Activation of the HMGB1‑TLR4‑NF‑κB pathway may occur in patients with atopic eczema

Leveraging machine learning models for peptide-protein interaction prediction

Peptides play a pivotal role in a wide range of biological activities through participating in up to 40% protein-protein interactions in cellular processes. They also demonstrate remarkable specificity and efficacy, making them promising candidates for drug development. However, predicting peptide-protein complexes by traditional computational approaches, such as docking and molecular dynamics simulations, still remains a challenge due to high computational cost, flexible nature of peptides, and limited structural information of peptide-protein complexes. In recent years, the surge of available biological data has given rise to the development of an increasing number of machine learning models for predicting peptide-protein interactions. These models offer efficient solutions to address the challenges associated with traditional computational approaches. Furthermore, they offer enhanced accuracy, robustness, and interpretability in their predictive outcomes. This review presents a comprehensive overview of machine learning and deep learning models that have emerged in recent years for the prediction of peptide-protein interactions.

Sophora flavescens-Angelica sinensis in the treatment of eczema by inhibiting TLR4/MyD88/NF-κB pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Sophora flavescens Ait.-Angelica sinensis(Oliv.) Diels drug pairing (SA) is a transformed drug pairing from Shengui pill, a traditional Chinese medicine prescription in the ninth volume of Traditional Chinese Medicine classic "Gu Jin Yi Jian", which is famous for clearing heat, moistening dryness, and promoting blood circulation. It is commonly used in the treatment of eczema, a skin condition that causes itching and inflammation. Despite its widespread use, there is still limited research on the mechanism of how SA treats eczema. This paper aims to fill this gap by conducting animal experiments to uncover the mechanism behind SA's therapeutic effects on eczema. Our findings provide a solid foundation for the clinical use of this TCM prescription.

AIM OF THE STUDY

The basic purpose of this study is to clarify the therapeutic mechanism of Sophora flavescens-Angelica sinensis (SA) in the treatment and control of eczema.

MATERIALS AND METHODS

The chemical compositions of SA were analyzed using HPLC-Q-Orbitrap-MS. In vivo, a mouse model of eczema was created, and the serum levels of TNF-α and IL-1β were quantified using an enzyme-linked immunosorbent assay (ELISA). Hematoxylin and eosin (HE) staining was performed to assess the pathological state of the mouse skin, and immunohistochemical technique (IHC) was employed to estimate the contents of TNF-α, TLR4, and NF-κB semi-quantitatively. The expression levels of TLR4, MyD88, and NF-κB mRNA were determined through real-time quantitative polymerase chain reaction (qRT-PCR). Western Blotting was utilized to identify the protein levels of TLR4, MyD88, and NF-κB in mouse skin tissue.

RESULTS

SA identified 18 active chemicals, some of which were shown in vivo to inhibit the TLR4/MyD88/NF-κB signaling pathway while reducing serum levels of TNF-α and IL-1β, making them ideal agents for the treatment of eczema.

CONCLUSIONS

SA's anti-inflammatory properties are attributed to its ability to reduce serum levels of TNF-α and IL-1β, likewise inhibit the TLR4/MyD88/NF-κB signaling pathway.

High mobility group box 1 cytokine targeted topical delivery of resveratrol embedded nanoemulgel for the management of atopic dermatitis

Resveratrol is a polyphenolic compound showing anti-inflammatory activity by inhibition of high mobility group box 1 cytokine responsible for the activation of nuclear factor-κB pathway in atopic dermatitis. To evaluate the efficacy of resveratrol through topical route we have developed resveratrol-loaded nanoemulgel for the effective management of atopic dermatitis in mice model. The resveratrol-loaded nanoemulsion (0.5%, 0.75% and 1% w/w) was optimized by spontaneous nano-emulsification. The optimized resveratrol-loaded nanoemulsions showed average globule size in the 180-230 nm range and found to be monodispersed. The resveratrol nanoemulgel was prepared with a SEPINEO™ P 600 gel base and propylene glycol. Ex vivo permeation and retention study resulted in significantly higher skin retention of resveratrol from resveratrol-loaded nanoemulgel than free resveratrol-loaded gel. Preclinical efficacy of resveratrol nanoemulgel displayed promising therapeutic outcomes where, western blotting of skin tissues disclosed a significant reduction in the relative expression of high mobility group box 1, the receptor for advanced glycation end products, toll-like receptor-4 and phosphorylated nuclear factor-κB. Further, real-time polymerase chain reaction also disclosed a significant reduction in pro-inflammatory cytokines such as thymic stromal lymphopoietin, interleukin-4, interleukin-13, interleukin-31, tumor necrosis factor-α and interleukin-6. The histopathological examination of skin sections showed improvement in the skin condition. Collectively, the findings from our study showcased the significant improvement in the atopic dermatitis skin condition in mice model after topical application of resveratrol loaded nanoemulgel.

