miR-31-5p suppresses myocardial hypertrophy by targeting Nfatc2ip.

Cardiac hypertrophy, worldwide known as an adaptive functional compensatory state of myocardial stress, is mainly believed to proceed to severe heart diseases, even to sudden death. Emerging studies have explored the microRNA alteration during hypertrophy. However, the mechanisms of microRNAs involved in cardiac hypertrophy are still uncertain. We studied young rats to establish abdominal aorta coarctation (AAC) for 4 weeks. With the significant downregulated cardiac function and upregulated hypertrophic biomarkers, AAC-induced rats showed enlarged myocardiocytes and alterations in microRNAs, especially downregulated miR-31-5p. miR-31-5p targets the 3'UTR of Nfatc2ip and inhibits myocardial hypertrophy in vitro and in vivo. Furthermore, we verified that Nfatc2ip is necessary and sufficient for cardiac hypertrophy in neonatal rat cardiomyocytes. Moreover, we found miR-31-5p inhibited the colocalization of Nfatc2ip and hypertrophic gene ß-Mhc. Luciferase assay and ChiP-qPCR test demonstrated that Nfatc2ip binded to the core-promoter of ß-Mhc and enhanced its transcriptional activity. Above all, our study found a new pathway, mir-31-5p/Nfatc2ip/ß-Mhc, which is involved in cardiac hypertrophy, suggesting a potential target for intervention of cardiac hypertrophy.

A pressure-induced high-pressure metallic GeTe phase.

As an important phase-change material, GeTe has many high-pressure phases as well, but its phase transitions under pressure are still lack of clarity. It is challenging to identify high-pressure GeTe crystal structures owing to the phase coexistence in a wide pressure range and the reversibility of phase transitions. Hence, first-principles calculations are required to provide further information in addition to limited experimental characterizations. In this work, a new orthorhombic Cmca GeTe high-pressure phase has been predicted via the CALYPSO method as the most energetically favorable phase in the pressure range between ∼30 and ∼38.5 GPa, which would update the GeTe high-pressure phase transition sequence. The crystal structure of the Cmca phase is composed of alternate stacking puckered layers of Ge six-membered rings and Te four-membered rings along the b direction. The high density of states near the Fermi level and delocalization of electrons from the two-dimensional electron localization function indicate a strong metallic property of the Cmca phase. Electron-phonon coupling calculations indicate that the Cmca phase is superconductive below ∼4.2 K at 35 GPa. The simulated x-ray diffraction pattern of the Cmca phase implies that this phase might coexist with the Pnma-boat phase under high pressure. These results offer further understanding on the high-pressure structural evolution and physical properties in GeTe and other IV-VI semiconductors.

Improved curdlan production with discarded bottom parts of Asparagus spear.

BACKGROUND: This work evaluated the improvement of curdlan production of Agrobacterium sp. ATCC 31749 by using culture medium containing juice of discarded bottom part of green Asparagus spear (MJDA). Curdlan production was carried out using Agrobacterium sp. ATCC 31749 in flasks with different volumes of MJDA and its non-juice-adding control (CK) incubated in shaker at 30 °C, 200 rpm rotation for 168 h. RESULTS: All MJDA media increased Agrobacterium sp. ATCC 31749 cell mass and enhanced the cells' ability to utilise sucrose, the carbon source for curdlan biosynthesis, and thereby produced higher concentration of curdlan than CK which is used for commercial production of curdlan. After 168 h of fermentation, 10% MJDA produced 40.2 g/l of curdlan whiles CK produced 21.1 g/l. Curdlan production was increased by 90.4% higher in 10% MJDA than CK. Curdlan produced by 10% MJDA contains 1.2 and 1.5 µg/ml of Asparagus flavonoids and saponins respectively as additives which have wide range of health benefits. The mass of sucrose needed to produce 1.0 g curdlan by Agrobacterium sp. ATCC 31749 in CK is 1.7-fold more than in 10% MJDA. CONCLUSION: The results strongly revealed that 5-10% MJDA is a good curdlan fermentation media which increase curdlan production yield with cheaper cost of production and simultaneously reduce environmental waste resulting from the large scaled discarded bottom parts of green Asparagus spear during Asparagus production.

CrdR function in a curdlan-producing Agrobacterium sp. ATCC31749 strain.

BACKGROUND: Agrobacterium sp. ATCC31749 is an efficient curdlan producer at low pH and under nitrogen starvation. The helix-turn-helix transcriptional regulatory protein (crdR) essential for curdlan production has been analyzed, but whether crdR directly acts to cause expression of the curdlan biosynthesis operon (crdASC) is uncertain. To elucidate the molecular function of crdR in curdlan biosynthesis, we constructed a crdR knockout mutant along with pBQcrdR and pBQNcrdR vectors with crdR expression driven by a T5 promoter and crdR native promoter, respectively. Also, we constructed a pAG with the green fluorescent protein (GFP) gene driven by a curdlan biosynthetic operon promoter (crdP) to measure the effects of crdR expression on curdlan biosynthesis. RESULTS: Compared with wild-type (WT) strain biomass production, the biomass of the crdR knockout mutant was not significantly different in either exponential or stationary phases of growth. Mutant cells were non-capsulated and planktonic and produced significantly less curdlan. WT cells were curdlan-capsulated and aggregated in the stationery phase. pBQcrdR transformed to the WT strain had a 38% greater curdlan yield and pBQcrdR and pBQNcrdR transformed to the crdR mutant strain recovered 18% and 105% curdlan titers of the WT ATCC31749 strain, respectively. Consistent with its function of promoting curdlan biosynthesis, curdlan biosynthetic operon promoter (crdP) controlled GFP expression caused the transgenic strain to have higher GFP relative fluorescence in the WT strain, and no color change was observed with low GFP relative fluorescence in the crdR mutant strain as evidenced by fluorescent microscopy and spectrometric assay. q-RT-PCR revealed that crdR expression in the stationary phase was greater than in the exponential phase, and crdR overexpression in the WT strain increased crdA, crdS, and crdC expression. We also confirmed that purified crdR protein can specifically bind to the crd operon promoter region, and we inferred that crdR directly acts to cause expression of the curdlan biosynthesis operon (crdASC). CONCLUSIONS: CrdR is a positive transcriptional regulator of the crd operon for promoting curdlan biosynthesis in ATCC31749. The potential binding region of crdR is located within the -98 bp fragment upstream from the crdA start codon.

