1,4-dihydroxy-2-naphthoic Acid Induces Apoptosis in Human Keratinocyte: Potential Application for Psoriasis Treatment

Cellular Stress-Induced Metabolites in Escherichia coli

Escherichia coli isolates commonly inhabit the human microbiota, yet the majority of E. coli's small-molecule repertoire remains uncharacterized. We previously employed erythromycin-induced translational stress to facilitate the characterization of autoinducer-3 (AI-3) and structurally related pyrazinones derived from "abortive" tRNA synthetase reactions in pathogenic, commensal, and probiotic E. coli isolates. In this study, we explored the "missing" tryptophan-derived pyrazinone reaction and characterized two other families of metabolites that were similarly upregulated under erythromycin stress. Strikingly, the abortive tryptophanyl-tRNA synthetase reaction leads to a tetracyclic indole alkaloid metabolite (1) rather than a pyrazinone. Furthermore, erythromycin induced two naphthoquinone-functionalized metabolites (MK-hCys, 2; and MK-Cys, 3) and four lumazines (7-10). Using genetic and metabolite analyses coupled with biomimetic synthesis, we provide support that the naphthoquinones are derived from 4-dihydroxy-2-naphthoic acid (DHNA), an intermediate in the menaquinone biosynthetic pathway, and the amino acids homocysteine and cysteine. In contrast, the lumazines are dependent on a flavin intermediate and α-ketoacids from the aminotransferases AspC and TyrB. We show that one of the lumazine members (9), an indole-functionalized analogue, possesses antioxidant properties, modulates the anti-inflammatory fate of isolated TH17 cells, and serves as an aryl-hydrocarbon receptor (AhR) agonist. These three systems described here serve to illustrate that new metabolic branches could be more commonly derived from well-established primary metabolic pathways.

Photothermal treatment by PLGA-gold nanorod-isatin nanocomplexes under near-infrared irradiation for alleviating psoriasiform hyperproliferation

Psoriasis is a chronic autoimmune skin disorder that involves keratinocyte hyperproliferation and inflammatory cell recruitment. A strategy to mitigate psoriatic lesions is to induce keratinocyte apoptosis for proliferation suppression. Herein we designed a nanoformulation capable of treating psoriasis via hyperthermia-induced apoptosis in response to near-infrared (NIR) irradiation. To this end, gold nanorods (GNRs) and isatin, which is an anti-inflammatory agent for synergizing antipsoriatic activity, were loaded into a poly (lactic-co-glycolic acid) (PLGA) matrix to form the nanocomplexes. The physicochemical and photothermal properties of the nanocomplexes were determined in terms of size, surface charge, NIR-absorbing feature, isatin release, keratinocyte uptake, and cytotoxicity. The nanocomplexes showed a spherical shape with an average size of about 180 nm. The GNR-loaded nanoparticles can efficiently convert NIR light at 0.42 W/cm² into heat with an increased temperature of 10 °C. When combined with NIR exposure, the nanocomplexes were internalized into keratinocyte cytoplasm with an inhibition of keratinocyte viability to about 60%. Live/dead cell assay and flow cytometry confirmed that the nanocomplexes could serve as NIR-absorbers to specifically elicit keratinocyte apoptosis through caspase and poly ADP-ribose polymerase (PARP) pathways. The in vivo psoriasiform murine model indicated that the combined nanocomplexes and NIR inhibited epidermal hyperplasia and neutrophil infiltration. The overexpressed cytokines in the lesion could be recovered to normal baseline level after the photothermal management. The subcutaneous nanocomplexes remained in the skin for at least 5 days. The nanocomposites produced a negligible toxicity in the skin or liver of healthy mice. The photothermal nanosystems, as designed in this study, shed new light on the therapeutic approach against psoriasis.

