The roles of epigenetic regulators in plant regeneration: Exploring patterns amidst complex conditions.

Plants possess remarkable capability to regenerate upon tissue damage or optimal environmental stimuli. This ability not only serves as a crucial strategy for immobile plants to survive through harsh environments, but also made numerous modern plant improvements techniques possible. At the cellular level, this biological process involves dynamic changes in gene expression that redirect cell fate transitions. It is increasingly recognized that chromatin epigenetic modifications, both activating and repressive, intricately interact to regulate this process. Moreover, the outcomes of epigenetic regulation on regeneration are influenced by factors such as the differences in regenerative plant species and donor tissue types, as well as the concentration and timing of hormone treatments. In this review, we focus on several well-characterized epigenetic modifications and their regulatory roles in the expression of widely studied morphogenic regulators, aiming to enhance our understanding of the mechanisms by which epigenetic modifications govern plant regeneration.

An inducible CRISPR activation tool for accelerating plant regeneration.

The inducible CRISPR activation (CRISPR-a) system offers unparalleled precision and versatility for regulating endogenous genes, making it highly sought after in plant research. In this study, we developed a chemically inducible CRISPR-a tool for plants called ER-Tag by combining the LexA-VP16-ER inducible system with the SunTag CRISPR-a system. We systematically compared different induction strategies and achieved high efficiency in target gene activation. We demonstrated that guide RNAs can be multiplexed and pooled for large-scale screening of effective morphogenic genes and gene pairs involved in plant regeneration. Further experiments showed that induced activation of these morphogenic genes can accelerate regeneration and improve regeneration efficiency in both eudicot and monocot plants, including alfalfa, woodland strawberry, and sheepgrass. Our study expands the CRISPR toolset in plants and provides a powerful new strategy for studying gene function when constitutive expression is not feasible or ideal.

Successful treatment of epidermodysplasia verruciformis with a combination of 5-aminolevulinic acid photodynamic therapy and surgery.

Epidermodysplasia verruciformis (EV) is a rare inherited immune disease characterized by pityriasis versicolor-like macules, hyperpigmented or hypopigmented warty papules and irregular reddish-brown plaques, mainly on the face, neck and extremities. Some therapeutic options include medications, lifestyle changes, ALA-PDT, surgery and so on. But there is no cure for EV and thus the clinical management is challenging. We report a case of EV that was refractory to multiple therapies and achieved an encouraging result with a combination therapy of surgery and 5-aminolevulinic acid photodynamic therapy (ALA-PDT).

Dual-mode vortex beam transmission metasurface antenna based on linear-to-circular polarization converter.

The generation of multi-mode vortex beams at the same aperture is currently emerging as a research hotspot. In this paper, a method based on a linearly polarized-circularly polarized translational transmission metasurface (TM) is proposed to enable a dual-circularly polarized dual-mode vortex beam generation. Through the judicious implementation of an additional rotational phase and the combination of the initial transmission phase, the phases of the left-hand circularly polarized (LHCP) and right-hand circularly polarized (RHCP) waves can be manipulated arbitrarily and independently. Meanwhile, the design of the array phase is utilized for the dual-mode dual-circularly polarized beam generation. Simulation and sample measurements provide validation data for the feasibility of this method, in which the measurement results are in excellent consistency with the simulation ones. This proposed method paves the way toward the enhancement of the channel capacity of mobile communication.

DDT-RELATED PROTEIN4-IMITATION SWITCH alters nucleosome distribution to relieve transcriptional silencing in Arabidopsis.

