Current topics in membranes最新文献

Sodium (Na⁺) concentration in solid tumours of different origin is highly dysregulated, and this corresponds to the aberrant expression of Na⁺ transporters. In particular, the α subunits of voltage gated Na⁺ channels (VGSCs) raise intracellular Na⁺ concentration ([Na⁺]_i) in malignant cells, which influences the progression of solid tumours, predominantly driving cancer cells towards a more aggressive and metastatic phenotype. Conversely, re-expression of VGSC β subunits in cancer cells can either enhance tumour progression or promote anti-tumourigenic properties. Metastasis is the leading cause of cancer-related mortality, highlighting an important area of research which urgently requires improved therapeutic interventions. Here, we review the extent to which VGSC subunits are dysregulated in solid tumours, and consider the implications of such dysregulation on solid tumour progression. We discuss current understanding of VGSC-dependent mechanisms underlying increased invasive and metastatic potential of solid tumours, and how the complex relationship between the tumour microenvironment (TME) and VGSC expression may further drive tumour progression, in part due to the interplay of infiltrating immune cells, cancer-associated fibroblasts (CAFs) and insufficient supply of oxygen (hypoxia). Finally, we explore past and present clinical trials that investigate utilising existing VGSC modulators as potential pharmacological options to support adjuvant chemotherapies to prevent cancer recurrence. Such research demonstrates an exciting opportunity to repurpose therapeutics in order to improve the disease-free survival of patients with aggressive solid tumours.

The immune system is capable of identifying and eliminating cancer, a complicated illness marked by unchecked cellular proliferation. The significance of ion channels in the complex interaction between the immune system and cancer has been clarified by recent studies. Ion channels, which are proteins that control ion flow across cell membranes, have variety of physiological purposes, such as regulating immune cell activity and tumor development. Immune cell surfaces contain ion channels, which have been identified to control immune cell activation, motility, and effector activities. The regulation of immune responses against cancer cells has been linked to a number of ion channels, including potassium, calcium, and chloride channels. As an example, potassium channels are essential for regulating T cell activation and proliferation, which are vital for anti-tumor immunity. Calcium channels play a crucial role when immune cells produce cytotoxic chemicals in order to eliminate cancer cells. Chloride channels also affect immune cell infiltration and invasion into malignancies. Additionally, tumor cells' own expressed ion channels have an impact on their behavior and in the interaction with the immune system. The proliferation, resistance to apoptosis, and immune evasion of cancer cells may all be impacted by changes in ion channel expression and function. Ion channels may also affect the tumor microenvironment by controlling angiogenesis, inflammatory responses, and immune cell infiltration. Ion channel function in the interaction between the immune system and cancer has important implications for cancer treatment. A possible method to improve anti-tumor immune responses and stop tumor development is to target certain ion channels. Small compounds and antibodies are among the ion channel modulators under investigation as possible immunotherapeutics. The complex interaction between ion channels, the immune system, and cancer highlights the significance of these channels for tumor immunity. The development of novel therapeutic strategies for the treatment of cancer will be made possible by unraveling the processes by which ion channels control immune responses and tumor activity. Hence, the main driving idea of the present chapter is trying to understand the possible function of ion channels in the complex crosstalk between cancer and immunoresponse. To this aim, after giving a brief journey of ion channels throughout the history, a classification of the main ion channels involved in cancer disease will be discussed. Finally, the last paragraph will focus on more recently advancements in the use of biomaterials as therapeutic strategy for cancer treatment. The hope is that future research will take advantage of the promising combination of ion channels, immunomodulation and biomaterials filed to provide better solutions in the treatment of cancer disease.

Ion channels play a crucial role in cellular signaling, homeostasis, and generation of electrical and chemical signals. Aberrant expression and dysregulation of ion channels have been associated with cancer development and resistance to conventional cancer treatment such as chemotherapy. Several molecular mechanisms have been proposed to explain this phenomenon. Including evasion of apoptosis, decreased drug accumulation in cancer cells, detoxifying and activation of alternative escape pathways such as autophagy. Each of these mechanisms leads to a reduction of the therapeutic efficacy of administered drugs, causing more difficulty in cancer treatment. This review highlights the linkages between ion channels and resistance to chemotherapy. Furthermore, it elaborates their molecular mechanisms and the potential of being therapeutic targets in clinical management.

The endothelial glycocalyx (EG) is a gel-like structure that forms a layer in between the surface of the endothelium and lumen. EG was once thought to be merely a structural support for the endothelium. However, in recent years, the importance of EG as a first line of defense and a key regulator to endothelial integrity has been illuminated. With advanced age, EG deterioration becomes more noticeable and at least partially associated with endothelial dysfunction. Hyaluronan (HA), one of the critical components of the EG, has distinct properties and roles to the maintenance of EG and endothelial function. Therefore, given the intimate relationship between the EG and endothelium during the aging process, HA may serve as a promising therapeutic target to prevent endothelial dysfunction.

