[Evidence mapping of traditional Chinese medicine intervention in diabetic retinopathy].

This study aims to assess the quality of evidence for the treatment of diabetic retinopathy with traditional Chinese medicine based on the systematic reviews/Meta-analyses of relevant studies. CNKI, Wanfang, VIP, SinoMed, PubMed, Web of Science, EMbase, and Cochrane Library were searched for the systematic reviews/Meta-analyses of traditional Chinese medicine interventions in diabetic retinopathy published from the inception to November 2023. A Measurement Tool to Assess Systematic Reviews 2(AMSTAR2) scale was used to assess the methodological quality of the included studies. An evidence map was built to present the information on intervention measures, the number of studies included in the systematic reviews/Meta-analyses, research conclusions, and methodological quality assessment results. A total of 51 studies were included. Traditional Chinese medicine interventions accounted for a large proportion of the intervention measures, followed by Chinese patent medicines. The treatment methods mainly included tonifying deficiency, activating blood, and resolving stasis. According to the AMSTAR2 scale assessment results, the descriptions of funding information for included studies, lists of excluded articles, and preliminary research protocols were particularly lacking. The evidence map showed that 48, 2, and 1 studies concluded with beneficial effects, possible beneficial effects, and unclear effects, respectively. On the whole, traditional Chinese medicine demonstrated definite efficacy in the treatment of diabetic retinopathy, while the evidence pre-sents moderate to low quality. It is suggested that higher-quality studies remain to be carried out to provide more evidence.

Efficacy of Intravitreal Injections Anti-Vascular Endothelial Growth Factor Treatment for Radiation Retinopathy: A Systematic Review and Meta-analysis.

PURPOSE: This study aims to appraise the therapeutic effectiveness of intravitreal injections anti-vascular endothelial growth factor (anti-VEGF) vs alternative therapies in managing radiation retinopathy (RR). DESIGN: Systematic review and meta-analysis. METHODS: We obtained comprehensive data retrieval using PubMed, Embase, Web of Science, Scopus, and the Cochrane Library from their inception until December 15, 2023. This review included randomized controlled trials (RCTs) and nonrandomized studies (NRSs) reporting on best-corrected visual acuity (BCVA) among RR patients treated with intravitreal anti-VEGF. Study selection and data extraction were meticulously performed by 2 independent reviewers. The Cochrane Risk of Bias Tool 2.0 (RoB 2.0) and Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) scales were utilized for bias risk assessment. Quantification of heterogeneity was executed using Q, H, and I2 statistics. The primary endpoint was the BCVA at the final observation point of each study. Secondary endpoints included central retinal thickness (CRT), foveal avascular zone (FAZ) area, and capillary density (CD) at the level of superficial capillary plexus. Subgroup analyses were undertaken to explore potential heterogeneity sources possibly due to treatment duration and study design. Sensitivity analyses were conducted to ascertain result stability. RESULTS: This analysis incorporated 7 studies (including 3 RCTs) encompassing 922 patients afflicted with RR. Relative to other treatment modalities, intravitreal anti-VEGF therapy was associated with a statistically significant mean decrease in BCVA of -0.34 logMAR (95% CI, -0.39 to -0.30 logMAR; I2 = 87.70%; P < .001), and a substantial reduction in CRT of -34.65 µm (95% CI, -50.70 to -18.60 µm; I2 = 30.40%; P < .001). Additionally, a reduction in the FAZ area by -0.69 mm² (95% CI, -0.91 to -0.46 mm², I2 = 0%; P < .001) was observed. A positive tendency was noted in CD at the superficial capillary plexus between anti-VEGF and other therapeutic interventions. CONCLUSIONS: Intravitreal anti-VEGF injections, in comparison to other treatments, demonstrate superior efficacy in enhancing BCVA and reducing CRT, thereby underscoring the potential of anti-VEGF in ameliorating radiation retinopathy outcomes. However, the conclusions are constrained by the incorporation of data from some NRSs and the small sample sizes.

The Molecular Logic of Gtr1/2 and Pib2 Dependent TORC1 Regulation in Budding Yeast.

