Plexin-B2 in psoriasis; a clinical and immunohistochemical study

Evaluation of OVOL1 and Filaggrin immunohistochemical expression and clinical relevance in psoriasis

BACKGROUND

Psoriasis is a disease of overactive immune system. OVOL1 and Filaggrin have been associated with many inflammatory skin lesions. To the best of our knowledge, the correlation between OVOL1 and Filaggrin in psoriasis was not previously investigated. This work aims to search the immunohistochemical expression and correlation between OVOL1 and Filaggrin in psoriasis.

MATERIALS AND METHODS

Slides cut from paraffin blocks of 30 psoriasis cases and 30 control subjects were stained with OVOL1 and Filaggrin. Clinicopathological data were correlated with the results of staining.

RESULTS

OVOL1 and Filaggrin expression in epidermis showed a significant gradual reduction from normal skin to peri-lesional and psoriasis biopsies (P < 0.001). In contrast, psoriasis dermis showed a significant overexpression of OVOL1 in inflammatory cells in relation to peri-lesional biopsies (P < 0.002). OVOL1 demonstrated a significant direct correlation with Filaggrin expression in psoriasis (r = 0.568, P < 0.004). OVOL1 and Filaggrin expression in psoriasis skin epidermis demonstrated a statistically significant negative correlation with PASI score.

CONCLUSION

OVOL1 and Filaggrin might be involved in psoriasis-associated inflammation and skin hyperproliferation. OVOL1 might have a protective barrier function in the skin and could be used to stratify progressive disease. Filaggrin may play a role in progression of psoriasis. OVOL1 inhibition could be considered in suppression of Filaggrin function. OVOL1 agonists may be beneficial in psoriasis treatment.

Biallelic variants in Plexin B2 (PLXNB2) cause amelogenesis imperfecta, hearing loss and intellectual disability

BACKGROUND

Plexins are large transmembrane receptors for the semaphorin family of signalling proteins. Semaphorin-plexin signalling controls cellular interactions that are critical during development as well as in adult life stages. Nine plexin genes have been identified in humans, but despite the apparent importance of plexins in development, only biallelic PLXND1 and PLXNA1 variants have so far been associated with Mendelian genetic disease.

METHODS

Eight individuals from six families presented with a recessively inherited variable clinical condition, with core features of amelogenesis imperfecta (AI) and sensorineural hearing loss (SNHL), with variable intellectual disability. Probands were investigated by exome or genome sequencing. Common variants and those unlikely to affect function were excluded. Variants consistent with autosomal recessive inheritance were prioritised. Variant segregation analysis was performed by Sanger sequencing. RNA expression analysis was conducted in C57Bl6 mice.

RESULTS

Rare biallelic pathogenic variants in plexin B2 (PLXNB2), a large transmembrane semaphorin receptor protein, were found to segregate with disease in all six families. The variants identified include missense, nonsense, splicing changes and a multiexon deletion. Plxnb2 expression was detected in differentiating ameloblasts.

CONCLUSION

We identify rare biallelic pathogenic variants in PLXNB2 as a cause of a new autosomal recessive, phenotypically diverse syndrome with AI and SNHL as core features. Intellectual disability, ocular disease, ear developmental abnormalities and lymphoedema were also present in multiple cases. The variable syndromic human phenotype overlaps with that seen in Plxnb2 knockout mice, and, together with the rarity of human PLXNB2 variants, may explain why pathogenic variants in PLXNB2 have not been reported previously.

Plexin B2 tissue expression and related gene polymorphisms in psoriasis and their relation to NB-UVB and Acitretin therapy

Psoriasis is a chronic, immune-mediated, hyperproliferative skin disease. Etiopathogenesis of psoriasis is not well understood. Plexin B2 was found to have effects on CD100-mediated T-cell morphology and expressed in the immune system. It may play a role in the pathogenesis of psoriasis. To assess the tissue level of plexin-B2 and plexin B2 related gene polymorphism which is signal regulatory protein gamma (SIRPγ-rs71212732) in psoriatic patients before and after NB-UVB, acitretin therapy alone or in combination and to detect correlation between level of tissue plexin B2 and disease severity and improvement. This single blinded randomized controlled trial was carried on 50 psoriatic patients and 50 healthy controls. Psoriasis Area and Severity Index score (PASI) was used to evaluate the disease severity. Tissue plexin-b2 level was measured using ELISA and SIRPγ-rs71212732 (T\C) was assessed using TaqMan™ assays and real-time PCR. A significant lower tissue plexin-B2 level was observed in control group (2.9 ± 0.6 pg/g) than cases (25.8 ± 2.8, pg/g) (p < 0.001). Also, a significantly higher tissue plexin-B2 level was observed in sever psoriasis (32.7 ± 3.8 pg/ml) in than moderate psoriasis (13.6 ± 2.1 pg/ml, p = 0.001). Tissue plexin B2 was positively correlated with diseases severity. Significantly higher (TC& TT) genotypes and mutant (C) allele among patients compared to the controls, p < 0.001 for all. Tissue plexin-b2 level was high in psoriasis vulgaris with positive correlation with disease severity and decreased after treatment. This may indicate a role of plexin-b2 in psoriasis vulgaris pathogenesis.

