Peroxisome proliferator-activator receptor γ and psoriasis, molecular and cellular biochemistry

Metabolic anomalies in vitiligo: a new frontier for drug repurposing strategies

Vitiligo is a chronic autoimmune condition characterized by the destruction of melanocytes, leading to patchy loss of skin depigmentation. Although its precise cause remains unclear, recent evidence suggests that metabolic disturbances, particularly oxidative stress and mitochondrial dysfunction, may play a significant role in the pathogenesis of the disease. Oxidative stress is thought to damage melanocytes and trigger inflammatory responses, culminating in melanocyte immune-mediate destruction. Additionally, patients with vitiligo often exhibit extra-cutaneous metabolic abnormalities such as abnormal glucose metabolism, dyslipidemia, high fasting plasma glucose levels, high blood pressure, out of range C-peptide and low biological antioxidant capacity, suggesting a potential link between metabolic impairment and vitiligo development. This implies that the loss of functional melanocytes mirrors a more general systemic targetable dysfunction. Notably, therapies targeting metabolic pathways, particularly those involving mitochondrial metabolism, such as the peroxisome proliferator-activated nuclear receptor γ (PPARγ) agonists, are currently being investigated as potential treatments for vitiligo. PPARγ activation restores mitochondrial membrane potential, mitochondrial DNA copy number and, consequently, ATP production. Moreover, PPARγ agonists counteract oxidative stress, reduce inflammation, inhibit apoptosis, and maintain fatty acid metabolism, in addition to the well-known capability to enhance insulin sensitivity. Additionally, increasing evidence of a strong relationship between metabolic alterations and vitiligo pathogenesis suggests a role for other approved anti-diabetic treatments, like metformin and fibrates, in vitiligo treatment. Taken together, these data support the use of approaches alternative to traditional immune-suppressive treatments for the treatment of vitiligo.

Microglial polarization in Alzheimer's disease: Mechanisms, implications, and therapeutic opportunities

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the accumulation of amyloid-β plaques, neurofibrillary tangles, and chronic neuroinflammation. Microglial cells, the resident immune cells in the central nervous system, play a crucial role in the pathogenesis of AD. Microglia can undergo polarization, shifting between pro-inflammatory (M1) and anti-inflammatory (M2) phenotypes in response to different stimuli. Dysregulation of microglial polarization towards the pro-inflammatory phenotype leads to the release of inflammatory cytokines, oxidative stress, and synaptic dysfunction. These processes contribute to neuronal damage and cognitive decline in AD. However, several challenges remain in this field. The complex molecular mechanisms governing microglial polarization in AD need to be further elucidated. In this review, we discuss the mechanisms underlying microglial polarization in AD and its implications in disease progression.

In Silico Screening of Phytochemicals as Potential Inhibitors of the JAK/STATs Pathway in Psoriasis

The skin is a dynamic tissue that consists of different layers such as stratum corneum, the site for keratinocyte development and maturation for the natural changeover of skin. In psoriasis, this natural development of keratinocytes gets disturbed and aggregation of nucleated keratinocytes takes place in the epidermis of the skin, leading to the presence of scaly skin, which makes the patient physically, socially, and psychologically ill. Various natural, semisynthetic, and synthetic treatments are available. Still, semisynthetic or synthetic are mainly used to treat psoriasis with side effects on different parts of the body, which is life threatening. Various molecular target sites are getting upregulated such as Janus kinase/Signal transducer and activator of transcription (JAK/STATs), phosphodiesterase 4 (PDE4), mitogen-activated protein kinase (MAPK), platelet selectin (Pan Selectin), Tumor Necrosis Factor Alpha (TNF-α), Interleukin-23 (IL-23), Interleukin-17 (IL-17), and Tyrosine Kinase 2 (Tyk2) in psoriasis. Plants and their bioactive compounds of flavonoids, alkaloids, resins, tannins, glycosides, and terpenoids category are used in the treatment of psoriasis as topical, oral, and biological forms. Using a computational approach, the inhibition of these molecular targets can be studied and potential molecules can be identified. This research article aims to find out the potential molecules that can inhibit the molecular sites and are effective than synthetic ones.

