Adiponectin's globular domain inhibits T cell activation by interacting with LAIR-1

Adipokine-Enriched Adipose Extract Restores Skin Barrier and Ameliorates Inflammatory Dysregulation in Atopic Dermatitis Mice

BACKGROUND

Atopic dermatitis (AD) is a chronic dermatosis with high incidence worldwide characterized by skin barrier abnormalities and immune dysregulation. Conventional therapies are usually limited by side effects and high cost. Given the antiinflammatory and repairing properties, adipokines are increasingly considered as promising therapeutic agents for dermatoses. Adipose collagen fragments (ACF), a novel adipokine-enriched product, may alleviate AD through modulating immune microenvironment and restoring skin barrier.

METHODS

ACF was extracted from adipose tissue by means of high-speed homogenization (10,000 rpm/min for 1 minute) and centrifugation (3000 g for 3 minutes). Ovalbumin-induced AD female BALB/c mice (6-week-old) were intradermally injected with 0.2 mL of ACF or phosphate-buffered saline (negative control), with normal mice being set as normal control ( n = 6). Dermatitis severity, inflammatory metrics (epidermal thickness, infiltrated mast cells, T helper cell [Th]-type cytokine expression), and skin barrier-related metrics (transepidermal water loss, skin barrier-related proteins expression) were evaluated after the AD induction period (day 50). ACF-derived bioactive components were also evaluated using proteomic analysis.

RESULTS

ACF-derived adipokines contained antiinflammatory, skin barrier- and lipid biosynthesis-related components. ACF treatment decreased dermatitis severity (6.2 ± 1.8 [ P < 0.0001]), epidermal thickness (25.7 ± 12.8 μm [ P = 0.0045]), infiltrated mast cells (31.3 ± 12.4 cells/field [ P = 0.0475]), and expression of Th-type cytokines (interferon-γ, tumor necrosis factor-α, interleukin [IL]-4, IL-4R, IL-13, and IL-17A [ P < 0.05]) in AD skins. Transepidermal water loss (29.8 ± 13.8 g/m 2 per hour [ P = 0.0306]) and skin barrier-related protein expression (filaggrin, 14,258 ± 4375 [ P = 0.0162]; loricrin, 6037 ± 1728 [ P = 0.0010]; claudin-1, 20,043 ± 6406 [ P = 0.0420]; and zonula occludens-1, 4494 ± 1114 [ P = 0.0134]) were also improved.

CONCLUSIONS

ACF improved AD in a murine model by ameliorating inflammatory dysregulation and skin barrier defects. Further validation is needed in more advanced animal models.

CLINICAL RELEVANCE STATEMENT

ACF is an injectable, adipose-derived collagen scaffold prepared from autologous harvested fat using fast and simple mechanical methods. ACF may reduce the limitations associated with health care regulatory issues and serve as a promising autologous therapeutic agent for skin disorders in clinics.

Predictive value of adipokines for the severity of acute pancreatitis: a meta-analysis

BACKGROUND

Severe acute pancreatitis (SAP) is a dangerous condition with a high mortality rate. Many studies have found an association between adipokines and the development of SAP, but the results are controversial. Therefore, we performed a meta-analysis of the association of inflammatory adipokines with SAP.

METHODS

We screened PubMed, EMBASE, Web of Science and Cochrane Library for articles on adipokines and SAP published before July 20, 2023. The quality of the literature was assessed using QUADAS criteria. Standardized mean differences (SMD) with 95% confidence intervals (CI) were calculated to assess the combined effect. Subgroup analysis, sensitivity analysis and publication bias tests were also performed on the information obtained.

RESULT

Fifteen eligible studies included 1332 patients with acute pancreatitis (AP). Pooled analysis showed that patients with SAP had significantly higher serum levels of resistin (SMD = 0.78, 95% CI:0.37 to 1.19, z = 3.75, P = 0.000). The difference in leptin and adiponectin levels between SAP and mild acute pancreatitis (MAP) patients were not significant (SMD = 0.30, 95% CI: -0.08 to 0.68, z = 1.53, P = 0.127 and SMD = 0.11, 95% CI: -0.17 to 0.40, z = 0.80, P = 0.425, respectively). In patients with SAP, visfatin levels were not significantly different from that in patients with MAP (SMD = 1.20, 95% CI: -0.48 to 2.88, z = 1.40, P = 0.162).