The Target of Rapamycin kinase Complex I (TORC1) regulates cell growth and metabolism in eukaryotes. Previous studies have shown that, in Saccharomyces cerevisiae, nitrogen and amino acid signals activate TORC1 via the highly conserved small GTPases, Gtr1/2, and the phosphatidylinositol 3-phosphate binding protein, Pib2. However, it was unclear if/how Gtr1/2 and Pib2 cooperate to control TORC1. Here we report that this dual regulator system pushes TORC1 into three distinct signaling states: (i) a Gtr1/2 on, Pib2 on, rapid growth state in nutrient replete conditions; (ii) a Gtr1/2 off, Pib2 on, adaptive/slow growth state in poor-quality growth medium; and (iii) a Gtr1/2 off, Pib2 off, quiescent state in starvation conditions. We suggest that other signaling pathways work in a similar way, to drive a multi-level response via a single kinase, but the behavior has been overlooked since most studies follow signaling to a single reporter protein.

Ait1 regulates TORC1 signaling and localization in budding yeast.

The target of rapamycin complex I (TORC1) regulates cell growth and metabolism in eukaryotes. Previous studies have shown that nitrogen and amino acid signals activate TORC1 via the highly conserved small GTPases, Gtr1/2 (RagA/C in humans), and the GTPase activating complex SEAC/GATOR. However, it remains unclear if, and how, other proteins/pathways regulate TORC1 in simple eukaryotes like yeast. Here, we report that the previously unstudied GPCR-like protein, Ait1, binds to TORC1-Gtr1/2 in Saccharomyces cerevisiae and holds TORC1 around the vacuole during log-phase growth. Then, during amino acid starvation, Ait1 inhibits TORC1 via Gtr1/2 using a loop that resembles the RagA/C-binding domain in the human protein SLC38A9. Importantly, Ait1 is only found in the Saccharomycetaceae/codaceae, two closely related families of yeast that have lost the ancient TORC1 regulators Rheb and TSC1/2. Thus, the TORC1 circuit found in the Saccharomycetaceae/codaceae, and likely other simple eukaryotes, has undergone significant rewiring during evolution.

Ionizing Radiation Upregulates Glutamine Metabolism and Induces Cell Death via Accumulation of Reactive Oxygen Species.

Glutamine metabolism provides energy to tumor cells and also produces reactive oxygen species (ROS). Excessive accumulation of ROS can damage mitochondria and eventually lead to cell death. xCT (SLC7A11) is responsible for the synthesis of glutathione in order to neutralize ROS. In addition, mitophagy can remove damaged mitochondria to keep the cell alive. Ionizing radiation kills tumor cells by causing the accumulation of ROS, which subsequently induces nuclear DNA damage. With this in mind, we explored the mechanism of intracellular ROS accumulation induced by ionizing radiation and hypothesized new methods to enhance the effect of radiotherapy. We used MCF-7 breast cancer cells and HCT116 colorectal cancer cells in our study. The above-mentioned cells were irradiated with different doses of X-rays or carbon ions. Clone formation assays were used to detect cell proliferation, enzyme-linked immunosorbent assay (ELISA) detected ATP, and glutathione (GSH) production, while the expression of proteins was detected by Western blot and quantitative real-time PCR analysis. The production of ROS was detected by flow cytometry, and immunofluorescence was used to track mitophagy-related processes. Finally, BALB/C tumor-bearing nude mice were irradiated with X-rays in order to further explore the protein expression found in tumors with the use of immunohistochemistry. Ionizing radiation increased the protein expressions of ASCT2, GLS, and GLUD in order to upregulate the glutamine metabolic flux in tumor cells. This caused an increase in ATP secretion. Meanwhile, ionizing radiation inhibited the expression of the xCT (SLC7A11) protein and reduced the generation of glutathione, leading to excessive accumulation of intracellular ROS. The mitophagy inhibitor, or knockdown Parkin gene, is able to enhance the ionizing radiation-induced ROS production and increase nucleus DNA damage. This combined treatment can significantly improve the killing effect of radiation on tumor cells. We concluded that ionizing radiation could upregulate the glutamine metabolic flux and enhance ROS accumulation in mitochondria. Ionizing radiation also decreased the SLC7A11 expression, resulting in reduced GSH generation. Therefore, inhibition of mitophagy can increase ionizing radiation-induced cell death.

lncRNA KCNQ1OT1 promotes the proliferation, migration and invasion of retinoblastoma cells by upregulating HIF-1α via sponging miR-153-3p.

