A critical role of AREG for bleomycin-induced skin fibrosis

Sustained amphiregulin expression in intermediate alveolar stem cells drives progressive fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal fibrotic disease. Recent studies have highlighted the persistence of an intermediate state of alveolar stem cells in IPF lungs. In this study, we discovered a close correlation between the distribution pattern of intermediate alveolar stem cells and the progression of fibrotic changes. We showed that amphiregulin (AREG) expression is significantly elevated in intermediate alveolar stem cells of mouse fibrotic lungs and IPF patients. High levels of serum AREG correlate significantly with profound deteriorations in lung function in IPF patients. We demonstrated that AREG in alveolar stem cells is both required and sufficient for activating EGFR in fibroblasts, thereby driving lung fibrosis. Moreover, pharmacological inhibition of AREG using a neutralizing antibody effectively blocked the initiation and progression of lung fibrosis in mice. Our study underscores the therapeutic potential of anti-AREG antibodies in attenuating IPF progression, offering a promising strategy for treating fibrotic diseases.

Areca nut-induced AREG promote oral epithelial cell proliferation, migration, and EMT

OBJECTIVE

To analyze the biological effect and mechanism of areca nut extract (ANE) on human oral keratinocyte (HOK) cells.

MATERIALS AND METHODS

The effect of gradient concentration of ANE on the proliferation activity of HOK cells was analyzed by cell counting kit-8 (CCK-8) assays. The differentially expressed genes between the ANE group and control group HOK cells were analyzed by second-generation transcriptome sequencing. Real-time PCR and western blot were, respectively, used to analyze the expression of AREG gene and protein in HOK cells. After AREG gene overexpression or knockdown, the proliferation, migration, and expression of proteins related to epithelial-mesenchymal transformation (EMT), MAPK signal pathway in HOK cells were, respectively, detected by CCK-8, wound healing, transwell, and western blot assays.

RESULTS

ANE (500 μg/mL) promoted the proliferation and migration of HOK cells, ANE (2 mg/mL) promoted the EMT of HOK cells, and ANE (50 mg/mL) inhibited the proliferation of HOK cells. AREG knockdown inhibited ANE-induced proliferation and migration of HOK cells, while AREG overexpression promoted the proliferation and migration of HOK cells. Western blot assay showed that ANE activated MAPK signal pathway by upregulating AREG protein in HOK cells.

CONCLUSIONS

ANE promoted HOK cell proliferation, migration, and EMT by mediating AREG-MAPK signaling pathway.

In Vitro Bioassay for Damage-Associated Molecular Patterns Arising from Injured Oral Cells

Gingival fibroblasts are a significant source of paracrine signals required to maintain periodontal homeostasis and to mediate pathological events linked to periodontitis and oral squamous cell carcinomas. Among the potential paracrine signals are stanniocalcin-1 (STC1), involved in oxidative stress and cellular survival; amphiregulin (AREG), a growth factor that mediates the cross-talk between immune cells and epithelial cells; chromosome 11 open reading frame 96 (C11orf96) with an unclear biologic function; and the inflammation-associated prostaglandin E synthase (PTGES). Gingival fibroblasts increasingly express these genes in response to bone allografts containing remnants of injured cells. Thus, the gene expression might be caused by the local release of damage-associated molecular patterns arising from injured cells. The aim of this study is consequently to use the established gene panel as a bioassay to measure the damage-associated activity of oral cell lysates. To this aim, we have exposed gingival fibroblasts to lysates prepared from the squamous carcinoma cell lines TR146 and HSC2, oral epithelial cells, and gingival fibroblasts. We report here that all lysates significantly increased the transcription of the entire gene panel, supported for STC1 at the protein level. Blocking TGF-β receptor 1 kinase with SB431542 only partially reduced the forced expression of STC1, AREG, and C11orf96. SB431542 even increased the PTGES expression. Together, these findings suggest that the damage signals originating from oral cells can change the paracrine activity of gingival fibroblasts. Moreover, the expression panel of genes can serve as a bioassay for testing the biocompatibility of materials for oral application.

Clinical significance of amphiregulin in patients with chronic kidney disease

BACKGROUND

Amphiregulin (AREG) is a ligand of epidermal growth factor receptor (EGFR), which plays an important role in injury-induced kidney fibrosis. However, the clinical significance of serum soluble AREG in chronic kidney disease (CKD) is unclear. In this study, we elucidated the clinical significance of serum soluble AREG in CKD by analyzing the association of serum soluble AREG levels with renal function and other clinical parameters in patients with CKD.

METHODS

In total, 418 Japanese patients with CKD were enrolled, and serum samples were collected for the determination of soluble AREG and creatinine (Cr) levels, and other clinical parameters. Additionally, these parameters were evaluated after 2 and 3 years. Moreover, immunohistochemical assay was performed ate AREG expression in the kidney tissues of patients with CKD.

