The cellular-centered view of hypoxia tumor microenvironment: Molecular mechanisms and therapeutic interventions.

Cancer is a profoundly dynamic, heterogeneous and aggressive systemic ailment, with a coordinated evolution of various types of tumor niches. Hypoxia plays an indispensable role in the tumor micro-ecosystem, drastically enhancing the plasticity of cancer cells, fibroblasts and immune cells and orchestrating intercellular communication. Hypoxia-induced signals, particularly hypoxia-inducible factor-1α (HIF-1α), drive the reprogramming of genetic, transcriptional, and proteomic profiles. This leads to a spectrum of interconnected processes, including augmented survival of cancer cells, evasion of immune surveillance, metabolic reprogramming, remodeling of the extracellular matrix, and the development of resistance to conventional therapeutic modalities like radiotherapy and chemotherapy. Here, we summarize the latest research on the multifaceted effects of hypoxia, where a multitude of cellular and non-cellular elements crosstalk with each other and co-evolve in a synergistic manner. Additionally, we investigate therapeutic approaches targeting hypoxic niche, encompassing hypoxia-activated prodrugs, HIF inhibitors, nanomedicines, and combination therapies. Finally, we discuss some of the issues to be addressed and highlight the potential of emerging technologies in the treatment of cancer.

Polychlorinated Biphenyl Concentrations and Estimated Intakes in Fish Oil Supplements on the Japanese Market.

Polychlorinated biphenyls (PCBs) are synthetic organic contaminants that are widespread in the environment. There are 209 PCB congeners. Fish oil produced from marine fish is widely used as a health supplement. PCB contamination of fish oil is of concern. We determined the concentrations of all 209 PCB congeners in commercially available fish oil supplements from Japan and estimated PCB intakes for humans consuming the supplements. We determined the concentrations of non-dioxin-like PCBs separately. The total PCB concentrations in 37 fish oil supplements purchased in Japan were 0.024-19 ng/g whole weight, and the non-dioxin-like PCB concentration range was also 0.024-19 ng/g whole weight. The total PCB intakes calculated for a 50 kg human consuming the supplements were 0.039-51 ng/day (0.00078-1.0 ng/(kg body weight per day)) and the non-dioxin-like PCB intake range was also 0.039-51 ng/day (0.00078-1.0 ng/(kg body weight per day)). The total PCB intakes were much lower than the tolerable daily intake of 20 ng/(kg body weight per day) recommended by the WHO. The results indicated that PCBs in the fish oil supplements pose acceptable risks to humans consuming the fish oil supplements daily.

Hepatic arterial infusion chemotherapy with anti-angiogenesis agents and immune checkpoint inhibitors for unresectable hepatocellular carcinoma and meta-analysis.

BACKGROUND: Hepatic arterial infusion chemotherapy (HAIC) has been proven to be an ideal choice for treating unresectable hepatocellular carcinoma (uHCC). HAIC-based treatment showed great potential for treating uHCC. However, large-scale studies on HAIC-based treatments and meta-analyses of first-line treatments for uHCC are lacking. AIM: To investigate better first-line treatment options for uHCC and to assess the safety and efficacy of HAIC combined with angiogenesis inhibitors, programmed cell death of protein 1 (PD-1) and its ligand (PD-L1) blockers (triple therapy) under real-world conditions. METHODS: Several electronic databases were searched to identify eligible randomized controlled trials for this meta-analysis. Study-level pooled analyses of hazard ratios (HRs) and odds ratios (ORs) were performed. This was a retrospective single-center study involving 442 patients with uHCC who received triple therapy or angiogenesis inhibitors plus PD-1/PD-L1 blockades (AIPB) at Sun Yat-sen University Cancer Center from January 2018 to April 2023. Propensity score matching (PSM) was performed to balance the bias between the groups. The Kaplan-Meier method and cox regression were used to analyse the survival data, and the log-rank test was used to compare the suvival time between the groups. RESULTS: A total of 13 randomized controlled trials were included. HAIC alone and in combination with sorafenib were found to be effective treatments (P values for ORs: HAIC, 0.95; for HRs: HAIC + sorafenib, 0.04). After PSM, 176 HCC patients were included in the analysis. The triple therapy group (n = 88) had a longer median overall survival than the AIPB group (n = 88) (31.6 months vs 14.6 months, P < 0.001) and a greater incidence of adverse events (94.3% vs 75.4%, P < 0.001). CONCLUSION: This meta-analysis suggests that HAIC-based treatments are likely to be the best choice for uHCC. Our findings confirm that triple therapy is more effective for uHCC patients than AIPB.