Leveraging Machine Learning Models for Peptide-Protein Interaction Prediction

Peptides play a pivotal role in a wide range of biological activities through participating in up to 40% protein-protein interactions in cellular processes. They also demonstrate remarkable specificity and efficacy, making them promising candidates for drug development. However, predicting peptide-protein complexes by traditional computational approaches, such as Docking and Molecular Dynamics simulations, still remains a challenge due to high computational cost, flexible nature of peptides, and limited structural information of peptide-protein complexes. In recent years, the surge of available biological data has given rise to the development of an increasing number of machine learning models for predicting peptide-protein interactions. These models offer efficient solutions to address the challenges associated with traditional computational approaches. Furthermore, they offer enhanced accuracy, robustness, and interpretability in their predictive outcomes. This review presents a comprehensive overview of machine learning and deep learning models that have emerged in recent years for the prediction of peptide-protein interactions.

Blockade of HMGB1 Reduces Inflammation and Pruritus in Atopic Dermatitis by Inhibiting Skin Fibroblasts Activation

INTRODUCTION

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by relapsed eczema and serious pruritus. High-mobility group box 1 protein (HMGB1) is a nuclear-binding protein and serves as an alarmin to promote inflammatory responses.

METHODS

In this study, we established an AD mouse model by topical use of MC903 on ears and then used a specific HMGB1-binding peptide cIY8 and a HMGB1 inhibitor of glycyrrhizin to investigate HMGB1 on fibroblast activation in the pathogenesis of AD-like symptoms.

RESULTS

Topical use of cIY8 and oral use of glycyrrhizin significantly improved the MC903-induced AD-like symptoms and pathological changes of the ears and scratching behavior in an AD mouse model; cIY8 treatment inhibited the higher mRNAs of IL-1α, IL-4, IL-5, IL-13, and IL-31 in the ears. In human fibroblasts, HMGB1 caused nuclear translocation of NF-kB, and the nuclear translocation could be inhibited by pre-treatment of HMGB1 with cIY8, suggesting that NF-κB signaling pathway participates in the HMGB1-induced inflammation of AD in fibroblasts and that cIY8 effectively impedes the function of HMGB1. Glycyrrhizin inhibited the Ca2+ signaling induced by ionomycin in mouse primary fibroblasts. The fibroblast-related proteins of α-SMA, Hsp47, and vimentin and the pruritus-related proteins of IL-33 and periostin were increased in the ears of the AD mouse model, the ratio of EdU incorporation became higher in mouse fibroblasts treated with MC903, and the higher proliferation and inflammatory responses of the fibroblasts could be reversed by glycyrrhizin treatment.

CONCLUSIONS

Fibroblast activation by HMGB1 is one of the critical processes in the development of inflammation and pruritus in the AD mouse model. The specific HMGB1-binding peptide cIY8 and the HMGB1 inhibitor glycyrrhizin inactivate skin fibroblasts to alleviate the inflammation and pruritus in the AD mouse model. Peptide cIY8 may be topically used to treat AD patients in the future.

Neutrophil extracellular traps enhance S. aureus skin colonization by oxidative stress induction and downregulation of epidermal barrier genes

Staphylococcus aureus is the most common cause of bacterial skin infections in humans, including patients with atopic dermatitis (AD). Polymorphonuclear neutrophils (PMNs) are the first cells to infiltrate an infection site, where they usually provide an effective first line of defense, including neutrophil extracellular trap (NET) formation. Here, we show that infiltrating PMNs in inflamed human and mouse skin enhance S. aureus skin colonization and persistence. Mechanistically, we demonstrate that a crosstalk between keratinocytes and PMNs results in enhanced NET formation upon S. aureus infection, which in turn induces oxidative stress and expression of danger-associated molecular patterns such as high-mobility-group-protein B1 (HMGB1) in keratinocytes. In turn, HMGB1 enhances S. aureus skin colonization and persistence by promoting skin barrier dysfunctions by the downregulation of epidermal barrier genes. Using patient material, we show that patients with AD exhibit enhanced presence of PMNs, NETs, and HMGB1 in the skin, demonstrating the clinical relevance of our finding.