DNA methylation is a conserved epigenetic modification that is typically associated with silencing of transposable elements and promoter methylated genes. However, some DNA-methylated loci are protected from silencing, allowing transcriptional flexibility in response to environmental and developmental cues. Through a genetic screen in Arabidopsis (Arabidopsis thaliana), we uncovered an antagonistic relationship between the MICRORCHIDIA (MORC) protein and the IMITATION SWITCH (ISWI) complex in regulating the DNA-methylated SUPPRESSOR OF DRM1 DRM2 CMT3 (SDC) reporter. We demonstrate that components of the plant-specific ISWI complex, including CHROMATIN REMODELING PROTEIN11 (CHR11), CHR17, DDT-RELATED PROTEIN4 (DDR4), and DDR5, function to partially derepress silenced genes and transposable elements (TEs), through their function in regulating nucleosome distribution. This action also requires the known transcriptional activator DNAJ proteins, providing a mechanistic link between nucleosome remodeling and transcriptional activation. Genome-wide studies revealed that DDR4 causes changes in nucleosome distribution at numerous loci, a subset of which is associated with changes in DNA methylation and/or transcription. Our work reveals a mechanism for balancing transcriptional flexibility and faithful silencing of DNA-methylated loci. As both ISWI and MORC family genes are widely distributed across plant and animal species, our findings may represent a conserved eukaryotic mechanism for fine-tuning gene expression under epigenetic regulation.

Mesenchymal stem cells shuttling miR-503 via extracellular vesicles enhance glioma immune escape.

Glioma is emerging as an aggressive type of glioma characterized by invasive growth pattern and dismal oncologic outcomes. microRNAs (miRNAs) have been attracting research attention in tumorigenesis. Herein, the aim of the current investigation was to explore the functional role of mesenchymal stem cells (MSCs)-derived extracellular vesicles (EVs) containing miR-503 in glioma. The glioma tissues and corresponding normal brain tissues were collected from patients with glioma, followed by quantification of miR-503, kinesin family member 5A (KIF5A) and interleukin-7 (IL-7). EVs were isolated from bone marrow MSCs and identified by transmission electron microscope and nanoparticle tracking analysis. EVs from miR-503 mimic-transfected MSCs, miR-503 agomir,, oe-KIF5A, or sh-IL-7 was delivered into glioma cells to determine their effects on biological behaviors of glioma and T cells as well as the release of immunosuppressive factors. Lastly, a mouse model of glioma was developed to validate the function in vivo. miR-503 was expressed at a high level in glioma tissues while KIF5A was poorly expressed and targeted by miR-503. Furthermore, miR-503 loaded in MSC-EVs or upregulated miR-503 was demonstrated to facilitate glioma cell proliferation, migration and invasion accompanied by promoted release of immunosuppressive factors. Effects of overexpressed KIF5A on T cell behavior modulation were dependent on the IL-7 signaling pathway. Such results were reproduced in mice with glioma. Collectively, the discovery of miR-503 incorporated in MSC-EVs being a regulator that controls immune escape in glioma provides a novel molecular insight that holds promises to develop therapeutic strategies against glioma.

miR-31 from Mesenchymal Stem Cell-Derived Extracellular Vesicles Alleviates Intervertebral Disc Degeneration by Inhibiting NFAT5 and Upregulating the Wnt/ß-Catenin Pathway.

In this study, we explored the regulatory mechanism of intervertebral disc degeneration (IDD) that involves miR-31 shuttled by bone marrow mesenchymal stem cell-derived extracellular vesicles (BMSC-EVs) and its downstream signaling molecules. Nucleus pulposus cells (NPCs) were isolated and treated with TNF-α to simulate IDD in vitro. The TNF-α-exposed NPCs were then cocultured with hBMSCs or hBMSC-EVs in vitro to detect the effects of hBMSC-EVs on NPC viability, apoptosis, and ECM degradation. Binding between miR-31 and NFAT5 was determined. A mouse model of IDD was prepared by vertebral disc puncture and injected with EVs from hBMSCs with miR-31 knockdown to discern the function of miR-31 in vivo. The results demonstrated that hBMSC-EVs delivered miR-31 into NPCs. hBMSC-EVs enhanced NPC proliferation and suppressed cell apoptosis and ECM degradation, which was associated with the transfer of miR-31 into NPCs. In NPCs, miR-31 bound to the 3'UTR of NFAT5 and inhibited NFAT5 expression, leading to activation of the Wnt/ß-catenin pathway and thus promoting NPC proliferation and reducing cell apoptosis and ECM degradation. In addition, miR-31 in hBMSC-EVs alleviated the IDD in mouse models. Taken together, miR-31 in hBMSC-EVs can alleviate IDD by targeting NFAT5 and activating the Wnt/ß-catenin pathway.

Long-term results of trans-scaphoid perilunate fracture dislocations treated by open reduction and internal fixation.

