Qinzhuliangxue mixture ameliorates psoriasis by restraining apoptosis in psoriasis via downregulating the MDA-5 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Psoriasis is characterized by hyperkeratosis that produces the classic silvery scales, and the pathogenesis of psoriasis involves abnormal proliferation of keratinocytes. Emerging evidence supports that apoptosis regulates keratinocyte proliferation and formation of stratum corneum, which maintains the homeostasis of the skin. Qinzhuliangxue mixture (QZLX) is a representative formula for the treatment of psoriasis, which was earliest recorded in the classic Chinese medicine book Xia's Surgery. In our previous clinical studies, QZLX demonstrated 83.33% efficacy with few side effects in the treatment of psoriasis. Furthermore, our published basic research has also proved that the QZLX mixture effectively inhibits the hyperproliferation of keratinocytes, thus exerting therapeutic effects on psoriasis. However, whether QZLX mixture can regulate keratinocytes apoptosis requires further clarification.

OBJECTIVE OF THE STUDY

To investigate the mechanism of QZLX in the treatment of psoriasis from the perspective of keratinocyte apoptosis.

MATERIALS AND METHODS

First, psoriasis-like mice with imiquimod (IMQ)-induced were given QZLX intragastric administration and Psoriasis Area Severity Index (PASI) scores were recored for 11 consecutive days to appraise the efficacy. Then, tissue samples were collected for transcriptome analysis. The DEseq2 method detected significantly differentially expressed genes (DEGs), Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway databases were used to analyze the functions and pathway enrichment of DEGs. After that, the therapeutic mechanisms of QZLX in intervening with psoriasis were explored using TUNEL, immunohistochemical staining, and western blotting.

RESULTS

QZLX ameliorated the symptoms and pathological characteristics of IMQ-induced psoriasis in mice. The epidermal cell hyperplasia in the skin was inhibited, in accordance with the suppressed expression of PCNA and Ki67 after treatment. Transcriptome sequencing showed that melanoma differentiation associated gene-5 (MDA-5) was downregulated. GO and KEGG enrichment analysis of the signaling pathways indicated that the differentially expressed genes were significantly enriched in apoptosis pathways. Besides, QZLX treatment decreased the apoptosis of keratinocyte as shown by reduced TUNEL-positive cells. As MDA-5 protein levels decreased, so did the expression of the downstream protein Caspase-8, which indicates that the apoptotic pathway was triggered. Furthermore, QZLX therapy might also help to balance the apoptotic Bcl-2 family expression.

CONCLUSION

QZLX restrains the apoptosis of keratinocyte in psoriasis-like mice by downregulating the MDA-5 pathway. The restoration of the balance between cell apoptosis and proliferation in the skin may lead to considerable psoriasis relief. Our study reveals the possible molecular processes behind the effects of QZLX therapy on the skin lesions of psoriasis, and lends support to its clinical efficacy.

Insight into the role of IRF7 in skin and connective tissue diseases

Interferons (IFNs) are signalling proteins primarily involved in initiating innate immune responses against pathogens and promoting the maturation of immune cells. Interferon Regulatory Factor 7 (IRF7) plays a pivotal role in the IFNs signalling pathway. The activation process of IRF7 is incited by exogenous or abnormal nucleic acids, which is followed by the identification via pattern recognition receptors (PRRs) and the ensuing signalling cascades. Upon activation, IRF7 modulates the expression of both IFNs and inflammatory gene regulation. As a multifunctional transcription factor, IRF7 is mainly expressed in immune cells, yet its presence is also detected in keratinocytes, fibroblasts, and various dermal cell types. In these cells, IRF7 is critical for skin immunity, inflammation, and fibrosis. IRF7 dysregulation may lead to autoimmune and inflammatory skin conditions, including systemic scleroderma (SSc), systemic lupus erythematosus (SLE), Atopic dermatitis (AD) and Psoriasis. This comprehensive review aims to extensively elucidate the role of IRF7 and its signalling pathways in immune cells and keratinocytes, highlighting its significance in skin-related and connective tissue diseases.

The discriminative role of PROX-1 immunohistochemistry between venous malformation and lymphatic malformation of the deep type with no visible diagnostic surface skin lesion

BACKGROUND

Venous malformations (VMs) are distinguished from lymphatic malformations (LMs) when specific diagnostic skin lesions are present. In the deep type, this is difficult by clinico-radiologic evaluation alone. We aimed to investigate the usefulness of lymphatic vessel endothelial cell (LEC) markers for the differential diagnosis of the deep VMs and LMs.

