Non­coding RNA: A promising diagnostic biomarker and therapeutic target for esophageal squamous cell carcinoma (Review).

Esophageal cancer (EC) is a common form of malignant tumor in the digestive system that is classified into two types: Esophageal squamous cell carcinomas (ESCC) and esophageal adenocarcinoma. ESCC is known for its early onset of symptoms, which can be difficult to identify, as well as its rapid progression and tendency to develop drug resistance to chemotherapy and radiotherapy. These factors contribute to the high incidence of disease and low cure rate. Therefore, a diagnostic biomarker and therapeutic target need to be identified for ESCC. Non-coding RNAs (ncRNAs) are a class of molecules that are transcribed from DNA but do not encode proteins. Initially, ncRNAs were considered to be non-functional segments generated during transcription. However, with advancements in high-throughput sequencing technologies in recent years, ncRNAs have been associated with poor prognosis, drug resistance and progression of ESCC. The present study provides a comprehensive overview of the biogenesis, characteristics and functions of ncRNAs, particularly focusing on microRNA, long ncRNAs and circular RNAs. Furthermore, the ncRNAs that could potentially be used as diagnostic biomarkers and therapeutic targets for ESCC are summarized to highlight their application value and prospects in ESCC.

PDGF-AA guides cell crosstalk between human dental pulp stem cells in vitro via the PDGFR-α/PI3K/Akt axis.

AIM: To explore the influence of PDGF-AA on cell communication between human dental pulp stem cells (DPSCs) by characterizing gap junction intercellular communication (GJIC) and its potential biomechanical mechanism. METHODOLOGY: Quantitative real-time PCR was used to measure connexin family member expression in DPSCs. Cell migration and CCK-8 assays were utilized to examine the influence of PDGF-AA on DPSC migration and proliferation. A scrape loading/dye transfer assay was applied to evaluate GJIC triggered by PDGF-AA, a PI3K/Akt signalling pathway blocker (LY294002) and a PDGFR-α blocker (AG1296). Western blotting and immunofluorescence were used to test the expression and distribution of the Cx43 and p-Akt proteins in DPSCs. Scanning electron microscopy (SEM) and immunofluorescence were used to observe the morphology of GJIC in DPSCs. RESULTS: PDGF-AA promoted gap junction formation and intercellular communication between human dental pulp stem cells. PDGF-AA upregulates the expression of Cx43 to enhance gap junction formation and intercellular communication. PDGF-AA binds to PDGFR-α and activates PI3K/Akt signalling to regulate cell communication. CONCLUSIONS: This research demonstrated that PDGF-AA can enhance Cx43-mediated GJIC in DPSCs via the PDGFR-α/PI3K/Akt axis, which provides new cues for dental pulp regeneration from the perspective of intercellular communication.

The synthesis of ectoine enhance the assimilation of ammonia nitrogen in hypersaline wastewater by the salt-tolerant assimilation bacteria sludge.

In contrast to nitrification-denitrification microorganisms that convert ammonia nitrogen in hypersaline wastewater into nitrogen for discharge, this research utilizes sludge enriched with salt-tolerant assimilation bacteria (STAB) to assimilate organic matter and ammonia nitrogen in hypersaline wastewater into ectoine - a biomass with high economic value and resistance to external osmotic pressure. The study investigates the relationship between the synthesis of ectoine and nitrogen removal efficiency of STAB sludge in three sequencing batch reactors (SBR) operated at different salinities (50, 75, and 100 g/L) and organic matter concentrations. The research reveals that, under low concentration carbon sources (TOC/N = 4, NH4+-N = 60 mg/L), the ammonia nitrogen removal efficiency of SBR reactors increased by 14.51 % and 17.25 % within 5 d and 2 d, respectively, when salinity increased from 50 g/L to 75 g/L and 100 g/L. Under high concentration carbon sources (TOC/N = 8, NH4+-N = 60 mg/L), the ammonia nitrogen removal efficiency of STAB sludge in the three reactors stabilized at 80.20 %, 76.71 %, and 72.87 %, and the total nitrogen removal efficiency was finally stabilized at 80.47 %, 73.15 %, and 65.53 %, respectively. The nitrogen removal performance by ammonium-assimilating of STAB sludge is more sustainable under low salinity, while it is more short-term explosive under high salinity. Moreover, the intracellular ectoine concentration of STAB sludge was found to be related to this behavior. Empirical formulas confirm that STAB sludge synthesizes ectoine from nutrients in wastewater through assimilation, and intracellular ectoine has a threshold defect (150 mg/gVss). The ectoine metabolism pathways of STAB sludge was constructed using the Kyoto Encyclopedia of Genes and Genomes (KEGG). The ammonia nitrogen in sewage is converted into glutamic acid under the action of assimilation genes. It then undergoes a tricarboxylic acid cycle to synthesize the crucial precursor of ectoine - aspartic acid. Subsequently, ectoine is produced through ectoine synthase. The findings suggest that when the synthesis of intracellular ectoine reaches saturation, it inhibits the continuous nitrogen removal performance of STAB sludge under high salinity. STAB sludge does not actively release ectoine through channels under stable external osmotic pressure.

