Transcriptome and small RNA analysis unveils novel insights into the C4 gene regulation in sugarcane.

MAIN CONCLUSION: This study reveals miRNA indirect regulation of C4 genes in sugarcane through transcription factors, highlighting potential key regulators like SsHAM3a. C4 photosynthesis is crucial for the high productivity and biomass of sugarcane, however, the miRNA regulation of C4 genes in sugarcane remains elusive. We have identified 384 miRNAs along the leaf gradients, including 293 known miRNAs and 91 novel miRNAs. Among these, 86 unique miRNAs exhibited differential expression patterns, and we identified 3511 potential expressed targets of these differentially expressed miRNAs (DEmiRNAs). Analyses using Pearson correlation coefficient (PCC) and Gene Ontology (GO) enrichment revealed that targets of miRNAs with positive correlations are integral to chlorophyll-related photosynthetic processes. In contrast, negatively correlated pairs are primarily associated with metabolic functions. It is worth noting that no C4 genes were predicted as targets of DEmiRNAs. Our application of weighted gene co-expression network analysis (WGCNA) led to a gene regulatory network (GRN) suggesting miRNAs might indirectly regulate C4 genes via transcription factors (TFs). The GRAS TF SsHAM3a emerged as a potential regulator of C4 genes, targeted by miR171y and miR171am, and exhibiting a negative correlation with miRNA expression along the leaf gradient. This study sheds light on the complex involvement of miRNAs in regulating C4 genes, offering a foundation for future research into enhancing sugarcane's photosynthetic efficiency.

Engaging learners in synchronous online learning.

Engagement is positively correlated with many educational outcomes. However, engaging learners in online learning is often challenging. In this study, a conceptual framework comprising five interrelated factors (instructors, learners, content, technology, and environments) was proposed. The purpose of the study was to explore how learners could be engaged by following the conceptual framework in synchronous online learning. Fifty-five adult learners took part in the study. Specific strategies were applied in four classes. A survey with 38 five-point Likert scale items and an open-ended question was administered. Quantitative and qualitative data were collected and analysed. Results showed that instructors, learners, and content were the core factors affecting learners' engagement. Comparatively, the learners' engagement was less affected by the factors of technology and environments. Results further showed that useful strategies to engage learners included providing opportunities for instructors and peers to interact frequently; having relevant content that could apply to practice; involving interactive activities like group discussions and peer feedback; and having informal conversations with individual learners. This study suggests that future studies can investigate facilitating synchronous online discussions, establishing social connectedness, and using technology to monitor learners' engagement automatically.

Alpha-1-antichymotrypsin as a novel biomarker for diagnosis, prognosis, and therapy prediction in human diseases.

The glycoprotein alpha-1-antichymotrypsin (AACT), a serine protease inhibitor, is mainly synthesized in the liver and then secreted into the blood and is involved in the acute phase response, inflammation, and proteolysis. The dysregulation of AACT and its glycosylation levels are associated with tumor progression and recurrence, and could be used as a biomarker for tumor monitoring. In this review, we summarized the expression level, glycosylation modification, and biological characteristics of AACT during inflammation, neurodegenerative or other elderly diseases, and tumorigenesis, as well as, focused on the biological roles of AACT in cancer. The aberrant expression of AACT in cancer might be due to genetic alterations and/or immune by bioinformatics analysis. Moreover, AACT may serve as a diagnostic or prognostic biomarker or therapeutic target in tumors. Furthermore, we found that the expression of AACT was associated with the overall survival of patients with human cancers. Decreased AACT expression was associated with poor survival in patients with liver cancer, increased AACT expression was associated with shorter survival in patients with pancreatic cancer, and decreased AACT expression was associated with shorter survival in patients with early lung cancer. The review confirmed the key roles of AACT in tumorigenesis, suggesting that the glycoprotein AACT may serve as a biomarker for tumor diagnosis and prognosis, and could be a potential therapeutic target for human diseases.

Gata3 Silencing Is Involved in Neuronal Differentiation and Its Abnormal Expression Impedes Neural Activity in Adult Retinal Neurocytes.

GATA binding protein 3 (Gata3), a zinc-finger transcription factor, plays an important role in neural development. However, its expression and bioactivity in the retina remain unclear. In the present study, our data indicated that Gata3 maintains the precursor state of 661W cells, and Gata3 silencing induces cell differentiation. The expression of Nestin, a marker of precursor cells, was significantly decreased in parallel, whereas the expression of Map2, a marker of differentiated neurons, was significantly increased following the decrease in Gata3. Neurite outgrowth was increased by 2.78-fold in Gata3-silenced cells. Moreover, Gata3 expression generally paralleled that of Nestin in developing mouse retinas. Both Gata3 and Nestin were expressed in the retina at postnatal day 1 and silenced in the adult mouse retina. Exogenous Gata3 significantly inhibited the neural activity of primary retinal neurocytes (postnatal day 1) by decreasing synaptophysin levels, neurite outgrowth, and cell viability. Furthermore, in vivo, exogenous Gata3 significantly induced apoptosis and the contraction of retinal outlay filaments and decreased the a- and b-waves in adult mouse intravitreal injected with AAV-Re-Gata3-T2A-GFP. Thus, Gata3 silencing promotes neuronal differentiation and neurite outgrowth. Its abnormal expression impedes neural activity in adult retinal neurocytes. This study provides new insights into Gata3 bioactivity in retinal neurocytes.