Chemico-biological interaction unraveled the potential mechanistic pathway of Ixeridium dentatum compounds against atopic dermatitis

This study aims to investigate the potential therapeutic application of Ixeridium dentatum (ID) in treating atopic dermatitis (AD) through network pharmacology, molecular docking, and molecular dynamic simulation. We employed GC-MS techniques and identified 40 bioactive compounds present in the ID and determined their targets by accessing public databases. The convergence of compounds and dermatitis related targets led to the identification of 32 common genes. Among them, IL1B, PTGS2, IL6, IL2, and RELA, were found to be significant targets which were analyzed using Cytoscape network topology. The KEGG pathway evaluation revealed that these targets were significantly enriched in the C-type lectin receptor signaling pathway. The therapeutic efficacy of Stigmasta-5,22-dien-3-ol, Urea, n-Heptyl-, and 3-Epimoretenol was demonstrated in molecular docking assay, as evidenced by their presence in the core compounds of the compound-target network. Furthermore, these compounds exhibited significant kinetic stability and chemical reactivity in DFT quantum analysis when compared to their co-crystallized ligands and reference drug, indicating their potential as key targets for future research. Among the top three docking complexes, namely IL6-3-Epimoretenol, and IL2- Stigmasta-5,22-dien-3-ol, both demonstrated exceptional dynamic characteristics in molecular dynamics simulations at 100 ns. The feasibility of these compounds could be attributed to the prior traditional interrelationship between ID and AD. Overall, this research elucidates the interplay between AD-associated signaling pathways and target receptors with the bioactive ID. The proposal posits the utilization of antecedent compounds as a substitute for the customary pharmaceutical intervention that obstructs the discharge of cytokines, which incite dermal inflammation in the C-type lectin receptor signaling pathway of atopic dermatitis.

Huanglian Jiedu plaster ameliorated X-ray-induced radiation dermatitis injury by inhibiting HMGB1-mediated macrophage-inflammatory interaction

ETHNOPHARMACOLOGICAL RELEVANCE

Huanglian Jiedu plaster (HJP) is a kind of Chinese patent medicine that contains four medicinal plants. It has been clinically proven to be beneficial for the treatment of tumor-associated radiation dermatitis. However, the underlying mechanism of HJP on radiation dermatitis remains unclear.

AIM OF THE STUDY

This study aims to investigate the therapeutic effect of HJP on X-ray-induced radiation dermatitis, and how HJP improves the inflammatory response and skin damage of radiation dermatitis.

MATERIALS AND METHODS

In this study, We selected a case of esophageal cancer as a clinical demonstration of the efficacy of radiation dermatitis. The patient received a total radiation dose of 7000cGY, and treatment by HJP for 14 days.RD mouse models were established through continuous irradiation with X-ray (800cGY) on the right hind limb of mice for 5 days, and the treatment group mice was applied HJP to the irradiated skin for 15 days from modeling. An inflammatory cellular model was induced through irradiation with X-ray (100cGY) in JB6 cells and a co-culture system of JB6 cell and macrophage was established to examine the effect and mechanism of HJP on the inflammatory interaction of these two cells. The activation of HMGB1-TLR4-NF-κB signaling pathway, and the levels of epidermal injury related factors and inflammatory cytokins were subsequently detected.

RESULTS

The results showed that HJP can significantly alleviate X-ray-induced skin injury, inhibiting skin inflammation and reducing the expression of inflammatory cytokins (IL-1β, IL-6, TNF-α) and epidermal damage related factors (Integrin β1, CXCL9 and Cytokeratin17), as well as significantly down-regulated the protein level of HMGB1 (a key DAMPs factor) in vivo and in vitro. Cell co-culture experiments demonstrated that HMGB1 released from X-ray-induced JB6 cells can promote inflammatory response of macrophage, which then feedback aggravate epithelial cell damage, notably, HJP can significantly improve radiation skin lesion by inhibiting HMGB1-mediated inflammatory interaction between epithelial cells and macrophages.

CONCLUSION

In summary, these findings indicated the role of HJP in the treatment of RD by inhibiting the inflammatory interaction between macrophage and JB6 cells mediated by HMGB1, which may provide a reliable therapeutic method for RD. Furthermore, HMGB1 may be an effective target for HJP to inhibit inflammation and ameliorate skin damage in RD.