Single-cell RNA sequencing analysis reveals the distinct features of colorectal cancer with or without Fusobacterium nucleatum infection in PD-L1 blockade therapy.

MSS/pMMR patients are unresponsive to PD-1/PD-L1 blockade in colorectal cancer (CRC), but the mechanisms are unclear. A better understanding of immunotherapy resistance in CRC may lead to more precise treatment and expand the benefit of immunotherapy to patients. In this study, we constructed mouse model of subcutaneous CRC tumor received anti-PD-L1 treatment with or without fusobacterium nucleatum (F. nucleatum) infection. Then we used single-cell RNA sequencing (scRNA-seq) to explore the comprehensive landscape of the tumor microenvironment (TME). Our data delineated the composition, subclonal diversity and putative function of distinct cells, tracked the developmental trajectory of tumor cells and highlighted cell-cell interactions. We found different compositions and functions of both tumor cells and immune cells. Single anti-PD-L1 monoclonal antibody (mAb) treated tumor exhibited two specific clusters which might be resistant to PD-L1 blockade. The accumulation of immune cells, including T cell, NK cell and pro-inflammatory macrophage subset in tumors infected with F. nucleatum may be one of the reasons for the increased sensitivity to PD-L1 blockade. Thus, targeting F. nucleatum to change the composition of tumor cell subclusters and enliven the immune response might help to overcome immune checkpoint blockade (ICB) resistance.

The RNA m6A-Binding Protein YTHDC1 Is Downregulated and Associated With M2 Macrophage Infiltration in Muscle-Invasive Bladder Cancer.

Background: Dysregulation of RNA N6-methyladenosine (m6A) modification is indispensable in tumorigenesis. However, in muscle-invasive bladder cancer (MIBC), the key regulators and mechanisms involved in this process remain largely unknown. This study aimed to screen the key m6A regulators and explore its possible role in MIBC. Methods: Aberrantly expressed m6A regulator genes were screened in The Cancer Genome Atlas (TCGA) MIBC cohort (n = 408) and validated using fresh-frozen and formalin-fixed paraffin-embedded (FFPE) specimens collected during this study. Clinicopathological relevance and association with tumor immune infiltration was further assessed. Results: We identified that the expression of YT521-B homology-domain-containing protein 1 (YTHDC1), an m6A RNA-binding protein, was downregulated in tumor tissues compared with adjacent noncancerous tissues in the TCGA MIBC cohort and our clinical samples. Low YTHDC1 expression correlated with short patient survival, advanced pathologic stage, lymph node metastasis, basal-squamous molecular subtype, non-papillary histological type, and certain genetic mutations important to MIBC. Remarkably, YTHDC1 expression exhibited negative association with tumor-infiltrating M2 macrophage abundance in MIBC. Conclusion: Among m6A regulators, we identified that YTHDC1 was downregulated in MIBC and might play an important role in the pathological process in MIBC, especially tumor microenvironment regulation.

A comprehensive survey of bat sarbecoviruses across China in relation to the origins of SARS-CoV and SARS-CoV-2.

SARS-CoV and SARS-CoV-2 have been thought to originate from bats. In this study, we screened pharyngeal and anal swabs from 13 064 bats collected between 2016 and 2021 at 703 locations across China for sarbecoviruses, covering almost all known southern hotspots, and found 146 new bat sarbecoviruses. Phylogenetic analyses of all available sarbecoviruses show that there are three different lineages-L1 as SARS-CoV-related CoVs (SARSr-CoVs), L2 as SARS-CoV-2-related CoVs (SC2r-CoVs) and novel L-R (recombinants of L1 and L2)-present in Rhinolophus pusillus bats, in the mainland of China. Among the 146 sequences, only four are L-Rs. Importantly, none belong in the L2 lineage, indicating that circulation of SC2r-CoVs in China might be very limited. All remaining 142 sequences belong in the L1 lineage, of which YN2020B-G shares the highest overall sequence identity with SARS-CoV (95.8%). The observation suggests endemic circulations of SARSr-CoVs, but not SC2r-CoVs, in bats in China. Geographic analysis of the collection sites in this study, together with all published reports, indicates that SC2r-CoVs may be mainly present in bats of Southeast Asia, including the southern border of Yunnan province, but absent in all other regions within China. In contrast, SARSr-CoVs appear to have broader geographic distribution, with the highest genetic diversity and sequence identity to human sarbecoviruses along the southwest border of China. Our data provide the rationale for further extensive surveys in broader geographical regions within, and beyond, Southeast Asia in order to find the most recent ancestors of human sarbecoviruses.