PURPOSE: The paper holds the research purpose of confirming the long-term results of trans-scaphoid perilunate fracture dislocations (TSPFD) under the treatment of open reduction and internal fixation. METHODS: Anteroposterial-lateral radiographs of the patient's wrist were taken before and after surgery. We use a dorsal approach for all cases. Postoperative clinical and radiographic assessments were performed routinely. The scapholunate angle (SLA), estradiol angle (RLA), as well as lunotriquetral distance (LTD) assisted in the radiographic assessment. Clinical assessment was performed using the Krimmer score, modified Mayo wrist score (MWS), active flexion extension arc (FEA), radial deviation and ulnar deviation arc (RUDA) and grip strength. A visual analog scale (VAS) assisted in the pain evaluation, the VAS score ranges from 0 to 10. RESULTS: Twenty-two TSPFD patients due to the wrist trauma received operative treatment and we retrospectively analyzed the surgical results, together with evaluating their clinical and radiological follow-up. These patients held a mean age of 30 years old. Herzberg's perilunate fracture-dislocation classification was taken into account to find that 19 males and 3 females suffered dorsal dislocation. The fellow-up time lasted 98.3 months on average. All cases obtained sufficient union after open reduction and internal fixation. The last follow-up found the median of grip strength was 20.00 (interquartile range, 20.00-21.25), which was 84.5% of the normal side. The modified Mayo wrist score evaluation scale considered 12 cases as excellent, and 10 good. The median of VAS and Krimmer scores at the final follow-up were 1.50 (interquartile range, 0.75-2.00) and 100.00 (interquartile range, 100.00-100.00), respectively, higher relative to the pre-operation (P < 0.001). No patients showed nerve damage preoperatively or postoperatively, or pin tract infection in any of the patient. CONCLUSIONS: It is necessary to diagnose such complicated biomechanical damage in early stage and adopt the open reduction and stable fixation for treatment; appropriate treatment can contribute to a functionally adequate and anatomically integrated wrist.

Oncologic and functional outcomes of different reconstruction modalities after resection of chondrosarcoma of the scapula: a medium- to long-term follow-up study.

OBJECTIVES: To evaluate the oncologic and functional results of scapular reconstruction after partial or total scapulectomy for chondrosarcoma. MATERIALS AND METHODS: Twenty-one patients with chondrosarcoma who underwent partial or total scapulectomy between January 2005 and July 2019 were reviewed retrospectively. RESULTS: At a mean follow-up of 62.6 months (range, 13-123 months), four patients developed local recurrence, and three developed distant metastases, one of which developed both recurrence and metastasis. The overall survival rate of patients at 5 years was 84.6%, the disease-free survival rate was 69.3%, and the complication rate was 19% (4/21). The 1993 American Musculoskeletal Tumor Society (MSTS93) scores of patients in the partial scapulectomy group, total scapulectomy + humeral suspension group and prosthetic reconstruction group were 26.50 ± 1.38, 19.00 ± 2.58, and 21.38 ± 2.62, respectively. There was a statistically significant difference between the partial scapulectomy group and the total scapulectomy + humeral suspension or prosthetic reconstruction group ( P = 0.006 and 0.0336, respectively). The range of motion of the shoulder joint for forward flexion was 80.83° ± 11.14°, 51.25° ± 21.36°, and 52.50° ± 11.02°, respectively. The p-values for the comparison between the partial scapulectomy group and the total scapulectomy + humeral suspension or prosthetic reconstruction group were 0.0493 and 0.0174, respectively. And the range of motion of abduction was 75.00° ± 10.49°, 32.50° ± 11.90°, 41.88° ± 11.63°, respectively. Patients in the partial scapulectomy group had significantly better postoperative shoulder abduction function than the total scapulectomy + humeral suspension or prosthetic reconstruction group (P = 0.0035 and 0.0304, respectively). There was no significant difference in MSTS93 scores and flexion and abduction function of the shoulder joint in the upper extremity after total scapulectomy with humeral suspension or prosthetic reconstruction (P > 0.05). CONCLUSIONS: Surgical treatment of chondrosarcoma of the scapula can achieve a satisfactory prognosis and shoulder function. Total scapulectomy followed by prosthetic reconstruction or humeral suspension are both feasible treatments.