Periostin activates distinct modules of inflammation and itching downstream of the type 2 inflammation pathway

Atopic dermatitis (AD) is a chronic relapsing skin disease accompanied by recurrent itching. Although type 2 inflammation is dominant in allergic skin inflammation, it is not fully understood how non-type 2 inflammation co-exists with type 2 inflammation or how type 2 inflammation causes itching. We have recently established the FADS mouse, a mouse model of AD. In FADS mice, either genetic disruption or pharmacological inhibition of periostin, a downstream molecule of type 2 inflammation, inhibits NF-κB activation in keratinocytes, leading to downregulating eczema, epidermal hyperplasia, and infiltration of neutrophils, without regulating the enhanced type 2 inflammation. Moreover, inhibition of periostin blocks spontaneous firing of superficial dorsal horn neurons followed by a decrease in scratching behaviors due to itching. Taken together, periostin links NF-κB-mediated inflammation with type 2 inflammation and promotes itching in allergic skin inflammation, suggesting that periostin is a promising therapeutic target for AD.

Tenebrio molitor Larva Trypsin Hydrolysate Ameliorates Atopic Dermatitis in C57BL/6 Mice by Targeting the TLR-Mediated MyD88-Dependent MAPK Signaling Pathway

Atopic dermatitis (AD) is a widely researched chronic inflammatory skin disease with a complex etiology. The increased prevalence of AD necessitates exploration of natural sources as potential therapeutic agents with limited side effects. In the current study, a 1-chloro-2,4-dinitrobenzene (DNCB)-induced AD mouse model was used to examine the anti-AD effects of Tenebrio molitor trypsin hydrolysate (TMTH) and its underlying molecular mechanism. DNCB-treated mice were treated with TMTH (1 and 10 mg/kg), and prednisolone (3 mg/kg) was used as the positive control. Serum and skin tissue samples were collected for subsequent analyses. The expression levels of proteins linked to the myeloid differentiation primary response 88 (MyD88)-dependent mitogen-activated protein kinase (MAPK) signaling pathway and serum IgE levels were estimated via Western blotting technique and ELISA (enzyme-linked immunosorbent assay), respectively. Inflammatory cell infiltration and thickening of the dorsal skin were measured using toluidine blue and hematoxylin and eosin staining, respectively. Oral administration of TMTH significantly reduced mast cell infiltration and dermal and epidermal thickness. Moreover, TMTH treatment reduced serum IgE levels. Western blotting confirmed that TMTH treatment suppressed the MyD88-dependent MAPK signaling pathway. Therefore, TMTH substantially inhibited AD-like skin lesion formation via immunomodulation, showing considerable potential for AD treatment.

Struct2Graph: a graph attention network for structure based predictions of protein–protein interactions

Background

Development of new methods for analysis of protein–protein interactions (PPIs) at molecular and nanometer scales gives insights into intracellular signaling pathways and will improve understanding of protein functions, as well as other nanoscale structures of biological and abiological origins. Recent advances in computational tools, particularly the ones involving modern deep learning algorithms, have been shown to complement experimental approaches for describing and rationalizing PPIs. However, most of the existing works on PPI predictions use protein-sequence information, and thus have difficulties in accounting for the three-dimensional organization of the protein chains.

Results

In this study, we address this problem and describe a PPI analysis based on a graph attention network, named Struct2Graph, for identifying PPIs directly from the structural data of folded protein globules. Our method is capable of predicting the PPI with an accuracy of 98.89% on the balanced set consisting of an equal number of positive and negative pairs. On the unbalanced set with the ratio of 1:10 between positive and negative pairs, Struct2Graph achieves a fivefold cross validation average accuracy of 99.42%. Moreover, Struct2Graph can potentially identify residues that likely contribute to the formation of the protein–protein complex. The identification of important residues is tested for two different interaction types: (a) Proteins with multiple ligands competing for the same binding area, (b) Dynamic protein–protein adhesion interaction. Struct2Graph identifies interacting residues with 30% sensitivity, 89% specificity, and 87% accuracy.

