Circulating immune cell phenotyping is potentially relevant for diabetic retinopathy risk assessment

BACKGROUND

Inflammation is believed to play a central role in the development of diabetes mellitus and is a common feature of type 2 diabetes mellitus (T2DM). However, the association with diabetic retinopathy (DR) remains a topic of debate.

METHODS

This study employed two-sample bidirectional Mendelian randomization (MR) analyses to establish causal associations between immune cell characteristics and DR. Using publicly available GWAS genetic data, we investigated the causal relationship between 731 immune cell characteristics and the risk of DR. A total of four types of immune features, including relative cell (RC), absolute cell (AC), median fluorescence intensities (MFI), and morphological parameters (MP), were included. Sensitivity analysis was conducted to assess the robustness, heterogeneity, and potential horizontal pleiotropy of the results.

RESULTS

Thirty-five immune cell phenotypes were correlated with the risk of developing DR among four immune traits (MFI, RC, AC, and MP), and DR resulted in altered expression of twenty-six immune cells.

CONCLUSION

We have demonstrated a strong correlation between immune cell traits and DR using a genetic approach. This finding offers valuable insights for early DR prevention and future clinical research and treatment.

Sepsis Impairs Purkinje Cell Functions and Motor Behaviors Through Microglia Activation

The most common clinical manifestation of sepsis-related encephalopathy (SAE) is the deterioration of cognitive function. Besides, increasing evidence shows that SAE patients exhibit coordination and sensorimotor dysfunctions, suggesting that SAE affects motor function with unclear mechanism. In the present work, we explored the effects of SAE on cerebellar Purkinje cells (PCs) using cecal ligation and perforation (CLP), a standard model for inducing sepsis symptoms similar to those in human patients. Our results show that the sepsis can activate microglia in the cerebellum and promote the secretion of inflammatory factor TNF-α, which increases intrinsic excitability and synaptic transmission of PCs, inhibits the synaptic plasticity of PCs, and impairs motor learning of mice. These findings address how SAE changes PC functions, and thereby are of great significance to reveal pathophysiological feathers of human patients suffering from SAE.

Activation of aryl hydrocarbon receptor by azatyrosine-phenylbutyric hydroxamide inhibits progression of diabetic retinopathy mice

Diabetic retinopathy (DR) is a severe consequence of long-term diabetes mellitus and may lead to vision loss. Retinal pigment epithelial (RPE) cells are a diverse group of retinal cells with varied metabolic and functional roles. In hypoxic conditions, RPE cells have been shown to produce angiogenic factors, such as vascular endothelial growth factor (VEGF), which is regulated by hypoxia-inducible factor 1-alpha (HIF1A). VEGF plays a crucial role in angiogenesis in DR. In the present study, we investigated whether azatyrosine-phenylbutyric hydroxamide (AZP) has therapeutic effect on DR therapy. In this study, we treated high glucose-activated human retinal pigment epithelial cells (ARPE-19) with and without AZP. The effector proteins were evaluated using western blotting. In the in vivo study, AZP was administered to the db/db mice as a DR animal model. Moreover, invasive imaging techniques such as optical coherence tomography (OCT), fundus photography, and fundus fluorescein angiography (FFA) were performed on the mice to assess DR progression. We found that treatment of AZP for 12 weeks reversed increasing DR retinal alterations in db/db mice, decreasing vascular density, retinal blood perfusion, retinal thickness, decreasing DR lesion, lipofuscin accumulation, HIF1A, VEGF, and inflammation factor expression. In addition, AZP treatment could activate the aryl hydrocarbon receptor AHR and reverse the high-glucose-induced HIF1A and VEGF in ARPE-19 cells and db/db mice. In conclusion, AZP activated AHR while inhibiting HIF1A and VEGF. This study indicates that AZP may be a promising therapeutic agent for treating DR.

