ELEVATED LEVEL OF URIC ACID, BUT NOT GLUCOSE, IN AQUEOUS HUMOR AS A RISK FACTOR FOR DIABETIC MACULAR EDEMA IN PATIENTS WITH TYPE 2 DIABETES.

PURPOSE: To determine the association of uric acid (UA) and glucose in aqueous humor with diabetic macular edema (DME) in patients with Type 2 diabetes. METHODS: Patients with DME or diabetes mellitus without retinopathy were enrolled from August 2016 to December 2020. Nondiabetic patients with age-related cataract or age-related macular degeneration were included as controls. RESULTS: A total of 585 eyes from 585 patients were included for this study. Statistical analysis showed that aqueous UA was associated with central retinal thickness (r = 0.39, P < 0.0001), with higher levels of UA in severe DME and lower levels in mild DME, suggesting an ocular source of UA from the diabetic retina. Aqueous UA {odds ratio (OR), 6.88 (95% confidence interval [CI], 2.61-18.12)}, but not aqueous glucose (0.95 [95% CI, 0.73-1.23]) or serum UA (0.90 [95% CI, 0.66-1.23]), was a stronger predictor for DME than the duration of DM (1.26 [95% CI, 1.12-1.42]) or hemoglobin A1c (1.35 [95% CI, 0.99-1.83]). If aqueous UA (<2.46 mg/dL) and aqueous glucose (<6.43 mmol/L) were used as reference, high UA (≥2.46 mg/dL) alone was associated with 5.83-fold increase in risk of DME, but high glucose (≥6.43 mg/dL) alone was not associated with DME. CONCLUSION: Increased aqueous UA, but not glucose, is an independent risk factor for DME. These data suggest that an intravitreal UA-lowering therapy could be beneficial for DME.

[Comparative study of rat serum pharmacochemistry between Puerariae Lobatae Radix and Puerariae Thomsonii Radix based on UPLC-Q-TOF-MS].

UPLC-Q-TOF-MS and serum pharmacochemistry were employed to study the migrating components in rat sera after intragastric administration of the water extracts of Puerariae Lobatae Radix(PLR) and Puerariae Thomsonii Radix(PTR). After the respective intragastric administration of PLR and PTR extracts, blood samples were collected from the orbital vein. The serum samples were treated by protein precipitation method with methanol and acetonitrile at a ratio of 1∶1 and then passed through Agilent ZORBAX RRHD SB-C_(18) column(3 mm×100 mm, 1.8 µm) and Agilent SB-C_(18) pre-column(3 mm×5 mm, 1.8 µm) with 0.1% formic acid aqueous solution(A)-acetonitrile(B) as the mobile phase. The elution was performed at the flow rate of 0.25 mL·min~(-1), the column temperature of 40 ℃, and the injection volume of 2 µL. By comparison of the total ion chromatogram and secondary fragment ion information of PLR and PTR water extracts, PLR-and PTR-containing sera, and blank serum, we found 42 migrating components(including 17 prototype components and 25 metabolites) in the sera of rats treated with PLR and 35 migrating components(including 15 prototype components and 20 metabolites) in the sera of rats treated with PTR. Thirty-three common components were shared by the two treatments, including 13 prototype components and 20 metabolites. The differences of migrating components in the PLR-and PTR-treated rat sera provide a scientific basis for further study of the active components and quality markers of PLR and PTR.

[Quality evaluation of Dalbergiae Odoriferae Lignum by HPLC fingerprint and multi-component quantitative analysis].

The present study detected the component content in Dalbergiae Odoriferae Lignum by HPLC fingerprint and the multi-component determination method. HPLC analysis was performed on the Agilent ZORBAX SB-C_(18) column(4.6 mm×250 mm, 5 µm). Acetonitrile-0.5% phosphoric acid aqueous solution with gradient elution was employed as the mobile phase. The flow rate was 1.0 mL·min~(-1) and the column temperature was maintained at 30 ℃. The detection wavelength was 210 nm and the sample volume was 10 µL. The similarity of 18 batches of Dalbergiae Odoriferae Lignum was 0.343-0.779, indicating that there were great differences between different batches of Dalbergiae Odoriferae Lignum. Eighteen common peaks were identified, including eight flavonoids such as liquiritigenin and latifolin. The mass fractions of liquiritigenin, luteolin, naringenin, isoliquiritigenin, formononetin, dalbergin, latifolin, and pinocembrin were in the ranges of 0.134 1%-0.495 2%, 0.028 2%-0.167 0%, 0.016 3%-0.591 3%, 0.053 5%-0.188 0%, 0.142 4%-0.640 1%, 0.068 0%-0.590 7%, 0.003 2%-1.980 7%, and 0.009 6%-0.740 2%, respectively. Eighteen batches of Dalbergiae Odoriferae Lignum were divided into three categories by cluster analysis and eight differential components in Dalbergiae Odoriferae Lignum were marked by partial least-squares discriminant analysis(PLS-DA). The cumulative variance contribution rate was 90.5%. The HPLC fingerprint combined with the multi-component determination method for Dalbergiae Odoriferae Lignum is easy in operation and accurate in results, with good repeatability and reliability. The quality of Dalbergiae Odoriferae Lignum can be evaluated and analyzed by the PLS-DA model. This study is expected to provide a reference for the quality control and clinical application of Dalbergiae Odoriferae Lignum.