Stiffened fibre-like microenvironment based on patterned equidistant micropillars directs chondrocyte hypertrophy.

Articular cartilage, composed of collagen type II as a major extracellular matrix and chondrocyte as a unique cell type, is a specialized connective tissue without blood vessels, lymphatic vessels and nerves. This distinctive characteristic of articular cartilage determines its very limited ability to repair when damaged. It is well known that physical microenvironmental signals regulate many cell behaviors such as cell morphology, adhesion, proliferation and cell communication even determine chondrocyte fate. Interestingly, with increasing age or progression of joint diseases such as osteoarthritis (OA), the major collagen fibrils in the extracellular matrix of articular cartilage become larger in diameter, leading to stiffening of articular tissue and reducing its resistance to external tension, which in turn aggravates joint damage or progression of joint diseases. Therefore, designing a physical microenvironment closer to the real tissue and thus obtaining data closer to the real cellular behaviour, and then revealing the biological mechanisms of chondrocytes in pathological states is of crucial importance for the treatment of OA disease. Here we fabricated micropillar substrates with the same topology but different stiffnesses to mimic the matrix stiffening that occurs in the transition from normal to diseased cartilage. It was first found that chondrocytes responded to stiffened micropillar substrates by showing a larger cell spreading area, a stronger enhancement of cytoskeleton rearrangement and more stability of focal adhesion plaques. The activation of Erk/MAPK signalling in chondrocytes was detected in response to the stiffened micropillar substrate. Interestingly, a larger nuclear spreading area of chondrocytes at the interface layer between the cells and top surfaces of micropillars was observed in response to the stiffened micropillar substrate. Finally, it was found that the stiffened micropillar substrate promoted chondrocyte hypertrophy. Taken together, these results revealed the cell responses of chondrocytes in terms of cell morphology, cytoskeleton, focal adhesion, nuclei and cell hypertrophy, and may be beneficial for understanding the cellular functional changes affected by the matrix stiffening that occurs during the transition from a normal state to a state of osteoarthritis.

Platelet-derived growth factor PDGF-AA upregulates connexin 43 expression and promotes gap junction formations in osteoblast cells through p-Akt signaling.

Gap junctions, which are mainly composed of connexin units, play an indispensable role in cell morphogenesis, proliferation, migration, adhesion and differentiation of osteoblast lineage cells, and thus mediate bone development, homeostasis and disease occurrence. Platelet-derived growth factor-AA (PDGF-AA) is proved to have a great influence on osteoblast cell lines and is widely applied in the field of bone defect and wound healing. However, the role of PDGF-AA on gap junction formation in the osteoblast lineage remains elusive. In the current study, we aimed to investigate the impact of PDGF-AA on gap junction formation and cell-to-cell communication in the osteoblast lineage and explore its underlying biomechanism. We first found that PDGF-AA promoted cell proliferation and thus increased gap junction formations in living primary osteoblasts and MC3T3-E1 cells through scrape loading and dye transfer (SL/DT) assay. We then confirmed that PDGF-AA enhanced gap junction formations through up-regulation of connexin 43 (Cx43). We next detected the activation of p-Akt signaling in primary osteoblasts and MC3T3-E1 cells that were induced by PDGF-AA. Through inhibitory experiments, we further confirmed that PDGF-AA-mediated gap junction formation occurred via the activation of PI3K/Akt signaling. Taking together, our results provided evidences that PDGF-AA promoted gap junction formation in the osteoblast lineage through p-Akt signaling, which helped to understand the role of PDGF-AA in bone regeneration and diseases.

First Report of Blight Caused by Rhizoctonia solani AG4-HGI on Pinellia ternata in Guizhou, China.