Parallel-Forms Reliability and Minimal Detectable Change of the Four Telerehabilitation Version Mobility-Related Function Scales in Stroke Survivors.

OBJECTIVE: To investigate the parallel-forms reliability, minimal detectable change with 95% confidence interval (MDC95), and feasibility of the 4 telerehabilitation version mobility-related function scales: Fugl-Meyer Assessment-lower extremity subscale (Tele-FMA-LE), Berg Balance Scale (Tele-BBS), Tinetti Performance Oriented Mobility Assessment-Gait subscale (Tele-POMA-G), and Rivermead Mobility Index (Tele-RMI). DESIGN: Reliability and agreement study and cross-sectional study. SETTING: Medical center. PARTICIPANTS: Stroke survivors' ability to independently walk 3 meters with assistive devices, age of ≥18 years for participants and their partners, stable physical condition, and absence of cognitive impairment (N=60). INTERVENTIONS: Not applicable. MAIN OUTCOMES MEASURES: Parallel-forms reliability and MDC95 of Tele-FMA-LE, Tele-BBS, Tele-POMA-G, and Tele-RMI. RESULTS: No significant differences (P>.05) were observed among the mean scores of the telerehabilitation version and face-to-face version mobility-related function scales. Intraclass correlation coefficients (ICCs) indicated good reliability for most scales, with Tele-FMA-LE, Tele-BBS, and Tele-RMI scores achieving values of 0.81, 0.78, and 0.84. Tele-POMA-G scores demonstrated moderate reliability (ICC=0.72). Weighted kappa (κw) showed good-to-excellent reliability for most individual items (κw>0.60). The MDCs of the Tele-FMA-LE, Tele-BBS, Tele-POMA-G, and Tele-RMI were 5.84, 8.10, 2.74, and 1.31, respectively. Bland-Altman analysis showed adequate agreement between tele-assessment and face-to-face assessment for all scales. The 5 dimensions affirm the robust feasibility of tele-assessment: assessment time, subjective fatigue perception, overall preference, participant satisfaction, and system usability. CONCLUSIONS: The study demonstrates good parallel-forms reliability, MDC, and promising feasibility of the 4 telerehabilitation version mobility-related function scales (Tele-FMA-LE, Tele-BBS, Tele-POMA-G, and Tele-RMI) in survivors of stroke.

The structure of B-ARR reveals the molecular basis of transcriptional activation by cytokinin.

The phytohormone cytokinin has various roles in plant development, including meristem maintenance, vascular differentiation, leaf senescence, and regeneration. Prior investigations have revealed that cytokinin acts via a phosphorelay similar to the two-component system by which bacteria sense and respond to external stimuli. The eventual targets of this phosphorelay are type-B ARABIDOPSIS RESPONSE REGULATORS (B-ARRs), containing the conserved N-terminal receiver domain (RD), middle DNA binding domain (DBD), and C-terminal transactivation domain. While it has been established for two decades that the phosphoryl transfer from a specific histidyl residue in ARABIDOPSIS HIS PHOSPHOTRANSFER PROTEINS (AHPs) to an aspartyl residue in the RD of B-ARRs results in a rapid transcriptional response to cytokinin, the underlying molecular basis remains unclear. In this work, we determine the crystal structures of the RD-DBD of ARR1 (ARR1RD-DBD) as well as the ARR1DBD-DNA complex from Arabidopsis. Analyses of the ARR1DBD-DNA complex have revealed the structural basis for sequence-specific recognition of the GAT trinucleotide by ARR1. In particular, comparing the ARR1RD-DBD and ARR1DBD-DNA structures reveals that unphosphorylated ARR1RD-DBD exists in a closed conformation with extensive contacts between the RD and DBD. In vitro and vivo functional assays have further suggested that phosphorylation of the RD weakens its interaction with DBD, subsequently permits the DNA binding capacity of DBD, and promotes the transcriptional activity of ARR1. Our findings thus provide mechanistic insights into phosphorelay activation of gene transcription in response to cytokinin.

