ROCK inhibition as a potential therapeutic target involved in apoptosis in hemangioma

Recent advances in the development of Rho kinase inhibitors (2015-2021)

Rho-associated coiled-coil kinases (ROCKs) are key downstream effectors of small GTPases. ROCK plays a central role in diverse cellular events with accumulating evidence supporting the concept that ROCK is important in tumor development and progression. Numerous ROCK inhibitors have been investigated for their therapeutic potential in the treatment of cancers. In this article, we review recent research progress on ROCK inhibitors, especially those with potential for the treatment of cancers, reported in the literature from 2015 to 2021. Most ROCK inhibitors show potent in vitro and in vivo antitumor activities and have potential in the treatment of cancers.

Application and Study of ROCK Inhibitors in Pulmonary Fibrosis: Recent Developments and Future Perspectives

Rho-associated coiled-coil-containing kinases (ROCKs), serine/threonine protein kinases, were initially identified as downstream targets of the small GTP-binding protein Rho. Pulmonary fibrosis (PF) is a lethal disease with limited therapeutic options and a particularly poor prognosis. Interestingly, ROCK activation has been demonstrated in PF patients and in animal PF models, making it a promising target for PF treatment. Many ROCK inhibitors have been discovered, and four of these have been approved for clinical use; however, no ROCK inhibitors are approved for the treatment of PF patients. In this article, we describe ROCK signaling pathways and the structure-activity relationship, potency, selectivity, binding modes, pharmacokinetics (PKs), biological functions, and recently reported inhibitors of ROCKs in the context of PF. We will also focus our attention on the challenges to be addressed when targeting ROCKs and discuss the strategy of ROCK inhibitor use in the treatment of PF.

Betaine alleviates right ventricular failure via regulation of Rho A/ROCK signaling pathway in rats with pulmonary arterial hypertension

Pulmonary vascular remodeling was shown to lead to pulmonary arterial hypertension (PAH), further trigger excessive apoptosis of cardiomyocytes, and ultimately cause right ventricular failure (RVF), which involves the activation of Rho A/ROCK signaling pathway. Betaine has been found efficacious for attenuating PAH through its anti-inflammatory effects in our previous research while its effects on RVF due to PAH remains inconclusive. Thus, we attempted to elucidate the protective effects of betaine on PAH, RVF due to PAH as well as the potential mechanisms. To this end, male Sprague Dawley rats received a single subcutaneous injection of monocrotaline (50 mg/kg) to imitate PAH and RVF, and subsequently oral administration of betaine (100, 200, and 400 mg/kg/day). Betaine treatment improved the hemodynamics and histomorphological parameters and echocardiographic changes. Moreover, betaine also alleviated the pulmonary vascular remodeling and cardiomyocyte apoptosis. The mechanisms study revealed that administration of betaine significantly increased the expression of Rho A, ROCK1, and ROCK2. Furthermore, betaine alleviated the changes of its downstream molecules P53, Bcl-2, Bax, phosphorylated MYPT1 (p-MYPT1), total MYPT1 (t-MYPT1), p27kip1, and Cleaved Caspase-3. According to what we observed, this study indicated that betaine treatment could protect RVF due to PAH, which may be achieved through an altered Rho A/ROCK signaling pathway.

Prolonged treatment with Y-27632 promotes the senescence of primary human dermal fibroblasts by increasing the expression of IGFBP-5 and transforming them into a CAF-like phenotype