Bone Marrow Mesenchymal Stem Cell-Derived Extracellular Vesicles Carrying circ_0050205 Attenuate Intervertebral Disc Degeneration.

Objective: It has been reported that bone marrow mesenchymal stem cells (BMSCs) are a potential source of autologous stem cells to support the nucleus pulposus (NP) regeneration in intervertebral disc degeneration (IDD). Herein, we aim to study the mechanism underlying the effects of BMSC-derived extracellular vesicles (BMSC-EVs) on nucleus pulposus cells (NPCs) in IDD. Methods: EVs were isolated from BMSCs. An IDD model was surgically established in C57BL/6J mice. NPCs were exposed to tBHP to establish an IDD cell model. RNA sequencing was performed to identify differentially expressed circRNAs in NP tissues harvested from mice with IDD. Interactions among circ_0050205, miR-665, and GPX4 were validated, and different interventions were used to study the roles of these molecules in NPC biological functions. Results: BMSC-EVs promoted NPC survival and inhibited NPC apoptosis and extracellular matrix (ECM) degradation. circ_0050205 expression was downregulated in the NP tissues of IDD mice, and BMSC-EVs facilitated NPC survival and suppressed ECM degradation in NPCs by transferring circ_0050205. circ_0050205 sponged miR-665 and upregulated GPX4 expression. BMSC-EVs expressing circ_0050205 promoted NPC survival-inhibited ECM degradation in NPCs and alleviated IDD in mice via the miR-665/GPX4 axis. Conclusion: In conclusion, BMSC-EVs promoted NPC survival-inhibited ECM degradation in NPCs and attenuated IDD progression via the circ_0050205/miR-665/GPX4 axis.

circ_0072464 Shuttled by Bone Mesenchymal Stem Cell-Secreted Extracellular Vesicles Inhibits Nucleus Pulposus Cell Ferroptosis to Relieve Intervertebral Disc Degeneration.

Ferroptosis, as an iron-dependent form of necrotic cell death, has been reported to affect activities of nucleus pulposus cells (NPCs). However, its role in the pathogenesis of intervertebral disc degeneration (IDD) is largely unknown. Notably, our bioinformatics analysis predicted that circ_0072464 was downregulated in nucleus pulposus of IDD mice. Therefore, this study is aimed at clarifying the mechanisms of extracellular vesicle- (EV-) encapsulated circ_0072464 derived from bone marrow mesenchymal stem cells (BMSCs) in NPC ferroptosis in IDD. EVs were extracted from mouse BMSCs (BMSC-EVs) and then cocultured with IL-1ß-induced NPCs, followed by detection of matrix synthesis, proliferation, and ferroptosis of NPCs based on gain- or loss-of-function experiments. It was found that the uptake of BMSC-EVs by NPCs alleviated IDD. circ_0072464 and NRF2 were downregulated, and miR-431 was upregulated in IDD. Mechanistically, circ_0072464 competitively bound to miR-431, which targeted and inhibited NRF2 expression. BMSC-derived EVs carrying circ_0072464 inhibited NPC ferroptosis to promote matrix synthesis and proliferation of NPCs by inhibiting miR-431 and upregulating NRF2. Besides, in vivo experiments also confirmed that BMSC-EVs alleviated intervertebral disc lesions in mice with IDD through the circ_0072464/miR-431/NRF2 axis. Collectively, BMSC-EV-loaded circ_0072464 inhibited NPC ferroptosis to relieve IDD via upregulation of miR-431-mediated NRF2, therefore providing a potential therapeutic target against IDD.

Dumbbell-type tenosynovial giant cell tumor of the buttocks: a report of two cases.

