Development of 4-phenylbutyric acid microsponge gel formulations for the treatment of lewisite-mediated skin injury.

Lewisite, a chemical warfare agent, causes skin blisters, erythema, edema, and inflammation, requiring mitigation strategies in case of accidental or deliberate exposure. 4-phenyl butyric acid (4-PBA), a chemical chaperone, reduces endoplasmic reticulum stress and skin inflammation. The study aimed to encapsulate 4-PBA in microsponges for effective, sustained delivery against lewisite injury. Porous microsponges in a topical gel would potentially sustain delivery and improve residence time on the skin. Microsponges were developed using the quasi-emulsion solvent diffusion method with Eudragit RS100. Optimized formulation showed 10.58%w/w drug loading was incorporated in a carboxymethylcellulose (CMC) and Carbopol gel for in vitro release and permeation testing using dermatomed human skin. A sustained release was obtained from all vehicles in the release study, and IVPT results showed that compared to the control (41.52 ± 2.54 µg/sq.cm), a sustained permeation profile with a reduced delivery was observed for microsponges in PBS (14.16 ± 1.23 µg/sq.cm) along with Carbopol 980 gel (12.55 ± 1.41 µg/sq.cm), and CMC gel (10.09 ± 1.23 µg/sq.cm) at 24 h. Optimized formulation showed significant protection against lewisite surrogate phenyl arsine oxide (PAO) challenged skin injury in Ptch1+/-/SKH-1 hairless mice at gross and molecular levels. A reduction in Draize score by 29%, a reduction in skin bifold thickness by 8%, a significant reduction in levels of IL-1ß, IL6, and GM-CSF by 54%, 30%, and 55%, respectively, and a reduction in apoptosis by 31% was observed. Thus, the translational feasibility of 4-PBA microsponges for effective, sustained delivery against lewisite skin injury is demonstrated.

Cutaneous Arsenical Exposure Induces Distinct Metabolic Transcriptional Alterations of Kidney Cells.

Arsenicals are deadly chemical warfare agents that primarily cause death through systemic capillary fluid leakage and hypovolemic shock. Arsenical exposure is also known to cause acute kidney injury, a condition that contributes to arsenical-associated death due to the necessity of the kidney in maintaining whole-body fluid homeostasis. Because of the global health risk that arsenicals pose, a nuanced understanding of how arsenical exposure can lead to kidney injury is needed. We used a nontargeted transcriptional approach to evaluate the effects of cutaneous exposure to phenylarsine oxide, a common arsenical, in a murine model. Here we identified an upregulation of metabolic pathways such as fatty acid oxidation, fatty acid biosynthesis, and peroxisome proliferator-activated receptor (PPAR)-α signaling in proximal tubule epithelial cell and endothelial cell clusters. We also revealed highly upregulated genes such as Zbtb16, Cyp4a14, and Pdk4, which are involved in metabolism and metabolic switching and may serve as future therapeutic targets. The ability of arsenicals to inhibit enzymes such as pyruvate dehydrogenase has been previously described in vitro. This, along with our own data, led us to conclude that arsenical-induced acute kidney injury may be due to a metabolic impairment in proximal tubule and endothelial cells and that ameliorating these metabolic effects may lead to the development of life-saving therapies. SIGNIFICANCE STATEMENT: In this study, we demonstrate that cutaneous arsenical exposure leads to a transcriptional shift enhancing fatty acid metabolism in kidney cells, indicating that metabolic alterations might mechanistically link topical arsenical exposure to acute kidney injury. Targeting metabolic pathways may generate promising novel therapeutic approaches in combating arsenical-induced acute kidney injury.

HSP90, a Common Therapeutic Target for Suppressing Skin Injury Caused by Exposure to Chemically Diverse Classes of Blistering Agents.