Daturataturin A Ameliorates Psoriasis by Regulating PPAR Pathway

Psoriasis is a kind of severe immune-mediated systemic skin disorder, becoming a worldwide public health concern. Daturataturin A (DTA), a withanolide compound, exerts excellent anti-inflammatory and anti-proliferative properties. The objective of this study is to elucidate the effect of DTA on psoriasis and its potential mechanism. We established psoriasis-like keratinocytes model by stimulating HaCaT cells with M5 cocktail cytokines including Interleukin (IL)-17A, IL-22, oncostatin M, IL-1α, and tumor necrosis factor-α (TNF-α), followed by intervention with DTA. The potential effects and mechanisms of DTA on psoriasis were evaluated in vitro. DTA was found to be able to inhibit hyperproliferation, promote apoptosis, decrease the release of pro-inflammatory cytokines, downregulate keratin expression, and improve lipid metabolism via regulating the peroxisome proliferator-activated receptor (PPAR) signaling pathway by M5 cocktail cytokines stimulation in HaCaT cells. DTA ameliorated lipid metabolism of psoriasis and exerted the potential anti-psoriasis effects by regulating PPAR pathway in vitro, suggesting that DTA may act as a new therapeutic agent for psoriasis.

Bcat2-Mediated Branched-Chain Amino Acid Catabolism Is Linked to the Aggravated Inflammation in Obese with Psoriasis Mice

SCOPE

The global prevalence of obesity has significantly increased, presenting a major health challenge. High-fat diet (HFD)-induced obesity is closely related to the disease severity of psoriasis, but the mechanism is not fully understood.

METHODS AND RESULTS

The study utilizes the HFD-induced obesity model along with an imiquimod (IMQ)-induced psoriasis-like mouse model (HFD-IMQ) to conduct transcriptomics and metabolomic analyses. HFD-induced obese mice exhibits more severe psoriasis-like lesions compared to normal diet (ND)-IMQ mice. The expression of genes of the IL-17 signaling pathway (IL-17A, IL-17F, S100A9, CCL20, CXCL1) is significantly upregulated, leading to an accumulation of T cells and neutrophils in the skin. Moreover, the study finds that there is an inhibition of the branched-chain amino acids (BCAAs) catabolism pathway, and the key gene branched-chain amino transferase 2 (Bcat2) is significantly downregulated, and the levels of leucine, isoleucine, and valine are elevated in the HFD-IMQ mice. Furthermore, the study finds that the peroxisome proliferator-activated receptor gamma (PPAR γ) is inhibited, while STAT3 activity is promoted in HFD-IMQ mice.

CONCLUSION

HFD-induced obesity significantly amplifies IL-17 signaling and exacerbates psoriasis, with a potential role played by Bcat2-mediated BCAAs metabolism. The study suggests that BCAA catabolism and PPAR γ-STAT3 exacerbate inflammation in psoriasis with obesity.

Emerging trends in combination strategies with phototherapy in advanced psoriasis management

Psoriasis is a non-contagious, chronic, relapsing inflammatory skin disease with cutaneous manifestations such as red, raised scaly plaques. Current treatment approaches for psoriasis comprise topical therapy, systemic therapy, phototherapy, psoralen with UVA(PUVA) and biologics. Regardless of the progression in therapeutic approaches (novel therapies like biologics) in psoriasis, phototherapy is also an economical, compelling and safe treatment option that lacks the immunosuppressive properties as well as the toxicities of traditional modalities. It can be combined safely with other therapeutic options such as topical therapies and novel biologics and provide effective therapy. The aim of the current review is to analyze the literature on the safety as well as the efficacy of phototherapy with various treatment modalities in the management of psoriasis. This review summarizes randomized controlled clinical trials addressing combinations of phototherapy with other treatment modalities for the management of psoriasis. The findings of these clinical studies are elaborated.

The role of short-chain fatty acids in inflammatory skin diseases

Short-chain fatty acids (SCFAs) are metabolites of gut microbes that can modulate the host inflammatory response, and contribute to health and homeostasis. Since the introduction of the gut-skin axis concept, the link between SCFAs and inflammatory skin diseases has attracted considerable attention. In this review, we have summarized the literature on the role of SCFAs in skin inflammation, and the correlation between SCFAs and inflammatory skin diseases, especially atopic dermatitis, urticaria, and psoriasis. Studies show that SCFAs are signaling factors in the gut-skin axis and can alleviate skin inflammation. The information presented in this review provides new insights into the molecular mechanisms driving gut-skin axis regulation, along with possible pathways that can be targeted for the treatment and prevention of inflammatory skin diseases.