Inflammation and Psoriasis: A Comprehensive Review

Psoriasis is an immune-mediated disease with a strong genetic component that brings many challenges to sick individuals, such as chronic illness, and which has multiple associated comorbidities like cardiovascular disease, metabolic syndrome, inflammatory bowel disease, and psychological disorders. Understanding the interplay between the innate and adaptative immune system has led to the discovery of specific cytokine circuits (Tumor Necrosis Factor-alpha (TNF-α), IL-23, IL-17), which has allowed scientists to discover new biomarkers that can be used as predictors of treatment response and pave the way for personalized treatments. In this review, we describe the footprint psoriasis leaves on the skin and beyond, key pathophysiological mechanisms, current available therapeutic options, and drawbacks faced by existing therapies, and we anticipate potential future perspectives that may improve the quality of life of affected individuals.

Muscone Can Improve Spinal Cord Injury by Activating the Angiogenin/Plexin-B2 Axis

Spinal cord injury (SCI) is a devastating neurological disorder that usually damages sensorimotor and autonomic functions. Signaling pathways can play a key role in the repair process of SCI. The plexin-B2 acts as a receptor for angiogenin and mediates ribosomal RNA transcription, influencing cell survival and proliferation. Protein kinase B serine/threonine kinase interacts with angiogenin to form a positive feedback effect. Brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor can induce angiogenin nuclear translocation. Moreover, the BDNF can promote the secretion of angiogenin. Interestingly, all of them can activate the angiogenin/plexin-B2 axis. Muscone has anti-inflammatory and proliferative features as it can inhibit nuclear transcription factor kappa-B (NF-κB) and activate the angiogenin/plexin-B2 axis, thus being significant agent in the SCI repair process. Herein, we review the potential mechanism of angiogenin/plexin-B2 axis activation and the role of muscone in SCI treatment. Muscone may attenuate inflammatory responses and promote neuronal regeneration after SCI.

The Neuroprotection of Verbascoside in Alzheimer’s Disease Mediated through Mitigation of Neuroinflammation via Blocking NF-κB-p65 Signaling

Verbascoside (VB) is a phenylethanoid glycoside extracted from the herbaceous plant Verbascum sinuatum and plays a neuroprotective role in Alzheimer’s disease (AD). The goal of this study was to explore the neuroprotective mechanism of VB. Based on the proteomics analysis, immunohistochemistry, immunofluorescence, Western blot, and ELISA were utilized to explore the neuroprotective mechanism of VB in context of neuroinflammation in APP/PS1 mice, LPS-induced BV2 cells, and/or Aβ_1-42-stimulated N2a cells. Proteomic analysis demonstrated that the neuroprotection of VB correlated closely to its anti-inflammatory effect. VB significantly blocked microglia and astrocyte against activation in brains of APP/PS1 mice, suppressed the generation of IL-1β as well as IL-6, and boosted that of IL-4, IL-10 and TGF-β in vivo, which were analogous to results acquired in vitro. Furthermore, VB effectively restrained the phosphorylation of IKKα+β, IκBα, and NF-κB-p65 in APP/PS1 mice; LPS-induced BV2 cells, and Aβ_1-42-stimulated N2a cells and lowered the tendency of NF-κB-p65 translocation towards nucleus in vitro. These results demonstrate that the neuroprotective effect of VB correlates to the modulation of neuroinflammation via NF-κB-p65 pathway, making VB as a hopeful candidate drug for the prevention and treatment of AD.