Vesicants such as arsenicals and mustards produce highly painful cutaneous inflammatory and blistering responses, hence developed as chemical weapons during World War I/II. Here, using lewisite and sulfur mustard surrogates, namely phenylarsine oxide (PAO) and 2-chloroethyl ethyl sulfide (CEES), respectively, we defined a common underlying mechanism of toxic action by these two distinct classes of vesicants. Murine skin exposure to these chemicals causes tissue destruction characterized by increase in skin bifold thickness, Draize score, infiltration of inflammatory cells, and apoptosis of epidermal and dermal cells. RNA sequencing analysis identified ∼346 inflammatory genes that were commonly altered by both PAO and CEES, along with the identification of cytokine signaling activation as the top canonical pathway. Activation of several proinflammatory genes and pathways is associated with phosphorylation-dependent activation of heat shock protein 90α (p-HSP90α). Topical treatment with known HSP90 inhibitors SNX-5422 and IPI-504 post PAO or CEES skin challenge significantly attenuated skin damage including reduction in overall skin injury and clinical scores. In addition, highly upregulated inflammatory genes Saa3, Cxcl1, Ccl7, IL-6, Nlrp3, Csf3, Chil3, etc. by both PAO and CEES were significantly diminished by treatment with HSP90 inhibitors. These drugs not only reduced PAO- or CEES-induced p-HSP90α expression but also its client proteins NLRP3 and pP38 and the expression of their target inflammatory genes. Our data confirm a critical role of HSP90 as a shared underlying molecular target of toxicity by these two distinct vesicants and provide an effective and novel medical countermeasure to suppress vesicant-induced skin injury. SIGNIFICANCE STATEMENT: Development of effective and novel mechanism-based antidotes that can simultaneously block cutaneous toxic manifestations of distinct vesicants is important and urgently needed. Due to difficulties in determining the exact nature of onsite chemical exposure, a potent drug that can suppress widespread cutaneous damage may find great utility. Thus, this study identified HSP90 as a common molecular regulator of cutaneous inflammation and injury by two distinct warfare vesicants, arsenicals and mustards, and HSP90 inhibitors afford significant protection against skin damage.

Epigenetic switch reshapes epithelial progenitor cell signatures and drives inflammatory pathogenesis in hidradenitis suppurativa.

Hidradenitis suppurativa (HS) is a complex inflammatory skin disease with undefined mechanistic underpinnings. Here, we investigated HS epithelial cells and demonstrated that HS basal progenitors modulate their lineage restriction and give rise to pathogenic keratinocyte clones, resulting in epidermal hyperproliferation and dysregulated inflammation in HS. When comparing to healthy epithelial stem/progenitor cells, in HS, we identified changes in gene signatures that revolve around the mitotic cell cycle, DNA damage response and repair, as well as cell-cell adhesion and chromatin remodeling. By reconstructing cell differentiation trajectory and CellChat modeling, we identified a keratinocyte population specific to HS. This population is marked by S100A7/8/9 and KRT6 family members, triggering IL1, IL10, and complement inflammatory cascades. These signals, along with HS-specific proinflammatory cytokines and chemokines, contribute to the recruitment of certain immune cells during the disease progression. Furthermore, we revealed a previously uncharacterized role of S100A8 in regulating the local chromatin environment of target loci in HS keratinocytes. Through the integration of genomic and epigenomic datasets, we identified genome-wide chromatin rewiring alongside the switch of transcription factors (TFs), which mediated HS transcriptional profiles. Importantly, we identified numerous clinically relevant inflammatory enhancers and their coordinated TFs in HS basal CD49fhigh cells. The disruption of the S100A enhancer using the CRISPR/Cas9-mediated approach or the pharmacological inhibition of the interferon regulatory transcription factor 3 (IRF3) efficiently reduced the production of HS-associated inflammatory regulators. Our study not only uncovers the plasticity of epidermal progenitor cells in HS but also elucidates the epigenetic mechanisms underlying HS pathogenesis.

Microneedle-mediated transdermal delivery of N-acetyl cysteine as a potential antidote for lewisite injury.

Lewisite is a chemical warfare agent intended for use in World War and a potential threat to the civilian population due to presence in stockpiles or accidental exposure. Lewisite-mediated skin injury is characterized by acute erythema, pain, and blister formation. N-acetyl cysteine (NAC) is an FDA-approved drug for acetaminophen toxicity, identified as a potential antidote against lewisite. In the present study, we have explored the feasibility of rapid NAC delivery through transdermal route for potentially treating chemical warfare toxicity. NAC is a small, hydrophilic molecule with limited passive delivery through the skin. Using skin microporation with dissolving microneedles significantly enhanced the delivery of NAC into and across dermatomed human skin in our studies. Microporation followed by application of solution (poke-and-solution) resulted in the highest in vitro delivery (509.84 ± 155.04 µg/sq·cm) as compared to poke-and-gel approach (474.91 ± 70.09 µg/sq·cm) and drug-loaded microneedles (226.89 ± 33.41 µg/sq·cm). The lag time for NAC delivery through poke-and-solution approach (0.23 ± 0.04 h) was close to gel application (0.25 ± 0.02 h), with the highest for drug-loaded microneedles (1.27 ± 1.16 h). Thus, we successfully demonstrated the feasibility of rapid NAC delivery using various skin microporation approaches for potential treatment against lewisite-mediated skin toxicity.