METHODS

A retrospective study was conducted based on the medical records of patients with VMs and LMs who underwent biopsy with both D2-40 and PROX-1 immunohistochemistry. We compared the initial clinico-radiological diagnosis with the final pathological diagnosis and identified which ones showed a difference.

RESULTS

From 261 patients who had VMs and LMs, 111 remained after the exclusion of those who showed definite surface diagnostic features. After pathological diagnosis with the expressions of D2-40 and PROX-1, 38 of 111 (34.2%) patients' final diagnoses were changed. Among these 38 cases, diagnosis was not changed by D2-40 positivity alone, but changed by PROX-1 positivity alone (52.6%) or by both (47.4%). The diagnostic changes were more frequent in the deep category (43.7%) than in the superficial category.

CONCLUSIONS

Identifying the expression of D2-40, and especially PROX-1, in the differential diagnosis of VMs and LMs may provide important treatment guidelines and understanding their natural course.

CLDN1 knock out keratinocytes as a model to investigate multiple skin disorders

The transmembrane protein claudin-1 is critical for formation of the epidermal barrier structure called tight junctions (TJ) and has been shown to be important in multiple disease states. These include neonatal ichthyosis and sclerosing cholangitis syndrome, atopic dermatitis and various viral infections. To develop a model to investigate the role of claudin-1 in different disease settings, we used CRISPR/Cas9 to generate human immortalized keratinocyte (KC) lines lacking claudin-1 (CLDN1 KO). We then determined whether loss of claudin-1 expression affects epidermal barrier formation/function and KC differentiation/stratification. The absence of claudin-1 resulted in significantly reduced barrier function in both monolayer and organotypic cultures. CLDN1 KO cells demonstrated decreases in gene transcripts encoding the barrier protein filaggrin and the differentiation marker cytokeratin-10. Marked morphological differences were also observed in CLDN1 KO organotypic cultures including diminished stratification and reduced formation of the stratum granulosum. We also detected increased proliferative KC in the basale layer of CLDN1 KO organotypic cultures. These results further support the role of claudin-1 in epidermal barrier and suggest an additional role of this protein in appropriate stratification of the epidermis.

F127-SE-tLAP thermosensitive hydrogel alleviates bleomycin-induced skin fibrosis via TGF-β/Smad pathway

BACKGROUND

Skin fibrosis affects the normal function of the skin. TGF-β1 is a key cytokine that affects organ fibrosis. The latency-associated peptide (LAP) is essential for TGF-β1 activation. We previously constructed and prepared truncated LAP (tLAP), and confirmed that tLAP inhibited liver fibrosis by affecting TGF-β1. SPACE peptide has both transdermal and transmembrane functions. SPACE promotes the delivery of macromolecules through the stratum corneum into the dermis. This study aimed to alleviate skin fibrosis through the delivery of tLAP by SPACE.

METHODS

The SPACE-tLAP (SE-tLAP) recombinant plasmid was constructed. SE-tLAP was purified by nickel affinity chromatography. The effects of SE-tLAP on the proliferation, migration, and expression of fibrosis-related and inflammatory factors were evaluated in TGF-β1-induced NIH-3T3 cells. F127-SE-tLAP hydrogel was constructed by using F127 as a carrier to load SE-tLAP polypeptide. The degradation, drug release, and biocompatibility of F127-SE-tLAP were evaluated. Bleomycin was used to induce skin fibrosis in mice. HE, Masson, and immunohistochemistry were used to observe the skin histological characteristics.

RESULTS

SE-tLAP inhibited the proliferation, migration, and expression of fibrosis-related and inflammatory factors in NIH-3T3 cells. F127-SE-tLAP significantly reduced ECM production, collagen deposition, and fibrotic pathological changes, thereby alleviating skin fibrosis.

CONCLUSION

F127-SE-tLAP could increase the transdermal delivery of LAP, reduce the production and deposition of ECM, inhibit the formation of dermal collagen fibers, and alleviate the progression of skin fibrosis. It may provide a new idea for the therapy of skin fibrosis.

The role of thymic stromal lymphopoietin in cutaneous disorders

Thymic Stromal Lymphopoietin (TSLP) is an important cytokine that invokes early immune responses. TSLP, an IL-7-like cytokine encoded by the TSLP gene, activates JAK1 and JAK2 signaling pathways, stimulating dendritic cells to induce inflammatory Th2 cells. This cytokine is associated with pruritus in various cutaneous disorders, particularly atopic dermatitis. Varying levels of the cytokine TSLP have been demonstrated in studies of different cutaneous disorders. Pharmacological treatment targeting TSLP has been explored recently, particularly in the realm of atopic dermatitis.This review explores the relation of TSLP to cutaneous diseases, highlighting its potential as a biomarker for monitoring disease progression in discoid lupus erythematosus (DLE). The pharmacological therapy involving TSLP is discussed, along with the potential role of TSLP promotion in the treatment of alopecia areata. This overview examines the background, structure, and functions of TSLP, with a focus on its association with cutaneous disorders and a special focus on the impact of the atopic march.