"No cell could exist without ion channels" (Clay Armstrong; 1999). Since the discovery in the early 1950s, that ions move across biological membranes, the idea that changes of ionic gradients can generate biological signals has fascinated scientists in any fields. Soon later (1960s) it was found that ionic flows were controlled by a class of specific and selective proteins called ion channels. Thus, it became clear that the concerted activities of these proteins can initiate, arrest, and finely tune a variety of biochemical cascades which offered the opportunity to better understand both biology and pathology. Cancer is a disease that is notoriously difficult to treat due its heterogeneous nature which makes it the deadliest disease in the developed world. Recently, emerging evidence has established that potassium channels are critical modulators of several hallmarks of cancer including tumor growth, metastasis, and metabolism. Nevertheless, the role of potassium ion channels in cancer biology and the therapeutic potential offered by targeting these proteins has not been explored thoroughly. This chapter is addressed to both cancer biologists and ion channels scientists and it aims to shine a light on the established and potential roles of potassium ion channels in cancer biology and on the therapeutic benefit of targeting potassium channels with activator molecules.

Chloride intracellular channel 1 (CLIC1) has emerged as a therapeutic target in various cancers. CLIC1 promotes cell cycle progression and cancer stem cell (CSC) self-renewal. Furthermore, CLIC1 is shown to play diverse roles in proliferation, cell volume regulation, tumour invasion, migration, and angiogenesis. In glioblastoma (GB), CLIC1 facilitates the G1/S phase transition and tightly regulates glioma stem-like cells (GSCs), a rare population of self-renewing CSCs with central roles in tumour resistance to therapy and tumour recurrence. CLIC1 is found as either a monomeric soluble protein or as a non-covalent dimeric protein that can form an ion channel. The ratio of dimeric to monomeric protein is altered in GSCs and depends on the cell redox state. Elucidating the mechanisms underlying the alterations in CLIC1 expression and structural transitions will further our understanding of its role in GSC biology. This review will highlight the role of CLIC1 in GSCs and its significance in facilitating different hallmarks of cancer.

The endothelial glycocalyx is an extracellular matrix that coats the endothelium and extends into the lumen of blood vessels, acting as a barrier between the vascular wall and blood flowing through the vessel. This positioning of the glycocalyx permits a variety of its constituents, including the major endothelial proteoglycans glypican-1 and syndecan-1, as well as the major glycosaminoglycans heparan sulfate and hyaluronic acid, to contribute to the processes of mechanosensation and subsequent mechanotransduction following such stimuli as elevated shear stress. To coordinate the vast array of processes that occur in response to physical force, the glycocalyx interacts with a plethora of membrane and cytoskeletal proteins to carry out specific signaling pathways resulting in a variety of responses of endothelial cells and, ultimately, blood vessels to mechanical force. This review focuses on proposed glycocalyx-protein relationships whereby the endothelial glycocalyx interacts with a variety of membrane and cytoskeletal proteins to transduce force into a myriad of chemical signaling pathways. The established and proposed interactions at the molecular level are discussed in context of how the glycocalyx regulates membrane/cytoskeletal protein function in the many processes of endothelial mechanotransduction.

The endothelial glycocalyx is a dynamic surface layer composed of proteoglycans, glycoproteins, and glycosaminoglycans with a key role in maintaining endothelial cell homeostasis. Its functions include the regulation of endothelial barrier permeability and stability, the transduction of mechanical forces from the vascular lumen to the vessel walls, serving as a binding site to multiple growth factors and vasoactive agents, and mediating the binding of platelets and the migration of leukocytes during an inflammatory response. Many of these processes are associated with changes in intracellular calcium levels that may occur through mechanisms that alter calcium entry in the endothelium or the release of calcium from the endoplasmic reticulum. Whether the endothelial glycocalyx can regulate calcium dynamics in endothelial cells is unresolved. Interestingly, during cardiovascular disease progression, changes in calcium dynamics are observed in association with the degradation of the glycocalyx and with changes in barrier permeability and vascular reactivity. Herein, we aim to provide a summarized overview of what is known regarding the role of the glycocalyx as a regulator of endothelial barrier and vascular reactivity during homeostatic and pathological conditions and to provide a perspective on how such processes may relate to calcium dynamics in endothelial cells, exploring a possible connection between components of the glycocalyx and calcium-sensitive pathways in the endothelium.

Cancer and neurodegenerative disease, albeit fundamental differences, share some common pathogenic mechanisms. Accordingly, both conditions are associated with aberrant cell proliferation and migration. Here, we review the causative role played by potassium (K⁺) channels, a fundamental class of proteins, in cancer and neurodegenerative disease. The concept that emerges from the review of the literature is that K⁺ channels can promote the development and progression of cancerous and neurodegenerative pathologies by dysregulating cell proliferation and migration. K⁺ channels appear to control these cellular functions in ways that not necessarily depend on their conducting properties and that involve the ability to directly or indirectly engage growth and survival signaling pathways. As cancer and neurodegenerative disease represent global health concerns, identifying commonalities may help understand the molecular basis for those devastating conditions and may facilitate the design of new drugs or the repurposing of existing drugs.