Enhanced Transdermal Delivery of N-Acetylcysteine and 4-Phenylbutyric Acid for Potential Use as Antidotes to Lewisite.

Lewisite is a highly toxic chemical warfare agent that leads to cutaneous and systemic damage. N-acetylcysteine (NAC) and 4-phenylbutryic acid (4-PBA) are two novel antidotes developed to treat toxicity caused by lewisite and similar arsenicals. Our in vivo studies demonstrated safety and effectiveness of these agents against skin injury caused by surrogate lewisite (Phenylarsine oxide) proving their potential for the treatment of lewisite injury. We further focused on exploring various enhancement strategies for an enhanced delivery of these agents via skin. NAC did not permeate passively from propylene glycol (PG). Iontophoresis as a physical enhancement technique and chemical enhancers were investigated for transdermal delivery of NAC. Application of cathodal and anodal iontophoresis with the current density of 0.2 mA/cm2 for 4 h followed by passive diffusion till 24 h significantly enhanced the delivery of NAC with a total delivery of 65.16 ± 1.95 µg/cm2 and 87.23 ± 7.02 µg/cm2, respectively. Amongst chemical enhancers, screened oleic acid, oleyl alcohol, sodium lauryl ether sulfate, and dimethyl sulfoxide (DMSO) showed significantly enhanced delivery of NAC with DMSO showing highest delivery of 28,370.2 ± 2355.4 µg/cm2 in 24 h. Furthermore, 4-PBA permeated passively from PG with total delivery of 1745.8 ± 443.5 µg/cm2 in 24 h. Amongst the chemical enhancers screened for 4-PBA, oleic acid, oleyl alcohol, and isopropyl myristate showed significantly enhanced delivery with isopropyl myristate showing highest total delivery of 17,788.7 ± 790.2 µg/cm2. These studies demonstrate feasibility of delivering these antidotes via skin and will aid in selection of excipients for the development of topical/transdermal delivery systems of these agents.

Cutaneous Exposure to Arsenicals Is Associated with Development of Constrictive Bronchiolitis in Mice.

Organoarsenicals, such as lewisite and related chloroarsine, diphenylchloroarsine (DPCA), are chemical warfare agents developed during World War I. Stockpiles in Eastern Europe remain a threat to humans. The well-documented effects of cutaneous exposure to these organoarsenicals include skin blisters, painful burns, and life-threatening conditions such as acute respiratory distress syndrome. In survivors, long-term effects such as the development of respiratory ailments are reported for the organoarsenical sulfur mustard; however, no long-term pulmonary effects are documented for lewisite and DPCA. No animal models exist to explore the relationship between skin exposure to vesicants and constrictive bronchiolitis. We developed and characterized a mouse model to study the long-term effects of cutaneous exposure on the lungs after exposure to a sublethal dose of organoarsenicals. We exposed mice to lewisite, DPCA, or a less toxic surrogate organoarsenic chemical, phenyl arsine oxide, on the skin. The surviving mice were followed for 20 weeks after skin exposure to arsenicals. Lung microcomputed tomography, lung function, and histology demonstrated increased airway resistance, increased thickness of the smooth muscle layer, increased collagen deposition in the subepithelium, and peribronchial lymphocyte infiltration in mice exposed to arsenical on skin.

Mechanistic understanding of the toxic effects of arsenic and warfare arsenicals on human health and environment.

Worldwide, more than 200 million people are estimated to be exposed to unsafe levels of arsenic. Chronic exposure to unsafe levels of groundwater arsenic is responsible for multiple human disorders, including dermal, cardiovascular, neurological, pulmonary, renal, and metabolic conditions. Consumption of rice and seafood (where high levels of arsenic are accumulated) is also responsible for human exposure to arsenic. The toxicity of arsenic compounds varies greatly and may depend on their chemical form, solubility, and concentration. Surprisingly, synthetic organoarsenicals are extremely toxic molecules which created interest in their development as chemical warfare agents (CWAs) during World War I (WWI). Among these CWAs, adamsite, Clark I, Clark II, and lewisite are of critical importance, as stockpiles of these agents still exist worldwide. In addition, unused WWII weaponized arsenicals discarded in water bodies or buried in many parts of the world continue to pose a serious threat to the environment and human health. Metabolic inhibition, oxidative stress, genotoxicity, and epigenetic alterations including micro-RNA-dependent regulation are some of the underlying mechanisms of arsenic toxicity. Mechanistic understanding of the toxicity of organoarsenicals is also critical for the development of effective therapeutic interventions. This review provides comprehensive details and a critical assessment of recently published data on various chemical forms of arsenic, their exposure, and implications on human and environmental health.