Trends in nanotechnology-based delivery systems for dermal targeting of drugs: an enticing approach to offset psoriasis

INTRODUCTION

Psoriasis is identified as an inflammatory, chronic, auto-immune disease requiring long-term treatment, imposing an unnecessary burden on the patient. A significant impediment for the treatment of dermatological disorders via transdermal route is the inability of drug molecules to cross the stratum corneum (SC), as the larger size of drug molecules inhibits them to pervade into the skin, thus hampering their absorption. Some drugs exhibit systemic side-effects, which curbs patient compliance, resulting in treatment discontinuation.

AREAS COVERED

This review aims to describe the detailed study such as demographic status, molecular factors of psoriasis, treatment with emerging combination therapy and role of nanotechnology tools in the treatment of psoriasis.

EXPERT OPINION

To overcome problems related to the conventional drug delivery system, several nanotechnology-based formulations have been devised to enhance bioavailability, drug permeation and accumulation in the skin. Nano-formulations provide better permeation, targeted delivery and enhanced efficacy, thus gaining enormous popularity for cutaneous disorders. This pervasive review provides an overview of the pathophysiology of the disease, its molecular targets and the available herbal, synthetic and combination treatment modalities. The review also systematizes recent works utilizing nano-carriers to improve the treatment denouement of psoriasis.

Plasma MicroRNA Expression Profiles in Psoriasis

Background

Psoriasis is an immune-mediated inflammatory chronic skin disease characterized by chronic inflammation in the dermis, parakeratosis, and excessive epidermal growth. MicroRNAs (miRNAs) are key regulators of immune responses. Although differential expression of miRNAs has been reported in certain inflammatory autoimmune diseases, their role in psoriasis has not been fully illuminated. Our aims were to confirm plasma miRNA expression signatures in psoriasis and to examine their potential influence on psoriasis pathogenesis.

Methods

A miRNome PCR array was used to analyse the plasma of psoriasis patients and healthy donors. We performed miRNA pathway enrichment and target gene network analyses on psoriasis plasma samples.

Results

We found several specific plasma miRNA signatures relevant to psoriasis. The miRNAs targeted pathways associated with psoriasis, such as the VEGF, MAPK, and WNT signaling pathways. Network analysis revealed pivotal deregulated plasma miRNAs and their relevant target genes and pathways regulating psoriasis pathogenesis.

Conclusions

This study analysed the expression of plasma miRNAs and their target pathways, elucidating the pathogenesis of psoriasis; these results may be used to design novel therapeutic strategies and to identify diagnostic biomarkers for psoriasis.

Apoptotic or Antiproliferative Activity of Natural Products against Keratinocytes for the Treatment of Psoriasis

Natural products or herbs can be used as an effective therapy for treating psoriasis, an autoimmune skin disease that involves keratinocyte overproliferation. It has been demonstrated that phytomedicine, which is used for psoriasis patients, provides some advantages, including natural sources, a lower risk of adverse effects, and the avoidance of dissatisfaction with conventional therapy. The herbal products’ structural diversity and multiple mechanisms of action have enabled the synergistic activity to mitigate psoriasis. In recent years, the concept of using natural products as antiproliferative agents in psoriasis treatment has attracted increasing attention in basic and clinical investigations. This review highlights the development of an apoptotic or antiproliferatic strategy for natural-product management in the treatment of psoriasis. We systematically introduce the concepts and molecular mechanisms of keratinocyte-proliferation inhibition by crude extracts or natural compounds that were isolated from natural resources, especially plants. Most of these studies focus on evaluation through an in vitro keratinocyte model and an in vivo psoriasis-like animal model. Topical delivery is the major route for the in vivo or clinical administration of these natural products. The potential use of antiproliferative phytomedicine on hyperproliferative keratinocytes suggests a way forward for generating advances in the field of psoriasis therapy.

