[Advances in the role of extracellular histones in the inflammatory process of liver injury]

Histones are important structural proteins of chromatin in the nucleus, which can regulate gene transcription, and can be released from the nucleus to the outside of the cell under injury and inflammatory stimulations, thereby causing cytotoxicity and immune stimulation, and aggravating tissue damage. Extracellular histones are involved in the occurrence and development of many diseases, including sepsis, autoimmune diseases, liver injury, and acute lung injury. Therefore, its application not only can be used as a body's biomarker of inflammation, but also it is expected to become a molecular target for the treatment of diseases. This article reviews the role of extracellular histones in the inflammatory process of liver injury.

Epigenetic Regulation of Hepatic Stellate Cell Activation and Macrophage in Chronic Liver Inflammation

Chronic liver inflammation is a complex pathological process under different stress conditions, and the roles of stellate cells and macrophages in chronic liver inflammation have been widely reported. Moderate liver inflammation can protect the liver from damage and facilitate the recovery of liver injury. However, an inflammatory response that is too intense can result in massive death of hepatocytes, which leads to irreversible damage to the liver parenchyma. Epigenetic regulation plays a key part in liver inflammation. This study reviews the regulation of epigenetics on stellate cells and macrophages to explore the new mechanisms of epigenetics on liver inflammation and provide new ideas for the treatment of liver disease.

[Current research on cytokine gene single nucleotide polymorphisms of Behcet's syndrome]

Behcet's syndrome (BS) is characterized by systemic vasculitis with unknown etiology. There is evidence that more than one mechanism underlies the pathogenesis of BS, involving genetic factors and environmental stimuli. Although human leucocyte antigen-B51 is by far the most strongly associated genetic factor to BS, it accounts for less than 20% of the genetic risk, which indicates that other genetic factors remain to be discovered. Cytokines are signal molecules of the immune system which modulate the inflammatory process of nearly all immune response. The single nucleotide polymorphism (SNP) of cytokine gene have been associated with BS in many studies, involving T helper cell 1-type cytokines, interleukin 1 cytokine, interleukin 17 and chemotactic cytokine. The impact of different SNPs on BS varies, most of which affect the risk of disease, while the remaining affect the phenotype, the cumulative effect of these minor genes (SNPs) might be the genetic mechanisms of BS pathogenesis. (Chin J Ophthalmol, 2020, 56: 876-880).

Extracellular Histone H3 Induces Pyroptosis During Sepsis and May Act Through NOD2 and VSIG4/NLRP3 Pathways

Background: Histones could be released from the nucleus when stimulated. Increasing evidence has shown that extracellular histones are associated with a variety of inflammation and diseases. Nucleotide binding oligomerzation domain 2 (NOD2) belongs to the NOD like receptor (NLR) family and is reported to promote apoptosis and aggravate inflammatory response. And V-set and immunoglobulin domain containing 4 (VSIG4), a B7 family-related protein, has been confirmed to mediate transcriptional inhibition of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3). However, little is known about the impact of extracellular histones on NOD2 or VSIG4 signal transduction. In this study, we aim to explore the effect and mechanism of extracellular histone H3 on pyroptosis. Aim: The purpose of this work was to investigate the mechanism of extracellular histone H3 on pyroptosis in sepsis. Methods: Lipopolysaccharide (LPS) and histone H3 were used to induce sepsis mice model and damage in ANA-1 macrophages. H3 antibody was applied to antagonize the effect of histone H3. NOD2 inhibitor NOD-IN-1 and VSIG4-siRNA were used to investigate the mechanism of histone H3 on pyroptosis. Enzyme linked immune sorbent assay (ELISA) was applied to detect the level of extracellular histone H3. Real-time PCR and Western blotting were employed to detect the key mRNA and protein levels. The pathology of tissues was detected. Results: The level of extracellular histone H3 was increased after LPS stimulation. The mRNA and protein levels of NLRP3, caspase-1, gasdermin D (GSDMD), interleukin (IL)-1β, IL-18 were increased in LPS group, but suppressed by H3 antibody. And the expression of NOD2, receptor-interacting protein 2 (RIP2) was elevated compared with control group. The expression of VSIG4 was inhibited by LPS and suppression of H3 promoted the protein level of VSIG4. H3 antibody alleviated pathological damages in tissues. Furthermore, the mRNA and protein levels of NOD2 in H3 group was higher compared with control group. The mRNA and protein levels of VSIG4 in H3 group was decreased compared with control group, but up-regulated by NOD-IN-1. Besides, the mRNA and protein levels of VSIG4 in NOD-IN-1 + VSIG4-siRNA group was elevated compared with VSIG4-siRNA group. Conclusions: Extracellular histone H3 induced by LPS could cause pyroptosis during sepsis via NOD2 and VSIG4/NLRP3 pathway.

[Clinical features of glucocorticoid eye drops induced ocular hypertension in pediatric and adult uveitic eyes]

Objective: To investigate the clinical features of glucocorticoid eye drops induced ocular hypertension in pediatric and adult uveitic eyes. Methods: Retrospective survey of consecutive uveitic patients attending referral service at Peking Union Medical College Hospital from March 2013 to August 2017. Incidences of glucocorticoid eye drops induced ocular hypertension were compared between the pediatric and adult uveitic groups. The clinical patterns of 1% prednisolone acetate eye drops induced ocular hypertension in pediatric and adult uveitic eyes were also investigated. Data were analyzed using the Mann-Whitney test and the χ(2) test. Results: The clinical data of 1 138 uveitic eyes [677 patients; 331 males and 346 females; mean age (31±16) years]receiving corticosteroid eye drops were reviewed, among which 246 eyes (143 patients) had pediatric uveitis and 892 eyes (534 patients) had adult uveitis. The incidence of glucocorticoid eye drops induced ocular hypertension was higher in pediatric eyes (39.8%, 98/246) as compared to adults (29.1%, 260/892) (χ(2)=9.880, P=0.002). One hundred and thirty eyes (75 patients) with 1% prednisolone acetate induced ocular hypertension were included in the clinical pattern analysis, including 49 [28 patients; 15 males and 13 females; mean age (11±3) years] pediatric and 81 [47 patients; 22 males and 25 females;mean age (34±12) years] adult uveitic eyes. No differences were found in daily doses of 1% prednisolone acetate between the pediatric group [4.60 (3.46, 5.36) drops/day] and the adult group [4.00 (3.30, 4.88) drops/day; Z=-1.675, P=0.094]. But the duration of medication in pediatric eyes [4.71 (2.79, 6.36) weeks] was significantly shorter as compared to the adults [6.00 (4.86, 9.00) weeks; Z=-3.446, P<0.001]. The intraocular pressure (IOP) was 26.00 (24.00, 31.00) mmHg (1 mmHg=0.133 kPa) in pediatric uveitic eyes and 26.00 (23.30, 31.15) mmHg in the adults, which showed no statistical significance (Z=-0.231,P=0.818). To achieve effective IOP control, 79.6% (39/49) of pediatric and 54.3% (44/81) of adult eyes received IOP-lowering drug therapy (χ(2)=8.447,P=0.004). And during the follow-up, the withdrawal rate of IOP-lowering drugs was much lower in pediatric eyes (48.7%, 19/39) as compared to the adult group (72.7%, 32/44) (χ(2)=5.031, P=0.025). Conclusion: Compared with adult patients with uveitis, children with uveitis are more prone to IOP elevation, which is more difficult to control after the use of glucocorticoid eye drops. (Chin J Ophthalmol, 2018, 54: 839-842).