Xian-Ling-Gu-Bao induced inflammatory stress rat liver injury: Inflammatory and oxidative stress playing important roles

ETHNOPHARMACOLOGICAL RELEVANCE

Xian-Ling-Gu-Bao (XLGB) Fufang is an herbal formula that has been used in clinical settings to treat osteoporosis, osteoarthritis, aseptic bone necrosis, and climacteric syndrome. Despite its uses, XLGB treatment has been linked to potential liver injury. To date, there is a lack of clear demonstration of such toxicity in animal models.

AIM OF THE STUDY

As animal models fail to reproduce the XLGB hepatotoxicity reported in humans, because human hepatocytes are clearly more sensitive to XLGB, this study was designed to investigate a more reliable animal model of such toxicity.

MATERIALS AND METHODS

We randomized rats into five groups, as follows: CON (control), XLGB, lipopolysaccharide (LPS), L-XLGB/LPS (XLGB, 0.125 g/kg; LPS, 0.1 mg/kg), and XLGB/LPS (XLGB, 1.25 g/kg; LPS, 0.1 mg/kg). These groups were treated with 0.5% sodium carboxymethyl cellulose (CMC-Na), XLGB suspension, normal saline, or LPS. The first administration of XLGB [0.125 g/kg or 1.25 g/kg, by mouth (PO)] or its solvent (0.5% CMC-Na) was delivered, and then food was removed. Twelve hours after the first administration of XLGB, rats received LPS [0.1 mg/kg, intravenously (IV)] or saline control. After 30 min, a second administration of XLGB (0.125 g/kg or 1.25 g/kg, PO) or solvent was administered. The rats were anesthetized at 12 h or 24 h following the second administration of XLGB. Liver function was evaluated by measuring liver weight, liver microscopy, serum biochemistry and plasma microRNA-122 (miR-122). The plasma levels of 27 cytokines were measured to evaluate inflammation. Moreover, the expression of cytochrome P450 2E1 (CYP2E1), nicotinic adenine dinucleotide phosphate (NADPH) oxidase and inducible nitric oxide synthase (iNOS) at protein levels were observed; immunofluorescence and immunohistochemistry were used to confirmed the hepatotoxicity of XLGB.

RESULTS

Hepatotoxicity in male rats with moderate inflammation induced by XLGB was indicated by liver histopathology, serum biochemical analysis, serum miR-122 levels, and immunofluorescent assessments. We observed significant increases in liver weight and liver indexes in male rats with moderate inflammation in response to XLGB. Histopathological assessment further showed that extensive hepatocellular necrosis and inflammatory infiltration were evident in rats co-treated with XLGB/LPS. The levels of serum transaminases [alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT)], total bilirubin (TBIL) and triglyceride (TG), which are markers of liver function, were also significantly increased by XLGB/LPS treatment. Similarly, miR-122 was significantly elevated in XLGB/LPS treated rats relative to other groups. An immunofluorescent assessment showed extensive apoptosis in hepatocytes from these co-treated rats. What is more, XLGB can dose-dependently induce liver injury in male rats with moderate inflammation. Hepatic CYP2E1, neutrophil chemotactic factor (NCF-1), iNOS, and NOX-2 (an NADPH oxidase subunit) levels were increased in response to XLGB treatment, and staining for DMPO nitrone adducts further showed elevated oxidative stress level in XLGB/LPS-treated rats relative to the other experimental groups.

CONCLUSION

LPS and XLGB co-treatment in rats led to marked hepatotoxicity. This toxicity was associated with disrupted lipid metabolism, extensive liver necrosis and inflammatory infiltration, apoptosis, and expression of oxidative stress-related proteins. These results demonstrate a valuable model for the study of iDILI in the context of XLGB treatment, and further provide insights into the potential mechanisms by which XLGB may induce hepatotoxicity in humans.