Retinal injury mouse model and pathophysiological assessment of the effect of arsenical vesicants.

The eye is ten times more vulnerable to chemical warfare agents than other organs. Consistently, exposure to vesicant arsenical lewisite (LEW) manifests significant corneal damage leading to chronic inflammation, corneal opacity, vascularization, and edema, culminating in corneal cell death. However, despite the progress has made in the research field investigating arsenical-induced pathogenesis of the anterior chamber of the eye, the retinal damage resulted from exposure to arsenicals has not been identified yet. Therefore, we investigated the effects of direct ocular exposure (DOE) to LEW and phenylarsine oxide (PAO) on the retina. DOE to arsenicals was conducted using the vapor cap method at the MRIGlobal facility or an eye patch soaked in solutions with different PAO concentrations at UAB. Animals were assessed at 1, 3, 14, and 28 days postexposure. Results of the study demonstrated that both arsenicals cause severe retinal damage, activating proinflammatory programs and launching apoptotic cell death. Moreover, the DOE to PAO resulted in diminishing ERG amplitudes in a dose-dependent manner, indicating severe retinal damage. The current study established a prototype mouse model of arsenical-induced ocular damage that can be widely used to identify the key cellular signaling pathways involved in retinal damage pathobiology and to validate medical countermeasures against the progression of ocular damage.

Development and Evaluation of a Topical Foam Formulation for Decontamination of Warfare Agents.

Lewisite is a highly toxic and potent chemical warfare vesicating agent capable of causing pain, inflammation, and blistering. Therapeutic strategies that safely and effectively attenuate this damage are important. Early and thorough decontamination of these agents from skin is required to prevent their percutaneous absorption. In our studies, we used phenylarsine oxide (PAO), a surrogate for arsenicals, to simulate lewisite exposure. Various parameters such as determination of extraction solvents, skin extraction efficiency, donor volume, and donor concentration were optimized for decontamination of PAO. We aimed to develop a novel, easy to apply foam formulation that can decontaminate arsenicals. We screened various foaming agents, vehicles, and chemical enhancers for the development of foam. Lead formulation foam F30 was further characterized for foam density, foam expansion, foam liquid stability, foam volume stability, and foam gas fraction. The amount of PAO delivered into human skin in 30 min of exposure was 228.57 ± 28.44 µg/sq·cm. The amount of PAO remaining in human skin after decontamination with blank foam F30 was 50.09 ± 9.71, demonstrating an overall percentage decontamination efficiency of over 75%. Furthermore, the decontamination efficacy of F30 was also tested in the porcine skin model and results indicated an even higher decontamination efficacy. These studies demonstrated that the developed foam formulation can be used for effective decontamination of chemical warfare agents.

Role of hair follicles in the pathogenesis of arsenical-induced cutaneous damage.

Arsenical vesicants cause skin inflammation, blistering, and pain. The lack of appropriate animal models causes difficulty in defining their molecular pathogenesis. Here, Ptch1+/- /C57BL/6 mice were employed to investigate the pathobiology of the arsenicals lewisite and phenylarsine oxide (PAO). Following lewisite or PAO challenge (24 h), the skin of animals becomes grayish-white, thick, leathery, and wrinkled with increased bi-fold thickness, Draize score, and necrotic patches. In histopathology, infiltrating leukocytes (macrophages and neutrophils), epidermal-dermal separation, edema, apoptotic cells, and disruption of tight and adherens junction proteins can be visualized. PCR arrays and nanoString analyses showed significant increases in cytokines/chemokines and other proinflammatory mediators. As hair follicles (HFs), which provide an immune-privileged environment, may affect immune cell trafficking and consequent inflammatory responses, we compared the pathogenesis of these chemicals in this model to that in Ptch1+/- /SKH-1 hairless mice. Ptch1+/- /SKH-1 mice have rudimentary, whereas Ptch1+/- /C57BL/6 mice have well-developed HFs. Although no significant differences were observed in qualitative inflammatory responses between the two strains, levels of cytokines/chemokines differed. Importantly, the mechanism of inflammation was identical; both reactive oxygen species induction and consequent activation of unfolded protein response signaling were similar. These data reveal that the acute molecular pathogenesis of arsenicals in these two murine models is similar.