Background: Tenosynovial giant cell tumor (TSGCT) is a benign tumor derived from the synovium of the joints, bursa, and tendon sheaths, which is mainly located around the tendon sheath of hand and foot. Extra-articular TSGCT are relatively rare and are mainly found in the soft tissue around the large joint. They are rarer when located purely intramuscular or subcutaneous, and mostly in the lower extremities. Case Description: We report two rare cases of completely extra-articular TSGCT located at the buttocks. One case was a 23-year-old young male presenting with left buttock swelling and pain for 1 year. Magnetic resonance imaging (MRI) examination revealed a dumbbell-type cystic solid mass in the left buttock, growing anteriorly from the deep surface of the gluteus muscle along the medial of the lesser trochanter. The lesion showed a heterogeneous mixed signal and was well-defined. MRI presentation needs to be differentiated with neurogenic or mesenchymal tumors, and radical resection of left gluteal tumor + neurovascular exploration surgery was performed. Another case of TSGCT we present here was diagnosed in a 55-year-old male elderly patient. Computed tomography angiography (CTA) revealed an irregular soft tissue mass in the left buttock involving the sacroiliac joint. T1-weighted imaging (T1WI) on MRI showed a mixed signal with predominantly isosignal, well-defined, and seemingly enveloped. A left buttock tumor resection with the scraping of the sacroiliac joint lesion was performed. Conclusions: Based on histopathological examination, the diagnosis was diffuse-type TSGCT for both cases. Both patients were periodically monitored after surgery, and one of them showed no imaging findings of recurrence or metastases seven years after surgery; the other case showed recurrence one year after surgery, which was resected and treated with radiotherapy, and there has been no recurrence so far. TSGCT occurring completely intramuscular is rare, with atypical clinical symptoms and imaging presentation, requiring differentiation with mesenchymal and giant cell-rich tumors.

Bevacizumab attenuates osteosarcoma angiogenesis by suppressing MIAT encapsulated by serum-derived extracellular vesicles and facilitating miR-613-mediated GPR158 inhibition.

Targeting angiogenesis has been considered a promising treatment for a large number of malignancies, including osteosarcoma. Bevacizumab (Bev) is an anti-vascular endothelial growth factor being used for this purpose. We herein investigate the therapeutic potential of Bev in angiogenesis during osteosarcoma and the related mechanisms. Bioinformatics were performed for identification of osteosarcoma-related microarray dataset to collect related lncRNA and miRNA, with MIAT and miR-613 obtained. The predicted binding site between miR-613 and GPR158 3'UTR region was further confirmed by luciferase assay. Then, their effects combined with treatment with Bev on osteosarcoma cells were explored by the gain- and loss-of-function. After extraction from osteosarcoma patients' serum (serum-EVs) and identification, EVs were co-cultured with osteosarcoma cells, the biological behaviors of which were detected by CCK-8 assay and microtubule formation in vitro. A mouse tumor xenograft model was used to determine the effect of Bev on tumor angiogenesis in vivo. Bev inhibited osteosarcoma cell proliferation and angiogenesis in vivo and in vitro. Besides, serum-EVs could transfer MIAT (EV-MIAT) into osteosarcoma cells, where it is competitively bound to miR-613 to elevate GPR158, thus promoting osteosarcoma cell proliferation and angiogenesis. Furthermore, Bev arrested osteosarcoma cell proliferation and angiogenesis by inhibiting EV-MIAT and inducing miR-613-mediated GPR158 inhibition. In conclusion, the Bev-mediated MIAT/miR-613/GPR158 regulatory feedback revealed a new molecular mechanism in the pathogenesis of osteosarcoma angiogenesis.

Depleted Long Noncoding RNA GAS5 Relieves Intervertebral Disc Degeneration via microRNA-17-3p/Ang-2.

