A Global Map of Lipid-Binding Proteins and Their Ligandability in Cells.

Lipids play central roles in physiology and disease, where their structural, metabolic, and signaling functions often arise from interactions with proteins. Here, we describe a set of lipid-based chemical proteomic probes and their global interaction map in mammalian cells. These interactions involve hundreds of proteins from diverse functional classes and frequently occur at sites of drug action. We determine the target profiles for several drugs across the lipid-interaction proteome, revealing that its ligandable content extends far beyond traditionally defined categories of druggable proteins. In further support of this finding, we describe a selective ligand for the lipid-binding protein nucleobindin-1 (NUCB1) and show that this compound perturbs the hydrolytic and oxidative metabolism of endocannabinoids in cells. The described chemical proteomic platform thus provides an integrated path to both discover and pharmacologically characterize a wide range of proteins that participate in lipid pathways in cells.

Notum produced by Paneth cells attenuates regeneration of aged intestinal epithelium.

A decline in stem cell function impairs tissue regeneration during ageing, but the role of the stem-cell-supporting niche in ageing is not well understood. The small intestine is maintained by actively cycling intestinal stem cells that are regulated by the Paneth cell niche1,2. Here we show that the regenerative potential of human and mouse intestinal epithelium diminishes with age owing to defects in both stem cells and their niche. The functional decline was caused by a decrease in stemness-maintaining Wnt signalling due to production of Notum, an extracellular Wnt inhibitor, in aged Paneth cells. Mechanistically, high activity of mammalian target of rapamycin complex 1 (mTORC1) in aged Paneth cells inhibits activity of peroxisome proliferator activated receptor α (PPAR-α)3, and lowered PPAR-α activity increased Notum expression. Genetic targeting of Notum or Wnt supplementation restored function of aged intestinal organoids. Moreover, pharmacological inhibition of Notum in mice enhanced the regenerative capacity of aged stem cells and promoted recovery from chemotherapy-induced damage. Our results reveal a role of the stem cell niche in ageing and demonstrate that targeting of Notum can promote regeneration of aged tissues.

Proposed guidelines for appropriate utilization of superficial radiation therapy in management of skin cancers. Zemtsov-Cognetta criteria.

OBJECTIVE: To develop appropriate use criteria (AUC) for the treatment of basal cell and squamous cell carcinoma by superficial radiation therapy (SRT) technique. MATERIAL AND METHODS: Delphi-type discussion of the experts. RESULTS: Presented in Figure 1. CONCLUSION: These AUCs are in compliance both with the position statement of the American Academy of Dermatology (AAD) and the ASTRO Clinical Practice Guideline on this subject. It is further recommended that SRT will be only performed by either a dermatologist who is board certified in Mohs surgery (MDS) and who had adequate SRT training or by radiation oncologists. Hopefully, this publication will stimulate further discussion on this topic.

A Rare Presentation of Dermatofibrosarcoma Protuberans of the Scalp Treated with "Slow-Mohs" Micrographic Surgery.

Dermatofibrosarcoma protuberans (DFSP) is a rare, fibrohistiocytic tumor with intermediate malignancy.1 While these tumors are slow-growing and only metastasize in 6% of cases,2 they are often locally destructive, with relatively high local recurrence rates after initial excision. Overall annual incidence rates in the US are 0.8-4.1 per million person-years,2 though incidence among African Americans is nearly double that of Caucasians.3 DFSP is most commonly seen on the trunk (42-50%), followed by the extremities (30-42%) and, rarely, on the head and neck (10-15%).2,4 Other studies report that DFSP of the scalp accounts for under 5% of total cases.5 However, the head and neck region is reported to have the highest tendency to recur locally, roughly 50-75% of cases.4 Further, DFSP tumors on the scalp have the potential to metastases to the brain,4 thus highlighting the importance for these tumors to be correctly diagnosed and treated early on. Partly due to its rarity and also its tendency to mimic other mainly benign lesions clinically, DFSP is often misdiagnosed, leading to years of delay in proper treatment and otherwise likely avoidable sequelae.6 We describe a rare presentation of DFSP on the scalp of a 45-year-old African American woman successfully treated with "slow-Mohs" micrographic surgery. We also discuss the most common misdiagnoses for DFSP and scenarios when this tumor should be included in the differential and subsequent work-up.J Drugs Dermatol. 2022;21(5):534-535. doi:10.36849/JDD.6719.

Pharmacological convergence reveals a lipid pathway that regulates C. elegans lifespan.

Phenotypic screening has identified small-molecule modulators of aging, but the mechanism of compound action often remains opaque due to the complexities of mapping protein targets in whole organisms. Here, we combine a library of covalent inhibitors with activity-based protein profiling to coordinately discover bioactive compounds and protein targets that extend lifespan in Caenorhabditis elegans. We identify JZL184-an inhibitor of the mammalian endocannabinoid (eCB) hydrolase monoacylglycerol lipase (MAGL or MGLL)-as a potent inducer of longevity, a result that was initially perplexing as C. elegans does not possess an MAGL ortholog. We instead identify FAAH-4 as a principal target of JZL184 and show that this enzyme, despite lacking homology with MAGL, performs the equivalent metabolic function of degrading eCB-related monoacylglycerides in C. elegans. Small-molecule phenotypic screening thus illuminates pure pharmacological connections marking convergent metabolic functions in distantly related organisms, implicating the FAAH-4/monoacylglyceride pathway as a regulator of lifespan in C. elegans.