The role of the cytochrome P450 superfamily in the skin

In mammals, the skin acts as a barrier to prevent harmful environmental stimuli from entering the circulation. CYP450s are involved in drug biotransformation, exogenous and endogenous substrate metabolism, and maintaining the normal physiological function of the skin, as well as facilitating homeostasis of the internal environment. The expression pattern of CYP450s in the skin is tissue-specific and thus differs from the liver and other organs. The development of skin topical medications, and knowledge of the toxicity and side effects of these medications require a detailed understanding of the expression and function of skin-specific CYP450s. Thus, we summarized the expression of CYP450s in the skin, their function in endogenous metabolic physiology, aberrant CYP450 expression in skin diseases and the influence of environmental variables and medications. This information will serve as a crucial foundation for future studies on the skin, as well as for the design and development of new drugs for skin diseases including topical medications.

Inflammatory and Immunomodulatory Effects of Tripterygium wilfordii Multiglycoside in Mouse Models of Psoriasis Keratinocytes

OBJECTIVE

To determine the role of Tripterygium wilfordii multiglycoside (TGW) in the treatment of psoriatic dermatitis from a cellular immunological perspective.

METHODS

Mouse models of psoriatic dermatitis were established by imiquimod (IMQ). Twelve male BALB/c mice were assigned to IMQ or IMQ+TGW groups according to a random number table. Histopathological changes in vivo were assessed by hematoxylin and eosin staining. Ratios of immune cells and cytokines in mice, as well as PAM212 cell proliferation in vitro were assessed by flow cytometry. Pro-inflammatory cytokine expression was determined using reverse transcription quantitative polymerase chain reaction.

RESULTS

TGW significantly ameliorated the severity of IMQ-induced psoriasis-like mouse skin lesions and restrained the activation of CD45+ cells, neutrophils and T lymphocytes (all P<0.01). Moreover, TGW significantly attenuated keratinocytes (KCs) proliferation and downregulated the mRNA levels of inflammatory cytokines including interleukin (IL)-17A, IL-23, tumor necrosis factor α, and chemokine (C-X-C motif) ligand 1 (P<0.01 or P<0.05). Furthermore, it reduced the number of γ δ T17 cells in skin lesion of mice and draining lymph nodes (P<0.01).

CONCLUSIONS

TGW improved psoriasis-like inflammation by inhibiting KCs proliferation, as well as the associated immune cells and cytokine expression. It inhibited IL-17 secretion from γ δ T cells, which improved the immune-inflammatory microenvironment of psoriasis.

The GRHL3-regulated long non-coding RNA lnc-DC modulates keratinocytes differentiation by interacting with IGF2BP2 and up-regulating ZNF750

BACKGROUND

Aberrant keratinocytes differentiation has been demonstrated to be associated with a number of skin diseases. The roles of lncRNAs in keratinocytes differentiation remain to be largely unknown.

OBJECTIVE

Here we aim to investigate the role of lnc-DC in regulating epidermal keratinocytes differentiation.

METHODS

Expression of lnc-DC in the skin was queried in AnnoLnc and verified by FISH. The lncRNA expression profiles during keratinocytes differentiation were reanalyzed and verified by qPCR and FISH. Gene knock-down and over-expression were used to explore the role of lnc-DC in keratinocytes differentiation. The downstream target of lnc-DC was screened by whole transcriptome sequencing. CUT&RUN assay and siRNAs transfection was used to reveal the regulatory effect of GRHL3 on lnc-DC. The mechanism of lnc-DC regulating ZNF750 was revealed by RIP assay and RNA stability assay.

RESULTS

Lnc-DC was biasedly expressed in skin and up-regulated during epidermal keratinocytes differentiation. Knockdown lnc-DC repressed epidermal keratinocytes differentiation while over-express lnc-DC showed the opposite effect. GRHL3, a well-known transcription factor regulating keratinocytes differentiation, could bind to the promoter of lnc-DC and regulate its expression. By whole transcriptome sequencing, we identified that ZNF750 was a downstream target of lnc-DC during keratinocytes differentiation. Mechanistically, lnc-DC interacted with RNA binding protein IGF2BP2 to stabilize ZNF750 mRNA and up- regulated its downstream targets TINCR and KLF4.