CONCLUSION

Elevated levels of resistin are associated with the development of SAP. Resistin may serve as biomarker for SAP and has promise as therapeutic target.

Role of Leptin and Adiponectin in Carcinogenesis

Hormones produced by adipocytes, leptin and adiponectin, are associated with the process of carcinogenesis. Both of these adipokines have well-proven oncologic potential and can affect many aspects of tumorigenesis, from initiation and primary tumor growth to metastatic progression. Involvement in the formation of cancer includes interactions with the tumor microenvironment and its components, such as tumor-associated macrophages, cancer-associated fibroblasts, extracellular matrix and matrix metalloproteinases. Furthermore, these adipokines participate in the epithelial-mesenchymal transition and connect to angiogenesis, which is critical for cancer invasiveness and cancer cell migration. In addition, an enormous amount of evidence has demonstrated that altered concentrations of these adipocyte-derived hormones and the expression of their receptors in tumors are associated with poor prognosis in various types of cancer. Therefore, leptin and adiponectin dysfunction play a prominent role in cancer and impact tumor invasion and metastasis in different ways. This review clearly and comprehensively summarizes the recent findings and presents the role of leptin and adiponectin in cancer initiation, promotion and progression, focusing on associations with the tumor microenvironment and its components as well as roles in the epithelial-mesenchymal transition and angiogenesis.

LAIR1, an ITIM-Containing Receptor Involved in Immune Disorders and in Hematological Neoplasms

Leukocyte-associated immunoglobulin (Ig)-like receptor 1 (LAIR1, CD305) belongs to the family of immune-inhibitory receptors and is widely expressed on hematopoietic mature cells, particularly on immune cells. Four different types of ligands of LAIR1 have been described, including collagens, suggesting a potential immune-regulatory function on the extracellular matrix. By modulating cytokine secretion and cellular functions, LAIR1 displays distinct patterns of expression among NK cell and T/B lymphocyte subsets during their differentiation and cellular activation and plays a major negative immunoregulatory role. Beyond its implications in physiology, the activity of LAIR1 can be inappropriately involved in various autoimmune or inflammatory disorders and has been implicated in cancer physiopathology, including hematological neoplasms. Its action as an inhibitory receptor can result in the dysregulation of immune cellular responses and in immune escape within the tumor microenvironment. Furthermore, when expressed by tumor cells, LAIR1 can modulate their proliferation or invasion properties, with contradictory pro- or anti-tumoral effects depending on tumor type. In this review, we will focus on its role in normal physiological conditions, as well as during pathological situations, including hematological malignancies. We will also discuss potential therapeutic strategies targeting LAIR1 for the treatment of various autoimmune diseases and cancer settings.

Understanding the contextual functions of C1q and LAIR-1 and their applications

The importance of the complement component C1q has been highlighted by its involvement in autoimmunity, infection, inflammatory diseases, and tumors. The unique tulip-like structure of C1q has both a collagen-like stalk (C1q tail) and heterotrimeric globular head (gC1q), each with different binding specificities, and the binding of these components to their respective receptors leads to functional complexities in the body and bridges innate and adaptive immunity. This review describes the fundamental roles of C1q in various microenvironments and focuses on the importance of the interactions of C1q and its receptors with the inhibitory receptor LAIR-1 in maintaining homeostasis. Current therapeutic opportunities modulating LAIR-1 are also discussed.

Research into the activities of the protein C1q, involved in a cascade of molecular interactions of the immune response called complement activation, is revealing new details of the protein’s role and opening up possible new therapeutic opportunities. Myoungsun Son at Feinstein Institutes for Medical Research in Manhasset, USA, reviews the involvement of C1q in infection, autoimmunity, inflammatory diseases and tumors. The interaction of C1q with a receptor protein called LAIR-1 seems to be particularly significant. LAIR-1 is present in the membrane of most blood-forming cells and is involved in maintaining the healthy balance of cellular activities referred to as homeostasis. Emerging research suggests that targeting the interactions between C1q and LAIR-1 could enable the development of new treatments for many diseases, including inflammatory diseases, the autoimmune condition lupus, a variety of cancers, and possibly Covid-19.