. After the rats were euthanized, immunological and molecular biological techniques were employed to assess vascular regeneration, pyroptosis, and inflammation.

RESULTS

Rivaroxaban upregulated VEGF expression, in turn enhancing angiogenesis, and it downregulated IL-1β, IL-6, and TNF-α expression, thereby mitigating inflammation. The drug also suppressed TLR4, NF-κB p65, NLRP3, caspase-1, and IL-18 syntheses, thus inhibiting pyroptosis.

CONCLUSIONS

Rivaroxaban enhanced random flap survival by down-regulating the TLR4/NF-κB/NLRP3 signaling pathway to suppress pyroptosis, promoting vascular regeneration and inhibiting inflammation.

Cytokine pattern in patients with ST-elevation myocardial infarction treated with the interleukin-6 receptor antagonist tocilizumab

BACKGROUND

Tocilizumab improves myocardial salvage index (MSI) in patients with ST-elevation myocardial infarction (STEMI), but its mechanisms of action are unclear. Here, we explored how cytokines were affected by tocilizumab and their correlations with neutrophils, C-reactive protein (CRP), troponin T, MSI and infarct size.

METHODS

STEMI patients were randomised to receive a single dose of 280 mg tocilizumab (n=101) or placebo (n=98) before percutaneous coronary intervention. Blood samples were collected before infusion of tocilizumab or placebo at baseline, during follow-up at 24-36, 72-168 hours, 3 and 6 months. 27 cytokines were analysed using a multiplex cytokine assay. Cardiac MRI was performed during hospitalisation and 6 months.

RESULTS

Repeated measures analysis of variance showed significant (p<0.001) between-group difference in changes for IL-6, IL-8 and IL-1ra due to an increase in the tocilizumab group during hospitalisation. IL-6 and IL-8 correlated to neutrophils in the placebo group (r=0.73, 0.68, respectively), which was attenuated in the tocilizumab group (r=0.28, 0.27, respectively). A similar pattern was seen for MSI and IL-6 and IL-8 in the placebo group (r=-0.29, -0.25, respectively) in patients presenting ≤3 hours from symptom onset, which was attenuated in the tocilizumab group (r=-0.09,-0.14, respectively).

CONCLUSIONS

Tocilizumab increases IL-6, IL-8 and IL-1ra in STEMI. IL-6 and IL-8 show correlations to neutrophils/CRP and markers of cardiac injury in the placebo group that was attenuated in the tocilizumab group. This may suggest a beneficial effect of tocilizumab on the ischaemia-reperfusion injury in STEMI patients.

TRIAL REGISTRATION NUMBER

NCT03004703.

Tocilizumab is effective in preventing ovarian injury induced by ischemia- reperfusion in rats

Ovarian torsion can be defined as the bending of the ovaries on the supporting ligament, disrupting both venous and arterial blood circulation. Insufficient blood flow causes ovarian tissue hypoxia and leads to ischemia. This study aimed to investigate whether tocilizumab has a protective effect on ischemia-reperfusion injury due to ovarian torsion in rats. Eighteen female Wistar albino rats were divided into three equal groups (Sham (SG), ischemia-reperfusion (OIR), and ischemia-reperfusion+tocilizumab (OIRT)). Degeneration, necrosis, vascular dilatation/congestion, interstitial edema, hemorrhage, and polymorphonuclear lymphocyte (PMNL) infiltration scores were significantly different between the groups (p=0.001 for all parameters). Moreover, the OIRT group had a significant improvement in these criteria compared to the OIR group (p<0.05). Additionally, there was a considerable difference between OIRT and OIR groups in the number of primordial, developing, and atretic follicles groups (p<0.05), while there was no difference in the number of corpus luteum (p=0.052). Stress markers or cytokines, such as MDA, tGSH, NF-κB, TNF-α, IL-1β, and IL-6, were significantly different between groups (p<0.05). Furthermore, a significant improvement was found in the measured variables when the OIRT group was compared with the OIR group (p<0.05). Tocilizumab may be an alternative option for treating ischemia-reperfusion injury due to ovarian torsion.