CONCLUSION

Our study revealed the novel role of GRHL3/lnc-DC/ZNF750 axis in regulating epidermal keratinocytes differentiation, which may provide new therapeutic targets of aberrant keratinocytes differentiation related skin diseases.

Penetration rates into the stratum corneum layer: A novel quantitative indicator for assessing skin barrier function

BACKGROUND

The stratum corneum (SC), the outermost layer of the skin epidermis, acts as an effective bi-directional barrier, preventing water loss (inside-outside barrier) and entry of foreign substances (outside-inside barrier). Although transepidermal water loss (TEWL) is a widely-used measure of barrier function, it represents only inside-outside protection. Therefore, we aimed to establish a non-invasive method for quantitative evaluation of the outside-inside barrier function and visually present a skin barrier model.

MATERIALS AND METHODS

Skin barrier damage was induced by applying a closed patch of 1% sodium dodecyl sulfate to the forearms of eight participants; they were instructed to apply a barrier cream on a designated damaged area twice daily for 5 days. The SC barrier was evaluated by measuring TEWL and fluorescein sodium salt penetration rate before, immediately after, and 5 days after damage. The penetration rate was assessed using tape-stripping (TS) technique and fluorescence microscopy.

RESULTS

The rates of fluorescein sodium salt penetration into the lower layers of SC differed significantly based on the degree of skin barrier damage. The correlation between penetration rate and TEWL was weak after two rounds of TS and became stronger after subsequent rounds. Five days after skin barrier damage, the penetration rate of all layers differed significantly between areas with and without the barrier cream application.

CONCLUSION

Our findings demonstrated that the penetration rate was dependent on skin barrier conditions. The penetration rate and corresponding fluorescence images are suitable quantitative indicators that can visually represent skin barrier conditions.

Myconoside and Calceolarioside E Restrain UV-Induced Skin Photoaging by Activating NRF2-Mediated Defense Mechanisms

Chronic and excessive ultraviolet (UVA/UVB) irradiation exposure is known as a major contributor to premature skin aging, which leads to excessive reactive oxygen species generation, disturbed extracellular matrix homeostasis, DNA damage, and chronic inflammation. Sunscreen products are the major preventive option against UVR-induced photodamage, mostly counteracting the acute skin effects and only mildly counteracting accelerated aging. Therefore, novel anti-photoaging and photopreventive compounds are a subject of increased scientific interest. Our previous investigations revealed that the endemic plant Haberlea rhodopensis Friv. (HRE) activates the antioxidant defense through an NRF2-mediated mechanism in neutrophiles. In the present study, we aimed to investigate the photoprotective potential of HRE and two of its specialized compounds-the phenylethanoid glycosides myconoside (MYC) and calceolarioside E (CAL)-in UVA/UVB-stimulated human keratinocytes in an in vitro model of photoaging. The obtained data demonstrated that the application of HRE, MYC, and CAL significantly reduced intracellular ROS formation in UVR-exposed HaCaT cells. The NRF2/PGC-1α and TGF-1β/Smad/Wnt signaling pathways were pointed out as having a critical role in the observed CAL- and MYC-induced photoprotective effect. Collectively, CAL is worth further evaluation as a potent natural NRF2 activator and a promising photoprotective agent that leads to the prevention of UVA/UVB-induced premature skin aging.

Expression of hornerin in skin lesions of atopic dermatitis and skin diseases

We have previously identified the filaggrin (FLG)-like protein, hornerin (HRNR). Recently, there have been several reports regarding the relationship between HRNR and atopic dermatitis (AD). In the present study, we examined HRNR expression in the skin lesions of seven unrelated patients with AD to clarify the role of HRNR in the pathogenesis of AD. HRNR was detected in chronic AD lesions (n = 4), whereas no HRNR signals were observed in acute AD lesions (n = 3). HRNR was detected in the cytokeratin 6-expressing epidermis, and Ki67-positive keratinocytes were more abundant in the HRNR-positive epidermis. These findings suggest that HRNR may be associated with epidermal hyperproliferation in AD lesions. Next, we examined HRNR expression in skin diseases associated with hyperkeratosis. HRNR signals were irregularly observed in different cells from those expressing FLG in epidermolytic ichthyosis and actinic keratosis. Therefore, HRNR may play a unique role in the molecular process of cornification.