Interrelationships Between Oxidative Stress, Cytokines, and Psychotic Symptoms and Executive Functions in Patients With Chronic Schizophrenia.

OBJECTIVE: Accumulating evidence has demonstrated that the pathophysiology of schizophrenia is involved in various abnormalities in oxidative stress markers and cytokines closely related to synaptic plasticity. However, the interactive effects among key cytokines, oxidative stress, and executive dysfunction and symptoms of schizophrenia have not been investigated yet. METHODS: A total of 189 patients with chronic schizophrenia and 60 controls were recruited in the current study. Tumor necrosis factor α (TNF-α), interleukin (IL)-8, IL-6, and IL-2 levels; catalase, glutathione peroxidase, and superoxide dismutase (SOD) activities; and malondialdehyde (MDA) levels were determined in patients and controls. Executive function was evaluated by the Wisconsin card sorting tests, the verbal fluency tests, and the Stroop word-color test. Clinical symptoms were evaluated by the Positive and Negative Syndrome Scale. RESULTS: Relative to the controls, the patients had lower activities of SOD and glutathione peroxidase and levels of TNF-α, but higher levels of MDA, IL-8, IL-6, and IL-2 (all p values < .05). A significant negative relationship between SOD activity and IL-8 levels was found only in patients (ß = -0.44, p = .008). Furthermore, we found that an interactive effect of low TNF-α level and high MDA level was associated with negative symptoms (ß = -0.02, p = .01). Moreover, the interactive effects of IL-8 and MDA or IL-8 and SOD were correlated with executive function only in patients (ß = 0.23, p = .02; ß = 0.09, p = .03). CONCLUSIONS: Our findings suggest that the interrelationships between oxidative stress markers and cytokines occur in schizophrenia patients, which may be the basis of their pathological mechanisms underlying clinical symptoms and cognitive dysfunction.

Identification of retinal thickness and blood flow in age-related macular degeneration with reticular pseudodrusen.

AIM: To investigate thickness characteristics and vascular plexuses in retinas with reticular pseudodrusen (RPD) as an early detection strategy for age-related macular degeneration (AMD). METHODS: This retrospective study included 24 subjects (33 eyes) with RPD and 25 heathy control subjects (34 eyes). The superficial capillary plexus (SCP) and the deep capillary plexus (DCP) of the retinal posterior poles were investigated with optical coherence tomography angiography (OCTA). Retinal thicknesses and vessel densities were analyzed statistically. RESULTS: The general retinal thicknesses of RPD eyes were significantly decreased (95%CI -14.080, -0.655; P=0.032). The vessel densities of DCP in RPD eyes were significantly increased in the global (95%CI 1.067, 7.312; P=0.027), parafoveal (95%CI 0.417, 5.241; P=0.022), and perifoveal (95%CI 0.181, 6.842; P=0.039) quadrants. However, the vessel densities of the SCP were rarely increased in the eyes with RPD. CONCLUSION: The thinning of retinas in the RPD group suggests a reduction in the number of cells. Additionally, the increased vessel density of the DCP in retinas with RPD indicates a greater demand for blood supply, possibly due to the hypoxia induced RPD compensation caused by RPD in the outer retina. This study highlights the pathological risks associated with RPD and emphasizes the importance of early intervention to retard the progression of AMD.

Phosphomannopentaose sulfate (PI-88) suppresses angiogenesis by downregulating heparanase and vascular endothelial growth factor in an oxygen-induced retinal neovascularization animal model.