Vismodegib as Eye-Sparing Neoadjuvant Treatment for Locally Advanced Periocular Basal Cell Carcinoma.

Locally-advanced periocular basal cell carcinoma (BCC) pose many therapeutic challenges due to the need to preserve functionality and cosmesis of the orbit and periocular area. Surgical excision and subsequent orbital exenteration are two recognized modalities of treatment. Vismodegib is currently an FDA-approved monotherapy for locally-advanced and metastatic BCC. We present a case of the use of vismodegib as neoadjuvant therapy prior to surgical excision of a locally-advanced periocular recurrent BCC in a 75-year-old male. The patient’s tumor successfully responded to vismodegib allowing surgical excision with clear margins. The orbit was saved in a patient who otherwise would have required complete orbital exenteration. J Drugs Dermatol. 20(5):552-554. doi:10.36849/JDD.5661.

Comparison of Grenz ray and photodynamic therapy for field treatment of actinic keratoses on the forearm: A case series.

BACKGROUND: Actinic Keratosis is an intraepidermal neoplasm that represents the second most common reason for dermatologic visits in the United States. Sustained clearance with existing therapies is highly variable. OBJECTIVE: To assess the effects of combination and monotherapy with photodynamic therapy (PDT), grenz ray therapy, and PDT with microneedling (microchannel skin system) for actinic damage of the dorsal forearms and hands. METHODS: Full ethics approval was obtained through a Human Subjects Committee. Four patients with diffuse actinic field damage on their forearms and hands were recruited for the study. The dorsal forearm and hand from the elbow to the metacarpophalangeal joint were divided into four equal sections. Section 1 was treated with PDT. Section 2 was treated with grenz ray. Section 3 was treated with PDT plus microneedling. Section 4 was treated with grenz ray and PDT with microneedling. Lesion counts were recorded with transparent grids, photographed and evaluated by the same investigator at baseline, 1, 2, 3 and 6 months. RESULTS: At month 6 post treatment, lesion counts, as a per cent reduction from baseline, were 91.7% in section 1 (PDT); 97.3% in section 2 (grenz ray); 92.9% in section 3 (PDT + microneedle); and 93.9% in section 4 (grenz ray + PDT + microneedle). CONCLUSION: The greatest reduction occurred in the grenz ray monotherapy section and the second greatest reduction in the grenz ray, PDT, microneedling section. Further research on the efficacy of grenz ray therapy for field treatment of actinic keratosis of the forearms and hands is needed.

AIG1 and ADTRP are atypical integral membrane hydrolases that degrade bioactive FAHFAs.

Enzyme classes may contain outlier members that share mechanistic, but not sequence or structural, relatedness with more common representatives. The functional annotation of such exceptional proteins can be challenging. Here, we use activity-based profiling to discover that the poorly characterized multipass transmembrane proteins AIG1 and ADTRP are atypical hydrolytic enzymes that depend on conserved threonine and histidine residues for catalysis. Both AIG1 and ADTRP hydrolyze bioactive fatty acid esters of hydroxy fatty acids (FAHFAs) but not other major classes of lipids. We identify multiple cell-active, covalent inhibitors of AIG1 and show that these agents block FAHFA hydrolysis in mammalian cells. These results indicate that AIG1 and ADTRP are founding members of an evolutionarily conserved class of transmembrane threonine hydrolases involved in bioactive lipid metabolism. More generally, our findings demonstrate how chemical proteomics can excavate potential cases of convergent or parallel protein evolution that defy conventional sequence- and structure-based predictions.

Rash and Poor Wound Healing After Mastectomy.

A patient who had recently undergone bilateral mastectomy had erythema, edema, pain, pruritus, serous fluid drainage at the incision sites, and an erythematous papulovesicular rash on the trunk and extremities. A skin swab bacterial culture result was negative, and the skin findings did not improve with antibiotics. What is the diagnosis and what would you do next?

The Role of Interleukin-1 in Inflammatory and Malignant Human Skin Diseases and the Rationale for Targeting Interleukin-1 Alpha.

Inflammation plays a major role in the induction and progression of several skin diseases. Overexpression of the major epidermal proinflammatory cytokines interleukin (IL) 1 alpha (IL-1α) and 1 beta (IL-1ß) is positively correlated with symptom exacerbation and disease progression in psoriasis, atopic dermatitis, neutrophilic dermatoses, skin phototoxicity, and skin cancer. IL-1ß and the interleukin-1 receptor I (IL-1RI) have been used as a therapeutic target for some autoinflammatory skin diseases; yet, their system-wide effects limit their clinical usage. Based on the local effects of extracellular IL-1α and its precursor, pro-IL-1α, we hypothesize that this isoform is a promising drug target for the treatment and prevention of many skin diseases. This review provides an overview on IL-1α and IL-ß functions, and their contribution to inflammatory and malignant skin diseases. We also discuss the current treatment regimens, and ongoing clinical trials, demonstrating the potential of targeting IL-1α, and not IL-1ß, as a more effective strategy to prevent or treat the onset and progression of various skin diseases.