Adipose-derived stem cells in immune-related skin disease: a review of current research and underlying mechanisms

Adipose-derived stem cells (ASCs) are a critical adult stem cell subpopulation and are widely utilized in the fields of regenerative medicine and stem cell research due to their abundance, ease of harvest, and low immunogenicity. ASCs, which are homologous with skin by nature, can treat immune-related skin diseases by promoting skin regeneration and conferring immunosuppressive effects, with the latter being the most important therapeutic mechanism. ASCs regulate the immune response by direct cell-cell communication with immune cells, such as T cells, macrophages, and B cells. In addition to cell-cell interactions, ASCs modulate the immune response indirectly by secreting cytokines, interleukins, growth factors, and extracellular vesicles. The immunomodulatory effects of ASCs have been exploited to treat many immune-related skin diseases with good therapeutic outcomes. This article reviews the mechanisms underlying the immunomodulatory effects of ASCs, as well as progress in research on immune-related skin diseases.

JAK1/JAK2 degraders based on PROTAC for topical treatment of atopic dermatitis

Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disease. The Janus kinase (JAK) has been identified as a target in AD, as it regulates specific inflammatory genes and adaptive immune responses. However, the efficacy of topically applied JAK inhibitors in AD is limited due to the unique structure of skin. We synthesized JAK1/JAK2 degraders (JAPT) based on protein degradation targeting chimeras (PROTACs) and prepared them into topical preparations. JAPT exploited the E3 ligase to mediate ubiquitination and degradation of JAK1/JAK2, offering a promising AD therapeutic approach with low frequency and dosage. In vitro investigations demonstrated that JAPT effectively inhibited the release of pro-inflammatory cytokines and reduced inflammation by promoting the degradation of JAK. In vivo studies further confirmed the efficacy of JAPT in degrading JAK1/JAK2, leading to a significant suppression of type I, II, and III adaptive immunity. Additionally, JAPT demonstrated a remarkable reduction in AD severity, as evidenced by improved skin lesion clearance and AD severity scores (SCORAD). Our study revealed the therapeutic potential of JAPT, surpassing conventional JAK inhibitors in the treatment of AD, which suggested that JAPT could be a promising topically applied anti-AD drug targeting the JAK-STAT signaling pathway.

ZNF750 Regulates Skin Barrier Function by Driving Cornified Envelope and Lipid Processing Pathways

The epidermis is a constantly renewing stratified epithelial tissue that provides essential protective barrier functions. The major barrier is located at the outermost layers of the epidermis, formed by terminally differentiated keratinocytes reinforced by proteins of their cornified envelope and sequestered intercellular lipids. Disruptions to epidermal differentiation characterize various skin disorders. ZNF750 is an epithelial transcription factor essential for in vitro keratinocyte differentiation, whose truncating mutation in humans causes autosomal dominant psoriasis-like skin disease. In this study, we utilized an epidermal-specific Znf750 conditional knockout mouse model to uncover the role ZNF750 plays in epidermal development. We show that deletion of Znf750 in the developing skin does not block epidermal differentiation completely, suggesting in vivo compensatory feedback mechanisms, although it does result in impaired barrier function and perinatal lethality. Molecular dissection revealed ultrastructural defects in the differentiated layers of the epidermis, accompanied by alterations in the expression of ZNF750-dependent genes encoding key cornified envelope precursor proteins and lipid-processing enzymes, including gene subsets known to be mutated in human skin diseases involving impaired barrier function. Together, our findings provide molecular insights into the pathogenesis of human skin disease by linking ZNF750 to a subset of epidermal differentiation genes involved in barrier formation pathways.

Livin expression promotes keratinocyte release of inflammatory mediators in psoriasis

BACKGROUND

Psoriasis is a prevalent, long-term skin condition characterized by inflammation. Keratinocytes (KCs) are important effector cells that release inflammatory factors and chemokines to promote the inflammatory cascade in psoriasis. However, the mechanisms underlying the activation of KCs in psoriasis remain unclear. Livin suppresses apoptotic proteins and directly affects the growth and spread of cancer cells. Livin expression reportedly increases significantly in lesions of patients with psoriasis; however, its specific role in KC activation remains unknown. This study aimed to examine the impact of Livin on KC activation and the subsequent release of inflammatory mediators.

METHODS

Immunofluorescence staining, reverse transcription-quantitative polymerase chain reaction, enzyme-linked immunosorbent assay (ELISA), and western blotting were used to assess Livin expression in patients with psoriasis, an imiquimod (IMQ)-induced psoriasis-like mouse model, and M5-treated HaCaT cells. To investigate the role of Livin in KCs, we performed RNA sequencing and proteomic analysis of Livin-knockdown (knockdown-HaCaT) and negative control (NC-HaCaT) cells. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes were used for enrichment analyses. Moreover, the effect of Livin expression on the release of inflammatory mediators in KCs was verified using ELISA.

