Parastoo Davari

Cutaneous and Mucosal Lichen Planus: A Comprehensive Review of Clinical Subtypes, Risk Factors, Diagnosis, and Prognosis

Lichen planus (LP) is a chronic inflammatory disorder that most often affects middle-aged adults. LP can involve the skin or mucous membranes including the oral, vulvovaginal, esophageal, laryngeal, and conjunctival mucosa. It has different variants based on the morphology of the lesions and the site of involvement. The literature suggests that certain presentations of the disease such as esophageal or ophthalmological involvement are underdiagnosed. The burden of the disease is higher in some variants including hypertrophic LP and erosive oral LP, which may have a more chronic pattern. LP can significantly affect the quality of life of patients as well. Drugs or contact allergens can cause lichenoid reactions as the main differential diagnosis of LP. LP is a T-cell mediated immunologic disease but the responsible antigen remains unidentified. In this paper, we review the history, epidemiology, and clinical subtypes of LP. We also review the histopathologic aspects of the disease, differential diagnoses, immunopathogenesis, and the clinical and genetic correlations.

Direct binding of the EGF-like domain of neuregulin-1 to integrins (αvβ3 and α6β4) is involved in neuregulin-1/ErbB signaling

Integrin-growth factor receptor cross-talk plays a role in growth factor signaling, but the specifics are unclear. In a current model, integrins and growth factor receptors independently bind to their ligands (extracellular matrix and growth factors, respectively). We discovered that neuregulin-1 (NRG1), either as an isolated EGF-like domain or as a native multi-domain form, binds to integrins αvβ3 (with a KD of 1.36 × 10−7 m) and α6β4. Docking simulation predicted that three Lys residues at positions 180, 184, and 186 of the EGF-like domain are involved in integrin binding. Mutating these residues to Glu individually or in combination markedly suppressed integrin binding and ErbB3 phosphorylation. Mutating all three Lys residues to Glu (the 3KE mutation) did not affect the ability of NRG1 to bind to ErbB3 but markedly reduced the ability of NRG1 to induce ErbB3 phosphorylation and AKT and Erk1/2 activation in MCF-7 and T47D human breast cancer cells. This suggests that direct integrin binding to NRG1 is critical for NRG1/ErbB signaling. Notably, stimulation of cells with WT NRG1 induced co-precipitation of ErbB3 with α6β4 and with αvβ3 to a much lower extent. This suggests that WT NRG1 induces integrin-NRG1-ErbB3 ternary complex formation. In contrast, the 3KE mutant was much less effective in inducing ternary complex formation than WT NRG1, suggesting that this process depends on the ability of NRG1 to bind to integrins. These results suggest that direct NRG1-integrin interaction mediates integrin-ErbB cross-talk and that α6β4 plays a major role in NRG-ErbB signaling in these cancer cells.

Cross-talk between Integrin α6β4 and Insulin-like Growth Factor-1 Receptor (IGF1R) through Direct α6β4 Binding to IGF1 and Subsequent α6β4-IGF1-IGF1R Ternary Complex Formation in Anchorage-independent Conditions