Coactivity of Mast Cells and Stem Cells on Angiogenesis and Antioxidants' Potentials at Inflammation, Proliferation, and Tissue Remodeling Phases of Wound

Background  Reactive oxygen species cause serious damage to the physiological function of tissues. Determination of total antioxidant capacity of skin tissue is one of the determinants of damaged tissue function. Mast cells (MCs) are one of the groups of cells that are invited to the site of injury. The healing process begins with the rapid release of various types of MCs' intermediate factors at the site of injury. Bone marrow mesenchymal stem cell (BMMSC) production and secretion have been shown to regenerate the skin. The aim of this research was to evaluate the wound-healing and antioxidant effects of BMMSCs per MCs.

Methods  Fifty-four albino Wistar male rats were divided into three groups: (1) nonsurgery, (2) surgery, and (3) surgery + BMMSCs. Groups 2 and 3 were operated with a 3 × 8 cm flap and in group 3, cell injections (7 × 10 ⁹ cell injection at the time of surgery) were performed. After days 4, 7, and 15, percentage of the surviving tissue, histological characteristics, superoxide dismutase (SOD) activity, and amount of malondialdehyde (MDA) were measured in the groups. For results, Graph Pad Prism 8 software was used, and data were analyzed and compared by analysis of variance and Tukey test.

Results  BMMSCs' application decreased the amount of MDA, increased SOD activity and survival rate of the flaps, and improved the histological characteristics.

Conclusion  This study revealed the protective effects BMMSCs alongside MCs against oxidative stress on the survival of the flaps. However, for clinical use, more research is needed to determine its benefits.

Inhibition of Interleukin-6 signaling: A novel therapeutic approach to necrotizing enterocolitis

OBJECTIVES

This study investigated the effects of tocilizumab on the prevention and treatment of experimental necrotizing enterocolitis (NEC) in newborn rats.

METHODS

Forty-two newborn Sprague-Dawley rats were randomly separated into three groups: NEC + placebo, NEC + tocilizumab, and the control group. NEC + placebo and NEC + tocilizumab groups were given 1 mg/kg lipopolysaccharide intraperitoneally once only on the first day, were fed with a special rodent formula every 3 h, inhaled 100% CO2 for 10 min, were exposed to cold stress at + 4 °C for 5 min, and 97% O2 for 5 min twice a day for 3 days. NEC + tocilizumab group was treated with 8 mg/kg/day tocilizumab (Actemra®) intraperitoneally, while NEC + placebo group was given intraperitoneal 0.9% saline at a dose of 2 mL/kg/day from the first day to the end of the study. All newborn rats were sacrificed on day 4. Specimens were taken for histopathologic, immunohistochemical and biochemical evaluation from the ileum and proximal colon.

RESULTS

NEC + tocilizumab group had higher weight gain and survival rate compared to NEC + placebo group and clinical sickness score was reduced in NEC + tocilizumab group (p < 0.05). Lower tissue damage and apoptosis were found in the NEC + tocilizumab group compared to the NEC + placebo group (p < 0.01). Tissue Interleukin-6, Interleukin-1β, TNF-α, myeloperoxidase and caspase-3 levels were significantly decreased in the NEC + tocilizumab group (p < 0.01).

CONCLUSIONS

Tocilizumab could be a potential option in the prevention and treatment of NEC.

Interleukin-6: A Novel Target for Cardio-Cerebrovascular Diseases

Cardio-Cerebrovascular Disease is a collective term for cardiovascular disease and cerebrovascular disease, being a serious threat to human health. A growing number of studies have proved that the content of inflammatory factors or mediators determines the stability of vascular plaque and the incidence of cardio-cerebrovascular event, and involves in the process of Cardio-Cerebrovascular Diseases. Interleukin-6 is a widely used cytokine that causes inflammation and oxidative stress, which would further result in cardiac and cerebral injury. The increased expression of interleukin-6 is closely related to atherosclerosis, myocardial infarction, heart failure and ischemic stroke. It is a key risk factor for these diseases by triggering inflammatory reaction and inducing other molecules release. Therefore, interleukin-6 may become a potential target for Cardio-Cerebrovascular Diseases in the future. This paper is aimed to discuss the expression changes and pathological mechanisms of interleukin-6 in Cardio-Cerebrovascular Diseases, and to provide a novel strategy for the prevention and treatment of Cardio-Cerebrovascular Diseases.