It is reported that lncRNA KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) is oncogenic in many cancers. This work aimed at probing into its expression and biological functions in retinoblastoma (RB) as well as its regulatory effects on miR-153-3p and hypoxia-inducible factor-1α (HIF-1α). In our study, RB samples in pair were collected, and quantitative real-time PCR (qRT-PCR) was employed for examining the expression levels of KCNQ1OT1, miR-153-3p and HIF-1α. KCNQ1OT1 short hairpin RNAs were transfected into SO-Rb50 and HXO-RB44 cell to inhibit the expression of KCNQ1OT1. The proliferative activity, colony formation ability and apoptosis were examined through cell counting kit-8 assay, colony formation assays, Transwell assay and flow cytometry, respectively. qRT-PCR and western blot analysis were used for analyzing the changes of miR-153-3p and HIF-1α induced by KCNQ1OT1. The regulatory relationships between miR-153-3p and KCNQ1OT1, miR-153-3p and HIF-1α were examined by dual luciferase reporter gene assay and RNA-binding protein immunoprecipitation assay. The results of our study showed that KCNQ1OT1 expression was markedly enhanced in RB tissue samples, and KCNQ1OT1 knockdown had an inhibitory effect on the proliferation, migration, invasion and viability of RB cells. There were two validated binding sties between KCNQ1OT1 and miR-153-3p, and KCNQ1OT1 negatively regulated the expression of miR-153-3p in RB cells. HIF-1α was a target gene of miR-153-3p, and could be positively regulated by KCNQ1OT1. In conclusion, our study indicates that KCNQ1OT1 can increase the malignancy of RB cells via regulating miR-153-3p/HIF-1α axis.

Alterations of signaling pathways in response to chemical perturbations used to measure mRNA decay rates in yeast.

Assessing variations in mRNA stability typically involves inhibiting transcription either globally or in a gene-specific manner. Alternatively, mRNA pulse-labeling strategies offer a means to calculate mRNA stability without inhibiting transcription. However, key stress-responsive cell signaling pathways, which affect mRNA stability, may themselves be perturbed by the approaches used to measure mRNA stability, leading to artifactual results. Here, we have focused on common strategies to measure mRNA half-lives in yeast and determined that commonly used transcription inhibitors thiolutin and 1,10 phenanthroline inhibit TORC1 signaling, PKC signaling, and partially activate HOG signaling. Additionally, 4-thiouracil (4tU), a uracil analog used in mRNA pulse-labeling approaches, modestly induces P-bodies, mRNA-protein granules implicated in storage and decay of nontranslating mRNA. Thiolutin also induces P-bodies, whereas phenanthroline has no effect. Doxycycline, which controls "Tet On/Tet Off" regulatable promoters, shows no impact on the above signaling pathways or P-bodies. In summary, our data argues that broad-acting transcriptional inhibitors are problematic for determining mRNA half-life, particularly if studying the impacts of the TORC1, HOG, or PKC pathway on mRNA stability. Regulatable promoter systems are a preferred approach for individual mRNA half-life studies, with 4tU labeling representing a good approach to global mRNA half-life analysis, despite modestly inducing P-bodies.

Integrated TORC1 and PKA signaling control the temporal activation of glucose-induced gene expression in yeast.

The growth rate of a yeast cell is controlled by the target of rapamycin kinase complex I (TORC1) and cAMP-dependent protein kinase (PKA) pathways. To determine how TORC1 and PKA cooperate to regulate cell growth, we performed temporal analysis of gene expression in yeast switched from a non-fermentable substrate, to glucose, in the presence and absence of TORC1 and PKA inhibitors. Quantitative analysis of these data reveals that PKA drives the expression of key cell growth genes during transitions into, and out of, the rapid growth state in glucose, while TORC1 is important for the steady-state expression of the same genes. This circuit design may enable yeast to set an exact growth rate based on the abundance of internal metabolites such as amino acids, via TORC1, but also adapt rapidly to changes in external nutrients, such as glucose, via PKA.

Multilayered regulation of TORC1-body formation in budding yeast.

The target of rapamycin kinase complex 1 (TORC1) regulates cell growth and metabolism in eukaryotes. In Saccharomyces cerevisiae, TORC1 activity is known to be controlled by the conserved GTPases, Gtr1/2, and movement into and out of an inactive agglomerate/body. However, it is unclear whether/how these regulatory steps are coupled. Here we show that active Gtr1/2 is a potent inhibitor of TORC1-body formation, but cells missing Gtr1/2 still form TORC1-bodies in a glucose/nitrogen starvation-dependent manner. We also identify 13 new activators of TORC1-body formation and show that seven of these proteins regulate the Gtr1/2-dependent repression of TORC1-body formation, while the remaining proteins drive the subsequent steps in TORC1 agglomeration. Finally, we show that the conserved phosphatidylinositol-3-phosphate (PI(3)P) binding protein, Pib2, forms a complex with TORC1 and overrides the Gtr1/2-dependent repression of TORC1-body formation during starvation. These data provide a unified, systems-level model of TORC1 regulation in yeast.

