Progranulin and beta-catenin in psoriasis: An immunohistochemical study

Analysis of Intracellular Communication Reveals Consistent Gene Changes Associated with Early-Stage Acne Skin

A comprehensive understanding of the intricate cellular and molecular changes governing the complex interactions between cells within acne lesions is currently lacking. Herein, we analyzed early papules from six subjects with active acne vulgaris, utilizing single-cell and high-resolution spatial RNA sequencing. We observed significant changes in signaling pathways across seven different cell types when comparing lesional skin samples (LSS) to healthy skin samples (HSS). Using CellChat, we constructed an atlas of signaling pathways for the HSS, identifying key signal distributions and cell-specific genes within individual clusters. Further, our comparative analysis revealed changes in 49 signaling pathways across all cell clusters in the LSS- 4 exhibited decreased activity, whereas 45 were upregulated, suggesting that acne significantly alters cellular dynamics. We identified ten molecules, including GRN, IL-13RA1 and SDC1 that were consistently altered in all donors. Subsequently, we focused on the function of GRN and IL-13RA1 in TREM2 macrophages and keratinocytes as these cells participate in inflammation and hyperkeratinization in the early stages of acne development. We evaluated their function in TREM2 macrophages and the HaCaT cell line. We found that GRN increased the expression of proinflammatory cytokines and chemokines, including IL-18, CCL5, and CXCL2 in TREM2 macrophages. Additionally, the activation of IL-13RA1 by IL-13 in HaCaT cells promoted the dysregulation of genes associated with hyperkeratinization, including KRT17, KRT16, and FLG. These findings suggest that modulating the GRN-SORT1 and IL-13-IL-13RA1 signaling pathways could be a promising approach for developing new acne treatments.

Progranulinopathy: A diverse realm of disorders linked to progranulin imbalances

Progranulin (PGRN), encoded by the GRN gene in humans, was originally isolated as a secreted growth factor that implicates in a multitude of processes ranging from regulation of tumorigenesis, inflammation to neural proliferation. Compelling evidence indicating that GRN mutation can lead to various common neuronal degenerative diseases and rare lysosomal storage diseases. These findings have unveiled a critical role for PGRN as a lysosomal protein in maintaining lysosomal function. The phenotypic spectrum of PGRN imbalance has expanded to encompass a broad spectrum of diseases, including autoimmune diseases, metabolic, musculoskeletal and cardiovascular diseases. These diseases collectively referred to as Progranulinopathy- a term encompasses the wide spectrum of disorders influenced by PGRN imbalance. Unlike its known extracellular function as a growth factor-like molecule associated with multiple membrane receptors, PGRN also serves as an intracellular co-chaperone engaged in the folding and traffic of its associated proteins, particularly the lysosomal hydrolases. This chaperone activity is required for PGRN to exert its diverse functions across a broad range of diseases, encompassing both the central nervous system and peripheral systems. In this comprehensive review, we present an update of the emerging role of PGRN in Progranulinopathy, with special focus on elucidating the intricate interplay between PGRN and a diverse array of proteins at various levels, ranging from extracellular fluids and intracellular components, as well as various pathophysiological processes involved. This review seeks to offer a comprehensive grasp of PGRN's diverse functions, aiming to unveil intricate mechanisms behind Progranulinopathy and open doors for future research endeavors.

Potential of Curcumin in the Management of Skin Diseases

Curcumin is a polyphenolic molecule derived from the rhizoma of Curcuma longa L. This compound has been used for centuries due to its anti-inflammatory, antioxidant, and antimicrobial properties. These make it ideal for preventing and treating skin inflammation, premature skin ageing, psoriasis, and acne. Additionally, it exhibits antiviral, antimutagenic, and antifungal effects. Curcumin provides protection against skin damage caused by prolonged exposure to UVB radiation. It reduces wound healing times and improves collagen deposition. Moreover, it increases fibroblast and vascular density in wounds. This review summarizes the available information on the therapeutic effect of curcumin in treating skin diseases. The results suggest that curcumin may be an inexpensive, well-tolerated, and effective agent for treating skin diseases. However, larger clinical trials are needed to confirm these observations due to limitations in its in vivo use, such as low bioavailability after oral administration and metabolism.

Mutations in PGRN gene associated with the risk of psoriasis in Pakistan: a case control study

BACKGROUND

Psoriasis is a chronic, autoimmune, papulosquamous skin disorder, characterized by the formation of drop-like papules and silvery-white plaques surrounded by reddened or inflamed skin, existing predominantly on the scalp, knees and elbows. The characteristic inflammation and hyperproliferation of keratinocytes in psoriasis is regulated by progranulin (PGRN), which suppresses the expression and release of inflammatory cytokines, such as TNF-α.

METHODOLOGY

In this study mutation analysis of the PGRN gene was performed by extracting the genomic DNA from blood samples of 171 diagnosed psoriasis patients and controls through standard salting-out method, followed by amplification and sequencing of the targeted region of exon 5-7 of PGRN gene.

