The Role of Estrogen Membrane Receptor (G Protein-Coupled Estrogen Receptor 1) in Skin Inflammation Induced by Systemic Lupus Erythematosus Serum IgG

G-Protein Coupled Receptor 1 Is Involved in Tetrachlorobisphenol A-Induced Inflammatory Response in Jurkat Cells

Estrogens can affect the immune inflammatory response through estrogen receptor alpha (ERα), but the specific role of estrogen member receptor G-protein coupled receptor 1 (GPER1) in this process remains unclear. In this study, we evaluated the effects of tetrachlorobisphenol A (TCBPA), which has estrogen activity, on immune inflammatory-related indicators of Jurkat cells, as well as investigated the role of GPER1 in these effects. The results showed that TCBPA at lower concentrations significantly promoted the viability of Jurkat cells, whereas higher concentrations decreased cell viability. TCBPA at concentrations ranging from 1 to 25 μM increased the intracellular reactive oxygen species (ROS) levels. Additionally, treatment with 10 μM TCBPA increased the protein expression of ERα and GPER1, elevated the phosphorylation of protein kinase B (p-Akt), and upregulated the mRNA levels of GPER1, Akt, and phosphoinositide 3-kinase (PI3K) genes. Treatment with 10 μM TCBPA also upregulated the protein or gene expression of pro-inflammatory cytokines, such as interleukins (IL1β, IL2, IL6, IL8, IL12α) and tumor necrosis factor alpha (TNFα) in Jurkat cells. Furthermore, pretreatment with a GPER1 inhibitor G15 significantly reduced the mRNA levels of Akt induced by 10 μM TCBPA. Moreover, the upregulation of mRNA expression of RelA (p65), TNFα, IL6, IL8, and IL12α induced by 10 μM TCBPA was also significantly attenuated after G15 pretreatment. These findings suggest that TCBPA upregulates the expression of genes related to inflammatory responses by activating the GPER1-mediated PI3K/Akt signaling pathway. This study provides new insights into the mechanism of TCBPA-induced inflammatory response.

Animal models of studying the pathogenesis of multi-organ tissue damage in lupus

Moderate-to-severe systemic lupus erythematosus (SLE) is characterized by extensive autoantibody deposition and persistent autoinflammation. As the existing animal models are limited in accurately reproducing the pathological characteristics of human SLE, we introduced a novel animal model simulating multi-organ autoinflammation through intra-organ injections. The model closely mimicked key features of SLE, including IgG deposition, inflammation, and tissue damage. The model could be used to assess the roles of IgG, immune cells, cytokines, and Fc gamma receptor (FcγR) in the pathogenesis of autoinflammation. The results obtained from this model could be confirmed by lupus MRL/lpr mice. The review suggested that the diagnostic criteria should be reconsidered to incorporate IgG deposition in tissues and highlighted the limitations of current T-cell and B-cell-focused treatments. To summarize, the IgG deposition model can be used to investigate the pathogenesis and treatment of multi-organ tissue damage associated with SLE.

Cardiac and vascular complications in lupus: Is there a role for sex?

Systemic lupus erythematosus (SLE) is a common systemic autoimmune disorder and is characterized by autoantibody formation and subsequent immune complex deposition into target organs. SLE affects nearly nine women to every one man worldwide. Patients with SLE are at an enhanced risk for cardiovascular disease (CVD) morbidity and mortality. CVD is the leading cause of death worldwide and includes heart and blood vessel disorders, cerebrovascular disease, and rheumatic heart disease. Specific mechanisms by which cardiac and vascular pathophysiology develops in patients with SLE are still not fully known. Not only do we not understand this correlation between SLE and CVD, but there is also a critical gap in scientific knowledge on the contribution of sex. In this review, we will discuss the cardiac and vascular pathological disease states that are present in some patients with SLE. More importantly, we will discuss the potential mechanisms for the role of sex and sex hormones in the development of CVD with SLE.

Immune-Mediated Diseases from the Point of View of Psychoneuroimmunoendocrinology

Immune-mediated inflammatory diseases (IMIDs) represent a large group of diseases (Crohn's, ulcerative colitis, psoriasis, lupus, and rheumatoid arthritis) evidenced by systemic inflammation and multiorgan involvement. IMIDs result in a reduced quality of life and an economic burden for individuals, health care systems, and countries. In this brief descriptive review, we will focus on some of the common biological pathways of these diseases from the point of view of psychoneuroimmunoendocrinology (PNIE). PNIE consists of four medical disciplines (psychology, nervous system, immune system, and endocrine system), which are key drivers behind the health-disease concept that a human being functions as a unit. We examine these drivers and emphasize the need for integrative treatments that addresses the disease from a psychosomatic point of view.

Amelioration of Lupus Serum-Induced Skin Inflammation in CD64-Deficient Mice

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disorder characterized by high autoantibodies levels and multiorgan tissue damage. The current study investigated the role of CD64 in SLE patients and animal models. According to a flow cytometry study, SLE patients showed an increase in CD64 expression in circulating monocytes. There was a correlation between CD64 and SLEDAI, blood urea nitrogen levels, and anti-Sm antibodies. In skin lesions of lupus MRL/lpr mice, there was high IgG deposition and CD64 expression. In vitro, cytokines IL-10 and IFN-γ upregulated CD64 expression in monocytes/macrophages that was inhibited by glucocorticoids. In CD64-deficient mice, skin inflammation induced by lupus serum was reduced. Furthermore, activation of spleen tyrosine kinase (Syk), Akt, and extracellular signal-regulated kinase (Erk) was inhibited in CD64-deficient monocytes. The results suggest that CD64 could be a biomarker for observing SLE progression, as well as a mechanistic checkpoint in lupus pathogenesis.

