Effect of transplantation of cardiac stem cells overexpressing integrin-linked kinase on cardiac function of rats with acute myocardial infarction

Endothelial ILK induces cardioprotection by preventing coronary microvascular dysfunction and endothelial-to-mesenchymal transition

Endothelial dysfunction is an early event in coronary microvascular disease. Integrin-linked kinase (ILK) prevents endothelial nitric oxide synthase (eNOS) uncoupling and, thus, endothelial dysfunction. However, the specific role of endothelial ILK in cardiac function remains to be fully elucidated. We hypothesised that endothelial ILK plays a crucial role in maintaining coronary microvascular function and contractile performance in the heart. We generated an endothelial cell-specific ILK conditional knock-out mouse (ecILK cKO) and investigated cardiovascular function. Coronary endothelial ILK deletion significantly impaired cardiac function: ejection fraction, fractional shortening and cardiac output decreased, whilst left ventricle diastolic internal diameter decreased and E/A and E/E' ratios increased, indicating not only systolic but also diastolic dysfunction. The functional data correlated with extensive extracellular matrix remodelling and perivascular fibrosis, indicative of adverse cardiac remodelling. Mice with endothelial ILK deletion suffered early ischaemic-like events with ST elevation and transient increases in cardiac troponins, which correlated with fibrotic remodelling. In addition, ecILK cKO mice exhibited many features of coronary microvascular disease: reduced cardiac perfusion, impaired coronary flow reserve and arterial remodelling with patent epicardial coronary arteries. Moreover, endothelial ILK deletion induced a moderate increase in blood pressure, but the antihypertensive drug Losartan did not affect microvascular remodelling whilst only partially ameliorated fibrotic remodelling. The plasma miRNA profile reveals endothelial-to-mesenchymal transition (endMT) as an upregulated pathway in endothelial ILK conditional KO mice. Our results show that endothelial cells in the microvasculature in endothelial ILK conditional KO mice underwent endMT. Moreover, endothelial cells isolated from these mice and ILK-silenced human microvascular endothelial cells underwent endMT, indicating that decreased endothelial ILK contributes directly to this endothelial phenotype shift. Our results identify ILK as a crucial regulator of microvascular endothelial homeostasis. Endothelial ILK prevents microvascular dysfunction and cardiac remodelling, contributing to the maintenance of the endothelial cell phenotype.

A Potential Role for Integrin-Linked Kinase in Colorectal Cancer Growth and Progression via Regulating Senescence and Immunity

Integrin-linked kinase (ILK) has been implicated as a molecular driver and mediator in both inflammation and tumorigenesis of the colon. ILK functions as an adaptor and mediator protein linking the extracellular matrix with downstream signaling pathways. ILK is broadly expressed in many human tissues and cells. It is also overexpressed in many cancers, including colorectal cancer (CRC). Inflammation, as evidenced by inflammatory bowel disease (IBD), is one of the highest risk factors for initiating CRC. This has led to the hypothesis that targeting ILK therapeutically could have potential in CRC, as it regulates different cellular processes associated with CRC development and progression as well as inflammation in the colon. A number of studies have indicated an ILK function in senescence, a cellular process that arrests the cell cycle while maintaining active metabolism and transcription. Senescent cells produce different secretions collectively known as the senescence-associated secretory phenotype (SASP). The SASP secretions influence infiltration of different immune cells, either positively for clearing senescent cells or negatively for promoting tumor growth, reflecting the dual role of senescence in cancer. However, a role for ILK in senescence and immunity in CRC remains to be determined. In this review, we discuss the possible role for ILK in senescence and immunity, paying particular attention to the relevance of ILK in CRC. We also examine how activating Toll-like receptors (TLRs) and their agonists in CRC could trigger immune responses against cancer, as a combination therapy with ILK inhibition.

Therapeutic effect of integrin-linked kinase gene-modified bone marrow-derived mesenchymal stem cells for streptozotocin-induced diabetic cystopathy in a rat model

Background

Diabetic cystopathy (DCP) is a chronic complication of diabetes mainly within the submucosal and muscular layers of the bladder due to the hyperglycemia-induced ischemia. As no effective therapies are currently available, the administration of optimized mesenchymal stem cells (MSCs) provides a potential treatment of DCP. Thus far, new strategy, such as genetic modification of MSCs, has been developed and has shown promising outcomes of various disorders.

Methods

This study was conducted using integrin-linked kinase (ILK) gene-modified bone marrow-derived stem cells (BMSCs) for streptozotocin (STZ)-induced diabetic cystopathy in a rat model. In total, 68 male Sprague-Dawley rats were randomized into five groups: sham control (control group, n = 10); DCP model alone (DM group, n = 10); DCP rats intravenously treated with BMSCs (BMSC group, n = 16); DCP rats accepted adenoviral vector-infected BMSCs (Ad-null-BMSC group, n = 16) and DCP rats accepted ILK adenoviral vector-infected BMSCs (Ad-ILK-BMSC group, n = 16). Diabetic rats accepted cell transplantation in the experimental group (2 rats per group) were sacrificed for the bladder tissue on the third day, 7th day, and 14th day of treatment respectively ahead of schedule. At 4 weeks after treatment, all rats in five groups accepted urodynamic studies to evaluate bladder function and were sacrificed for bladder tissue.

Results

Our data showed that the underactive bladder function was significantly improved in DCP rats intravenously treated with ILK gene-modified BMSCs compared to those in the DM, BMSCs, and Ad-null-BMSC group. Meanwhile, we found that gene-modified BMSC treatment significantly promoted the activation of the AKT/GSK-3β pathway by increasing phosphorylation and led to the enhancement of survival. In addition, the expression levels of angiogenesis-related protein vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and stromal cell-derived factor-1 (SDF-1) were significantly higher in the Ad-ILK-BMSC group than that in the DM, BMSCs, and Ad-null-BMSC group as assessed by enzyme-linked immunosorbent assay and western blot. As two indicators of vascular endothelial cell markers, the expression of von Willebrand factor (vWF) and CD31 by western blot and immunofluorescent staining revealed that the percentage of the vascular area of the bladder tissue significantly increased in Ad-ILK-BMSC group compared with the BMSCs and Ad-null-BMSC group on the 14th day of treatment. Histological and immunohistochemical staining (hematoxylin and eosin (HE), vWF, Ki67, and TUNNEL) on the bladder tissue revealed statistically different results between groups.

Conclusion

ILK gene-modified BMSCs restored the bladder function and histological construction via promoting the process of angiogenesis and protecting cells from high glucose-associated apoptosis in STZ-induced DCP rat model, which provides a potential for the treatment of patients with DCP.