Intervertebral disc degeneration (IVDD) remains a clinical challenge and requires more effective therapeutic targets. Long noncoding RNAs (lncRNAs) have emerged as critical modulators of multiple biological processes, such as cell proliferation and extracellular matrix (ECM) remodeling. Accordingly, the current study sets out to explore the influence of the lncRNA growth arrest-specific 5 (GAS5) on IVDD and investigate the possible involvement of microRNA-17-3p (miR-17-3p)/Angiopoietin-2 (Ang-2) axis. Firstly, the expression patterns of GAS5, miR-17-3p, and Ang-2 were characterized by RNA quantification from the isolated human degenerative nucleus pulposus (NP) tissues. miR-17-3p was found to express at an abnormal low level while GAS5 and Ang-2 expressed at aberrant high level in the human degenerative NP tissues. Utilizing dual-luciferase reporter, RNA immunoprecipitation, and pull-down assays, GAS5 was found to competitively bound to miR-17-3p and further upregulate the expression of Ang-2, a target gene of miR-17-3p. Employing gain- and loss-of-function approaches, their expressions were altered in human degenerative nucleus pulposus cells (NPCs), followed by IL-1ß treatment, in order to identify their roles in NP cell proliferation, apoptosis, and ECM metabolism. Silencing of GAS5 expression restrained the levels of cleaved caspase-3, cleaved caspase-7, cleaved caspase-9, MMP3, MMP13, ADAMTS4, and ADAMTS5 and increased collagen II and aggrecan levels. In vitro experiments also revealed that GAS5 depletion inhibited apoptosis and ECM degradation in HDNPCs, while elevating the proliferation through downregulation of Ang-2 by increasing miR-17-3p. Furthermore, in vivo data further validated that either GAS5 silencing or miR-17-3p reexpression alleviated IVDD degree with the help of IVDD mouse models. Altogether, our findings substantiated that downregulation of GAS5 reduced NPC apoptosis and promoted ECM remodeling, ultimately ameliorating the IVDD via miR-17-3p-dependent inhibition of Ang-2. We hope our discoveries offer a fresh molecular insight that can aid the development of novel therapies against IVDD.

Risk factors for lymph node metastasis of soft tissue sarcomas of the head, neck, and extremities, and the clinical significance of negative lymph node dissection.

BACKGROUND: This study sought to define the risk factors for lymph node metastasis (LNM) of soft tissue sarcomas (STS) of the head, neck, and extremities, and the clinical significance of negative lymph node dissection (NLND). METHODS: STS patient data in the Surveillance, Epidemiology, and End Results (SEER) database from 1988 to 2015 were extracted and pooled. Logistics regression analysis was used to identify risk factors for LNM, Cox proportional hazards and Fine-Grey's models were used for survival analysis, and Propensity score matching analysis (PSM) was used to assess the impact of NLND on patient prognosis. RESULTS: A total of 3276 patients were enrolled in the study, of whom 283 (8.6%) developed LNM. Rhabdomyosarcoma had the highest rate of LNM (25.3%), followed by clear cell sarcoma (16.8%) and epithelioid sarcoma (12.4%), while leiomyosarcoma had the lowest rate of LNM (1.3%). Sex, tumor size, grade, histology, and site were significantly associated with LNM. For specific histologic subtypes of STS, NLND significantly improves overall survival (HR: 0.718, 95%CI 0.535-0.962; P = 0.026) and cancer-specific survival (HR: 0.699, 95%CI 0.506-0.967; P = 0.031) and reduces cancer-specific mortality (Gray's test, P = 0.017). However, NLND did not improve overall survival (P = 0.46) or reduce cancer-specific mortality (Gray's test, P = 0.772) of patients with leiomyosarcoma. CONCLUSIONS: Histology is an independent risk factor for LNM in STS of the head, neck, and extremities. Prophylactic NLND treatment was necessary and had a clinical benefit for patients with STS who were at high risk for LNM but had no significant impact on the prognosis of patients with leiomyosarcoma.

The role of ATXR6 expression in modulating genome stability and transposable element repression in Arabidopsis.

ARABIDOPSIS TRITHORAX-RELATED PROTEIN 5 (ATXR5) AND ATXR6 are required for the deposition of H3K27me1 and for maintaining genomic stability in Arabidopsis Reduction of ATXR5/6 activity results in activation of DNA damage response genes, along with tissue-specific derepression of transposable elements (TEs), chromocenter decompaction, and genomic instability characterized by accumulation of excess DNA from heterochromatin. How loss of ATXR5/6 and H3K27me1 leads to these phenotypes remains unclear. Here we provide extensive characterization of the atxr5/6 hypomorphic mutant by comprehensively examining gene expression and epigenetic changes in the mutant. We found that the tissue-specific phenotypes of TE derepression and excessive DNA in this atxr5/6 mutant correlated with residual ATXR6 expression from the hypomorphic ATXR6 allele. However, up-regulation of DNA damage genes occurred regardless of ATXR6 levels and thus appears to be a separable process. We also isolated an atxr6-null allele which showed that ATXR5 and ATXR6 are required for female germline development. Finally, we characterize three previously reported suppressors of the hypomorphic atxr5/6 mutant and show that these rescue atxr5/6 via distinct mechanisms, two of which involve increasing H3K27me1 levels.