Background: Integrin αvβ3-extracellular matrix interaction and/or αvβ3 binding to insulin-like growth factor-1 (IGF1; and integrin-IGF1-IGF1 receptor ternary complex formation) is critical for IGF signaling. Results: α6β4 directly bound to IGF1 and mediated IGF1 signaling through ternary complex formation. α6β4 is required when cell-matrix adhesion is reduced or in three-dimensional culture. Conclusion: α6β4-IGF1 binding is important for IGF signaling in anchorage-independent conditions. Significance: The integrin-IGF interaction is a novel therapeutic target. Integrin αvβ3 plays a role in insulin-like growth factor-1 (IGF1) signaling (integrin-IGF1 receptor (IGF1R) cross-talk). The specifics of the cross-talk are, however, unclear. In a current model, “ligand occupancy” of αvβ3 (i.e. the binding of extracellular matrix proteins) enhances signaling induced by IGF1 binding to IGF1R. We recently reported that IGF1 directly binds to αvβ3 and induces αvβ3-IGF1-IGF1R ternary complex formation. Consistently, the integrin binding-defective IGF1 mutant (R36E/R37E) is defective in inducing ternary complex formation and IGF signaling, but it still binds to IGF1R. Like αvβ3, integrin α6β4 is overexpressed in many cancers and is implicated in cancer progression. Here, we discovered that α6β4 directly bound to IGF1, but not to R36E/R37E. Grafting the β4 sequence WPNSDP (residues 167–172), which corresponds to the specificity loop of β3, to integrin β1 markedly enhanced IGF1 binding to β1, suggesting that the WPNSDP sequence is involved in IGF1 recognition. WT IGF1 induced α6β4-IGF1-IGF1R ternary complex formation, whereas R36E/R37E did not. When cells were attached to matrix, exogenous IGF1 or α6β4 expression had little or no effect on intracellular signaling. When cell-matrix adhesion was reduced (in poly(2-hydroxyethyl methacrylate-coated plates), IGF1 induced intracellular signaling and enhanced cell survival in an α6β4-dependent manner. Also IGF1 enhanced colony formation in soft agar in an α6β4-dependent manner. These results suggest that IGF binding to α6β4 plays a major role in IGF signaling in anchorage-independent conditions, which mimic the in vivo environment, and is a novel therapeutic target.

Mucosal Lichen Planus: An Evidence-Based Treatment Update

BackgroundMucosal lichen planus (MLP) is a chronic mucosal disorder that often poses a therapeutic challenge to dermatologists, dentists, and gynecologists. To relieve patients’ pain and discomfort, improve their quality of life, and achieve clinical improvement, various therapeutic approaches can be considered for this disease. Based on the current literature it is difficult to define any particular treatment as the main therapeutic modality.ObjectiveWe aimed to systematically review the current literature for the effectiveness of available treatment modalities for MLP.MethodsAll of the randomized controlled trials and systematic reviews of MLP were collected by searching Pubmed, EMBASE, the Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, Health Technology Assessment Database, and China National Knowledge Infrastructure. Meta-analysis was performed, if possible.ResultsTopical betamethasone valerate, clobetasol-17-propionate, and fluocinonide are effective in the treatment of oral lichen planus (OLP) when compared with placebo. Calcineurin inhibitors and topical retinoids are also beneficial treatment options.LimitationsThe review does not include therapies with a lower level of evidence.ConclusionTopical corticosteroids are the mainstay of therapy for OLP. High-quality evidence is lacking for the treatment of lichen planus.

Ustekinumab for the treatment of psoriatic arthritis: an update

Psoriatic arthritis occurs in 30% of psoriasis patients, and the treatment can be challenging in some patients. Recently, the US Food and Drug Administration approved ustekinumab, a fully human monoclonal antibody, for the management of psoriatic arthritis. In this article, we review large-scale randomized clinical trials addressing the efficacy and safety profile of ustekinumab for the treatment of psoriatic arthritis.

Clinical features of Behçet's disease: A retrospective chart review of 26 patients.

Abstract Background: Behçet’s disease (BD) is a multi-organ inflammatory disorder with mucocutaneous, ocular, neurological, musculoskeletal, gastrointestinal, and pulmonary manifestations. The aim of this study was to determine the clinical features of BD in a cohort of patients diagnosed at the University of California, Davis, United States. Methods: The medical records of 59 patients with an ICD9-code of BD were retrospectively reviewed. The International Criteria for BD was used to identify patients with a point score ≥5. The clinical manifestations of BD were investigated over a 10-year period in this cohort. Results: Twenty-six patients (20 women, six men; female:male ratio = 3.3:1.0) had a point score ≥5 based on the International Criteria. The average age of onset of BD was 29.25 ± 14.25 years. Oral ulcers (100%), genital ulcers (84.6%), articular involvement (69.2%), ocular involvement (65.3%), and skin lesions (50.0%) were the most prevalent manifestations of BD in this cohort. Conclusion: Oral ulcers were the most common presenting and lifetime sign of BD. In our cohort, oral and genital ulcers were hallmarks of BD, independent of patient demographics. Thus, patients with these signs require close surveillance for other manifestations of the disease.