Genome-Wide Analysis of the TORC1 and Osmotic Stress Signaling Network in Saccharomyces cerevisiae.

The Target of Rapamycin kinase Complex I (TORC1) is a master regulator of cell growth and metabolism in eukaryotes. Studies in yeast and human cells have shown that nitrogen/amino acid starvation signals act through Npr2/Npr3 and the small GTPases Gtr1/Gtr2 (Rags in humans) to inhibit TORC1. However, it is unclear how other stress and starvation stimuli inhibit TORC1, and/or act in parallel with the TORC1 pathway, to control cell growth. To help answer these questions, we developed a novel automated pipeline and used it to measure the expression of a TORC1-dependent ribosome biogenesis gene (NSR1) during osmotic stress in 4700 Saccharomyces cerevisiae strains from the yeast knock-out collection. This led to the identification of 440 strains with significant and reproducible defects in NSR1 repression. The cell growth control and stress response proteins deleted in these strains form a highly connected network, including 56 proteins involved in vesicle trafficking and vacuolar function; 53 proteins that act downstream of TORC1 according to a rapamycin assay--including components of the HDAC Rpd3L, Elongator, and the INO80, CAF-1 and SWI/SNF chromatin remodeling complexes; over 100 proteins involved in signaling and metabolism; and 17 proteins that directly interact with TORC1. These data provide an important resource for labs studying cell growth control and stress signaling, and demonstrate the utility of our new, and easily adaptable, method for mapping gene regulatory networks.

Snf1/AMPK promotes the formation of Kog1/Raptor-bodies to increase the activation threshold of TORC1 in budding yeast.

The target of rapamycin complex I (TORC1) regulates cell growth and metabolism in eukaryotes. Previous studies have shown that nitrogen and amino acid signals activate TORC1 via the small GTPases, Gtr1/2. However, little is known about the way that other nutrient signals are transmitted to TORC1. Here we report that glucose starvation triggers disassembly of TORC1, and movement of the key TORC1 component Kog1/Raptor to a single body near the edge of the vacuole. These events are driven by Snf1/AMPK-dependent phosphorylation of Kog1 at Ser 491/494 and two nearby prion-like motifs. Kog1-bodies then serve to increase the threshold for TORC1 activation in cells that have been starved for a significant period of time. Together, our data show that Kog1-bodies create hysteresis (memory) in the TORC1 pathway and help ensure that cells remain committed to a quiescent state under suboptimal conditions. We suggest that other protein bodies formed in starvation conditions have a similar function.

State transitions in the TORC1 signaling pathway and information processing in Saccharomyces cerevisiae.

TOR kinase complex I (TORC1) is a key regulator of cell growth and metabolism in all eukaryotes. Previous studies in yeast have shown that three GTPases-Gtr1, Gtr2, and Rho1-bind to TORC1 in nitrogen and amino acid starvation conditions to block phosphorylation of the S6 kinase Sch9 and activate protein phosphatase 2A (PP2A). This leads to downregulation of 450 Sch9-dependent protein and ribosome synthesis genes and upregulation of 100 PP2A-dependent nitrogen assimilation and amino acid synthesis genes. Here, using bandshift assays and microarray measurements, we show that the TORC1 pathway also populates three other stress/starvation states. First, in glucose starvation conditions, the AMP-activated protein kinase (AMPK/Snf1) and at least one other factor push the TORC1 pathway into an off state, in which Sch9-branch signaling and PP2A-branch signaling are both inhibited. Remarkably, the TORC1 pathway remains in the glucose starvation (PP2A inhibited) state even when cells are simultaneously starved for nitrogen and glucose. Second, in osmotic stress, the MAPK Hog1/p38 drives the TORC1 pathway into a different state, in which Sch9 signaling and PP2A-branch signaling are inhibited, but PP2A-branch signaling can still be activated by nitrogen starvation. Third, in oxidative stress and heat stress, TORC1-Sch9 signaling is blocked while weak PP2A-branch signaling occurs. Together, our data show that the TORC1 pathway acts as an information-processing hub, activating different genes in different conditions to ensure that available energy is allocated to drive growth, amino acid synthesis, or a stress response, depending on the needs of the cell.

Inositol pyrophosphates regulate cell growth and the environmental stress response by activating the HDAC Rpd3L.