Conclusions

In this manuscript, we address the problem of prediction of PPIs using a first of its kind, 3D-structure-based graph attention network (code available at https://github.com/baranwa2/Struct2Graph). Furthermore, the novel mutual attention mechanism provides insights into likely interaction sites through its unsupervised knowledge selection process. This study demonstrates that a relatively low-dimensional feature embedding learned from graph structures of individual proteins outperforms other modern machine learning classifiers based on global protein features. In addition, through the analysis of single amino acid variations, the attention mechanism shows preference for disease-causing residue variations over benign polymorphisms, demonstrating that it is not limited to interface residues.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12859-022-04910-9.

The role of HMGB1 in inflammatory skin diseases

High-mobility group box 1 protein (HMGB1) is a highly abundant, non-histone nuclear protein that can serve as an alarmin to promote the pathogenesis of inflammatory diseases. In response to various stimuli, HMGB1 can translocate from the nucleus to the cytoplasm as well as the extracellular space through passive or active release, accompanied with different post-translational modifications. Depending on the redox state of three cysteine residues, HMGB1 determines its activity to induce cytokine production or tissue repair through binding with several different receptors. In addition, HMGB1 can form immunostimulatory complexes with cytokines and other endogenous/exogenous molecules and synergistically enhance their biological effect. Cell death is an important source of HMGB1 and major cell death forms such as apoptosis, necrosis and pyroptosis can modulate the redox state of HMGB1. In various human skin diseases as well as animal models, HMGB1 levels in cytoplasm, tissue and blood are increased and blockade of HMGB1 attenuates disease severity in animal models. These findings indicate that HMGB1 can serve as a unique biomarker as well as a target of new therapy in many inflammatory skin diseases.

Remote ischemic preconditioning causes transient cell-cycle arrest and renal protection by a NF-kB-dependent Sema5B pathway

Acute kidney injury increases morbidity and mortality, and previous studies have shown that remote ischemic preconditioning (RIPC) reduces the risk of acute kidney injury after cardiac surgery. RIPC increases urinary high mobility group box protein-1 (HMGB1) levels in patients, and this correlates with kidney protection. Here, we show that RIPC reduces renal ischemia-reperfusion injury and improves kidney function in mice. Mechanistically, RIPC increases HMGB1 levels in the plasma and urine, and HMGB1 binds to TLR4 on renal tubular epithelial cells, inducing transcriptomic modulation of renal tubular epithelial cells and providing renal protection, whereas TLR4 activation on nonrenal cells was shown to contribute to renal injury. This protection is mediated by activation of induction of AMPKα and NF-κB; this induction contributes to the upregulation of Sema5b, which triggers a transient, protective G₁ cell cycle arrest. In cardiac surgery patients at high risk for postoperative acute kidney injury, increased HMGB1 and Sema5b levels after RIPC were associated with renal protection after surgery. The results may help to develop future clinical treatment options for acute kidney injury.

Inhibition of miR-155 Attenuates CD14+ Monocyte-Mediated Inflammatory Response and Oxidative Stress in Psoriasis Through TLR4/MyD88/NF-κB Signaling Pathway

Purpose

Previous studies showed the link of CD14⁺ monocytes to inflammation and oxidation in psoriasis. In the present study, we investigated the regulatory role of miR-155 in CD14⁺ monocyte function in psoriasis.

Materials and Methods

CD14⁺ monocytes were isolated from peripheral blood by magnetic bead separation method and its function was assessed following silence of miR-155 by lentivirus transfection with or without inhibition of TLR4 pathway. CCK8 and EdU were used to assess the proliferation of CD14⁺ monocytes. Expression levels of SOCS1, TLR4 and MyD88 proteins were determined by Western blotting, while expression levels of IL-6, TNF-α, ROS, MDA and T-AOC were measured by ELISA kit. The expression levels of mRNA for miR-155, NF-κB and its subunit NF-κB-p65 were assessed by q-PCR.

Results

The results showed that compared with normal control CD14⁺ monocytes, the expression levels of miR-155, NF-κB and NF-κB-p65, TLR4, MyD88 and IL-6, TNF-α were increased, while expression levels of SOCS1 were decreased in CD14⁺ monocytes from psoriatic patients. Enhanced cell proliferation and oxidation were also observed in CD14⁺ monocytes from psoriatic patients. Inhibition of miR-155 partially corrected the abnormalities of cell proliferation and expression levels of biomarkers mentioned above in CD14⁺ monocytes from psoriatic patients. Inhibitions of both TLR4 pathway and miR-155 further corrected abnormalities of proliferation and the above biomarkers in CD14⁺ monocytes from psoriatic patients.