Camrelizumab (a PD-1 inhibitor) plus apatinib (an VEGFR-2 inhibitor) and hepatic artery infusion chemotherapy for hepatocellular carcinoma in Barcelona Clinic Liver Cancer stage C (TRIPLET): a phase II study.

Hepatic arterial infusion chemotherapy (HAIC) using a combination of oxaliplatin, fluorouracil, and leucovorin (FOLFOX) has shown promise for hepatocellular carcinoma (HCC) patients classified under Barcelona Clinic Liver Cancer (BCLC) stage C. In China, the combined therapy of camrelizumab and apatinib is now an approved first-line approach for inoperable HCC. This study (NCT04191889) evaluated the benefit of combining camrelizumab and apatinib with HAIC-FOLFOX for HCC patients in BCLC stage C. Eligible patients were given a maximum of six cycles of HAIC-FOLFOX, along with camrelizumab and apatinib, until either disease progression or intolerable toxicities emerged. The primary outcome measured was the objective response rate (ORR) based on the Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. Thirty-five patients were enrolled. Based on RECIST v1.1 criteria, the confirmed ORR stood at 77.1% (95% CI: 59.9% to 89.6%), with a disease control rate of 97.1% (95% CI: 85.1% to 99.9%). The median progression-free survival was 10.38 months (95% CI: 7.79 to 12.45). Patient quality of life had a transient deterioration within four cycles of treatment, and generally recovered thereafter. The most frequent grade ≥3 or above treatment-related adverse events included reduced lymphocyte count (37.1%) and diminished neutrophil count (34.3%). The combination of camrelizumab, apatinib, and HAIC demonstrated encouraging results and manageable safety concerns for HCC at BCLC stage C.

Quantitative study of peripapillary retinal nerve fiber layer thickness and peripapillary vessel density in patients with different stages of Parkinson's disease.

AIM: To observe the changes in the thickness of peripapillary retinal nerve fiber layer (pRNFL) and peripapillary vessel density (pVD) in patients with different stages of Parkinson's disease (PD). METHODS: Totally 47 patients (47 eyes) with primary PD were divided into the mild group and the moderate-to-severe group according to Hoehn & Yahr (H&Y) stage. Among them, there were 27 cases (27 eyes) in mild group and 20 cases (20 eyes) in moderate-to-severe group. And 20 cases (20 eyes) who were included in the control group were healthy people who came to our hospital for health screening at the same time. All participants underwent optical coherence tomography angiography (OCTA) examinations. The pRNFL thickness, total vessel density (tVD) and capillary vessel density (cVD) of the optic disc in average, superior half, inferior half, superior nasal (SN), nasal superior (NS), nasal inferior (NI), inferior nasal (IN), inferior temporal (IT), temporal inferior (TI), temporal superior (TS), and superior temporal (ST) were measured. One-way ANOVA was used to compare the differences of optic disc parameters among the three groups, and Pearson and Spearman correlations were used to analyze the correlation between pRNFL, pVD and the disease duration, H&Y stage and UPDRS-III score in patients with PD, respectively. RESULTS: There were significant differences in pRNFL thickness in average, superior half, inferior half, SN, NS, IN, IT and ST quadrants among the three groups (P<0.05). In PD group, the pRNFL thickness in average, superior half, inferior half, NS and IT quadrants were negatively correlated with H&Y stage and UPDRS-III score, respectively (P<0.05). There were statistically significant differences in the cVD of whole image, inferior half, NI and TS quadrants, the tVD of the whole image, inferior half, and peripapillary among the three groups (P<0.05). In PD group, the tVD of whole image and the cVD of NI and TS quadrants were negatively correlated with the H&Y stage, respectively (P<0.05); the cVD of TS quadrant was negatively correlated with UPDRS-III score (P<0.05). CONCLUSION: The thickness of pRNFL in PD patients is significantly decreased, and it is negatively correlated with H&Y stage and UPDRS-III score. With the increase of the severity of the disease, the pVD parameters in PD patients increase at first in the mild group, and then decrease in the moderate-to-severe group, and negatively correlate with H&Y stage and UPDRS-III score.