Syndecans in chronic inflammatory and autoimmune diseases: Pathological insights and therapeutic opportunities

Syndecans (SDCs) are a family of heparan sulfate proteoglycans (HSPGs) glycoproteins ubiquitously expressed on the cell surfaces and extracellular matrix of all mammalian tissues. There are four mammalian syndecans, SDC-1 thorough 4, which play a critical role in cell adhesion, migration, proliferation, differentiation, and angiogenesis through independent and growth factor mediated signaling. An altered expression of SDCs is often observed in autoimmune disorders, cancer, HIV infection, and many other pathological conditions. SDCs modulate disease progression by interacting with a diverse array of ligands, receptors, and other proteins, including extracellular matrix, glycoproteins, integrins, morphogens, and various growth factors and chemokines, along with their receptors and kinases. Specifically, SDCs present on cell surface can bind directly to chemokines to enhance their binding to receptors, downstream signaling, and migration. Alternatively, SDCs can be cleaved and shed to mediate negative regulation of chemokine and growth factor signaling pathways and ligand sequestration. Importantly, SDC shedding may be a biomarker of inflammation, especially in chronic inflammatory diseases. While the current therapies for cancer and several autoimmune disorders have revolutionized treatment outcomes, understanding the pathophysiological role of SDCs and the use of HSPG mimetic or antagonists on cytokine signaling networks may uncover potentially novel targeted therapeutic approaches. This review mainly summarizes the current findings on the role of individual SDCs in disease processes, mechanisms through which SDCs mediate their biological functions, and the possibility of targeting SDCs as future potential therapeutic approaches.

Antiproliferation of keratinocytes and alleviation of psoriasis by the ethanol extract of Artemisia capillaris

The therapeutic potentials of the ethanol extract of Artemisia capillaris (ACE) for psoriasis were verified in HaCaT cells (as an immortalized human keratinocyte cell line) and imiquimod (IMQ)-induced psoriasis-like mouse models. In HaCaT cells, IC₅₀ value of ACE was 37.5 μg/ml after incubating for 72 hr. The antiproliferation activity of ACE in HaCaT cells was further verified by apoptosis assays. The percentage of apoptotic population in ACE-treated group was significantly higher than that of control group (p < .05). The result of cell cycle arrest assay also supported the observed antiproliferation efficacy of ACE in HaCaT cells. In IMQ-induced psoriasis-like mouse models, the Psoriasis Area and Severity Index score of ACE (50 mg/ml; ACE50)-treated group was significantly lower than that of IMQ group on Day 4 (p < .05). After topical application of ACE on psoriasis-like lesion for 4 days, the epidermal thickness of (IMQ + ACE50) group was significantly lower than that of IMQ group (p < .05). The expression levels of Ki-67 and intracellular adhesion molecule-1 in excised skin tissues of (IMQ + ACE50) group were also lower than those of IMQ group. All these findings suggest that ACE can be used as a promising antipsoriatic agent.

Editor's Highlight: Microbial-Derived 1,4-Dihydroxy-2-naphthoic Acid and Related Compounds as Aryl Hydrocarbon Receptor Agonists/Antagonists: Structure-Activity Relationships and Receptor Modeling

1,4-Dihydroxy-2-naphthoic acid (1,4-DHNA) is a bacterial-derived metabolite that binds the aryl hydrocarbon receptor (AhR) and exhibits anti-inflammatory activity in the gut. The structure-dependent AhR activity of hydroxyl/carboxy-substituted naphthoic acids (NAs) was determined in young adult mouse colonic (YAMC) cells and human Caco2 colon cancer cells using CYP1A1/CYP1B1 mRNAs as Ah-responsive genes. Compounds used in this study include 1,4-, 3,5-, and 3,7-DHNA, 1,4-dimethoxy-2-naphthoic acid (1,4-DMNA), 1- and 4-hydroxy-2-naphthoic acid (1-HNA, 4-HNA), 1- and 2-naphthoic acid (1-NA, 2-NA), and 1- and 2-naphthol (1-NOH, 2-NOH). 1,4-DHNA was the most potent compound among hydroxyl/carboxy naphthalene derivatives, and the fold induction response for CYP1A1 and CYP1B1 was similar to that observed for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in YAMC and Caco2 cells. 1- and 4-HNA were less potent than 1,4-DHNA but induced maximal (TCDD-like) response for CYP1B1 (both cell lines) and CYP1A1 (Caco2 cells). With the exception of 1- and 2-NA, all compounds significantly induced Cyp1b1 in YAMC cells and these responses were not observed in AhR-deficient YAMC cells generated using CRISPR/Cas9 technology. In addition, we also observed that 1- and 2-NOH (and 1,4-DHNA) were weak AhR agonists, and 1- and 2-NOH also exhibited partial AhR antagonist activity. Structure-activity relationship studies for CYP1A1 but not CYP1B1 were similar in both cell lines, and CYP1A1 induction required one or both 1,4-dihydroxy substituents and activity was significantly enhanced by the 2-carboxyl group. We also used computational analysis to show that 1,4-DHNA and TCDD share similar interactions within the AhR binding pocket and differ primarily due to the negatively charged group of 1,4-DHNA.