PURPOSE: Vascular endothelial growth factor (VEGF) is the most potent angiogenic mitogen, and has been associated with angiogenesis. Heparanase is an endoglycosidase that specifically cleaves heparan sulfate side chains, which can induce VEGF expression. The aims of the present study were to evaluate the heparanase expression and its relationship with VEGF in the retina of oxygen-induced retinopathy (OIR) mice, and to investigate the effect of the heparanase inhibitor phosphomannopentaose sulfate (PI-88) in the OIR retinas. METHODS: Seventy-seven newborn C57BL/6 mice were involved in this study. On postnatal day 7 (P7), pups were exposed to a hyperoxia condition (75% oxygen) for 5 days, and on P12, the mice were returned to room air. Control mice were exposed to room air from birth until P17, with normally developing retinal vasculature. PI-88 was administered intraperitoneally to OIR mice at a dose of 35.7 mg/kg/day for 5 consecutive days. The expression level of heparanase and VEGF in the retinas was assayed using immunohistochemistry, Q-RT-PCR, and western blot. RESULTS: The expression levels of heparanase and VEGF were increased in the OIR retinas compared with the control mice. The Q-RT-PCR results showed that the mRNA expression levels of heparanase and VEGF in OIR retina were increased 1.71 fold (p<0.0001) and 4.34 fold (p<0.0001), respectively. The western blot results showed that the protein expression levels of heparanase and VEGF were increased 1.49 fold (p<0.0001) and 1.72 fold (p<0.0001), respectively, in the OIR retinas compared with the normal retinas. The immunohistochemistry analysis revealed that the heparanase and VEGF signals were intense in the retinal vascular endothelia of the OIR mice but faint in those of the normal controls. The increased protein and mRNA expression levels of heparanase and VEGF in the mouse retinas were significantly decreased by PI-88 administration (p<0.0001). CONCLUSIONS: Heparanase expression was upregulated and correlated with an increase in VEGF expression in the OIR mouse retinas, and might be involved in the progress of retinopathy of prematurity. Inhibition of heparanase expression by PI-88 could be used as a novel therapeutic method for retinopathy of prematurity.

Absence of ephrin-A2/A3 increases retinal regenerative potential for Müller cells in Rhodopsin knockout mice.

Müller cells (MC) are considered dormant retinal progenitor cells in mammals. Previous studies demonstrated ephrin-As act as negative regulators of neural progenitor cells in the retina and brain. It remains unclear whether the lack of ephrin-A2/A3 is sufficient to promote the neurogenic potential of MC. Here we investigated whether the MC is the primary retinal cell type expressing ephrin-A2/A3 and their role on the neurogenic potential of Müller cells. In this study, we showed that ephrin-A2/A3 and their receptor EphA4 were expressed in retina and especially enriched in MC. The level of ephrinAs/EphA4 expression increased as the retina matured that is correlated with the reduced proliferative and progenitor cell potential of MC. Next, we investigated the proliferation in primary MC cultures isolated from wild-type and A2-/- A3-/- mice by 5-ethynyl-2'-deoxyuridine (EdU) incorporation. We detected a significant increase of EdU+ cells in MC derived from A2-/- A3-/- mice. Next, we investigated the role of ephrin-A2/A3 in mice undergoing photoreceptor degeneration such as Rhodopsin knockout (Rho-/-) mice. To further evaluate the role of ephrin-A2/A3 in MC proliferation in vivo, EdU was injected intraperitoneally to adult wild-type, A2-/- A3-/- , Rho-/- and Rho-/- A2-/- A3-/- mice and the numbers of EdU+ cells distributed among different layers of the retina. EphrinAs/EphA4 expression was upregulated in the retina of Rho-/- mice compared to the wild-type mice. In addition, cultured MC derived from ephrin-A2-/- A3-/- mice also expressed higher levels of progenitor cell markers and exhibited higher proliferation potential than those from wild-type mice. Interestingly, we detected a significant increase of EdU+ cells in the retinas of adult ephrin-A2-/- A3-/- mice mainly in the inner nuclear layer; and these EdU+ cells were co-localized with MC marker, cellular retinaldehyde-binding protein, suggesting some proliferating cells are from MC. In Rhodopsin knockout mice (Rho-/- A2-/- A3-/- mice), a significantly greater amount of EdU+ cells were located in the ciliary body, retina and RPE than that of Rho-/- mice. Comparing between 6 and 12 weeks old Rho-/- A2-/- A3-/- mice, we recorded more EdU+ cells in the outer nuclear layer in the 12-week-old mice undergoing severe retinal degeneration. Taken together, Ephrin-A2/A3 are negative regulators of the proliferative and neurogenic potentials of MC. Absence of ephrin-A2/A3 promotes the migration of proliferating cells into the outer nuclear layer and may lead to retinal cell regeneration. All experimental procedures were approved by the Animal Care and Use Committee at Schepens Eye Research Institute, USA (approval No. S-353-0715) on October 24, 2012.

Increased Expression of Growth Hormone-Releasing Hormone in Fibrinous Inflammation of Proliferative Diabetic Retinopathy.

