IL-17A Orchestrates Reactive Oxygen Species/HIF1α-Mediated Metabolic Reprogramming in Psoriasis.

Immune cell-derived IL-17A is one of the key pathogenic cytokines in psoriasis, an immunometabolic disorder. Although IL-17A is an established regulator of cutaneous immune cell biology, its functional and metabolic effects on nonimmune cells of the skin, particularly keratinocytes, have not been comprehensively explored. Using multiomics profiling and systems biology-based approaches, we systematically uncover significant roles for IL-17A in the metabolic reprogramming of human primary keratinocytes (HPKs). High-throughput liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance spectroscopy revealed IL-17A-dependent regulation of multiple HPK proteins and metabolites of carbohydrate and lipid metabolism. Systems-level MitoCore modeling using flux-balance analysis identified IL-17A-mediated increases in HPK glycolysis, glutaminolysis, and lipid uptake, which were validated using biochemical cell-based assays and stable isotope-resolved metabolomics. IL-17A treatment triggered downstream mitochondrial reactive oxygen species and HIF1α expression and resultant HPK proliferation, consistent with the observed elevation of these downstream effectors in the epidermis of patients with psoriasis. Pharmacological inhibition of HIF1α or reactive oxygen species reversed IL-17A-mediated glycolysis, glutaminolysis, lipid uptake, and HPK hyperproliferation. These results identify keratinocytes as important target cells of IL-17A and reveal its involvement in multiple downstream metabolic reprogramming pathways in human skin.

Study to Determine the Effect of Diaper-Based Wound Care Method in Reducing Wound Contamination Period in Patients Suffering from Perianal Burn Wound.

Background Local wound care in perianal burn wounds is difficult owing to the risk of contamination from fecal soiling. The problem is aggravated in small children and bedridden critical patients who are unable to convey passage of stools. We used diaper-based wound care to reduce contamination. Materials and Methods We used ethylene trioxide sterilized diaper-based dressings in such patients. These were changed at 6-hour interval. Total and mean prevented period of contamination was noted as primary objective parameters. Time to heal, maceration of surrounding skin, and wound culture swab results were noted as other parameters. Result The diaper-based wound care led to reduced mean daily and total contamination period. Conclusion This diaper-based wound care method reduces contamination period of perianal wounds in patients suffering from perianal burn.

Outcomes of Tendon Transfer Surgery for Correction of Ulnar Claw Hand: A Case Series.

This case series presents detailed postoperative physiotherapeutic rehabilitation and functional outcomes of 3 patients following tendon transfer surgery for the correction of claw hand due to traumatic nerve injury. Three patients with different etiologies of claw hand and sociodemographic characteristics presented to the hand therapy center after claw correction surgery. Two patients underwent flexor digitorum superficialis 4-tail tendon transfer, and 1 patient underwent the Zancolli lasso procedure. Hand therapy began after 4 weeks of appropriate postoperative immobilization. It began with the activation and strengthening of the new muscle-tendon unit and its integration into functional activities. All patients returned to work 12 weeks after surgery, followed by an assessment of outcomes at 16 weeks. Satisfactory improvements in the functional outcomes based on the Brand criteria, the Patient-Rated Wrist and Hand Evaluation, and the Patient-Specific Functional Scale were observed in all patients at 16 weeks.

Multiomics Analysis and Systems Biology Integration Identifies the Roles of IL-9 in Keratinocyte Metabolic Reprogramming.

IL-9‒producing T cells are present in healthy skin as well as in the cutaneous lesions of inflammatory diseases and cancers. However, the roles of IL-9 in human skin during homeostasis and in the pathogenesis of inflammatory disorders remain obscure. In this study, we examined the roles of IL-9 in metabolic reprogramming of human primary keratinocytes (KCs). High-throughput quantitative proteomics revealed that IL-9 signaling in human primary KCs disrupts the electron transport chain by downregulating multiple electron transport chain proteins. Nuclear magnetic resonance-based metabolomics showed that IL-9 also reduced the production of tricarboxylic acid cycle intermediates in human primary KCs. An integration of multiomics data with systems-level analysis using the constraint-based MitoCore model predicted marked IL-9-dependent effects on central carbohydrate metabolism, particularly in relation to the glycolytic switch. Stable isotope metabolomics and biochemical assays confirmed increased glucose consumption and redirection of metabolic flux toward lactate by IL-9. Functionally, IL-9 inhibited ROS production by IFN-γ and promoted human primary KC survival by inhibiting apoptosis. In conclusion, our data reveal IL-9 as a master regulator of KC metabolic reprogramming and survival.

Blockade of ROCK inhibits migration of human primary keratinocytes and malignant epithelial skin cells by regulating actomyosin contractility.

Actomyosin contractility, crucial for several physiological processes including migration, is controlled by the phosphorylation of myosin light chain (MLC). Rho-associated protein kinase (ROCK) and Myosin light chain kinase (MLCK) are predominant kinases that phosphorylate MLC. However, the distinct roles of these kinases in regulating actomyosin contractility and their subsequent impact on the migration of healthy and malignant skin cells is poorly understood. We observed that blockade of ROCK in healthy primary keratinocytes (HPKs) and epidermal carcinoma cell line (A-431 cells) resulted in loss of migration, contractility, focal adhesions, stress fibres, and changes in morphology due to reduction in phosphorylated MLC levels. In contrast, blockade of MLCK reduced migration, contractile dynamics, focal adhesions and phosphorylated MLC levels of HPKs alone and had no effect on A-431 cells due to the negligible MLCK expression. Using genetically modified A-431 cells expressing phosphomimetic mutant of p-MLC, we show that ROCK dependent phosphorylated MLC controls the migration, focal adhesion, stress fibre organization and the morphology of the cells. In conclusion, our data indicate that ROCK is the major kinase of MLC phosphorylation in both HPKs and A-431 cells, and regulates the contractility and migration of healthy as well as malignant skin epithelial cells.