The Rho-kinases (ROCK) inhibitor Y-27632 has been shown to promote the growth of epidermal cells, however, its potential effects on human dermal fibroblasts (HDFs) need to be clarified. Here we show that prolonged treatment of HDFs with Y-27632 decreased their growth by inducing senescence, which was associated with induction of the senescence markers p16 and p21, and downmodulation of the ERK pathways. The senescent HDFs induced by Y-27632 acquired a cancer-associated-fibroblast (CAF)-like phenotype to promote squamous cell carcinoma (SCC) cell growth in vitro. Expression of a newly identified target of Y-27632 by RNA-seq, insulin growth factor binding protein 5 (IGFBP-5), was dramatically increased after 24 h of treatment with Y-27632. Adding recombinant IGFBP-5 protein to the culture medium produced similar phenotypes of HDFs as did treatment with Y-27632, and knockdown of IGFBP-5 blocked the Y-27632-induced senescence. Furthermore, Y-27632 induced the expression of an IGFBP-5 upstream gene, GATA4, and knockdown of GATA4 also reduced the Y-27632-induced senescence. In summary, these results demonstrate for the first time that Y-27632 promotes cellular senescence in primary HDFs by inducing the expression of IGFBP-5 and that prolonged treatment with Y-27632 potentially transforms primary HDFs into CAF-like cells.

miR-4458 directly targets IGF1R to inhibit cell proliferation and promote apoptosis in hemangioma

Hemangiomas (HAs) are benign neoplasms of the vasculature. MicroRNA-4458 (miR-4458) has been reported to function as a tumor suppressor in multiple malignancies, but its biological function in HAs remains unknown. In the present study, the potential role of miR-4458 in HA-derived endothelial cells (HDECs) was investigated. Firstly, reverse-transcription-quantitative PCR analysis was used to confirm the expression of miR-4458 in HDECs following transfection with miR-4458 mimics or inhibitor. Subsequently, MTT and EdU assays were performed and subsequently determined that miR-4458 overexpression significantly inhibited proliferation, and knockdown promoted cell proliferation in HDECs. Flow cytometry analysis revealed that miR-4458 overexpression induced cell cycle arrest, whereas knockdown reversed G0/G1 phase arrest and apoptosis. Furthermore, insulin-like growth factor 1 receptor (IGF1R) was identified as a target of miR-4458. IGF1R knockdown enhanced the effects of miR-4458 on cell proliferation, cell cycle G0/G1 phase arrest and apoptosis in HDECs. Taken together, the results revealed that miR-4458 targeting of IGF1R may serve as a novel therapeutic strategy for treating patients with HAs.

ROCK Inhibitor Y-27632 Promotes Human Retinal Pigment Epithelium Survival by Altering Cellular Biomechanical Properties

Purpose:

Dysfunction or death of retinal pigment epithelial (RPE) cells is a common pathogenesis of various types of retinal degenerative diseases. Recent reports indicated that ROCK pathway inhibitors regulate cell proliferation or apoptosis in a cell-type-dependent manner. Here, we aim to investigate the effect of ROCK inhibitor Y-27632 on the human retinal pigment epithelium (RPE) in vitro.

Methods:

Cell proliferation and apoptosis were analyzed by CCK-8 and flow cytometry respectively. Cell proliferation markers were detected by immunofluorescence and western blot. Cell morphology was evaluated using scanning electron microscopy. The topography and biomechanical properties of living cells were assessed using atomic force microscope (AFM). In addition, cytoskeleton and epithelial-mesenchymal transition (EMT) markers were detected by western blot and immunofluorescence.

Results:

30μM Y-27632 significantly promoted cell proliferation and decreased apoptosis. Compared with control group, human retinal pigment epithelial cell line ARPE-19 cells treated with 30μM Y-27632 exhibited significantly decreased cytomembrane roughness (Ra: 41.04±1.63nm vs. 24.41±0.75nm, P<0.01; Rq: 51.56±2.03nm vs. 30.81±0.95nm, P<0.01) and increased elasticity modulus (16.66±0.83KPa vs. 32.55±1.48KPa, P<0.01). In addition, the inhibition of ROCK activity by Y-27632 caused cell elongation and reorganization of microfilaments and microtubules of cytoskeletons.

Conclusion:

Taken together, our data demonstrated that Y-27632 could alter biomechanical properties and reorganized cytoskeletons to promote RPE cell survival. These results are an important step toward the future application of Y-27632 in retinal degenerative diseases.

Mechanotransduction in tumor progression: The dark side of the force

Broders-Bondon et al. review the pathological mechanical properties of tumor tissues and how abnormal mechanical signals result in oncogenic biochemical signals during tumor progression.