The role of organ-deposited IgG in the pathogenesis of multi-organ and tissue damage in systemic lupus erythematosus

Systemic lupus erythematosus (SLE), often known simply as lupus, is a severe chronic autoimmune disease that is characterized by multi-organ and tissue damage and high levels of autoantibodies in serum. We have recently investigated, using animal models, the role of organ-deposited IgG autoantibodies in the pathogenesis of organ and tissue damage in SLE. We found that intra-organ injection of serum from mice with lupus (i.e., lupus mice) into healthy mice triggered inflammation in tissue and organs but that serum from other healthy mice did not, and that the severity of inflammation was related to the dose of serum injected. Immunohistochemistry showed that a large number of IgG molecules are deposited at the site of organ and tissue damage in lupus mice, and that IgG is a major contributor to the development of tissue inflammation triggered by serum from lupus mice or patients. The development of tissue inflammation induced by IgG in serum from lupus mice requires the presence of monocytes/macrophages, but not of lymphocytes or neutrophils; tumor necrosis factor (TNF)/tumor necrosis factor receptor 1 (TNFR1) and interleukin 1 (IL-1) also play essential roles in the development of tissue inflammation triggered by IgG. In addition, it has been found that TNFR1 inhibitors can suppress skin injury in lupus mice and that spleen tyrosine kinase (Syk) inhibitors, which can block the signaling transduction of IgG/Fc gamma receptors (FcγRs), can prevent and treat skin injury and kidney damage in lupus mice. We have also observed that lupus IgG might protect against bone erosion. Based on these results, we conclude that IgG plays a crucial role in the development of organ and tissue damage in SLE and in protecting bone erosion and arthritis, and we suggest that the IgG/FcγR signaling pathway is an important therapeutic target in SLE.

Evaluation of serum G protein-coupled estrogen receptor 1 (GPER-1) levels in patients with androgenetic alopecia

The effect of oestrogens in androgenetic alopecia (AGA) pathophysiology has not been clearly understood. However, they are considered to have a place in the AGA pathogenesis as the androgens do. The effects of estrogen occur via the estrogen receptors alpha and beta, and the recently discovered G protein-coupled estrogen receptor 1 (GPER-1). Aim of this study is to examine serum GPER-1 levels of AGA patients and to evaluate the place of them in AGA pathogenesis for the first time through the literature. 40 AGA patients with clinical AGA stage 2-3-4 diagnoses according to the Hamilton-Norwood classification for males, and AGA stage 2 according to Ludwig system for females and with normal serum dihydroepiandrosterone sulfate, estradiol, total testosterone, progesterone, follicle stimulating hormone and luteinizing hormone were included in the study in addition to 40 healthy controls with similar characteristics by means of age and gender. We received the medical history and performed the physical examinations. We measured serum GPER-1 levels. Serum GPER-1 levels of AGA patients and the control group were 30.43 ± 3.83 ng/mL and 14.18 ± 3.61 ng/mL (mean ± SD), respectively. The levels were detected as significantly increased in AGA group compared with the control group (p = 0.007). No serum GPER-1 level differences were found among female and male patients (p = 0.101). Significantly high levels of serum GPER-1 levels in AGA patients without any relationship between gender and GPER-1 Levels compared with healthy controls reminded us that GPER-1 might have a role in AGA pathogenesis independent from the gender.

G Protein-Coupled Estrogen Receptor 1 (GPER1) Mediates Aldosterone-Induced Endothelial Inflammation in a Mineralocorticoid Receptor-Independent Manner

OBJECTIVE

It has been increasingly appreciated that G protein-coupled estrogen receptor 1 (GPER1) mediates both proinflammatory and anti-inflammatory response of estrogen. It is also involved in some rapid vascular effects of aldosterone in a mineralocorticoid receptor (MR) independent manner. However, whether GPER1 mediates aldosterone-induced inflammation response in endothelial cells and its relationship with MR are yet undetermined and therefore require further explanation.

METHOD

Based on the hypothesis that GPER1 plays a role in the aldosterone-related vascular inflammation, the present study utilized a model of human umbilical vein endothelial cells transfected with MR siRNA and induced for inflammatory response with increasing concentration of aldosterone.

RESULTS

It was discovered that induction of aldosterone had no effect on the expression of GPER1 but promoted the expression of MR. Suppression of MR did not influence GPER1 expression, and GPER1 was capable of mediating part of aldosterone-induced endothelial inflammatory response. This effect may involve phosphoinositide 3-kinases (PI3K) pathway signaling.

CONCLUSION

These findings not only demonstrated the role of GPER1 in aldosterone-induced vascular inflammation but also suggested an alternative for pharmaceutical treatment of hyperaldosteronism considering the unsatisfying effect on cardiovascular risks with MR antagonists.