MicroRNA-181b negatively regulates the proliferation of human epidermal keratinocytes in psoriasis through targeting TLR4

Our study aims to explore the role of microRNA‐181b (miR‐181b) and TLR in the regulation of cell proliferation of human epidermal keratinocytes (HEKs) in psoriasis. Twenty‐eight patients diagnosed with psoriasis vulgaris were selected as a case group with their lesional and non‐lesional skin tissues collected. A control group consisted of 20 patients who underwent plastic surgery with their healthy skin tissues collected. Real‐time quantitative fluorescence polymerase chain reaction (RT‐qPCR), in situ hybridization and immunohistochemistry were used to detect the expressions of miR‐181b and TLR4 in HEKs of healthy skin, psoriatic lesional skin and non‐lesional skin respectively. The 3′ untranslated region (3′UTR) of TLR4 combined with miR‐181b was verified by a dual‐luciferase reporter assay. Western blotting and bromodeoxyuridine were applied for corresponding detection of TLR4 expression and cell mitosis. The expression of miR‐181b in HEKs of psoriatic lesional skin was less than healthy skin and psoriatic non‐lesional skin. In psoriatic lesional and non‐lesional skin, TLR4‐positive cell rates and the number of positive cells per square millimetre were higher than healthy skin. The dual‐luciferase reporter assay verified that miR‐181b targets TLR4. HEKs transfected with miR‐181b mimics had decreased expression of TLR4, along with the decrease of mitotic indexes and Brdu labelling indexes. However, HEKs transfected with miR‐181b inhibitors showed increased TLR4 expression, mitotic indexes and Brdu labelling indexes. HEKs transfected with both miR‐181b inhibitors and siTLR4 had decreased mitotic indexes and Brdu labelling indexes. These results indicate that miR‐181b can negatively regulate the proliferation of HEKs in psoriasis by targeting TLR4.

Zanthoxylum bungeanum essential oil induces apoptosis of HaCaT human keratinocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Zanthoxylum bungeanum (ZB), a Chinese herb medicine, has been shown to possess a wide range of biological activities including anti-tumor, anti-inflammatory, and anti-microbial activity and has long been used to treat a variety of skin diseases including psoriasis. However, the underlying mechanism of action has not been systematically elucidated.

AIM OF THE STUDY

to analyze the chemical composition of the hydro-distilled Zanthoxylum bungeanum essential oil (ZBEO), and to investigate its anti-proliferative activity on HaCaT cells as well as the underlying anti-psoriasis mechanisms.

MATERIALS AND METHODS

The chemical composition of ZBEO was analyzed with gas chromatography coupled to mass spectrometry (GC-MS). HaCaT cells was exposed to different dose of ZBEO added in medium prior to morphologic features analysis as well as cell cycle arrest examination with Flow cytometry. Western blot analysis was employed to estimate the expression level of proteins including caspase-8/9/3, PARP, Bax and Bcl-2.

RESULTS

Thirty-nine compounds of the ZBEO were identified GC-MS. ZBEO-treated HaCaT cells showed typical apoptotic morphologic features by DAPI staining assay. The ZBEO significantly inhibited proliferation of HaCaT cells in a dose- and time-dependent manner and induced S phase arrest apoptosis in HaCaT cells. Furthermore, western blot analysis revealed that the ZBEO increased expression of cleaved caspase-8/9/3, PARP, and Bax, decreased Bcl-2 levels.