Conclusion

These results suggest that increased expression levels of miR-155 contribute to CD14⁺ monocyte-mediated inflammation and oxidation in psoriasis via TLR4 pathway.

HMGB-1 in Psoriasis

Psoriasis is a multifactorial pathology linked to systemic inflammation. Enhanced keratinocytes proliferation and a minor maturation state of the cells are typical features. Perivascular T cells, dendritic cells, macrophages, and neutrophilic granulocytes are part of the scenario completed by apoptosis dysregulation. Several proinflammatory mediators, alarmins and growth factors are increased too, both in the skin and the patients’ blood. HMGB1 is important as an alarmin in several inflammatory conditions. Released after cellular damage, HMGB1 acts as a danger signal. Several studies have considered its role in psoriasis pathogenesis. We evaluated its level in psoriasis and the potential of the alarmin blockade through standard therapies, biological treatments and using monoclonal antibodies. PV patients were shown to have significantly increased levels of HMGB1 both in lesional skin and in serum, which were linked, in some cases, to other pro-inflammatory markers and alarmins. In most cases these parameters were correlated with PASI score. Data demonstrated that blocking HMGB1 is effective in ameliorating psoriasis. Focusing on this approach could be valuable in terms of a therapeutic option for counteracting immune-related diseases in a way unthinkable until few years ago.

Fe2+: Fe3+ Molar Ratio Influences the Immunomodulatory Properties of Maghemite (γ-Fe2O3) Nanoparticles in an Atopic Dermatitis Model

Here, we report the different antioxidant and physiological effects of maghemite nanoparticles (γ-Fe2O3 NPs) obtained using various Fe2+: Fe3+ molar ratios (FM1 = 1: 1, FM2 = 1: 2, and FM3 = 2: 3) via coprecipitation from ferrous/ferric salts. We investigated the physical, optical, and antioxidant properties of FM1, FM2, and FM3 nanoparticles by conducting UV, Raman, FTIR, and EDX spectroscopic analyses along with DPPH radical scavenging activity. Results showed the highest DPPH scavenging activity in the FM2 group (50.76%), while the activity in the FM1 and FM3 groups was 23.60% and 34.63%, respectively. In addition, topical application of nanoparticles induced significant but different anti-inflammatory and immunomodulatory effects in Dermatophagoides farinae extract/2,4-dinitrochlorobenzene (DFE/DNCB)-sensitized BALB/c mice. The FM2 treatment alleviates more effectively the DFE/DNCB-induced atopic dermatitis-like (AD-like) symptoms in mouse ears (edema, excoriation, scaling, and hemorrhage). In comparison with the DFE/DNCB-sensitized mice, FM2 treatment greatly reduced the size and weight of the spleen and the lymph nodes. It also suppressed mast cell infiltration (2-fold) and reduced dermal and epidermal thickness in mice. In addition, FM2 treatment exhibited better inhibition of the mRNA levels of Th1 (IFN-γ and TNF-α) and Th2 cytokines (IL-4, IL-5, IL-6, IL-10, IL-13, and IL-31), as well as the levels of various inflammation-related proteins (COX-2, iNOS, and TNF-α). Moreover, we demonstrated that an increasing proportion of Fe3+ in Fe2+: Fe3+ enhances the antioxidant activity and increases the anti-inflammatory and immunomodulatory effects of γ-Fe2O3 NPs in an AD mouse model. Thus, γ-Fe2O3 NPs could be used in the formulation of nonsteroidal drugs for AD treatment.

Dysregulated microRNA expression in IL-4 transgenic mice, an animal model of atopic dermatitis

IL-4 plays an important role in the pathogenesis of atopic dermatitis (AD). Previously we showed that the expression of genes in chemotaxis, angiogenesis, inflammation and barrier functions is dysregulated in IL-4 transgenic (Tg) mice, a well-characterized AD mouse model. In this study, we aim to study differential expression of microRNAs in IL-4 Tg mice. As compared with wild-type mice, we found that 10 and 79 microRNAs are dysregulated in the skin of IL-4 mice before and after the onset of skin lesions, respectively. Bioinformatic analysis and previous reports show that these dysregulated microRNAs may be involved in the NF-κB, TLRs, IL-4/IL-13, MAPK and other pathways. We also found that miR-139-5p and miR-196b-3p are significantly up-regulated in the peripheral blood of IL-4 Tg mice. Taken together, our data have identified many dysregulated microRNAs in IL-4 Tg mice, which may play important roles in AD pathogenesis and pathophysiology.