Cancer has been characterized as a genetic disease, associated with mutations that cause pathological alterations of the cell cycle, adhesion, or invasive motility. Recently, the importance of the anomalous mechanical properties of tumor tissues, which activate tumorigenic biochemical pathways, has become apparent. This mechanical induction in tumors appears to consist of the destabilization of adult tissue homeostasis as a result of the reactivation of embryonic developmental mechanosensitive pathways in response to pathological mechanical strains. These strains occur in many forms, for example, hypervascularization in late tumors leads to high static hydrodynamic pressure that can promote malignant progression through hypoxia or anomalous interstitial liquid and blood flow. The high stiffness of tumors directly induces the mechanical activation of biochemical pathways enhancing the cell cycle, epithelial–mesenchymal transition, and cell motility. Furthermore, increases in solid-stress pressure associated with cell hyperproliferation activate tumorigenic pathways in the healthy epithelial cells compressed by the neighboring tumor. The underlying molecular mechanisms of the translation of a mechanical signal into a tumor inducing biochemical signal are based on mechanically induced protein conformational changes that activate classical tumorigenic signaling pathways. Understanding these mechanisms will be important for the development of innovative treatments to target such mechanical anomalies in cancer.

Delivery of sodium morrhuate to hemangioma endothelial cells using immunoliposomes conjugated with anti-VEGFR2/KDR antibody

Hemangioma is a common benign tumor affecting infants. In this study, we prepared sodium morrhuate immunoliposomes through encapsulation of sodium morrhuate with liposomes coupled with an anti-VEGFR2/KDR antibody and examined its effect on the biology of human hemangioma endothelial cells (HECs). It was found that compared to the liposomal sodium morrhuate group, treatment with sodium morrhuate immunoliposomes facilitated cell detachment and apoptotic death. Confocal microscopy analysis revealed that sodium morrhuate immunoliposomes had a higher binding activity to HECs than liposomal sodium morrhuate. Apoptosis analysis further demonstrated that treatment with liposomal sodium morrhuate or sodium morrhuate immunoliposomes significantly induced apoptosis in HECs, compared to the control group. Western blot analysis revealed an induction of caspase-3 and caspase-9 levels and reduction of caspase-8 and Bcl-2 levels in HECs treated with liposomal sodium morrhuate or sodium morrhuate immunoliposomes. Taken together, these results indicate that sodium morrhuate immunoliposomes have an increased capacity to target HECs and promote mitochondrial apoptosis. Therefore, sodium morrhuate immunoliposomes may represent a promising agent in the treatment of hemangiomas.

Inhibition of Rho Kinase Induces Antioxidative Molecules and Suppresses Reactive Oxidative Species in Trabecular Meshwork Cells

Purpose

To investigate the effect of rho kinase inhibitors on oxidative stress in trabecular meshwork (TM) cells.

Methods

TM cells were isolated from the eyes of cynomolgus monkeys. Y-27632 and menadione were used to inhibit rho kinase and induce production of reactive oxygen species (ROS), respectively. The cynomolgus monkey array and 12,613 probes were used in DNA microarray analysis, and the affected genes were categorized using gene ontology analysis. The mRNA levels of the target genes were confirmed by real-time RT-PCR. Intracellular oxidative stress was detected using a fluorescent reagent sensitive to ROS. Cell viability was assessed by the WST-8 assay.

Results

Gene ontology analysis revealed upregulation of genes involved in antioxidant activity, and upregulation of catalase was confirmed by real-time RT-PCR after 30 min treatment with Y-27632. Production of ROS was increased by menadione, and the effect was partly suppressed by pretreatment with Y-27632. At a lower dose of menadione, Y-27632 stimulated TM cells and significantly increased their viability following menadione treatment compared to control cells.

Conclusion

Using microarray analysis, Y-27632 was shown to upregulate antioxidative genes including catalase and partially reduce ROS production and cell death by oxidative stress caused by menadione.