RESULTS

Three single nucleotide polymorphisms, rs25646, rs850713 and a novel point mutation 805A/G were identified in the PGRN gene with significant association with the disease. The variant alleles of the polymorphisms were significantly distributed among cases and controls, and statistical analysis suggested that the mutant genotypes conferred a higher risk of psoriasis development and progression. Multi-SNP haplotype analysis indicated that the CAA (OR = 8.085, 95% CI = 5.16-12.66) and the CAG (OR = 3.204, 95% CI = 1.97-5.21) haplotypes were significantly associated with psoriasis pathogenesis.

CONCLUSIONS

These findings demonstrate that polymorphisms in PGRN might act as potential molecular targets for early diagnosis of psoriasis in susceptible individuals.

Construction of a three commitment points for S phase entry cell cycle model and immune-related ceRNA network to explore novel therapeutic options for psoriasis

While competing endogenous RNAs (ceRNAs) play pivotal roles in various diseases, the proliferation and differentiation of keratinocytes are becoming a research focus in psoriasis. Therefore, the three commitment points for S phase entry (CP1-3) cell cycle model has pointed to a new research direction in these areas. However, it is unclear what role ceRNA regulatory mechanisms play in the interaction between keratinocytes and the immune system in psoriasis. In addition, the ceRNA network-based screening of potential therapeutic agents for psoriasis has not been explored. Therefore, we used multiple bioinformatics approaches to construct a ceRNA network for psoriasis, identified CTGF as the hub gene, and constructed a ceRNA subnetwork, after which validation datasets authenticated the results' accuracy. Subsequently, we used multiple online databases and the single-sample gene-set enrichment analysis algorithm, including the CP1-3 cell cycle model, to explore the mechanisms accounting for the increased proliferation and differentiation of keratinocytes and the possible roles of the ceRNA subnetwork in psoriasis. Next, we performed cell cycle and cell trajectory analyses based on a single-cell RNA-seq dataset of psoriatic skin biopsies. We also used weighted gene co-expression network analysis and single-gene batch correlation analysis-based gene set enrichment analysis to explore the functions of CTGF. Finally, we used the Connectivity Map to identify MS-275 (entinostat) as a novel treatment for psoriasis, SwissTargetPrediction to predict drug targets, and molecular docking to investigate the minimum binding energy and binding sites of the drug to target proteins.

Progranulin as a Potential Therapeutic Target in Immune-Mediated Diseases

Progranulin (PGRN), a secretory glycoprotein consisting of 593 amino acid residues, is a key actor and regulator of multiple system functions such as innate immune response and inflammation, as well as tissue regeneration. Recently, there is emerging evidence that PGRN is protective in the development of a variety of immune-mediated diseases, including rheumatoid arthritis (RA), inflammatory bowel disease (IBD), type 1 diabetes mellitus (T1DM) and multiple sclerosis (MS) by regulating signaling pathways known to be critical for immunology, particularly the tumor necrosis factor alpha/TNF receptor (TNF-α/TNFR) signaling pathway. Whereas, the role of PGRN in psoriasis, systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) is controversial. This review summarizes the immunological functions of PGRN and its role in the pathogenesis of several immune-mediated diseases, in order to provide new ideas for developing therapeutic strategies for these diseases.

Curcumin alleviates imiquimod-induced psoriasis in progranulin-knockout mice

Recent advances have revealed that progranulin (PGRN) is related to the aetiology of psoriasis. Moreover, curcumin, a compound derived from turmeric, has been proposed as a potential therapeutic approach in psoriasis-like dermatitis, but it is still unclear whether curcumin affects the development of psoriasis-like skin lesions under PGRN-deficient conditions. Therefore, in this study, we developed a mouse model of psoriatic skin lesions using topical application of imiquimod (IMQ) in both wild type and PGRN-knockout mice to test this possibility. We observed that PGRN deficiency not only increased proinflammatory cytokine IL-17A levels and aggravated psoriasis-like damaged appearance and epidermal thickening but also directly mediated changes in keratinocyte proliferation (Krt 14, cyclinD1 and c-Myc) and differentiation (Krt 10 and Filaggrin) associated gene expression following IMQ challenge, compared to those in the control group. Furthermore, curcumin treatment (50 mg/kg and 200 mg/kg, intragastrically) for 21 consecutive days suppressed the IMQ exposure-induced increase in PGRN expression. Importantly, curcumin treatment significantly alleviated the PGRN deficiency-induced exacerbation of psoriatic appearance, histological features and keratinocyte proliferation after IMQ exposure. In summary, these results demonstrate the direct regulation of PGRN in keratinocyte proliferation and differentiation in psoriatic lesions and demonstrate the protective effect of curcumin on PGRN deficiency-induced psoriatic skin lesion exacerbation.