PURPOSE: To investigate the involvement of growth hormone-releasing hormone (GHRH) - growth hormone (GH) signaling in pathogenesis of proliferative diabetic retinopathy (PDR). DESIGN: Experimental laboratory study. METHODS: Vitreous humor, aqueous humor, and serum were obtained from 36 eyes of 36 patients with or without type 2 diabetes from 2017 to 2019. For histologic examination, 6 fibrovascular membranes were excised from eyes with active PDR. Three fibrovascular membranes were excised from nondiabetic patients with proliferative vitreoretinopathy (PVR) as controls. RESULTS: In PDR, the fibrovascular tissues consisted of a mature region containing fibrocytes, and an immature region populated by abundant polymorphonuclear leukocytes in a fibrinogen meshwork. Clusters of leukocytes were found adhering to the vascular walls. In PVR, no fibrinogen and polymorphonuclear leukocyte was observed in the fibrovascular membranes. The levels of GHRH and GH in PDR were significantly increased (P < .001), with 1.8-fold and 72.8-fold in vitreous humor, and 2-fold and 4.9-fold in aqueous humor, respectively, when compared with corresponding levels in controls. No significant difference was detected for insulin-like growth factor-1. Immunohistochemistry showed intense expression of GHRH and its receptor GHRH-R in polymorphonuclear leukocytes, vascular endothelial cells, and fibrocytes in fibrovascular membranes of PDR. GHRH staining was not detectable in infiltrating cells within the fibrovascular membrane of PVR. CONCLUSIONS: These findings reveal a possible involvement of GHRH/GHRH-R in fibrinous inflammation that might contribute to the formation of fibrovascular membrane in PDR through mediating activities of leukocytes, vascular endothelial cells, and fibrocytes. Targeting GHRH/GHRH-R may be considered as a potential therapeutic approach for the treatment of PDR.

Protective effects of lipoic acid-niacin dimers against blue light-induced oxidative damage to retinal pigment epithelium cells.

AIM: To evaluate the protective effects of lipoic acid-niacin (N2L) dimers against blue light (BL)-induced oxidative damage to human retinal pigment epithelium (hRPE) cells in vitro. METHODS: hRPE cells were divided into a control group (CG), a BL group, an N2L plus BL irradiation group, an α-lipoic acid (ALA) plus BL group, an ALA-only group, and an N2L-only group. hRPE cellular viability was detected by performing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) bromide assays, and apoptosis was evaluated by annexin-V-PE/7-AAD staining followed by flow cytometry. Ultrastructural changes in subcellular organelles were observed by transmission electron microscopy. Reactive oxygen species formation was assayed by flow cytometry. The expression levels of the apoptosis-related proteins BCL-2 associated X protein (BAX), B-cell leukmia/lymphoma 2 (BCL-2), and caspase-3 were quantified by Western blot analysis. RESULTS: BL exposure with a light density of 4±0.5 mW/cm2 exceeding 6h caused hRPE toxicity, whereas treatment with a high dose of N2L (100 mol/L) or ALA (150 mol/L) maintained cell viability at control levels. BL exposure caused vacuole-like degeneration, mitochondrial swelling, and reduced microvillus formation; however, a high dose of N2L or ALA maintained the ultrastructure of hRPE cells and their organelles. High doses of N2L and ALA also protected hRPE cells from BL-induced apoptosis, which was confirmed by Western blot analysis: BCL-2 expression significantly increased, while BAX and caspase-3 expression slightly decreased compared to the CG. CONCLUSION: High-dose N2L treatment (>100 mol/L) can reduce oxidative damage in degenerating hRPE cells exposed to BL with an efficacy similar to ALA.

Electrophysiological Characteristics in Depressive Personality Disorder: An Event-Related Potential Study.

This study aimed to investigate the neurophysiological characteristics of young people with depressive personality disorder using event-related potentials (ERP). To explore the effects of visual-emotional words on ERP, mainly N350, we recruited 19 individuals with a depressive personality disorder and 10 healthy controls. ERP were recorded while the subjects took decisions on target words that were classified into three categories: emotionally positive, negative, and neutral. The ERP signals were then separately averaged according to the subjects' classifications. Data analysis showed that the amplitude of N350 was larger in response to positive and negative words than to neutral words. The latency of N350 was longer in negative words, in contrast with positive and neutral words. However, no difference was found between the two groups. These results suggest that neurophysiological characteristics of young people with a depressive personality disorder in visual-emotional word processing have not yet been influenced by their personality traits. To some extent, N350 reflected semantic processes and was not sensitive to participants' mood state.