Diterpenoids and Triterpenoids From Frankincense Are Excellent Anti-psoriatic Agents: An in silico Approach

Psoriasis is a chronic autoimmune disease that affects 2–3% of the global population and requires an effective treatment. Frankincense has been long known for its potent anti-inflammatory activities. In this study, a structural bioinformatics approach was used to evaluate the efficacy of individual active components of frankincense, macrocyclic diterpenoid derivatives (1-27), and boswellic acids (28-46) in the treatment of psoriasis. Initially, major druggable targets of psoriasis were identified. Subsequently, structure-based screening was employed by using three different docking algorithms and scoring functions (MOE, AutoDock Vina, and MVD) for the target fishing of compounds against 18 possible targets of psoriasis. Janus Kinase 1, 2, 3 (JAK 1/2/3), eNOS, iNOS, interleukin-17 (IL-17), and Tumor necrosis factor-α (TNF-α) were identified as the preferred molecular targets for these compounds. This computational analysis reflects that frankincense diterpenoids and triterpenoids can serve as excellent anti-psoriatic agents by targeting major cytokines (TNF-α, IL-17, IL-13, IL-23, and IL-36γ,) exacerbated in psoriasis, and inflammatory pathways particularly JAK1/2/3, eNOS, iNOS, MAPK2, and IFNγ. The results were compared with the reported experimental findings which correlates well with our in-silico verdicts.

Johnny on the Spot-Chronic Inflammation Is Driven by HMGB1

Although much has been made of the role of HMGB1 acting as an acute damage associated molecular pattern (DAMP) molecule, prompting the response to tissue damage or injury, it is also released at sites of chronic inflammation including sites of infection, autoimmunity, and cancer. As such, the biology is distinguished from homeostasis and acute inflammation by the recruitment and persistence of myeloid derived suppressor cells, T regulatory cells, fibrosis and/or exuberant angiogenesis depending on the antecedents and the other individual inflammatory partners that HMGB1 binds and focuses, including IL-1β, CXCL12/SDF1, LPS, DNA, RNA, and sRAGE. High levels of HMGB1 released into the extracellular milieu and its persistence in the microenvironment can contribute to the pathogenesis of many if not all autoimmune disorders and is a key factor that drives inflammation further and worsens symptoms. HMGB1 is also pivotal in the maintenance of chronic inflammation and a “wound healing” type of immune response that ultimately contributes to the onset of carcinogenesis and tumor progression. Exosomes carrying HMGB1 and other instructive molecules are released and shape the response of various cells in the chronic inflammatory environment. Understanding the defining roles of REDOX, DAMPs and PAMPs, and the host response in chronic inflammation requires an alternative means for positing HMGB1's central role in limiting and focusing inflammation, distinguishing chronic from acute inflammation.

TLR4 in skin cancer: From molecular mechanisms to clinical interventions

The health and economic burden imposed by skin cancer is substantial, creating an urgent need for the development of improved molecular strategies for its prevention and treatment. Cutaneous exposure to solar ultraviolet (UV) radiation is a causative factor in skin carcinogenesis, and TLR4-dependent inflammatory dysregulation is an emerging key mechanism underlying detrimental effects of acute and chronic UV exposure. Direct and indirect TLR4 activation, upstream of inflammatory signaling, is elicited by a variety of stimuli, including pathogen-associated molecular patterns (such as lipopolysaccharide) and damage-associated molecular patterns (such as HMGB1) that are formed upon exposure to environmental stressors, such as solar UV. TLR4 involvement has now been implicated in major types of skin malignancies, including nonmelanoma skin cancer, melanoma and Merkel cell carcinoma. Targeted molecular interventions that positively or negatively modulate TLR4 signaling have shown promise in translational, preclinical, and clinical investigations that may benefit skin cancer patients in the near future.

The Immunogenetics of Psoriasis and Implications for Drug Repositioning

Psoriasis is a genetically-regulated, T lymphocyte-mediated autoimmune skin disease that causes systemic damage, seriously affecting patient quality of life and survival. Psoriasis treatments, which aim to control the disease’s development, are greatly limited because its etiology and pathogenesis have not yet been fully elucidated. A large number of studies have demonstrated that immunogenetic elements are the most important factors responsible for psoriasis susceptibility. This paper delineates the immunogenetic mechanisms of psoriasis and provides useful information with regards to performing drug repositioning for the treatment of psoriasis.