A zebrafish model of granulin deficiency reveals essential roles in myeloid cell differentiation

Granulin is a pleiotropic protein involved in inflammation, wound healing, neurodegenerative disease, and tumorigenesis. These roles in human health have prompted research efforts to use granulin to treat rheumatoid arthritis and frontotemporal dementia and to enhance wound healing. But how granulin contributes to each of these diverse biological functions remains largely unknown. Here, we have uncovered a new role for granulin during myeloid cell differentiation. We have taken advantage of the tissue-specific segregation of the zebrafish granulin paralogues to assess the functional role of granulin in hematopoiesis without perturbing other tissues. By using our zebrafish model of granulin deficiency, we revealed that during normal and emergency myelopoiesis, myeloid progenitors are unable to terminally differentiate into neutrophils and macrophages in the absence of granulin a (grna), failing to express the myeloid-specific genes cebpa, rgs2, lyz, mpx, mpeg1, mfap4, and apoeb. Functionally, macrophages fail to recruit to the wound, resulting in abnormal healing. Our CUT&RUN experiments identify Pu.1, which together with Irf8, positively regulates grna expression. In vivo imaging and RNA sequencing experiments show that grna inhibits the expression of gata1, leading to the repression of the erythroid program. Importantly, we demonstrated functional conservation between the mammalian granulin and the zebrafish ortholog grna. Our findings uncover a previously unrecognized role for granulin during myeloid cell differentiation, which opens a new field of study that can potentially have an impact on different aspects of human health and expand the therapeutic options for treating myeloid disorders such as neutropenia or myeloid leukemia.

Progranulin Regulates Inflammation and Tumor

Progranulin (PGRN) mediates cell cycle progression and cell motility as a pleiotropic growth factor and acts as a universal regulator of cell growth, migration and transformation, cell cycle, wound healing, tumorigenesis, and cytotoxic drug resistance as a secreted glycoprotein. PGRN overexpression can induce the secretion of many inflammatory cytokines, such as IL-8, -6,-10, TNF-α. At the same time, this protein can promote tumor proliferation and the occurrence and development of many related diseases such as gastric cancer, breast cancer, cervical cancer, colorectal cancer, renal injury, neurodegeneration, neuroinflammatory, human atherosclerotic plaque, hepatocarcinoma, acute kidney injury, amyotrophic lateral sclerosis, Alzheimer’s disease and Parkinson’s disease. In short, PGRN plays a very critical role in injury repair and tumorigenesis, it provides a new direction for succeeding research and serves as a target for clinical diagnosis and treatment, thus warranting further investigation. Here, we discuss the potential therapeutic utility and the effect of PGRN on the relationship between inflammation and cancer.

Genetically programmed changes in transcription of the novel progranulin regulator

Abstract

Progranulin is a glycoprotein marking chronic inflammation in obesity and type 2 diabetes. Previous studies suggested PSRC1 (proline and serine rich coiled-coil 1) to be a target of genetic variants associated with serum progranulin levels. We aimed to identify potentially functional variants and characterize their role in regulation of PSRC1. Phylogenetic module complexity analysis (PMCA) prioritized four polymorphisms (rs12740374, rs629301, rs660240, rs7528419) altering transcription factor binding sites with an overall score for potential regulatory function of S_all > 7.0. The effects of these variants on transcriptional activity and binding of transcription factors were tested by luciferase reporter and electrophoretic mobility shift assays (EMSA). In parallel, blood DNA promoter methylation of two regions was tested in subjects with a very high (N = 100) or a very low (N = 100) serum progranulin. Luciferase assays revealed lower activities in vectors carrying the rs629301-A compared with the C allele. Moreover, EMSA indicated a different binding pattern for the two rs629301 alleles, with an additional prominent band for the A allele, which was finally confirmed with the supershift for the Yin Yang 1 transcription factor (YY1). Subjects with high progranulin levels manifested a significantly higher mean DNA methylation (P < 1 × 10⁻⁷) in one promoter region, which was in line with a significantly lower PSRC1 mRNA expression levels in blood (P = 1 × 10⁻³). Consistently, rs629301-A allele was associated with lower PSRC1 mRNA expression (P < 1 × 10⁻⁷). Our data suggest that the progranulin-associated variant rs629301 modifies the transcription of PSRC1 through alteration of YY1 binding capacity. DNA methylation studies further support the role of PSRC1 in regulation of progranulin serum levels.

Key messages

PSRC1 (proline and serine rich coiled-coil 1) SNPs are associated with serum progranulin levels.

rs629301 regulates PSRC1 expression by affecting Yin Yang 1 transcription factor (YY1) binding.

PSRC1 is also epigenetically regulated in subjects with high progranulin levels.

Electronic supplementary material

The online version of this article (10.1007/s00109-020-01942-7) contains supplementary material, which is available to authorized users.