Combined inhibition of BET bromodomain and mTORC1/2 provides therapeutic advantage for rhabdomyosarcoma by switching cell death mechanism.

Aberrant activation of multiple complex signaling pathways underlies the pathogenesis of rhabdomyosarcoma (RMS), which remains a cause of mortality in approximately 30% of children with RMS. Bromodomain and extraterminal (BET) domain chromatin remodeling regulates several of these pathways. Here, we targeted bromodomain 4 (BRD4) in combination with another molecular metabolic tumor driver, the Akt/mTOR signaling pathway, to provide a highly effective treatment for this neoplasm. We demonstrated that a nexus of these two molecular pathways underlies RMS pathogenesis. Our data show that the combined inhibition of the BET bromodomain and mTORC1/2 signaling abrogates aggressive RMS growth. Thus, the bromodomain inhibitor RVX-208 significantly augmented the therapeutic effects of the dual mTORC1/2 inhibitors, OSI-027 and PP242, both in vitro and in a human xenograft murine model. Drug-treated residual tumors showed a decrease in the activation of underlying signaling mechanisms characterized by a reduction in the expression of p-AKT, p-mTOR, p-p70S6K, cyclin D1, and proliferation. Our ChIP-seq data demonstrated that RVX-208 effectively blocked BRD4 occupancy on its target promoters. ChIP-qPCR assays further confirmed that RVX-208 treatment resulted in a significant decrease in H3K27ac and H4K8ac signals at their target loci. While single RVX-208 treatment induces apoptosis and a single mTORC1/2 inhibitor induces macropinocytosis, their combined treatment led to necroptosis-mediated cell death. These data suggest that combined treatment with drugs targeting BRD4 and mTORC1/2 may be an effective therapeutic intervention for drug-resistant RMS.

Development of BRD4 inhibitors as anti-inflammatory agents and antidotes for arsenicals.

Arsenicals belong to the class of chemical warfare agents known as vesicants, which are highly reactive, toxic and cause robust inflammatory response. Cutaneous exposure to arsenicals causes a wide range of systemic organ damage, beginning with cutaneous injuries, and later manifest multi-organ damage and death. Thus, the development of suitable antidotes that can effectively block injury following exposure to these agents is of great importance. Bromodomain 4 (BRD4), a member of the bromodomain and extra terminal domain (BET) family, plays crucial role in regulating transcription of inflammatory, proliferation and cell cycle genes. In this context, the development of potent small molecule inhibitors of BRD4 could serve as potential antidotes for arsenicals. Herein, we describe the synthesis and biological evaluation of a series of compounds.

NETosis in the pathogenesis of acute lung injury following cutaneous chemical burns.

Despite the high morbidity and mortality among patients with extensive cutaneous burns in the intensive care unit due to the development of acute respiratory distress syndrome, effective therapeutics remain to be determined. This is primarily because the mechanisms leading to acute lung injury (ALI) in these patients remain unknown. We test the hypothesis that cutaneous chemical burns promote lung injury due to systemic activation of neutrophils, in particular, toxicity mediated by the deployment of neutrophil extracellular traps (NETs). We also demonstrate the potential benefit of a peptidyl arginine deiminase 4 (PAD4) inhibitor to prevent NETosis and to preserve microvascular endothelial barrier function, thus reducing the severity of ALI in mice. Our data demonstrated that phenylarsine oxide (PAO) treatment of neutrophils caused increased intracellular Ca2+-associated PAD4 activity. A dermal chemical burn by lewisite or PAO resulted in PAD4 activation, NETosis, and ALI. NETs disrupted the barrier function of endothelial cells in human lung microvascular endothelial cell spheroids. Citrullinated histone 3 alone caused ALI in mice. Pharmacologic or genetic abrogation of PAD4 inhibited lung injury following cutaneous chemical burns. Cutaneous burns by lewisite and PAO caused ALI by PAD4-mediated NETosis. PAD4 inhibitors may have potential as countermeasures to suppress detrimental lung injury after chemical burns.