RESULTS

Livin expression was higher in KCs of patients with psoriasis than in those healthy controls. Livin expression in HaCaT cells treated with M5 increased significantly over time. Livin expression was higher in the skin lesions of the IMQ mouse model than in the control group. Proteomic analysis and RNA sequencing used to investigate the function of Livin in HaCaT cells revealed its potential role in mediating KC activation and inflammatory mediator release, which affected the pathology of psoriasis.

CONCLUSIONS

Livin expression played an effect on KCs activation, which induced release of inflammatory mediators and up-regulation of keratin. This study provides a new effector molecule for the mechanism of inflammatory response in psoriasis.

Emerging Role of the IL-36/IL-36R Axis in Multiple Inflammatory Skin Diseases

IL-36 is a most recent member of the IL-1 cytokine family, primarily expressed at barrier sites of the body such as the skin, lungs, and intestine. It plays a vital role in inflammation and is implicated in the development of various cutaneous; intestinal; and pulmonary disorders, including psoriasis, inflammatory bowel disease, and chronic obstructive pulmonary disease. IL-36 comprises 4 isoforms: the proinflammatory IL-36α, IL-36β, and IL-36γ and the anti-inflammatory IL-36R antagonist. An imbalance between proinflammatory and anti-inflammatory IL-36 isoforms can contribute to the inflammatory fate of cells and tissues. IL-36 cytokines signal through an IL-36R heterodimer mediating their function through canonical signaling cacade, including the NF-B pathway. Prominent for its role in psoriasis, IL-36 has recently been associated with disease mechanisms in atopic dermatitis, hidradenitis suppurativa, neutrophilic dermatoses, autoimmune blistering disease, and Netherton syndrome. The major cutaneous source of IL-36 cytokines is keratinocytes, pointing to its role in the communication between the epidermis, innate (neutrophils, dendritic cells) immune system, and adaptive (T helper [Th]1 cells, Th17) immune system. Thus, cutaneous IL-36 signaling is crucial for the immunopathological outcome of various skin diseases. Consequently, the IL-36/IL-36R axis has recently been recognized as a promising drug target for the treatment of inflammatory disorders beyond psoriasis. This review summarizes the current update on IL-36 cytokines in inflammatory skin diseases.

Polygonum perfoliatum L. ethanol extract ameliorates 2,4-dinitrochlorobenzene-induced atopic dermatitis-like skin inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Polygonum perfoliatum L. (PP) is classified as a heat-clearing and detoxifying agent in traditional Chinese medicine, and is believed to possess therapeutic properties for treating eczema, furuncles, and venomous snake bites. Previous studies have demonstrated that PP extract exhibits multiple bioactivities, including antibacterial, anti-inflammatory, antitumor, antioxidation, and antiviral properties. However, no existing studies have evaluated the effects of PP on animal models of atopic dermatitis (AD)-like skin symptoms, which are closely associated with traditional ethnic usage.

AIM OF THE STUDY

In present study, therefore, we aimed to explore the potential anti-atopic effect of Polygonum perfoliatum L. ethanol extract (PPE) in 2,4-Dinitrochlorobenzene (DNCB)-induced dermatitis-like skin lesions.

MATERIALS AND METHODS

For reaching this aim, DNCB-induced mice with AD-like skin inflammation were subjected to topical administration of PPE gels for a period of 21 days, and subsequently, the biological impacts of PPE were evaluated.

RESULTS

PPE gels effectively mitigated AD-like skin symptoms induced by DNCB in mice, as demonstrated by a marked reduction in epidermal thickness and dermatitis severity. Moreover, PPE significantly decreased the production of various cytokines, including TNF-α, IL-6, IL-1β, IL-4, IL-5, IL-13 and IgE, in addition to suppressed the production of key inflammation-related enzymes (iNOS and COX-2) and decreased the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB in AD-like skin samples. Furthermore, PPE treatment inhibited the abnormally elevated CD4+/CD8+ ratio in DNCB-induced AD mice. The results of the skin irritation test revealed that PPE exhibited no adverse toxicity in mice at dose of 10 mg/day.

CONCLUSIONS

PPE exhibits potential as a safe therapeutic agent for atopic dermatitis by efficiently mitigating DNCB-induced atopic symptoms and diminishing inflammation, and does not carry the risk of over-immunosuppression or treatment-associated adverse effects.

