Multimodal roles of transient receptor potential channel activation in inducing pathological tissue scarification

Epidermal Mechanical Scratching-Induced ROS Exacerbates the Itch-Scratch Cycle through TRPA1 Activation on Mast Cells in Atopic Dermatitis

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by the itch-scratch cycle. Itching, induced by irritants or allergens that stimulate pruriceptive neurons, triggers uncontrollable mechanical scratching, leading to epidermal barrier disruption, immune response activation, inflammatory mediator release, and further stimulation of pruritus conduction. Although oxidative stress and immune cells can exacerbate this cycle, the correlation between mechanical scratching, epidermal oxidative stress, and dermal mast cell activation in AD remains unclear. In this study, by examining clinical specimens of AD, establishing a 3-dimensional coculture system of HaCaT and LAD2 cells, and utilizing a mechanical scratching mouse model of AD, we found that ROS produced by mechanically stimulated HaCaT can activate TRPA1 on mast cells presenting tryptase. Implementing a free radical scavenger and TRPA1 inhibitor can inhibit mast cell activation and type II inflammatory response, thereby alleviating itching and skin lesions in AD. These results indicate that active oxygen scavenging combined with TRPA1 inhibition can inhibit the itch-scratch cycle, which may present a potential approach for treatment of AD.

Perspectives on health, illness, disease and management approaches among Baganda traditional spiritual healers in Central Uganda

In Uganda, spirituality is closely associated with traditional healthcare; however, though prevalent, it is considered controversial, mystical, less documented and often misunderstood. There is a paucity of literature on the description of health, illness, disease, and management approaches among traditional spiritual healers. This article examines the perspectives on health, illness, disease, and management approaches among Baganda traditional spiritual healers, the Balubaale, in Central Uganda, who engage ancestral spirits during health care and management. We used a qualitative study design in particular grounded theory. We used semi-structured, qualitative interviews and observation on 12 male and female purposively selected Balubaale in Central Uganda. Data was transcribed, coded, and thematically analyzed using ATLAS ti. 22 Computer software based on an inductive approach. Findings show that the words and concepts describing health, illness, disease, and management approaches are descriptive and contextualized to include the problem, the prospected root-causes, and the therapeutic approaches involved. The words for illness "olumbe", disease "obulwadde" and the management approaches such as divination (kulagula), ritual cleansing (kwambulula), amulets (ensiriba and yirizi), and scarification (kusandaga) have spiritual and social dimensions, contextual meanings and attachments. Further research is recommended among other tribes and larger sample size to compare findings and terminologies to facilitate communication and policy considerations.

Impact of TRP Channels on Extracellular Matrix Remodeling: Focus on TRPV4 and Collagen

Disturbed remodeling of the extracellular matrix (ECM) is frequently observed in several high-prevalence pathologies that include fibrotic diseases of organs such as the heart, lung, periodontium, liver, and the stiffening of the ECM surrounding invasive cancers. In many of these lesions, matrix remodeling mediated by fibroblasts is dysregulated, in part by alterations to the regulatory and effector systems that synthesize and degrade collagen, and by alterations to the functions of the integrin-based adhesions that normally mediate mechanical remodeling of collagen fibrils. Cell-matrix adhesions containing collagen-binding integrins are enriched with regulatory and effector systems that initiate localized remodeling of pericellular collagen fibrils to maintain ECM homeostasis. A large cadre of regulatory molecules is enriched in cell-matrix adhesions that affect ECM remodeling through synthesis, degradation, and contraction of collagen fibrils. One of these regulatory molecules is Transient Receptor Potential Vanilloid-type 4 (TRPV4), a mechanically sensitive, Ca2+-permeable plasma membrane channel that regulates collagen remodeling. The gating of Ca2+ across the plasma membrane by TRPV4 and the consequent generation of intracellular Ca2+ signals affect several processes that determine the structural and mechanical properties of collagen-rich ECM. These processes include the synthesis of new collagen fibrils, tractional remodeling by contractile forces, and collagenolysis. While the specific mechanisms by which TRPV4 contributes to matrix remodeling are not well-defined, it is known that TRPV4 is activated by mechanical forces transmitted through collagen adhesion receptors. Here, we consider how TRPV4 expression and function contribute to physiological and pathological collagen remodeling and are associated with collagen adhesions. Over the long-term, an improved understanding of how TRPV4 regulates collagen remodeling could pave the way for new approaches to manage fibrotic lesions.

Wound Repair and Ca2+ Signalling Interplay: The Role of Ca2+ Channels in Skin

The process of wound healing is intricate and tightly controlled, involving a number of different cellular and molecular processes. Numerous cellular functions, especially those related to wound healing, depend critically on calcium ions (Ca2+). Ca2+ channels are proteins involved in signal transduction and communication inside cells that allow calcium ions to pass through cell membranes. Key Ca2+ channel types involved in wound repair are described in this review.