Dynamic Regulation of the Nexus Between Stress Granules, Roquin, and Regnase-1 Underlies the Molecular Pathogenesis of Warfare Vesicants.

The use of chemical warfare agents is prohibited but they have been used in recent Middle Eastern conflicts. Their accidental exposure (e.g. arsenical lewisite) is also known and causes extensive painful cutaneous injury. However, their molecular pathogenesis is not understood. Here, we demonstrate that a nexus of stress granules (SGs), integrated stress, and RNA binding proteins (RBPs) Roquin and Reganse-1 play a key role. Lewisite and its prototype phenylarsine oxide (PAO) induce SG assembly in skin keratinocytes soon after exposure, which associate with various RBPs and translation-related proteins. SG disassembly was detected several hours after exposure. The dynamics of SG assembly-disassembly associates with the chemical insult and cell damage. Enhanced Roquin and Regnase-1 expression occurs when Roquin was recruited to SGs and Regnase-1 to the ribosome while in the disassembling SGs their expression is decreased with consequent induction of inflammatory mediators. SG-targeted protein translational control is regulated by the phosphorylation-dependent activation of eukaryotic initiation factors 2α (eIF2α). Treatment with integrated stress response inhibitor (ISRIB), which blocks eIF2α phosphorylation, impacted SG assembly dynamics. Topical application of ISRIB attenuated the inflammation and tissue disruption in PAO-challenged mice. Thus, the dynamic regulation of these pathways provides underpinning to cutaneous injury and identify translational therapeutic approach for these and similar debilitating chemicals.

5'-Cap‒Dependent Translation as a Potent Therapeutic Target for Lethal Human Squamous Cell Carcinoma.

Skin squamous cell carcinomas (SCCs) are a major cause of death in patients who have undergone or will undergo organ transplantation. Moreover, these neoplasms cause significant disease and economic burden and diminish patients' life quality. However, no effective treatment or intervention strategies are available. In this study, we investigated the pathologic role of 5'-cap translation, which is regulated by the formation of a ternary initiation factor complex involving eIF4E, eIF4G, and eIF4A1. We detected increased expression of phosphorylated eIF4E, eIF4G, and eIF4A1 in human and murine skin SCCs. The increase in these ternary initiation factor complex proteins was associated with enhanced eIF4E translation targets cyclin D1 and c-Myc. Conversely, small interfering RNA-mediated depletion of eIF4E in human SCC cells (A431 and SCC-13) reduced eIF4G and proteins that regulate the cell cycle and proliferation. Notably, inhibition of Raf/MAPK/extracellular signal-regulated kinase signaling decreased eIF4E and phosphorylated eIF4E accumulation and significantly diminished cell-cycle gene expression and tumor volume of A431-derived xenograft tumors. Furthermore, disrupting the eIF4E with an allosteric inhibitor of eIF4E and eIF4G binding, 4EGI-1, decreased the eIF4E/eIF4G expression and reduced the proliferation. Finally, combined inhibition of the Raf/MAPK/extracellular signal-regulated kinase axis and eIF4E impaired 5'-cap‒dependent translation and abrogated tumor cell proliferation. These data demonstrate that 5'-cap‒dependent translation is a potential therapeutic target for abrogating lethal skin SCCs in patients who have undergone or will undergo organ transplantation.

Protective role of HO-1 against acute kidney injury caused by cutaneous exposure to arsenicals.

Lewisite and many other similar arsenicals are warfare vesicants developed and weaponized for use in World Wars I and II. These chemicals, when exposed to the skin and other epithelial tissues, cause rapid severe inflammation and systemic damage. Here, we show that topically applied arsenicals in a murine model produce significant acute kidney injury (AKI), as determined by an increase in the AKI biomarkers NGAL and KIM-1. An increase in reactive oxygen species and ER stress proteins, such as ATF4 and CHOP, correlated with the induction of these AKI biomarkers. Also, TUNEL staining of CHOP-positive renal tubular cells suggests CHOP mediates apoptosis in these cells. A systemic inflammatory response characterized by a significant elevation in inflammatory mediators, such as IL-6, IFN-α, and COX-2, in the kidney could be the underlying cause of AKI. The mechanism of arsenical-mediated inflammation involves activation of AMPK/Nrf2 signaling pathways, which regulate heme oxygenase-1 (HO-1). Indeed, HO-1 induction with cobalt protoporphyrin (CoPP) treatment in arsenical-treated HEK293 cells afforded cytoprotection by attenuating CHOP-associated apoptosis and cytokine mRNA levels. These results demonstrate that topical exposure to arsenicals causes AKI and that HO-1 activation may serve a protective role in this setting.