Mechanical stretch aggravates aortic dissection by regulating MAPK pathway and the expression of MMP-9 and inflammation factors

This study aimed to explore whether mechanical stretch aggravated aortic dissection through regulating MAPK pathway, MMP-9, and inflammation factors. We first established aortic dissection model rats. Mechanical stretch (3 g) was exerted on vascular ring of aortic dissection which was also treated by inhibitors of MAPK pathway (SB203580, SP600125, and U0126). HE and Masson staining showed that aortic dissection severity with 3 g tension was worse than that without tension (0 g); after the treatments of diverse inhibitors, the fracture and breakage of the elastic fibers decreased. The expression of MMP-9, TNF-α, IL-1β) p38/p-p38, JNK1/p-JNK1, and ERK1/2/p-ERK1/2 were determined by immunohistochemical analysis, RT-PCR, and western blot. No matter whether tension was exerted or inhibitors were added, there was no change in the expression of p38, JNK1, and ERK1/2. However, compared to the 0 g group, the expression of MMP-9, TNF-α, IL-1β, p-p38, p-JNK1, and p-ERK1/2 was significantly upregulated in the 3 g group (P < 0.05). In both 0 g and 3 g groups, the expression of MMP-9, TNF-α, IL-1β, p-p38, p-JNK1, and p-ERK1/2 was remarkably downregulated after inhibitors treatment (P < 0.05). In conclusion, mechanical stretch aggravated aortic dissection by regulating the MAPK pathway and the consequent expression of MMP-9 and inflammation factors.

Intracerebroventricular injection of miR-146a relieves seizures in an immature rat model of lithium-pilocarpine induced status epilepticus

OBJECTIVE

Status epilepticus (SE) is a common, life-threatening neurological emergency that confers a high degree of morbidity and mortality. Increasing evidence indicates that neuroinflammation plays a critical role in the pathogenesis of SE. MicroRNA-146a (miR-146a) has been reported to be an important posttranscriptional inflammation-associated microRNA. The aim of this study was to investigate the effect of miR-146a in SE and the mechanism by which it operates.

METHODS

To study the effect of miR-146a in SE, we chose intracerebroventricular injection for rat at 21-28days old, and made a lithium-pilocarpine-induced SE rat model. We assessed latency time and Lado grade by behavior observation. We performed qPCR, ELISA and western blot tests on rat hippocampus to measure the expression levels of miR-146a, IL-1β, TNF-α, TLR4 and NF-κB.

RESULTS

In the miR-146a antagomir injection group, the latency to generalized convulsions was shorter, the duration and degree of seizures were more severe, the expression level of miR-146a was clearly decreased, and IL-1β, TNF-α, TLR4 and NF-κB were all significantly up-regulated. The opposite was true for rats treated with miR-146a agomir.

CONCLUSION

Our findings elucidate the role of inflammation in the pathogenesis of SE in immature rats, and show that regulating the expression level of miR-146a may provide a novel insights into the pathogenesis of SE.

Increased Mobilization of CD45+CD34+VLA-4+ Cells in Acute Viral Myocarditis Induced by Coxsackievirus B3

OBJECTIVES

Bone marrow-derived cells (BMCs) have recently been identified to play a vital role in repairing damaged myocardium; however, it is not known whether or not mobilization of BMCs is involved in the pathogenesis of acute viral myocarditis (VMC). Thus, we analyzed the expression of CD45+CD34+VLA-4+ cells and vascular cell adhesion protein-1 (VCAM-1) in a murine model of acute VMC.

METHODS

Male BALB/c mice were intraperitoneally infected with coxsackievirus B3 to establish acute VMC. The frequency of CD45+CD34+VLA-4+ cells in the heart, peripheral blood, and bone marrow was examined by flow cytometry 3, 7, 14, and 28 days after injection. Cardiac VCAM-1 and pathology scores were determined by immunohistochemistry, and myocardial VCAM-1, IL-1β, and TNF-α were analyzed by RT-PCR and Western blot.

RESULTS

In mice with acute VMC, the CD45+CD34+VLA-4+ cell population in the heart was significantly increased by day 7 and then decreased; in contrast, the CD45+CD34+VLA-4+ cell population decreased in the bone marrow and peripheral blood by day 3 and then increased. High expression of VCAM-1 was detected in the heart in parallel with CD45+CD34+VLA-4+ cell expression.

CONCLUSIONS

In mice with acute VMC, VCAM-1-induced CD45+CD34+VLA-4+ cell mobilization into the injured heart is involved in the repair of injured myocardium.