Practical pearls for oral procedures

We provide an overview of clinically relevant principles of oral surgical procedures required in the workup and management of oral mucosal diseases. An understanding of the fundamental concepts of how to perform safely and effectively minor oral procedures is important to the practicing dermatologist and can minimize the need for patient referrals. This chapter reviews the principles of minor oral procedures, including incisional, excisional, and punch biopsies, as well as minor salivary gland excision. Pre- and postoperative patient care is also discussed.

Ultraviolet Radiation Inhibits Mammary Carcinogenesis in an ER-Negative Murine Model by a Mechanism Independent of Vitamin D3

Three decades ago, the Garlands postulated that vitamin D3 produced in the skin by ultraviolet radiation (UVR)-induced conversion of 7-dehydrocholesterol to pre-D3 has anticancer effects, thus triggering more than 9,500 publications on D3 and cancer. Here, we report that UVR treatment of transgenic mice of the well-established C3(1)/SV40 Tag mammary cancer model significantly inhibits both autochthonous carcinogenesis and allograft tumor growth, but in contrast neither dietary nor topical D3 influences mammary carcinogenesis in this specific mouse model. Furthermore, UVRs inhibitory effects occur irrespective of whether or not the treatment increases circulating D3 in the mice. The inhibitory effect of UVR on autochthonous tumors occurs at or before the stage of ductal carcinoma in situ. Our studies indicate clearly that UVR can exert D3-independent anticancer effects in C3(1)/SV40 Tag mice. Therefore, supplemental D3 may not mimic all possible beneficial effects of UVR, and uncovering non–D3-mediated mechanisms of UVR tumor inhibition may lead to novel strategies for cancer prevention. Cancer Prev Res; 11(7); 383–92. ©2018 AACR.

Stromal cell-derived factor-1 (CXCL12) activates integrins by direct binding to an allosteric ligand-binding site (site 2) of integrins without CXCR4.

Leukocyte arrest on the endothelial cell surface during leukocyte extravasation is induced by rapid integrin activation by chemokines. We recently reported that fractalkine induces integrin activation without its receptor CX3CR1 through binding to the allosteric site (site 2) of integrins. Peptides from site 2 bound to fractalkine and suppressed integrin activation by fractalkine. We hypothesized that this is not limited to membrane-bound fractalkine. We studied whether stromal cell-derived factor-1 (SDF1), another chemokine that plays a critical role in leukocyte arrest, activates integrins through binding to site 2. We describe here that (1) SDF1 activated soluble integrin αvβ3 in cell-free conditions, suggesting that SDF1 can activate αvβ3 without CXCR4; (2) site 2 peptide bound to SDF1, suggesting that SDF1 binds to site 2; (3) SDF1 activated integrins αvβ3, α4β1, and α5β1 on CHO cells (CXCR4-negative) and site 2 peptide suppressed the activation; (4) A CXCR4 antagonist AMD3100 did not affect the site 2-mediated integrin activation by SDF1; (5) Cell-surface integrins were fully activated in 1 min (much faster than activation of soluble αvβ3) and the activation lasted at least for 1 h. We propose that the binding of SDF1 to cell-surface proteoglycan facilitates the allosteric activation process; (6) Mutations in the predicted site 2-binding site in SDF1 suppressed integrin activation. These results suggest that SDF1 (e.g. presented on proteoglycans) can rapidly activate integrins in an allosteric manner by binding to site 2 in the absence of CXCR4. The allosteric integrin activation by SDF1 is a novel target for drug discovery.