Hydrogel scaffold with substrate elasticity mimicking physiological-niche promotes proliferation of functional keratinocytes.

High numbers of autologous human primary keratinocytes (HPKs) are required for patients with burns, wounds and for gene therapy of skin disorders. Although freshly isolated HPKs exhibit a robust regenerative capacity, traditional methodology fails to provide a sufficient number of cells. Here we demonstrated a well characterized, non-cytotoxic and inert hydrogel as a substrate that mimics skin elasticity, which can accelerate proliferation and generate higher numbers of HPKs compared to existing tissue culture plastic (TCP) dishes. More importantly, this novel method was independent of feeder layer or any exogenous pharmaceutical drug. The HPKs from the hydrogel-substrate were functional as demonstrated by wound-healing assay, and the expression of IFN-γ-responsive genes (CXCL10, HLADR). Importantly, gene delivery efficiency by a lentiviral based delivery system was significantly higher in HPKs cultured on hydrogels compared with TCP. In conclusion, our study provides the first evidence that cell-material mechanical interaction is enough to provide a rapid expansion of functional keratinocytes that might be used as autologous grafts for skin disorders.

Differential Influence of IL-9 and IL-17 on Actin Cytoskeleton Regulates the Migration Potential of Human Keratinocytes.

T cells mediate skin immune surveillance by secreting specific cytokines and regulate numerous functions of keratinocytes, including migration during homeostasis and disease pathogenesis. Keratinocyte migration is mediated mainly by proteolytic cleavage of the extracellular matrix and/or by cytoskeleton reorganization. However, the cross-talk between T cell cytokines and actomyosin machinery of human primary keratinocytes (HPKs), which is required for cytoskeleton reorganization and subsequent migration, remains poorly examined. In this study, we describe that IL-9 profoundly reduced the actin stress fibers, inhibited contractility, and reduced the cortical stiffness of HPKs, which resulted in inhibition of the migration potential of HPKs in an adhesion- and MMP-independent manner. Similarly, IL-9 inhibited the IFN-γ-induced migration of HPKs by inhibiting the actomyosin machinery (actin stress fibers, contractility, and stiffness). IL-17A increased the actin stress fibers, promoted cellular contractility, and increased proteolytic collagen degradation, resulting in increased migration potential of HPKs. However, IL-9 inhibited the IL-17A-mediated HPKs migration. Mechanistically, IL-9 inhibited the IFN-γ- and IL-17A-induced phosphorylation of myosin L chain in HPKs, which is a major regulator of the actomyosin cytoskeleton. Finally, in addition to HPKs, IL-9 inhibited the migration of A-431 cells (epidermoid carcinoma cells) induced either by IFN-γ or IL-17A. In conclusion, our data demonstrate the influence of T cell cytokines in differentially regulating the actomyosin cytoskeleton and migration potential of human keratinocytes, which may have critical roles in skin homeostasis and pathogenesis of inflammatory diseases as well as skin malignancies.

Anaplastic large cell lymphoma presenting as bilateral endobronchial tumor in a young boy.

A 15-year-old boy presented to us with a 4-month history of fever with worsening dyspnea since 1 month. His contrast-enhanced computed tomography scan of the thorax showed bilateral endobronchial lesions with complete collapse-consolidation of the left lung and partial collapse of the right lower lobe. His fiberoptic bronchoscopy guided biopsy had been reported in outside hospital as a neuroendocrine tumor. Due to worsening breathlessness, he had to be intubated. We repeated the endobronchial biopsy and combined with outside slides and blocks, was diagnosed to have an anaplastic lymphoma kinase-1 positive anaplastic large cell lymphoma (ALCL). We started the patient on chemotherapy to which he had a dramatic response radiologically and clinically. ALCL presenting as endobronchial mass is an extremely rare occurrence and it presenting with bilateral endobronchial masses has not been reported yet in literature. Pathologists and clinicians should be aware of this presentation as prompt diagnosis and treatment give promising results.

A Rare Cause of Chronic Life Threatening Bleeding in a Girl: The Ulcerated Blind Loops.

Ulceration in a blind loop can lead to massive gastrointestinal tract (GIT) bleeding. A 13-year old girl presented with symptomatic melena requiring repeated blood transfusion since childhood. She was an operated case of small bowel atresia in neonatal life. Her upper and lower gastrointestinal endoscopies were normal. Operation showed presence of multiple ulcers in two blind loops (parts of previous side to side anastomosis) and at the anastomotic site. She underwent resection and end-to-end anastomosis of the small bowel leading to complete resolution of melena and anemia.

Methylene blue dye injection for identification of occult gastrointestinal bleeding.

The exact site of small bowel bleeding is difficult to detect intraoperatively. We present a simple method of on-table identification of the site of the bleed. A 55-year-old lady presented with recurrent episodes of melena and drop in hemoglobin. Digital subtraction angiography (DSA) revealed angiodysplasia of a vessel supplying the proximal jejunum. A microcatheter was placed at this site in the DSA suite, just prior to laparotomy. Two cubic centimeters of methylene blue dye was injected into the microcatheter on-table which demarcated the 6 in. of involved jejunum which was then resected. Patient is currently doing well over a 6-month follow up with no further episodes of melena. In conclusion, preoperative DSA and selective catheterization of the affected vessel allow for on-table localization of the exact site of bleed. This simple method avoids more invasive techniques of detection and enables limited segmental resection of the affected bowel.