Brca1 Is Regulated by the Transcription Factor Gata3, and Its Silencing Promotes Neural Differentiation in Retinal Neurons.

Previous studies have indicated that Brca1 (Breast cancer suppressor gene 1) plays an important role in neural development and degenerative diseases. However, the bioactivity and regulatory mechanism of Brca1 expression in retinal neurocytes remain unclear. In the present study, our data indicated that Brca1 maintains the state of neuronal precursor cells. Brca1 silencing induces differentiation in 661W cells. Nestin, a marker of precursor cells, was significantly decreased in parallel with Brca1 silencing in 661W cells, whereas Map2 (Microtubule associated protein 2), a marker of differentiated neurons, was significantly increased. Neurite outgrowth was increased by ~4.0-fold in Brca1-silenced cells. Moreover, DNA affinity purification assays and ChIP assays demonstrated that Gata3 (GATA binding protein 3) regulates Brca1 transcription in 661W cells. Silencing or overexpressing Gata3 could significantly regulate the expression of Brca1 and affect its promoter inducibility. Furthermore, the expression of Gata3 generally occurred in parallel with that of Brca1 in developing mouse retinas. Both Gata3 and Brca1 are expressed in the neonatal mouse retina but are developmentally silenced with age. Exogenous Gata3 significantly inhibited neural activity by decreasing synaptophysin and neurite outgrowth. Thus, this study demonstrated that Brca1 is transcriptionally regulated by Gata3. Brca1/Gata3 silencing is involved in neuronal differentiation and maturation.

Brca1 Is Upregulated by 5-Aza-CdR and Promotes DNA Repair and Cell Survival, and Inhibits Neurite Outgrowth in Rat Retinal Neurons.

Previous studies have reported that Brca1 acts as a “hinge” in the development of the central nervous system (CNS). However, the precise role of Brca1 in rat retinal neurons remains unclear. Here, we found that Brca1 is developmentally downregulated and silenced in adult retina. Brca1 was upregulated in rat primary retinal neurons by 5-Aza-2′-deoxycytidine (5-Aza-CdR) treatment. Moreover, the upregulation of Brca1 by both 5-Aza-CdR and transgenic Brca1 promoted genomic stability and improved cell viability following exposure to ionizing radiation (IR). Furthermore, transgenic Brca1 significantly inhibited neurite outgrowth of retinal neurons, which implicates that Brca1 silencing promotes cell differentiation and determines neuronal morphology. Taken together, our results reveal a biological function of Brca1 in retinal development.

Discordant mRNA and protein expression of CXCR4 under in vitro CoCl2-induced hypoxic conditions.

Cobalt chloride (CoCl2) has long been accepted as a suitable in vitro hypoxia-mimetic agent. The gene CXCR4, which encodes a chemokine receptor, plays a key role in hypoxic retinal disease. Here, we investigated the mRNA and protein expression of CXCR4 in WERI-Rb1 retinoblastoma cells and human umbilical vein endothelial cells (HUVECs) under CoCl2-induced hypoxic conditions, by means of real-time PCR and western blot. We found that CoCl2-induced hypoxia profoundly increased CXCR4 expression at the mRNA level, but not at the protein level, at 12, 24, 48 and 72 h in these cells. Interestingly, this result differed from observations of 1% O2 hypoxic conditions. Additionally, luciferase assays demonstrated that CoCl2-induced hypoxia significantly increased transcription at the CXCR4 promoter. In order to compare our in vitro findings with the effects of hypoxia in vivo, an OIR (Oxygen-induced retinopathy) rat model was constructed. However, both CXCR4 mRNA and protein levels in OIR rats were significantly increased compared to controls. Thus taken together, our findings suggest that the relationship between CXCR4 mRNA and protein expression is not strictly linear under in vitro CoCl2-induced hypoxic conditions. through comparative in vitro and in vivo experiments, this study implies that CoCl2 is an imperfect simulation of hypoxia in retinal disease.

Tunnel and underground engineering rock mass water inrush damage and acoustic emission characteristics.