Anisotropic cell growth at the leaf base promotes age-related changes in leaf shape in Arabidopsis thaliana.

Plants undergo extended morphogenesis. The shoot apical meristem (SAM) allows for reiterative development and the formation of new structures throughout the life of the plant. Intriguingly, the SAM produces morphologically different leaves in an age-dependent manner, a phenomenon known as heteroblasty. In Arabidopsis thaliana, the SAM produces small orbicular leaves in the juvenile phase, but gives rise to large elliptical leaves in the adult phase. Previous studies have established that a developmental decline of microRNA156 (miR156) is necessary and sufficient to trigger this leaf shape switch, although the underlying mechanism is poorly understood. Here we show that the gradual increase in miR156-targeted SQUAMOSA PROMOTER BINDING PROTEIN-LIKE transcription factors with age promotes cell growth anisotropy in the abaxial epidermis at the base of the leaf blade, evident by the formation of elongated giant cells. Time-lapse imaging and developmental genetics further revealed that the establishment of adult leaf shape is tightly associated with the longitudinal cell expansion of giant cells, accompanied by a prolonged cell proliferation phase in their vicinity. Our results thus provide a plausible cellular mechanism for heteroblasty in Arabidopsis, and contribute to our understanding of anisotropic growth in plants.

[Pollution Characteristics and Source Analysis of Atmospheric PM2.5-bound Polycyclic Aromatic Hydrocarbons in a Port Area].

In order to explore the pollution characteristics and potential sources of polycyclic aromatic hydrocarbons (PAHs) in the polluted air of a port area, PM2.5 samples (n=59) were collected from Qingdao Port for four seasons from August 2018 to May 2019. The seasonal variation and composition characteristics of PM2.5-bound PAHs were analyzed, the influence of meteorological factors on PAH concentrations was explored using correlation analysis, and the potential sources were analyzed using positive definite matrix factorization and potential source contribution function models. The results showed that the total mean concentration of PAHs was (8.11±12.31) ng·m-3, which was higher in autumn and winter than that in spring and summer. The seasonal molecular compositions of PAHs were similar, dominated by 4-5 ring PAHs (75.43%). Fluoranthene, benzo[e]pyrene, benzo[a]anthracene, phenanthrene, pyrene, and chrysene were the dominant species of PAHs in the study area, which are similar to the major compounds in ship exhaust. Correlation analysis showed that PAH concentrations were significantly negatively correlated with temperature and relative humidity and significantly positively correlated with atmospheric pressure and wind direction and had a poor correlation with wind speed. PMF analysis extracted six contribution factors, and the results indicated that Qingdao Port was mainly influenced by shipping emissions (28.83%), followed by vehicle emissions (20.49%), as well as crude oil volatilization (13.47%). Summer had the greatest impact on shipping emissions. The PSCF results suggested that Beijing-Tianjin-Hebei, Bohai Rim, and northern Shandong were the main source regions for long-range transport.

Long non-coding RNA RPL34-AS1 ameliorates oxygen-glucose deprivation-induced neuronal injury via modulating miR-223-3p/IGF1R axis.

Ribosomal protein L34-antisense RNA 1 (RPL34-AS1), one of the long non-coding RNAs (lncRNAs), plays an important function in regulating diverse human malignant tumors. Nevertheless, the functions of RPL34-AS1 in ischemic stroke remain unclear. The present work focused on determining the candidate targets of RPL34-AS1 and its related mechanism in ischemic injury. The oxygen-glucose deprivation (OGD/R) in vitro cell model and middle cerebral artery occlusion (MCAO) in vivo rat model were utilized to simulate the pathological process of ischemic stroke. Additionally, the CCK8, WB (detecting Bcl-2 and Bax protein levels), and caspase-3 activity assays were done to investigate the anti-apoptotic functions of RPL34-AS1. The relationship among RPL34-AS1, insulin-like growth factor 1 receptor (IGF1R), and microRNA-223-3p (miR-223-3p) was determined through luciferase reporter assay. In this study, RPL34-AS1 expression was reduced in patients suffering from ischemic stroke. The overexpression of RPL34-AS1 reduced ischemic brain damage. However, the cell viability and glucose uptake were increased, and the apoptosis rate was decreased in the OGD/R-induced neurons. Further, miR-223-3p resulted in the decreased cell viability and glucose uptake and the increased cell apoptosis to cause ischemic brain damage. Besides, the neuroprotective effects of RPL34-AS1 on OGD/R injury were partly reversed by miR-223-3p. Mechanistically, lncRNA RPL34-AS1 could function as the competing endogenous RNA (ceRNA) of miR-223-3p to regulate IGF1R. Collectively, our study demonstrated that lncRNA RPL34-AS1 attenuated OGD/R-induced neuronal injury by mediating miR-223-3p/IGF1R axis. This discovery might serve as the candidate therapeutic target for ischemic stroke.

