The interplay of oxidative stress and ARMS2-HTRA1 genetic risk in neovascular AMD

Age-related macular degeneration (AMD) is the leading cause of vision loss in adults over 60 years old globally. There are two forms of advanced AMD: “dry” and “wet”. Dry AMD is characterized by geographic atrophy of the retinal pigment epithelium and overlying photoreceptors in the macular region; whereas wet AMD is characterized by vascular penetrance from the choroid into the retina, known as choroidal neovascularization (CNV). Both phenotypes eventually lead to loss of central vision. The pathogenesis of AMD involves the interplay of genetic polymorphisms and environmental risk factors, many of which elevate retinal oxidative stress. Excess reactive oxygen species react with cellular macromolecules, forming oxidation-modified byproducts that elicit chronic inflammation and promote CNV. Additionally, genome-wide association studies have identified several genetic variants in the age-related maculopathy susceptibility 2/high-temperature requirement A serine peptidase 1 (ARMS2-HTRA1) locus associated with the progression of late-stage AMD, especially the wet subtype. In this review, we will focus on the interplay of oxidative stress and HTRA1 in drusen deposition, chronic inflammation, and chronic angiogenesis. We aim to present a multifactorial model of wet AMD progression, supporting HTRA1 as a novel therapeutic target upstream of vascular endothelial growth factor (VEGF), the conventional target in AMD therapeutics. By inhibiting HTRA1’s proteolytic activity, we can reduce pro-angiogenic signaling and prevent proteolytic breakdown of the blood-retina barrier. The anti-HTRA1 approach offers a promising alternative treatment option to wet AMD, complementary to anti-VEGF therapy.

Expressions of IL-1α and MMP-9 in degenerated lumbar disc tissues and their clinical significance

OBJECTIVE

To observe the expression levels of interleukin-1α (IL-1α) and matrix metalloproteinase-9 (MMP-9) in degenerated lumbar disc tissues and to investigate their clinical significance.

PATIENTS AND METHODS

Fifty patients with lumbar disc degeneration received the operative treatment were divided into three groups according to the magnetic resonance imaging (MRI) results: protrusion group, extrusion group, and free group. The degenerated intervertebral disc tissues were taken, and the normal intervertebral disc tissues of 20 patients received the operative treatment due to lumbar bursting fracture, and were selected as the control group. The bone mineral densities of all patients were measured. The mRNA and protein expression levels of MMP-9 and IL-1α were detected via Real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively.

RESULTS

The bone mass of patients with lumbar disc degeneration was significantly decreased compared with that of the control group, and the bone mass was decreased more significantly in a free group than that in protrusion group. The mRNA and protein levels in IL-1α and MMP-9 of patients with lumbar disc degeneration were significantly increased compared with those in control group; the mRNA and protein levels in IL-1α and MMP-9 of extrusion group and free group were significantly higher than those in protrusion group, and the mRNA and protein levels in IL-1α and MMP-9 of free group were significantly higher than those in extrusion group.

CONCLUSIONS

The levels of IL-1α and MMP-9 in degenerated lumbar disc tissues are higher than normal levels, and the increasing levels are positively correlated with the disease condition.

Induced immune tolerance of autoantigen loaded immature dendritic cells in homogenic lupus mice

This study investigated the induced immune tolerance of autoantigen dendritic cells (imDCs) in homogenic lupus mice to support the use of dendritic cell treatment against autoimmune diseases, such as systemic lupus erythematosus. A lupus mouse was used to model based on in vitro cell culture. An immunohistochemistry assay was used to assess CD8(+), CD4(+) cell ratio in mouse spleen cells. The ratio of CD4(+)CD25(+) cells in mouse spleen lymphocytes was detected by flow cytometry, whereas the kidney was directly measured by immunofluorescence. After the injection of mouse antigen loaded bone marrow-derived antigen imDCs with a homogenetic background, mouse nucleoprotein immune with a homogenetic background was carried out. The results were compared against the simple mouse nucleoprotein immune model with a homogenic background. The 24-h urine protein, serum antinuclear antibody and anti-ds-DNA antibodies of the simple mouse model were lower compared to group S1. The CD4(+)CD25(+) cell percentage of spleen was higher in the simple mouse model compared to group S1. In the spleen, the number of lymphocyte CD8(+) cells declined, whereas the number of CD4(+) cells increased. In conclusion, after autoantigen uptake, imDCs are able to induce immune tolerance to the antigen by reinfusion, which appears to prevent or mitigate systemic lupus erythematosus-like illness.