Anti-Photoaging Effects of Upcycled Citrus junos Seed Anionic Peptides on Ultraviolet-Radiation-Induced Skin Aging in a Reconstructed Skin Model

Side streams and byproducts of food are established sources of natural ingredients in cosmetics. In the present study, we obtained upcycled low-molecular-weight anionic peptides (LMAPs) using byproducts of the post-yuzu-juicing process by employing an enzyme derived from Bacillus sp. For the first time, we isolated anionic peptides less than 500 Da in molecular weight from Citrus junos TANAKA seeds via hydrolysis using this enzyme. The protective effect of LMAPs against UVR-induced photoaging was evaluated using a reconstructed skin tissue (RST) model and keratinocytes. The LMAPs protected the keratinocytes by scavenging intracellular reactive oxygen species and by reducing the levels of paracrine cytokines (IL-6 and TNF-α) in UVR (UVA 2 J/cm2 and UVB 15 mJ/cm2)-irradiated keratinocytes. Additionally, the increase in melanin synthesis and TRP-2 expression in RST caused by UVR was significantly inhibited by LMAP treatment. This treatment strongly induced the expression of filaggrin and laminin-5 in UVR-irradiated RST. It also increased type I collagen expression in the dermal region and in fibroblasts in vitro. These results suggest that a hydrolytic system using the enzyme derived from Bacillus sp. can be used for the commercial production of LMAPs from food byproducts and that these LMAPs can be effective ingredients for improving photoaging-induced skin diseases.

Qingre Lishi Decoction ameliorates imiquimod-induced psoriasis-like skin lesions in SKH-1 mice by regulating the Treg-DC-Th17 axis and inhibiting MAPK-mediated DC maturation

ETHNOPHARMACOLOGICAL RELEVANCE

Psoriasis, an immune system disorder, is a chronic relapsing disease that cannot be cured. Chinese herbal medicine is gradually considered a promising alternative treatment for psoriasis due to its multiple effects, ability to target multiple pathways and lower toxicity. Qingre Lishi Decoction (QRLSD) is effective in clinical treatment. However, its related molecular mechanism remains to be elucidated.

AIM OF THE STUDY

The purpose of this research was to investigate the therapeutic impacts of Qingre Lishi Decoction on the murine model of psoriasis-like skin lesions induced by imiquimod and to reveal the underlying mechanisms.

MATERIALS AND METHODS

First, QRLSD was orally administered to evaluate its efficacy in an imiquimod (IMQ)-induced psoriasis mouse model. Further, UPLC-Q-TOF/MS was used to analyze the compounds of QRLSD. To investigate the mechanism and main targets of QRLSD for treating psoriasis, network pharmacology and molecular docking methods were utilized. Finally, To further confirm the anti-psoriasis target, dendritic cells derived from bone marrow (BMDCs) were cultured in vitro.

RESULTS

In vivo experiments found that QRLSD could regulate the ratio of dendritic cells, Treg cells, and Th17 cells in the body and inhibit inflammation and keratinocyte proliferation in psoriasis-like skin lesions. Further analysis showed that the p38-MAPK pathway is one of its main signaling pathways. In vitro experiments confirmed that QRLSD suppressed the maturation and activation of BMDCs via the p38-MAPK signaling pathway.

CONCLUSIONS

This study suggests that Qingre Lishi Decoction has the promise to be an effective formula for treating psoriasis through the p38-MAPK pathway, which can help break through the current limitations of psoriasis in clinical treatment.

Endoplasmic reticulum stress in skin aging induced by UVB

Aging is a normal and complex biological process. Skin is located in the most superficial layer of the body, and its degree of aging directly reflects the aging level of the body. Endoplasmic reticulum stress refers to the aggregation of unfolded or misfolded proteins in the endoplasmic reticulum and the disruption of the calcium ion balance when cells are stimulated by external stimuli. Mild endoplasmic reticulum stress can cause a series of protective mechanisms, including the unfolded protein response, while sustained high intensity stimulation leads to endoplasmic reticulum stress and eventually apoptosis. Photoaging caused by ultraviolet radiation is an important stimulus in skin aging. Many studies have focused on oxidative stress, but increasing evidence shows that endoplasmic reticulum stress plays an important role in photoaging. This paper reviews the development and mechanism of endoplasmic reticulum stress (ERS) in skin photoaging, and provides research directions for targeting the ERS pathway to slow aging.