Differential Long Non-Coding RNA Expression Analysis in Chronic Non-Atrophic Gastritis, Gastric Mucosal Intraepithelial Neoplasia, and Gastric Cancer Tissues.

Gastric cancer (GC) has a high incidence worldwide, and when detected, the majority of patients have already progressed to advanced stages. Long non-coding RNAs (lncRNAs) have a wide range of biological functions and affect tumor occurrence and development. However, the potential role of lncRNAs in GC diagnosis remains unclear. We selected five high-quality samples from each group of chronic non-atrophic gastritis, gastric mucosal intraepithelial neoplasia, and GC tissues for analysis. RNA-seq was used to screen the differentially expressed lncRNAs, and we identified 666 differentially expressed lncRNAs between the chronic non-atrophic gastritis and GC groups, 13 differentially expressed lncRNAs between the gastric mucosal intraepithelial neoplasia and GC groups, and 507 differentially expressed lncRNAs between the chronic non-atrophic gastritis and gastric mucosal intraepithelial neoplasia groups. We also identified six lncRNAs (lncRNA H19, LINC00895, lnc-SRGAP2C-16, lnc-HLA-C-2, lnc-APOC1-1, and lnc-B3GALT2-1) which not only differentially expressed between the chronic non-atrophic gastritis and GC groups, but also differentially expressed between the gastric mucosal intraepithelial neoplasia and GC groups. Furthermore, RT-qPCR was used to verify the differentially co-expressed lncRNAs. LncSEA was used to conduct a functional analysis of differentially expressed lncRNAs. We also predicted the target mRNAs of the differentially expressed lncRNAs through bioinformatics analysis and analyzed targeting correlations between three differentially co-expressed lncRNAs and mRNAs (lncRNA H19, LINC00895, and lnc-SRGAP2C-16). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases were used to explore the functions of target mRNAs of differentially expressed lncRNAs. In conclusion, our study provides a novel perspective on the potential functions of differentially expressed lncRNAs in GC occurrence and development, indicating that the differentially expressed lncRNAs might be new biomarkers for early GC diagnosis.

Subvisible Particles Derived by Dropping Stress Enhance Anti-PEG Antibody Production and Clearance of PEGylated Proteins in Mice.

Bioconjugation with polyethylene glycol (PEG) is important for protein drug development as it has improved biological stability. In contrast, proteins including PEGylated ones are susceptible to physicochemical stresses. Particularly, protein drugs in solution may form aggregates or subvisible particles if they are exposed to dropping stress during transportation. However, many PEGylation studies have focused on its usefulness, such as the extension of half-life in blood, and changes in the physical properties or biological responses of PEGylated proteins under dropping stress remain unexplored. Here, we prepared four PEGylated ovalbumin (PEG-OVA) molecules conjugated with different lengths (5 or 20 kDa) and numbers (large [L] or small [S]) of PEG, analyzed the formation of subvisible particles under dropping stress, and examined their impact on antibody production and clearance. Under dropping stress, the aggregated particle concentration of 20 kDa PEG-OVA (S) and (L) solutions was approximately 3-fold that of the OVA solution. Moreover, administration of 20 kDa PEG-OVA with dropping stress induced anti-PEG antibody production and clearance of PEG-OVA. As a mechanism, dropping stress could enhance the uptake of 20 kDa PEG-OVA (L) by macrophages. These findings could provide insights into proper transportation conditions to ensure the quality of PEGylated protein drugs.