Design of Benzoxathiazin-3-one 1,1-Dioxides as a New Class of Irreversible Serine Hydrolase Inhibitors: Discovery of a Uniquely Selective PNPLA4 Inhibitor.

The design and examination of 4,1,2-benzoxathiazin-3-one 1,1-dioxides as candidate serine hydrolase inhibitors are disclosed, and represent the synthesis and study of a previously unexplored heterocycle. This new class of activated cyclic carbamates provided selective irreversible inhibition of a small subset of serine hydrolases without release of a leaving group, does not covalently modify active site catalytic cysteine and lysine residues of other enzyme classes, and was found to be amenable to predictable structural modifications that modulate intrinsic reactivity or active site recognition. Even more remarkable and within the small pilot series of candidate inhibitors examined in an initial study, an exquisitely selective inhibitor for a poorly characterized serine hydrolase (PNPLA4, patatin-like phospholipase domain-containing protein 4) involved in adipocyte triglyceride homeostasis was discovered.

Radiation Therapy in Dermatology: Non-Melanoma Skin Cancer.

Background: Dermatologists were historically well versed in the use of radiation therapy for the management of non-melanoma skin cancers and various inflammatory dermatologic conditions. With the advent of Mohs micrographic surgery and therapeutic discoveries for treating inflammatory dermatoses, radiotherapy assumed loss of a role in the clinical repertoire of the dermatologist. In recent years, its importance has again been realized for the management of non-melanoma skin cancers not amenable to surgical treatment or as adjuvant or palliative therapy.

Objective: To review the evolving use of radiation therapy in the treatment of non-melanoma skin cancer.

Methods and Materials: All published literature regarding the applications of radiotherapy for the treatment of non-melanoma skin cancer were analyzed and collated.

Results: A comprehensive review of radiotherapy for the treatment of non-melanoma skin cancer was outlined.

Conclusion: Dermatologists should be well versed in radiation therapy in order to deliver the best possible care for patients, as radiotherapy is an important adjuvant tool for the treatment of non-melanoma skin cancer.

J Drugs Dermatol. 2017;16(5):464-469.

Proteome-wide mapping of cholesterol-interacting proteins in mammalian cells.

Cholesterol is an essential structural component of cellular membranes and serves as a precursor for several classes of signaling molecules. Cholesterol exerts its effects and is, itself, regulated in large part by engagement in specific interactions with proteins. The full complement of sterol-binding proteins that exist in mammalian cells, however, remains unknown. Here we describe a chemoproteomic strategy that uses clickable, photoreactive sterol probes in combination with quantitative mass spectrometry to globally map cholesterol-protein interactions directly in living cells. We identified over 250 cholesterol-binding proteins, including receptors, channels and enzymes involved in many established and previously unreported interactions. Prominent among the newly identified interacting proteins were enzymes that regulate sugars, glycerolipids and cholesterol itself as well as proteins involved in vesicular transport and protein glycosylation and degradation, pointing to key nodes in biochemical pathways that may couple sterol concentrations to the control of other metabolites and protein localization and modification.

Palmoplantar keratoses and Bowen's disease in a Vietnam veteran: Could Agent Blue be implicated?

Agent Blue was an arsenical herbicide used extensively in the Vietnam War. Arsenic is one of the known causes of acquired palmoplantar keratoderma (PPK). The most common manifestation of arsenic exposure in susceptible individuals is bilateral palmoplantar hyperkeratosis. We report a 67-year-old man with no known prior exposure to arsenic in the USA or family history of PPK who developed multiple squamous cell carcinoma in situ (SCCIS) and palmoplantar hyperkeratotic lesions beginning 23 years after service in Vietnam. The SCCIS were located on the trunk and extremities in both sun-exposed and non-sun-exposed sites and his palmoplantar lesions were diagnosed concurrently with his SCCIS. He has continued to develop SCCIS since his first visit to our clinic 25 years ago.

Remodeling natural products: chemistry and serine hydrolase activity of a rocaglate-derived ß-lactone.

Flavaglines are a class of natural products with potent insecticidal and anticancer activities. ß-Lactones are a privileged structural motif found in both therapeutic agents and chemical probes. Herein, we report the synthesis, unexpected light-driven di-epimerization, and activity-based protein profiling of a novel rocaglate-derived ß-lactone. In addition to in vitro inhibition of the serine hydrolases ABHD10 and ACOT1/2, the most potent ß-lactone enantiomer was also found to inhibit these enzymes, as well as the serine peptidases CTSA and SCPEP1, in PC3 cells.