To achieve the actual situation of water pressure stabilization during underground and tunnel water inrush disasters, the team independently developed a stable water pressure test system and conducted fracture and failure tests on fissured rock masses under the coupling effect of 1MPa stable water pressure and stress and without water pressure. Combined with data collected by acoustic emission instruments, the mechanical characteristics of fracture and failure, crack propagation mechanism, and acoustic emission response mechanism of fissured rock masses under the coupling effect of stable hydraulic pressure and stress were studied. The results showed that throughout the entire experimental process, the hydraulic pressure remained continuously stable, with a decrease of only 0.14%; The variation pattern of peak strength of fissured rock mass with increasing crack inclination angle under stable hydraulic pressure changes from a decrease and then an increase in the absence of hydraulic pressure to an increasing trend; The crack propagation length of low angle fissured rock mass is generally higher than that of high angle fissured specimens. The longer propagation path increases the range and effect of hydraulic pressure, and the initial crack propagation length of fissured rock mass under hydraulic pressure is also significantly longer than that of specimens without hydraulic pressure; During the loading process, both the acoustic emission ringing count and damage variable can be divided into four stages. From the cumulative total number of acoustic emission ringing counts, it can be seen that during the loading process, the total number of acoustic emission ringing in fissured rock masses subjected to hydraulic pressure is significantly lower than that of specimens without hydraulic pressure, and the trend is also relatively stable.

Distinctive Imaging Characteristics of Retinal and Cerebral Vessels between Central and Branch Retinal Vein Occlusion by MRI and AI-Based Image Analyzer.

Retinal vessels have been good predictive and prognostic imaging biomarkers for systemic or eye diseases. Numerous studies have shown that the two retinal vein occlusion entities may correlate with cardiovascular and cerebrovascular events or primary open-angle glaucoma. This study aims to investigate if there is a disparity in the correlations between branch RVO (BRVO) and central RVO (CRVO) with systemic disorders or POAG, thus explaining the pathogenic difference between BRVO and CRVO. This retrospective case-control study enrolled 59 RVO subjects (118 eyes), including 25 CRVO and 34 BRVO subjects, who received routine eye and brain MRI examinations. The geometric characteristics of the caliber of the retinal and cerebral blood vessels and the optic nerve subarachnoid space width (ONSASW) were measured. Multivariable logistic regression analysis showed that ONSASW at 3 mm behind the globe (p = 0.044) and the relative retinal venular calibers (p = 0.031) were independent risk factors for the CRVO-affected eyes group in comparison with the BRVO-affected eyes group after adjusting for age, duration of hypertension, BMI, and IOP. In the CRVO-affected eyes, narrower relative retinal arteriolar calibers (p = 0.041) and wider relative venular calibers (p = 0.011) were independent risk factors compared with the CRVO-contralateral normal eyes when adjusting for IOP. We concluded that BRVO may be more associated with cerebrovascular diseases, and CRVO may be correlated with primary angle glaucoma. The geometric characteristics difference between the retinal and cerebrovascular may explain the pathological difference between CRVO and BRVO.

Comparative analysis of co-culture and monoculture models in simulating diabetic neurovascular dysfunction: insights into diabetic retinopathy.

Background: Interaction between retinal vascular endothelial cells and neurons plays a critical role in the pathogenesis of diabetic retinopathy (DR). This study aims to compare an in vitro model over a monoculture model to simulate the neurovascular coupling under the hyperglycemic microenvironment of diabetes. Methods: Rat retinal vascular endothelial cells (RRMECs) and ganglion cells (RGCs) were seeded mono- or co-cultured in a normal (NG, 5.5 mM) and high (HG, 75 mM) glucose concentrations culture medium. Cell viability was detected by the cell counting kit-8 (CCK-8) assay. The ability of migration and lumen formation of RRMECs were determined by scratch wound, transwell migration, and lumen formation assays. The apoptosis index of cells was calculated and detected by propidium iodide (PI)/Hoechst staining. Quantitative and morphological analysis of RGCs was performed through the labeling of RGCs by brain-specific homeobox/POU domain protein 3A (BRN3A) and anti-beta-III tubulin (TUJ1). The gene and protein expression levels of occludin (OCLN) and zonula occludens-1 (ZO-1) were evaluated by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Results: The viability, migration, and lumen formation abilities of RRMECs in the HG group significantly increased (P<0.05) in both mono- and co-culture models. Migration and lumen formation abilities of RRMECs in the co-culture with HG were lower than that in the monoculture group (P<0.05). The viability of RGCs cells with HG significantly decreased in both mono- and co-culture models (Pmono<0.001, Pco<0.001), the apoptosis index of RGCs in the co-culture with HG was higher than that in the monoculture (P=0.010). The protein and gene expression of OCLN, and ZO-1 in RRMECs significantly decreased with HG culture medium in both culture models (P<0.05). In the HG group, the protein and gene expression level of the ZO-1 and OCLN of RRMECs significantly decreased in the co-culture model than that in the monoculture model (P<0.05). Conclusion: Compared with mono cell culture, the established co-culture in vitro system for diabetic neurovascular dysfunction can better stimulate the micro-environment of the retinal neurovascular unit.