IL6 receptor blockade preserves articular cartilage and increases bone volume following ischemic osteonecrosis in immature mice

OBJECTIVE

Juvenile ischemic osteonecrosis (JIO) of the femoral head is one of the most serious hip disorders causing a permanent deformity of the femoral head in childhood. We recently reported that interleukin 6 (IL6) is predominantly increased in the hip synovial fluid of patients with JIO and that articular chondrocytes are primary source of IL6. This study investigated whether an inhibition of IL6 receptor improves cartilage preservation and bone healing in JIO.

METHOD

A small animal model (i.e., 6-week-old mouse) of JIO was treated with either saline or tocilizumab, an IL6 receptor blocker, for 6 weeks.

RESULTS

TUNEL-positive chondrocytes in the articular cartilage were reduced by the tocilizumab treatment, concomitant with the increase in cartilage matrix. The levels of a cartilage anabolic marker Sox9 was significantly increased in the articular cartilage of mice treated with tocilizumab. Micro-CT assessment showed tocilizumab treatment significantly increased trabecular epiphyseal bone volume (P = 0.001, n = 10), thickness (P = 0.007) and number (P = 0.014) and decreased bone separation (P = 0.002) and its deformity (P = 0.003). A bone formation marker, BMP2, and an angiogenic marker, vascular endothelial growth factor (VEGF), were both significantly increased by tocilizumab treatment under hypoxia using human chondrocytes while the bone resorption marker, RANKL/OPG ratio, was reduced.

CONCLUSION

Tocilizumab treatment following ischemic osteonecrosis has cartilage anabolic effect and increases bone volume in JIO mouse model. The findings lead to a possible application of tocilizumab for preclinical study using a large animal model of JIO and a clinical trial to validate this treatment.

Effects of SB202190 on expression levels of IL-6 and NF-κB in flap ischemia-reperfusion injury

The aim of the current study was to investigate the effect of SB202190, a specific inhibitor of p38 MAPK signaling pathway, on the expression levels of IL-6 and NF-κB in flap ischemia-reperfusion injury. Healthy Sprague-Dawley rats were randomly divided into four groups of 12 each. For the ischemia-reperfusion group, the flap was constructed and then sutured after 8 h of ischemia. For the saline group, rats were intraperitoneally infused with saline at regular intervals after flap ischemia-reperfusion. For the inhibitor group, rats were intraperitoneally infused with SB202190 at regular intervals after flap ischemia-reperfusion. For the control group, the flap was constructed and then sutured immediately. The flap survival rate of each group was measured after 7 days. The concentration of IL-6 in serum was measured by ELISA kit. The mRNA and protein expression levels of IL-6 and NF-κB in the flap were measured using RT-PCR and western blot analysis, respectively. In the ischemia-reperfusion group and the saline group, the flap survival rates were much lower than that in the control group (P<0.05). By contrast, the mRNA and protein expression levels of IL-6 and NF-κB in the flap and the concentration of IL-6 in serum were much higher (P<0.05). In the inhibitor group, the flap survival rate was significantly higher than those in the ischemia-reperfusion and saline groups (P<0.05). By contrast, the concentration of IL-6 in serum and the mRNA and protein expression levels of NF-κB and IL-6 in the flap were significantly decreased (P<0.05). The results show that, SB202190 played a role in the protection of the flap by reducing the inflammatory response in flap ischemia-reperfusion injury.

[Interleukin-6 inhibition and cardiovascular disease in patients with rheumatoid arthritis]

Rheumatoid arthritis (RA) is a' disease conferring high risk for cardiovascular events (CVE). Systemic inflammation underlying RA favors development of CVE. The safety of biological agents, acting on the cardiovascular system has been inadequately investigated. On the one hand, they decrease RA activity and, on the other, may increase the risk of CVE. This review analyzes' the literature data predominantly published in recent years on the effect of an IL-6 receptor inhibitor on the cardiovascular system. Tocilizumab is shown to be a promising agent to reduce cardiovascular risk the findings need to be clinically verified. Long-term prospective investigations should be conducted to determine more exactly the impact of IL-6 receptor inhibition on. the development of CVE.