Dual Regulation of Cytochrome P450 Gene Expression by Two Distinct Small RNAs, a Novel tasiRNA and miRNA, in Marchantia polymorpha.

The miR390-derived TAS3 trans-acting short-interfering RNAs (tasiRNAs) module represents a conserved RNA silencing pathway in the plant kingdom; however, its characterization in the bryophyte Marchantia polymorpha is limited. This study elucidated that MpDCL4 processes MpTAS3 double-stranded RNA (dsRNA) to generate tasiRNAs, primarily from the 5'- and 3'-ends of dsRNA. Notably, we discovered a novel tasiRNA, tasi78A, which can negatively regulate a cytochrome P450 gene, MpCYP78A101. Additionally, tasi78A was abundant in MpAGO1, and transient expression assays underscored the role of tasi78A in repressing MpCYP78A101. A microRNA, miR11700, also regulates MpCYP78A101 expression. This coordinate regulation suggests a role in modulating auxin signaling at apical notches of gemma, influencing the growth and sexual organ development of M. polymorpha and emphasizing the significance of RNA silencing in MpCYP78A101 regulation. However, phylogenetic analysis identified another paralog of the CYP78 family, Mp1g14150, which may have a redundant role with MpCYP78A101, explaining the absence of noticeable morphological changes in loss-of-function plants. Taken together, our findings provide new insights into the combined regulatory roles of miR390/MpTAS3/miR11700 in controlling MpCYP78A101 and expand our knowledge about the biogenesis and regulation of tasiRNAs in M. polymorpha.

Molecular insights into MpAGO1 and its regulatory miRNA, miR11707, in the high-temperature acclimation of Marchantia polymorpha.

As a model plant for bryophytes, Marchantia polymorpha offers insights into the role of RNA silencing in aiding early land plants navigate the challenges posed by high-temperature environments. Genomic analysis revealed unique ARGONAUTE1 ortholog gene (MpAGO1) in M. polymorpha that is regulated by two species-specific microRNAs (miRNAs), miR11707.1 and miR11707.2. Comparative studies of small RNA profiles from M. polymorpha cellular and MpAGO1 immunoprecipitation (MpAGO1-IP) profiles at various temperatures, along with analyses of Arabidopsis AGO1 (AtAGO1), revealed that MpAGO1 has a low-selectivity for a diverse range of small RNA species than AtAGO1. Protein structural comparisons revealed no discernible differences in the MID domains of MpAGO1 and AtAGO1, suggesting the complexity of miRNA species specificity and necessitating further exploration. Small RNA profiling and size exclusion chromatography have pinpointed a subset of M. polymorpha miRNAs, notably miR11707, that remain in free form within the cell at 22°C but are loaded into MpAGO1 at 28°C to engage in RNA silencing. Investigations into the mir11707 gene editing (mir11707ge) mutants provided evidence of the regulation of miR11707 in MpAGO1. Notably, while MpAGO1 mRNA expression decreases at 28°C, the stability of the MpAGO1 protein and its associated miRNAs is essential for enhancing the RISC activity, revealing the importance of RNA silencing in enabling M. polymorpha to survive thermal stress. This study advances our understanding of RNA silencing in bryophytes and provides groundbreaking insights into the evolutionary resilience of land plants to climatic adversities.

Endovascular recanalization of symptomatic non-acute intracranial artery occlusion: Procedural and mid-term clinical outcomes in the anterior circulation.

OBJECTIVE: Symptomatic non-acute intracranial arterial occlusion (NAICO) is not uncommon. We report a single-center experience of the feasibility and safety of endovascular treatment of anterior circulation NAICO and summarize the outcomes of patient groups with successful or failed recanalization. METHODS: Patients who underwent endovascular therapy for intracranial arterial stenosis between January 2010 and May 2017 were retrospectively reviewed. Thirty-eight patients with symptomatic NAICO (symptom onset > 24 hours) in the anterior circulation were identified. RESULTS: Successful recanalization was achieved in 76.3% of patients (29/38). Intraprocedural events occurred in 10.5% (4/38), including intima dissection (n = 1), parent artery rupture (n = 1) and acute in-stent thrombosis (n = 2). Mean follow-up duration after successful recanalization was 36.5 months. One patient died 68 days after the procedure because of a newly developed posterior circulation stroke. Acute reocclusion was observed in two patients (6.7%); subacute or delayed reocclusion was observed in three patients (10%). Good final outcome (modified Rankin Scale score ≤ 2) was achieved in 25 of 28 patients (89.3%) at three months. Mean follow-up duration of the nine patients with failed recanalization was 41.4 months. Three patients underwent extra-intracranial bypass for worsening symptoms. The other six patients showed stable or improved neurological status with antiplatelet medications. Good final outcome was achieved in eight of nine patients (88.9%) at three months. CONCLUSIONS: Endovascular revascularization can be a viable option with an acceptable safety profile in selected patients with symptomatic NAICO in the anterior circulation. Further characterization of aborted cases would facilitate proper patient selection for endovascular treatment.

Genetic immunotherapy for hepatocellular carcinoma by endothelial progenitor cells armed with cytosine deaminase.

Endothelial progenitor cells (EPCs) serve as cellular vehicles for targeting cancer cells and are a powerful tool for delivery of therapeutic genes. Cytosine deaminase (CD), a kind of frequent suicide gene which can kill carcinoma cells by converting a non-poisonous pro-drug 5-flucytosine (5-FC) into a poisonous cytotoxic 5-fluorouracil (5-FU). We combined super-paramagnetic iron oxide (SPIO) nanoparticles labeled EPCs with CD gene to treat grafted liver carcinomas and tracked them with 7.0 T Magnetic resonance imaging (MRI). Results showed that the therapeutic EPCs loaded with CD plus 5-Fc provided stronger carcinoma growth suppression compared with treatment using CD alone. The CD/5-Fc significantly inhibited the growth of endothelial cells and induced carcinoma cells apoptosis. These results indicate that EPCs transfected with anti-carcinoma genes can be used in carcinoma therapy as a novel therapeutic modality.