Spatio-temporal model of Meox1 expression control involvement of Sca-1-positive stem cells in neointima formation through the synergistic effect of Rho/CDC42 and SDF-1α/CXCR4

The Role of Cdc42 in the Insulin and Leptin Pathways Contributing to the Development of Age-Related Obesity

Age-related obesity significantly increases the risk of chronic diseases such as type 2 diabetes, cardiovascular diseases, hypertension, and certain cancers. The insulin-leptin axis is crucial in understanding metabolic disturbances associated with age-related obesity. Rho GTPase Cdc42 is a member of the Rho family of GTPases that participates in many cellular processes including, but not limited to, regulation of actin cytoskeleton, vesicle trafficking, cell polarity, morphology, proliferation, motility, and migration. Cdc42 functions as an integral part of regulating insulin secretion and aging. Some novel roles for Cdc42 have also been recently identified in maintaining glucose metabolism, where Cdc42 is involved in controlling blood glucose levels in metabolically active tissues, including skeletal muscle, adipose tissue, pancreas, etc., which puts this protein in line with other critical regulators of glucose metabolism. Importantly, Cdc42 plays a vital role in cellular processes associated with the insulin and leptin signaling pathways, which are integral elements involved in obesity development if misregulated. Additionally, a change in Cdc42 activity may affect senescence, thus contributing to disorders associated with aging. This review explores the complex relationships among age-associated obesity, the insulin-leptin axis, and the Cdc42 signaling pathway. This article sheds light on the vast molecular web that supports metabolic dysregulation in aging people. In addition, it also discusses the potential therapeutic implications of the Cdc42 pathway to mitigate obesity since some new data suggest that inhibition of Cdc42 using antidiabetic drugs or antioxidants may promote weight loss in overweight or obese patients.

Silencing of CDC42 inhibits contraction and growth-related functions in prostate stromal cells, which is mimicked by ML141

BACKGROUND

Prostate smooth muscle contraction and stromal growth may contribute to lower urinary tract symptoms suggestive of benign prostatic hyperplasia, but are incompletely understood. A role of the monomeric GTPase CDC42 for smooth muscle contraction and proliferation appears possible, but is unknown for the prostate. Here, we silenced CDC42 expression in prostate stromal cells (WPMY-1), and examined contractility, growth-related functions and responses to the presumed CDC42 inhibitor, ML141.

METHODS

WPMY-1 cells were transfected with scrambled or CDC42-specific siRNA, and characterized for GTPase activities, contraction, proliferation, colony formation, apoptosis, cell death and viability. Effects of ML141 were examined in cells with and without silencing.

RESULTS

CDC42 silencing was confirmed by reduced mRNA and protein expression, and reduced CDC42 activity. Silencing impaired contraction (23-47 %), actin organization (25 %), proliferation (17-63 %), colony formation and viability (64-89 %), and increased the percentage of dead cells (2.6-fold). ML141 mimicked the phenotype of silencing in scrambled siRNA-transfected controls, and in non-transfected WPMY-1 cells, including inhibition of contraction, proliferation, colony formation and viability, breakdown of actin organization and increased cell death. In CDC42-silenced cells, ML141 still affected phalloiding organization, proliferation and cell death, with effect sizes resembling controls without silencing. ML141 inhibited RhoA activity in CDC42-silenced cells, but not in cells without silencing.

CONCLUSIONS

CDC42 promotes contraction of prostate stromal cells, and drives stromal growth by CDC42-mediated proliferation and suppression of apoptosis-independent cell death. ML141 mimicks all effects of CDC42 silencing, but its specificity may be limited and depends on GTPase phenotypes of cells.

The role of MEOX1 in non-neoplastic and neoplastic diseases

Targeted gene therapy has shown durable efficacy in non-neoplastic and neoplastic patients. Therefore, finding a suitable target has become a key area of research. Mesenchyme homeobox 1 (MEOX1) is a transcriptional factor that plays a significant role in regulation of somite development. Evidence indicates that abnormalities in MEOX1 expression and function are associated with a variety of pathologies, including non-neoplastic and neoplastic diseases. MEOX1 expression is upregulated during progression of most diseases and plays a critical role in maintenance of the cellular phenotypes such as cell differentiation, cell cycle arrest and senescence, migration, and proliferation. Therefore, MEOX1 may become an important molecular target and therapeutic target. This review will discuss the current state of knowledge on the role of MEOX1 in different diseases.

Correlation between stem cell molecular phenotype and atherosclerotic plaque neointima formation and analysis of stem cell signal pathways

Vascular stem cells exist in the three-layer structure of blood vessel walls and play an indispensable role in angiogenesis under physiological conditions and vascular remodeling under pathological conditions. Vascular stem cells are mostly quiescent, but can be activated in response to injury and participate in endothelial repair and neointima formation. Extensive studies have demonstrated the differentiation potential of stem/progenitor cells to repair endothelium and participate in neointima formation during vascular remodeling. The stem cell population has markers on the surface of the cells that can be used to identify this cell population. The main positive markers include Stem cell antigen-1 (Sca1), Sry-box transcription factor 10 (SOX10). Stromal cell antigen 1 (Stro-1) and Stem cell growth factor receptor kit (c-kit) are still controversial. Different parts of the vessel have different stem cell populations and multiple markers. In this review, we trace the role of vascular stem/progenitor cells in the progression of atherosclerosis and neointima formation, focusing on the expression of stem cell molecular markers that occur during neointima formation and vascular repair, as well as the molecular phenotypic changes that occur during differentiation of different stem cell types. To explore the correlation between stem cell molecular markers and atherosclerotic diseases and neointima formation, summarize the differential changes of molecular phenotype during the differentiation of stem cells into smooth muscle cells and endothelial cells, and further analyze the signaling pathways and molecular mechanisms of stem cells expressing different positive markers participating in intima formation and vascular repair. Summarizing the limitations of stem cells in the prevention and treatment of atherosclerotic diseases and the pressing issues that need to be addressed, we provide a feasible scheme for studying the signaling pathways of vascular stem cells involved in vascular diseases.