Topical delivery of nordihydroguaretic acid for attenuating cutaneous damage caused by arsenicals.

This study evaluated the topical delivery of nordihydroguaretic acid (NDGA), a molecule that can potentially alleviate cutaneous damage caused by exposure to arsenic warfare chemicals. N-acetylcysteine (NAC 0.2% w/v) was added as an antioxidant, preventing the oxidation of NDGA to toxic quinones. A 24 h study was performed to arrive at a minimum concentration of NDGA needed to deliver maximum drug. A solution of 3% w/v delivered the maximum amount of drug at the end of 24 h (37.45 ± 4.32 µg). Short duration studies were carried out to determine the time needed to saturate skin with NDGA. There was no significant difference in the skin concentrations for 24 h and 8 h (14.89 ± 2.36 µg), due to skin saturation. However, there was significant difference in the amount of drug delivered to the epidermis (12.29 ± 1.87 µg) and dermis (2.54 ± 0.56 µg) at the end of 8 h. Solution of NDGA was applied on UV treated skin to assess changes in drug delivery. In vivo studies revealed that 3% NDGA was non-toxic for topical administration.

Development of Autonomous Advanced Disinfection Tunnel to Tackle External Surface Disinfection of COVID-19 Virus in Public Places.

This paper describes a robust autonomous disinfection tunnel to disinfect external surfaces of COVID-19 virus such as clothes and open body sections in public places such as airports, office complexes, schools, and malls. To make the tunnel effective and highly efficient, it has been provided with two chambers with three disinfection processes. Due to the multiple processes, the possibility of neutralizing the virus is quite high and higher than other solutions available at this point for this purpose. Chamber 1 sprays the solution of a disinfectant on the person. This solution can be either a dilute solution of approved chemical or any Ayurvedic/herbal disinfectant. Once the person enters chamber 2, he/she is exposed to hot air at 70 °C along with far-ultraviolet C rays (207-222 nm). Both chambers function autonomously by detecting a person in a chamber using ultrasonic sensors. The proposed tunnel is developed under industry-academia collaboration jointly by Technopark@iitk and ALIMCO under the ambit of the Ministry of Human Resources Development and the Ministry of Social Justice and Empowerment, respectively. The tunnel is referred to as the 'Techno Advanced Disinfection Tunnel' (TADT).

Combined mTORC1/mTORC2 inhibition blocks growth and induces catastrophic macropinocytosis in cancer cells.

The mammalian target of rapamycin (mTOR) pathway, which plays a critical role in regulating cellular growth and metabolism, is aberrantly regulated in the pathogenesis of a variety of neoplasms. Here we demonstrate that dual mTORC1/mTORC2 inhibitors OSI-027 and PP242 cause catastrophic macropinocytosis in rhabdomyosarcoma (RMS) cells and cancers of the skin, breast, lung, and cervix, whereas the effects are much less pronounced in immortalized human keratinocytes. Using RMS as a model, we characterize in detail the mechanism of macropinocytosis induction. Macropinosomes are distinct from endocytic vesicles and autophagosomes in that they are single-membrane bound vacuoles formed by projection, ruffling, and contraction of plasma membranes. They are positive for EEA-1 and LAMP-1 and contain watery fluid but not organelles. The vacuoles then merge and rupture, killing the cells. We confirmed the inhibition of mTORC1/mTORC2 as the underpinning mechanism for macropinocytosis. Exposure to rapamycin, an mTORC1 inhibitor, or mTORC2 knockdown alone had little or reduced effect relative to the combination. We further demonstrate that macropinocytosis depends on MKK4 activated by elevated reactive oxygen species. In a murine xenograft model, OSI-027 reduced RMS tumor growth. Molecular characterization of the residual tumors was consistent with the induction of macropinocytosis. Furthermore, relative to the control xenograft tumors, the residual tumors manifested reduced expression of cell proliferation markers and proteins that drive the epithelial mesenchymal transition. These data indicate a role of mTORC2 in regulating tumor growth by macropinocytosis and suggest that dual inhibitors could help block refractory or recurrent RMS and perhaps other neoplasms and other cancer as well.