Cells respond to stress and starvation by adjusting their growth rate and enacting stress defense programs. In eukaryotes this involves inactivation of TORC1, which in turn triggers downregulation of ribosome and protein synthesis genes and upregulation of stress response genes. Here we report that the highly conserved inositol pyrophosphate (PP-IP) second messengers (including 1-PP-IP5, 5-PP-IP4, and 5-PP-IP5) are also critical regulators of cell growth and the general stress response, acting in parallel with the TORC1 pathway to control the activity of the class I histone deacetylase Rpd3L. In fact, yeast cells that cannot synthesize any of the PP-IPs mount little to no transcriptional response to osmotic, heat, or oxidative stress. Furthermore, PP-IP-dependent regulation of Rpd3L occurs independently of the role individual PP-IPs (such as 5-PP-IP5) play in activating specialized stress/starvation response pathways. Thus, the PP-IP second messengers simultaneously activate and tune the global response to stress and starvation signals.

Metabolomics study of diabetic retinopathy using gas chromatography-mass spectrometry: a comparison of stages and subtypes diagnosed by Western and Chinese medicine.

Diabetic retinopathy (DR) is a serious microvascular syndrome of diabetes, and is one of the most frequent causes of blindness in the world. It has three progressive stages with complex metabolic deregulations in the holistic system of Western medicine. Chinese medicine classifies DR into two different syndrome types; integrating Western and Chinese medicine to treat DR is a validated therapeutic approach in China. In this research, the systemic metabolite change of DR was investigated from the viewpoint of both Western and Chinese medicine, using metabolomics based on gas chromatography-mass spectrometry. The data revealed both perspectives can reflect the metabolic patterns, development and differentiation of DR, and the data also had good correlation and complementarity in characterizing the process of DR. Potential biomarkers of DR based on the two perspectives indicated the alterative modes of metabolites and metabolic pathways in the disease, e.g. the disturbance in fatty acids, amino acids and glucose, etc. The results showed the usefulness and validity of combining both Western and Chinese medicine to study the subtypes of DR and the mechanisms involved.

Functional characterization of cis-acting elements mediating flavone-inducible expression of CYP321A1.

How plant allelochemicals elicit herbivore counterdefense genes remains largely unknown. To define the cis-acting elements for flavone inducibility of the allelochemical-metabolizing CYP321A1 from Helicoverpa zea, functions of varying length of CYP321A1 promoter are examined in H. zea fatbody cells. Progressive 3' deletions reveal presence of positive elements in the 5' untranslated region (UTR). Progressive 5' deletions map out regions of one essential element, four enhancers, and two silencers. Further progressive 5'deletions localize the essential element to a 36-bp region from -109 to -74. This essential element, designated as xenobiotic response element to flavone (XRE-Fla), contains a 5' AT-only TAAT inverted repeat, a GCT mirror repeat and a 3' antioxidant response element-like element. Internal deletions and substitution mutations show that the TAAT repeat is only necessary for the maximal flavone inducibility, whereas the other two components are necessary for the basal and flavone-induced expression of CYP321A1. Electrophoresis mobility shift assays demonstrate that XRE-Fla specifically binds to H. zea fatbody cell nuclear extracts and flavone treatment increases the nuclear concentrations of the yet-to-be characterized transcription factors binding to XRE-Fla. Taken together, CYP321A1 expression is regulated primarily by XRE-Fla and secondarily by other cis elements scattered in its promoter and 5' UTR.

Effect of qiming granule on retinal blood circulation of diabetic retinopathy: a multicenter clinical trial.

OBJECTIVE: To objectively assess the effect of Qiming Granule in the treatment of diabetic retinopathy (DR) by fluorescence fundus angiography (FFA). METHODS: In a multi-center, randomized, parallel controlled clinical trial, patients with DR were randomly assigned to the control group (calcium dobesilate capsule) and the test group (Qiming Granule). Changes in the retinal blood circulation time were recorded by FFA after 3 months of medication. RESULTS: Significant reduction was observed in the retinal arterio-venous circulation time (AVCT) in both groups (P<0.01), the value was 7.635+/-3.149 s before treatment and 5.165 +/-3.382 s after treatment in the treated group, and 7.737+/-3.413 s and 5.313+/-3.472 s in the control group respectively. Qiming Granule also reduced the arm-to-retinal circulation time (ARCT, P<0.05). The value was 17.867+/-3.872 s before treatment and 15.643+/-4.648 s after treatment in the treated group, and 17.217+/-3.833 s and 16.312+/-3.613 s in the control group (P>0.05) respectively. The ARCT in the tested group was reduced, with a statistically significant difference post-medication (P<0.01). CONCLUSION: As a Chinese medicine complex prescription, Qiming Granule may alleviate retinal hypoxia and ischemia by increasing retinal blood flow and improving the blood circulation.