Increased airway epithelial cell-derived exosomes activate macrophage-mediated allergic inflammation via CD100 shedding

Airway epithelial cells (AECs) participate in allergic airway inflammation by producing mediators in response to allergen stimulation. Whether ovalbumin (OVA) challenge promotes exosome release from AECs (OVA‐challenged AEC‐derived exosomes (OAEs)), thereby affecting airway inflammation, as well as the underlying mechanisms, is unknown. Our study showed that AECs released an increased number of exosomes after OVA challenge, and the expression of Plexin B2 (PLXNB2; a natural CD100 ligand) was increased by a massive 85.7‐fold in OAEs than in PBS‐treated AEC‐derived exosomes (PAEs). CD100⁺F4/80⁺ macrophages engulfed OAEs to trigger the transcription of pro‐inflammatory chemokines and cytokines. Plxnb2 transcripts increased in asthmatic lungs, and similarly, PLXNB2 protein was highly enriched in exosomes purified from asthmatic bronchoalveolar lavage (BAL) fluid. Furthermore, aspiration of PLXNB2 or OAEs increased the recruitment of lung neutrophils, monocytes, eosinophils and dendritic cells in OVA‐challenged mice. Mechanistically, OAE aspiration enhanced the cleavage of CD100 by MMP14, which manifested as an increase in the soluble CD100 (sCD100) level in BAL fluid and lung homogenates. Knockdown of Mmp14 in macrophages prevented the cleavage of CD100 and reduced Ccl2, Ccl5 and Cxcl2 transcription. These data indicate that PLXNB2‐containing OAEs aggravate airway asthmatic inflammation via cleavage of CD100 by MMP14, suggesting potential therapeutic targets of OAE‐mediated asthma exacerbations.

Expression of Transient Receptor Potential Channel of Melastatin number 8 (TRPM8) in Non- Melanoma Skin Cancer: A Clinical and Immunohistochemical study

Transient Receptor Potential Channel of Melastatin number 8 (TRPM8) is abnormally expressed in many cancers as lung, however little is known about TRPM8 expression in non-melanoma skin cancer (NMSC) including cutaneous squamous cell carcinoma (SCC) and basal cell carcinoma (BCC). This work aimed to study TRPM8 expression in NMSC. It included 100 skin biopsies (50 normal skin as control group, 15 BCC and 35 SCC). Immunohistochemical staining for TRPM8 was done and results were correlated with clinicopathological characters. There was significant higher TRPM8 H-score in NMSC than control skin. On comparing SCC cases to control, there was significant positive TRPM8 expression, strong intensity, diffuse pattern, cytoplasmic and nucleo-cytoplasmic localization and higher range of H-score in SCC. In contrast, BCC showed significant lower TRPM8 positive expression when compared to control skin. Higher TRPM8 H-score in SCC showed significant positive correlation with large tumor size and poor tumor differentiation.TRPM8 may be implicated in pathogenesis of NMSC. Its association with bad prognostic characters; potentiates its role as prognostic biomarker and open new chances for therapeutic intervention in NMSC. TRPM8 antagonists may share in decreasing tumor growth and progression and may serve as potential target for tumor immunotherapy.

Role of CYR61 in psoriatic lesional and perilesional skin: A clinical and immunohistochemical study

BACKGROUND

Psoriasis is considered as an immune-mediated disorder with significant epidermal hyperplasia and inflammation. Cysteine-rich angiogenic inducer 61 (CYR61), known as CCN family member 1 (CCN1), plays an important role in cell proliferation and neovascularization which may trigger psoriasis development.

AIMS

This study aimed to assess the immunostaining of CYR61 in psoriatic skin (lesional and perilesional) compared to control skin.

PATIENTS/METHODS

This is a case-control study. The Psoriasis Area and Severity Index (PASI) was used to evaluate disease severity. A punch biopsy was taken from psoriatic skin lesions (30), perilesional (30) skin, and matched site of controls (20). The pathological and immunostaining assessments of CYR61 were conducted.

RESULTS

There was a significant gradual progressive overexpression of CYR61 in keratinocytes from control skin to perilesional and lesional psoriatic skin (P = .00). Moreover, lesional psoriatic skin showed overexpression of CYR61 in inflammatory cells in the dermis than controls. CYR61 expression (lesional epidermis) revealed a significant positive correlation with the PASI score (r = .63; P = .00). There was a significant relationship between intensity and H-core of CYR61 in the lesional psoriatic epidermis with joint affection.

CONCLUSION

CYR61 may trigger epidermal hyperplasia and potentiate inflammatory infiltration in psoriasis vulgaris patients, and therapies targeting CYR61 may be effective in the management of psoriasis vulgaris.