RESULTS

Soluble AREG levels were positively correlated with serum Cr (p < 0.0001). Notably, initial AREG levels were positively correlated with changes in renal function (ΔCr) after 2 (p < 0.0001) and 3 years (P = 0.048). Additionally, soluble AREG levels were significantly higher (p < 0.05) in patients with diabetic nephropathy or primary hypertension. Moreover, AREG was highly expressed in renal tubular cells in patients with advanced CKD, but only weakly expressed in patients with preserved renal function.

CONCLUSION

Serum soluble AREG levels were significantly correlated with renal function, and changes in renal function after 2 and 3 years, indicating that serum soluble AREG levels might serve as a biomarker of renal function and renal prognosis in CKD.

Qilongtian ameliorate bleomycin-induced pulmonary fibrosis in mice via inhibiting IL-17 signal pathway

Pulmonary fibrosis (PF) is a special type of pulmonary parenchymal disease, with chronic, progressive, fibrosis, and high mortality. There is a lack of safe, effective, and affordable treatment methods. Qilongtian (QLT) is a traditional Chinese prescription that is composed of Panax notoginseng, Earthworm, and Rhodiola, and shows the remarkable clinical curative effect of PF. However, the mechanism of QLT remains to be clarified. Therefore, we studied the effectivity of QLT in treating Bleomycin (BLM) induced PF mice. 36 C57BL/6 J mice were randomized into the control group, the model group, the low-, medium- and high-dose QLT group, and Pirfenidone group. After establishing a model of pulmonary fibrosis in mice, the control and model groups were infused with a normal saline solution, and the delivery group was infused with QLT. Pulmonary function in the mice from each group was detected. Pulmonary tissue morphologies and collagen deposition were stained by HE and Masson. The content of hydroxyproline (HYP) was detected by alkaline hydrolysis and the mRNA and protein expression of related genes in pulmonary tissues were detected by using q-PCR, ELISA, and Western blot. Our studies have shown that QLT significantly reduced the inflammatory injury, hydroxy-proline content, and collagen deposition of pulmonary tissue in BLM-induced PF mice and down-regulated the cytokine related to inflammation and fibrosis and PF expression on the mRNA and protein level in PF mice. To identify the mechanism of QLT, the Transcriptome was measured and the IL-17 signal pathway was screened out for further research. Further studies indicated that QLT reduced the mRNAs and protein levels of interleukin 17 (IL-17), c-c motif chemokine ligand 12 (CCL12), c-x-c motif chemokine ligand 5 (CXCL5), fos-like antigen 1 (FOSL1), matrix metalloproteinase-9 (MMP9), and amphiregulin (AREG), which are inflammation and fibrosis-related genes in the IL-17 signal pathway. The results indicated that the potential mechanism for QLT in the prevention of PF progression was by inhibiting inflammation resulting in the IL-17 signal pathway. Our study provides the novel scientific basis of QLT and represents new therapeutics for PF in clinical.

Ca2+ homeostasis maintained by TMCO1 underlies corpus callosum development via ERK signaling

Transmembrane of coiled-coil domains 1 (TMCO1) plays an important role in maintaining homeostasis of calcium (Ca²⁺) stores in the endoplasmic reticulum (ER). TMCO1-defect syndrome shares multiple features with human cerebro-facio-thoracic (CFT) dysplasia, including abnormal corpus callosum (CC). Here, we report that TMCO1 is required for the normal development of CC through sustaining Ca²⁺ homeostasis. Tmco1^-/- mice exhibit severe agenesis of CC with stalled white matter fiber bundles failing to pass across the midline. Mechanistically, the excessive Ca²⁺ signals caused by TMCO1 deficiency result in upregulation of FGFs and over-activation of ERK, leading to an excess of glial cell migration and overpopulated midline glia cells in the indusium griseum which secretes Slit2 to repulse extension of the neural fiber bundles before crossing the midline. Supportingly, using the clinical MEK inhibitors to attenuate the over-activated FGF/ERK signaling can significantly improve the CC formation in Tmco1^-/- brains. Our findings not only unravel the underlying mechanism of abnormal CC in TMCO1 defect syndrome, but also offer an attractive prevention strategy to relieve the related agenesis of CC in patients.

Single-cell analysis of human skin identifies CD14+ type 3 dendritic cells co-producing IL1B and IL23A in psoriasis

Inflammatory skin diseases including atopic dermatitis (AD) and psoriasis (PSO) are underpinned by dendritic cell (DC)-mediated T cell responses. Currently, the heterogeneous human cutaneous DC population is incompletely characterized, and its contribution to these diseases remains unclear. Here, we performed index-sorted single-cell flow cytometry and RNA sequencing of lesional and nonlesional AD and PSO skin to identify macrophages and all DC subsets, including the newly described mature LAMP3+BIRC3+ DCs enriched in immunoregulatory molecules (mregDC) and CD14+ DC3. By integrating our indexed data with published skin datasets, we generated a myeloid cell universe of DC and macrophage subsets in healthy and diseased skin. Importantly, we found that CD14+ DC3s increased in PSO lesional skin and co-produced IL1B and IL23A, which are pathological in PSO. Our study comprehensively describes the molecular characteristics of macrophages and DC subsets in AD and PSO at single-cell resolution, and identifies CD14+ DC3s as potential promoters of inflammation in PSO.