Pinellia ternata (Thumb.) has been used for over 1000 years as a traditional Chinese herbal medicine (Ying et al. 2007) and is widely cultivated in Guizhou Province, China. It is cultivated over an area of 2000 hectares, and is of great value to underdeveloped regions. In April 2020, blight was observed in a field of P. ternatain Bijie County, Guizhou Province, China (27°30'N, 105°28'E). Around 20 hectares of P. ternata were surveyed and the disease incidence ranged from 10 to 12%. The disease symptoms included light brown lesions formed on the stems near the soil line. The color of the lesions became darker, and the stems became constricted around the lesions and broke, associated with the leaf blight. To identify the causal agent of this blight, 22 diseased plants (about 30 d-old） were collected, the margins of the infected parts were cut into small pieces (5 mm) and surface disinfested with 1% NaOCl for 10 min, 75% ethanol for 30 s, and rinsed three times in sterile distilled water. The pieces were blotted dry with sterile filter paper and placed on potato dextrose agar (PDA, Hopebio, China), incubated at 28℃ in darkness until fungal hyphae growth was visible. Sixteen cultures with different morphologies were recovered from the samples. When representative isolates of each culture type were inoculated onto plants, one produced similar blight symptoms. The representative isolate was called CD-1. The colony color was first white but turned light brown after grown on PDA for 6-7 d, and produced dark brown sclerotia. The hyphae were branched at right angles, with a slight constriction at the base of the branches and a septum near the junction where the branch separates from the main hyphae. Hyphal cells were stained with 0.5% Safranin O and 3% KOH and were observed to be multinucleate. These morphological features indicated that CD-1 likely is R. solani (Sneh et al. 1991). When paired with tester strains AG1 and AG4(provided by Dr. Genhua Yang, Yunnan Agricultural University). CD-1 showed anastomosis with isolate of AG4 (Fenille et al. 2002). Genomic DNA was extracted from the isolate (Thangaraj et al. 2018) using a fungal genomic DNA extraction kit (Tiangen, China). The internal transcribed spacer (ITS) regions were amplified using the primers ITS1/ITS4 (White et al. 1990). A 535 bp fragment was amplified that showed 99% coverage and 99.4% identity with an isolate of R. solani AG4-HGI (GenBank: HG934417). The gene sequence was deposited in GenBank as accession #OL518945. Pathogenicity tests were performed using 30 d-old plants planted in sterilized soil in pots. Cut mycelial discs (diameter 6 mm) from 3-day-old PDA cultures and placed beside stems of 21 healthy plants. Nine plants treated with agar plugs were control samples. Inoculated plants were maintained at 24 ± 5℃ in a green house and watered every two days with sterilized water. Typical blight symptoms developed on the inoculated plants at d 3-5 post inoculation, whereas the control plants remained healthy. The experiments were repeated three times, and the isolates was re-isolated from the inoculated plants and identified as R. solaniAG4 by morphological features and molecular method. R. solani has been reported to cause blight of many plants such as coffee (Ren et al. 2018) and sesame (Cochran et al. 2018). To the best of our knowledge, this is the first report of R. solani AG4-HGI causing disease on P. ternate, both in China and worldwide. This finding suggests that this pathogen may cause a threat to cultivation and production of P. terenata.

Transcriptomic analysis of Pinellia ternata (Thunb.) Breit T2 plus line provides insights in host responses resist Pectobacterium carotovorum infection.

Transcriptome is used to determine the induction response of Pinellia ternata (Thunb.) Breit T2 plus line (abbreviated as PT2P line) infected with Pectobacterium carotovorum. The main objective of the study was to deal with the transcriptome database of PT2P line resistance to soft rot pathogens to provide a new perspective for identifying the resistance-related genes and understanding the molecular mechanism. Results indicated that water soaking and tissue collapse started at 20 h after PT2P line was infected by P. carotovorum. A total of 1360 and 5768 differentially expressed genes (DEGs) were identified at 0 h and 20 h, respectively. After 20 h of infection, growth and development-related pathways were inhibited. Meanwhile, DEGs were promoted the colonization of P. carotovorum pathogens in specific cell wall modification processes at the early infected stage. A shift to a defensive response was triggered at 0 h. A large number of DEGs were mainly up-controlled at 20 h and were substantially used in the pathogen recognition and the introduction of signal transformation cascades, secondary metabolites biosynthesis, pathogenic proteins activation, transcription aspects and numerous transporters. Furthermore, our data provided novel insights into the transcript reprogramming of PT2P line in response to P. carotovorum infestation.