RETRACTED: Liposomal valinomycin mediated cellular K+ leak promoting apoptosis of liver cancer cells.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the corresponding author. It has been found that Fig 2B contains manipulated components, and Fig 5A partially overlaps with Fig 6 of a published paper authored by Mirza Muhammad Faran Ashraf Baig, et, al., The effective transfection of a low dose of negatively charged drug-loaded DNA-nanocarriers into cancer cells via scavenger receptors, J. Pharm. Anal. 11 (2021) 174-182, https://doi.org/10.1016/j.jpha.2020.10.003. The corresponding author indicated that they cannot guarantee the integrity of the images in the manuscript, as well as the conclusions of the paper. As a result, the Editor-in-Chief has decided to retract the paper. The corresponding author deeply regrets the circumstances and apologizes to the scientific community for not having detected this prior to publication.

Radiofrequency versus microwave ablation for hepatocellular carcinoma within the Milan criteria in challenging locations: a retrospective controlled study.

PURPOSE: The aim of this study was to compare the safety and efficacy of radiofrequency ablation (RFA) with microwave ablation (MWA) for hepatocellular carcinoma (HCC) within the Milan criteria in challenging locations. METHODS: This study retrospectively investigated 201 consecutive patients with Milan criteria HCCs who underwent RFA (RFA group, n = 150) or MWA (MWA group, n = 51) between January 2012 and December 2016. Overall survival (OS), recurrence-free survival (RFS), local tumor control, and treatment-related complications were compared between the two groups. Prognostic factors were analyzed using the Cox proportional hazard regression model. RESULTS: Median follow-up duration was 36.7 months (range: 6.2-64.0 months). Cumulative 1-, 3-, and 5-year OS rates were 97.9%, 92.3%, and 80.6% in the MWA group and 96.4%, 87.4%, and 78.2% in the RFA group, respectively, (P = 0.450). Cumulative RFS rates at 1, 3, and 5 years were 93.2%, 74.4%, and 63.7% in the MWA group and 80.3%, 57.3%, and 49.6% in the RFA group, respectively, (P = 0.097). Multivariate analyses showed that variable categories "patient age above 65 years" (P = 0.004) and "more than one tumor" (P = 0.004) were associated with overall mortality, and "patient age above 65 years" (P = 0.048) and "tumor size greater than 3 cm" (P = 0.009) were associated with inferior RFS. The incidences of major complications were not significantly different between the two groups (3.3% vs 3.9%, P = 0.843). CONCLUSIONS: RFA and MWA were associated with comparable safety and efficacy for HCC within the Milan criteria in challenging locations. Further study in a large, multi-center patient cohort is necessary to validate the results.

Single-cell transcriptome atlas and chromatin accessibility landscape reveal differentiation trajectories in the rice root.

Root development relies on the establishment of meristematic tissues that give rise to distinct cell types that differentiate across defined temporal and spatial gradients. Dissection of the developmental trajectories and the transcriptional networks that underlie them could aid understanding of the function of the root apical meristem in both dicots and monocots. Here, we present a single-cell RNA (scRNA) sequencing and chromatin accessibility survey of rice radicles. By temporal profiling of individual root tip cells we reconstruct continuous developmental trajectories of epidermal cells and ground tissues, and elucidate regulatory networks underlying cell fate determination in these cell lineages. We further identify characteristic processes, transcriptome profiles, and marker genes for these cell types and reveal conserved and divergent root developmental pathways between dicots and monocots. Finally, we demonstrate the potential of the platform for functional genetic studies by using spatiotemporal modeling to identify a rice root meristematic mutant from a cell-specific gene cohort.

A single-cell analysis of the Arabidopsis vegetative shoot apex.