Transdermal delivery of Fn14 siRNA using a novel composite ionic liquid for treatment of psoriasis-like skin lesions

Psoriasis is a chronic inflammatory skin disease characterised by the abnormal proliferation of keratinocytes and dysregulation of immune cells. The upregulation of fibroblast growth factor-inducible molecule 14 (Fn14) in psoriatic lesions has been linked to the development of psoriasis. Transdermal delivery of siRNAs for Fn14 inhibition is challenging. In this study, we developed a composite ionic liquid (CIL) for the transdermal delivery of Fn14 siRNA (siFn14) into keratinocytes, with the aim of modulating the inflammatory response associated with psoriasis. The results showed that CIL-siFn14 effectively suppressed Fn14 expression, resulting in a reduction in both the Psoriasis Area and Severity Index (PASI) score and skin thickness. Furthermore, CIL-siFn14 effectively inhibited the abnormal proliferation of keratinocytes, decreased the production of inflammatory factors associated with psoriasis, prevented the over-activation of CD4+ and CD8+ T cells, and restored the balance of Type 1 T helper (Th1), Th2, Th17 and Treg cells. In conclusion, our findings unveiled the critical role of Fn14 in the pathogenesis of psoriasis and demonstrated the potential of CIL-siFn14 as a novel and effective topical treatment for its management.

Exosomes derived from human dermal fibroblasts (HDFn-Ex) alleviate DNCB-induced atopic dermatitis (AD) via PPARα

Atopic dermatitis (AD) is a chronic inflammatory skin disease. Skin barrier dysfunction is the initial step in the development of AD. Recently, exosomes have been considered as potential cell-free medicine for skin defects such as aging, psoriasis and wounds. The aim of this study was to investigate the effects of human dermal fibroblast-neonatal-derived exosome (HDFn-Ex) on AD. HDFn-Ex increased the expression of peroxisome proliferator activated receptor α (PPARα) and alleviated the 1-chloro-2,4-dinitrobenzene (DNCB)-mediated downregulation of filaggrin, involucrin, loricrin, hyaluronic acid synthase 1 (HAS1) and HAS2 in human keratinocyte HaCaT cells. However, these effects were inhibited by the PPARα antagonist GW6471. In the artificial skin model, HDFn-Ex significantly inhibited DNCB-induced epidermal hyperplasia and the decrease in filaggrin and HAS1 levels via a PPARα. In the DNCB-induced AD-like mouse model, HDFn-Ex administration reduced epidermis thickening and mast cell infiltration into the dermis compared to DNCB treatment. Moreover, the decreases in PPARα, filaggrin and HAS1 expression, as well as the increases in IgE and IL4 levels induced by DNCB treatment were reversed by HDFn-Ex. These effects were blocked by pre-treatment with GW6471. Furthermore, HDFn-Ex exhibited an anti-inflammatory effect by inhibiting the DNCB-induced increases in IκBα phosphorylation and TNF-α expression. Collectively, HDFn-Ex exhibited a protective effect on AD. Notably, these effects were regulated by PPARα. Based on our results, we suggest that HDFn-Ex is a potential candidate for treating AD by recovering skin barrier dysfunction and exhibiting anti-inflammatory activity.

Particulate matter 10 induces oxidative stress and apoptosis in rhesus macaques skin fibroblast

Background

Particulate matter (PM) is a major air pollutant that affects human health worldwide. PM can pass through the skin barrier, thus causing skin diseases such as heat rash, allergic reaction, infection, or inflammation. However, only a few studies have been conducted on the cytotoxic effects of PM exposure on large-scale animals. Therefore, herein, we investigated whether and how PM affects rhesus macaque skin fibroblasts.

Methods

Rhesus macaque skin fibroblasts were treated with various concentrations of PM10 (1, 5, 10, 50, and 100 μg/mL) and incubated for 24, 48, and 72 h. Then, cell viability assay, TUNEL assay, and qRT-PCR were performed on the treated cells. Further, the reactive oxygen species, glutathione, and cathepsin B levels were determined. The MTT assay revealed that PM10 (>50 μg/mL) proportionately reduced the cell proliferation rate.

Results

PM10 treatment increased TUNEL-positive cell numbers, following the pro-apoptosis-associated genes (CASP3 and BAX) and tumor suppressor gene TP53 were significantly upregulated. PM10 treatment induced reactive oxidative stress. Cathepsin B intensity was increased, whereas GSH intensity was decreased. The mRNA expression levels of antioxidant enzyme-related genes (CAT, GPX1 and GPX3) were significantly upregulated. Furthermore, PM10 reduced the mitochondrial membrane potential. The mRNA expression of mitochondrial complex genes, such as NDUFA1, NDUFA2, NDUFAC2, NDUFS4, and ATP5H were also significantly upregulated. In conclusion, these results showed that PM10 triggers apoptosis and mitochondrial damage, thus inducing ROS accumulation. These findings provide potential information on the cytotoxic effects of PM10 treatment and help to understand the mechanism of air pollution-induced skin diseases.