IGF2BP2 Induces U251 Glioblastoma Cell Chemoresistance by Inhibiting FOXO1-Mediated PID1 Expression Through Stabilizing lncRNA DANCR.

Glioma is the most common type of malignant tumor of the nervous system and is characterized by high mortality and poor outcome. This study aims to investigate the mechanism underlying IGF2 mRNA-binding protein 2 (IGF2BP2) and long noncoding RNA DANCR in etoposide resistance of glioblastoma (GBM) cells. Bioinformatics analysis identified the IGF2BP2-related regulators and DANCR target genes, which were subsequently evaluated by RNA pull-down and RIP assays. We exposed GBM cells to etoposide and thus established etoposide-resistant cells. Through functional experiments, we evaluated the interrelationship among IGF2BP2, DANCR, phosphotyrosine interaction domain containing 1 (PID1), and forkhead box protein O1 (FOXO1) and further assessed their impact on the sensitivity of GBM cells to etoposide. IGF2BP2 and DANCR were highly expressed in glioma cells and tissues, whereas PID1 and FOXO1 were poorly expressed. Mechanistically, overexpression of IGF2BP2 promoted DANCR stability and reduced DANCR methylation, whereas silencing of IGF2BP2 reduced survival of GBM cells and etoposide-resistant cells. Besides, DANCR interacted with FOXO1 to promote the ubiquitination of FOXO1. FOXO1 promoted the transcriptional expression of PID1, enhancing the chemotherapy sensitivity of GBM cells, but overexpression of PID1 reversed the impact of IGF2BP2. Collectively, IGF2BP2 inhibits PID1 expression through the DANCR/FOXO1 axis, inducing drug resistance in GBM cells, and promoting glioma progression.

The characterization of Mediator 12 and 13 as conditional positive gene regulators in Arabidopsis.

Mediator 12 (MED12) and MED13 are components of the Mediator multi-protein complex, that facilitates the initial steps of gene transcription. Here, in an Arabidopsis mutant screen, we identify MED12 and MED13 as positive gene regulators, both of which contribute broadly to morc1 de-repressed gene expression. Both MED12 and MED13 are preferentially required for the expression of genes depleted in active chromatin marks, a chromatin signature shared with morc1 re-activated loci. We further discover that MED12 tends to interact with genes that are responsive to environmental stimuli, including light and radiation. We demonstrate that light-induced transient gene expression depends on MED12, and is accompanied by a concomitant increase in MED12 enrichment during induction. In contrast, the steady-state expression level of these genes show little dependence on MED12, suggesting that MED12 is primarily required to aid the expression of genes in transition from less-active to more active states.

Genome mining and biosynthesis of a polyketide from a biofertilizer fungus that can facilitate reductive iron assimilation in plant.

Fungi have the potential to produce a large repertoire of bioactive molecules, many of which can affect the growth and development of plants. Genomic survey of sequenced biofertilizer fungi showed many secondary metabolite gene clusters are anchored by iterative polyketide synthases (IPKSs), which are multidomain enzymes noted for generating diverse small molecules. Focusing on the biofertilizer Trichoderma harzianum t-22, we identified and characterized a cryptic IPKS-containing cluster that synthesizes tricholignan A, a redox-active ortho-hydroquinone. Tricholignan A is shown to reduce Fe(III) and may play a role in promoting plant growth under iron-deficient conditions. The construction of tricholignan by a pair of collaborating IPKSs was investigated using heterologous reconstitution and biochemical studies. A regioselective methylation step is shown to be a key step in formation of the ortho-hydroquinone. The responsible methyltransferase (MT) is fused with an N-terminal pseudo-acyl carrier protein (ψACP), in which the apo state of the ACP is essential for methylation of the growing polyketide chain. The ψACP is proposed to bind to the IPKS and enable the trans MT to access the growing polyketide. Our studies show that a genome-driven approach to discovering bioactive natural products from biofertilizer fungi can lead to unique compounds and biosynthetic knowledge.