The shoot apical meristem allows for reiterative formation of new aerial structures throughout the life cycle of a plant. We use single-cell RNA sequencing to define the cellular taxonomy of the Arabidopsis vegetative shoot apex at the transcriptome level. We find that the shoot apex is composed of highly heterogeneous cells, which can be partitioned into 7 broad populations with 23 transcriptionally distinct cell clusters. We delineate cell-cycle continuums and developmental trajectories of epidermal cells, vascular tissue, and leaf mesophyll cells and infer transcription factors and gene expression signatures associated with cell fate decisions. Integrative analysis of shoot and root apical cell populations further reveals common and distinct features of epidermal and vascular tissues. Our results, thus, offer a valuable resource for investigating the basic principles underlying cell division and differentiation in plants at single-cell resolution.

Redundant and specific roles of individual MIR172 genes in plant development.

Evolutionarily conserved microRNAs (miRNAs) usually have high copy numbers in the genome. The redundant and specific roles of each member of a multimember miRNA gene family are poorly understood. Previous studies have shown that the miR156-SPL-miR172 axis constitutes a signaling cascade in regulating plant developmental transitions. Here, we report the feasibility and utility of CRISPR-Cas9 technology to investigate the functions of all 5 MIR172 family members in Arabidopsis. We show that an Arabidopsis plant devoid of miR172 is viable, although it displays pleiotropic morphological defects. MIR172 family members exhibit distinct expression pattern and exert functional specificity in regulating meristem size, trichome initiation, stem elongation, shoot branching, and floral competence. In particular, we find that the miR156-SPL-miR172 cascade is bifurcated into specific flowering responses by matching pairs of coexpressed SPL and MIR172 genes in different tissues. Our results thus highlight the spatiotemporal changes in gene expression that underlie evolutionary novelties of a miRNA gene family in nature. The expansion of MIR172 genes in the Arabidopsis genome provides molecular substrates for the integration of diverse floral inductive cues, which ensures that plants flower at the optimal time to maximize seed yields.

[Mechanism of astragaloside â £ alleviating PC12 cell injury by activating PI3K/AKT signaling pathway: based on network pharmacology and in vitro experiments].

In this study, the molecular mechanism of astragaloside Ⅳ(AS-Ⅳ) in the treatment of Parkinson's disease(PD) was explored based on network pharmacology, and the potential value of AS-Ⅳ in alleviating neuronal injury in PD by activating the PI3 K/AKT signaling pathway was verified through molecular docking and in vitro experiments. Such databases as SwissTargetPrediction, BTMAN-TAM, and GeneCards were used to predict the targets of AS-Ⅳ for the treatment of PD. The Search Tool for the Retrieval of Interacting Genes/Proteins(STRING) was employed to analyze protein-protein interaction(PPI) and construct a PPI network, and the Database for Annotation, Visualization and Integrated Discovery(DAVID) was used for Gene Ontology(GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis. Based on the results of GO enrichment analysis and KEGG pathway analysis, the PI3 K/AKT signaling pathway was selected for further molecular docking and in vitro experiments in this study. The in vitro cell model of PD was established by MPP~+. The cell viability was measured by MTT assay and effect of AS-Ⅳ on the expression of the PI3 K/AKT signaling pathway-related genes and proteins by real-time polymerase chain reaction(RT-PCR) and Western blot. Network pharmacology revealed totally 122 targets of AS-Ⅳ for the treatment of PD, and GO enrichment analysis yielded 504 GO terms, most of which were biological processes and molecular functions. Totally 20 related signaling pathways were screened out by KEGG pathway analysis, including neuroactive ligand-receptor interaction, PI3 K/AKT signaling pathway, GABAergic synapse, and calcium signaling pathway. Molecular docking demonstrated high affinity of AS-Ⅳ to serine/threonine-protein kinases(AKT1, AKT2), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit gamma(PIK3 CG), and phosphoinositide-3-kinase, catalytic, alpha polypeptide(PIK3 CA) on the PI3 K/AKT signaling pathway. In vitro experiments showed that AS-Ⅳ could effectively inhibit the decrease of the viability of PC12 induced by MPP~+ and up-regulate the mRNA expression levels of AKT1 and PI3 K as well as the phosphorylation levels of AKT and PI3 K. As an active component of Astragali Radix, AS-Ⅳ acts on PD through multiple targets and pathways. Furthermore, it inhibits neuronal apoptosis and protects neurons by activating the PI3 K/AKT signaling pathway, thereby providing reliable theoretical and experimental supports for the treatment of PD with AS-Ⅳ.