CONCLUSION

ZBEO inhibits the proliferation of HaCaT cells, resulting from the induction of cellular apoptosis through both intrinsic and extrinsic pathways. ZBEO is a potential candidate that may be considered for development into an anti-psoriasis drug.

Recent progress on the traditional Chinese medicines that regulate the blood

In traditional Chinese medicine, the herbs that regulate blood play a vital role. Here, nine herbs including Typhae Pollen, Notoginseng Root, Common Bletilla Tuber, India Madder Root and Rhizome, Chinese Arborvitae Twig, Lignum Dalbergiae Oderiferae, Chuanxiong Rhizoma, Corydalis Tuber, and Motherwort Herb were selected and reviewed for their recent studies on anti-tumor, anti-inflammatory and cardiovascular effects. Besides, the analytical methods developed to qualify or quantify the active compounds of the herbs are also summarized.

FOS-like antigen 1 is highly expressed in human psoriasis tissues and promotes the growth of HaCaT cells in vitro

Psoriasis is a multifactorial disease and the mechanisms involved in its pathogenesis remain to be elucidated. FOS‑like antigen 1 (Fra‑1) is a proto‑oncogene. It is a negative inhibitor of activator protein‑1 activity and possesses transforming activity. The effect of and possible mechanisms underlying Fra‑1 in psoriasis remain to be elucidated. In the present study, western blot analysis and reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) techniques were used to identify differentially expressed Fra‑1 in psoriatic and in normal control tissues. Compared with the control samples, the expression of normalized Fra‑1 genes in psoriasis was 12.6 times higher. Western blot analysis was used to assess the protein levels of Fra‑1. The results demonstrated that the protein expression of Fra-1 was high in tissues affected by psoriasis. This also corresponded with the results of RT‑qPCR. Fra‑1‑stable expressing HaCaT/Fra‑1 or control HaCaT/vector cell lines were then generated to elucidate the function of Fra‑1 in the growth of HaCaT cells. The results demonstrated that Fra‑1 promoted the growth of HaCaT cells in vitro by arresting the cell cycle and inhibiting cell apoptosis. These results suggested that Fra‑1 may be important in psoriasis.

Silencing of EEF2K (eukaryotic elongation factor-2 kinase) reveals AMPK-ULK1-dependent autophagy in colon cancer cells

EEF2K (eukaryotic elongation factor-2 kinase), also known as Ca²⁺/calmodulin-dependent protein kinase III, functions in downregulating peptide chain elongation through inactivation of EEF2 (eukaryotic translation elongation factor 2). Currently, there is a limited amount of information on the promotion of autophagic survival by EEF2K in breast and glioblastoma cell lines. However, the precise role of EEF2K in carcinogenesis as well as the underlying mechanism involved is still poorly understood. In this study, contrary to the reported autophagy-promoting activity of EEF2K in certain cancer cells, EEF2K is shown to negatively regulate autophagy in human colon cancer cells as indicated by the increase of LC3-II levels, the accumulation of LC3 dots per cell, and the promotion of autophagic flux in EEF2K knockdown cells. EEF2K negatively regulates cell viability, clonogenicity, cell proliferation, and cell size in colon cancer cells. Autophagy induced by EEF2K silencing promotes cell survival and does not potentiate the anticancer efficacy of the AKT inhibitor MK-2206. In addition, autophagy induced by silencing of EEF2K is attributed to induction of protein synthesis and activation of the AMPK-ULK1 pathway, independent of the suppression of MTOR activity and ROS generation. Knockdown of AMPK or ULK1 significantly abrogates EEF2K silencing-induced increase of LC3-II levels, accumulation of LC3 dots per cell as well as cell proliferation in colon cancer cells. In conclusion, silencing of EEF2K promotes autophagic survival via activation of the AMPK-ULK1 pathway in colon cancer cells. This finding suggests that upregulation of EEF2K activity may constitute a novel approach for the treatment of human colon cancer.