Characterization and acceleration of genome shuffling and ploidy reduction in synthetic allopolyploids by genome sequencing and editing

Polyploidy and the subsequent ploidy reduction and genome shuffling are the major driving forces of genome evolution. Here, we revealed short-term allopolyploid genome evolution by sequencing a synthetic intergeneric hybrid (Raphanobrassica, RRCC). In this allotetraploid, the genome deletion was quick, while rearrangement was slow. The core and high-frequency genes tended to be retained while the specific and low-frequency genes tended to be deleted in the hybrid. The large-fragment deletions were enriched in the heterochromatin region and probably derived from chromosome breaks. The intergeneric translocations were primarily of short fragments dependent on homoeology, indicating a gene conversion origin. To accelerate genome shuffling, we developed an efficient genome editing platform for Raphanobrassica. By editing Fanconi Anemia Complementation Group M (FANCM) genes, homoeologous recombination, chromosome deletion and secondary meiosis with additional ploidy reduction were accelerated. FANCM was shown to be a checkpoint of meiosis and controller of ploidy stability. By simultaneously editing FLIP genes, gene conversion was precisely introduced, and mosaic genes were produced around the target site. This intergeneric hybrid and genome editing platform not only provides models that facilitate experimental evolution research by speeding up genome shuffling and conversion but also accelerates plant breeding by enhancing intergeneric genetic exchange and creating new genes.     

Intra‐amniotic mesenchymal stem cell therapy improves the amniotic fluid microenvironment in rat spina bifida aperta fetuses

ObjectivesSpina bifida aperta (SBA) is one of the most common neural tube defects. Neural injury in SBA occurs in two stages involving failed neural tube closure and progressive degeneration through contact with the amniotic fluid. We previously suggested that intra‐amniotic bone marrow‐derived mesenchymal stem cell (BMSC) therapy for fetal rat SBA could achieve beneficial functional recovery through lesion‐specific differentiation. The aim of this study is to examine whether the amniotic fluid microenvironment can be improved by intra‐amniotic BMSC transplantation.MethodsThe intra‐amniotic BMSC injection was performed using in vivo rat fetal SBA models. The various cytokine expressions in rat amniotic fluid were screened by protein microassays. Intervention experiments were used to study the function of differentially expressed cytokines.ResultsA total of 32 cytokines showed significant upregulated expression in the BMSC‐injected amniotic fluid. We focused on Activin A, NGF, BDNF, CNTF, and CXCR4. Intervention experiments showed that the upregulated Activin A, NGF, BDNF, and CNTF could inhibit apoptosis and promote synaptic development in fetal spinal cords. Inhibiting the activity of these factors weakened the anti‐apoptotic and pro‐differentiation effects of transplanted BMSCs. Inhibition of CXCR4 activity reduced the engraftment rate of BMSCs in SBA fetuses.ConclusionBMSC transplantation can improve the amniotic fluid environment, and this is beneficial for SBA repair.

In utero intra‐amniotic BMSC or PBS microinjection in the E15 fetuses was performed in E15 rat fetuses with spina bifida aperta, and amniotic fluid was collected at E21 for protein array detection. Venn diagram shows the relationship of three biological processes (GO: 0030335, 0048699, and 0043524) and the attribution of differentially expressed proteins. Comparative analysis of five proteins with the largest fold changes in the process of generation of neurons.     

CDT1 is the major functional regulatory subunit of the pre‐replication complex in zygotes

Pre‐replication complex (pre‐RC) is critical for DNA replication initiation. CDT1 and MCM2 are the subunits of pre‐RC, and proper regulation of CDT1 and MCM2 are necessary for DNA replication and cell proliferation. The present study aimed to explore the role of CDT1 and MCM2 in oocyte meiotic maturation and early embryonic development. The depletion and overexpression of Cdt1 and Mcm2 in oocyte and zygote were achieved by microinjecting specific siRNA and mRNA to explored their functions in oocyte meiotic maturation and embryonic development. Then, we examined the effect of CDT1 and MCM2 on other signal pathways by immunostaining the expression of related maker genes. We showed that neither depletion nor overexpression of Cdt1 affected oocyte meiotic progressions. The CDT1 was degraded in S phase and remained at a low level in G2 phase of zygote. Exogenous expression of Cdt1 in G2 phase led to embryo attest at zygote stage. Mechanistically, CDT1 overexpression induced DNA re‐replication and thus DNA damage check‐point activation. Protein abundance of MCM2 was stable throughout the cell cycle, and embryos with overexpressed MCM2 could develop to blastocysts normally. Overexpression or depletion of Mcm2 also had no effect on oocyte meiotic maturation. Our results indicate that pre‐RC subunits CDT1 and MCM2 are not involved in oocyte meiotic maturation. In zygote, CDT1 but not MCM2 is the major regulator of DNA replication in a cell cycle dependent manner. Furthermore, its'' degradation is essential for zygotes to prevent from DNA re‐replication in G2 stage.

Pre‐replication complex (pre‐RC) is formed in G1 phase during which CDT1 is localized in nucleus. When zygote enters S phase, CDT1 is degraded and stays at a low level in G2 phase. However, the expression of exogenous Cdt1 mRNA in G2 phase of fertilized egg, mimicking events in which CDT1 degradation is disrupted, pre‐RC reassembles and leads to DNA re‐replication, and thus DNA damage check point activation, which results in embryo arrest at G2/M phase.     

Karyotype evolution of the Asterids insights from the first genome sequences of the family Cornaceae

Cornaceae is a core representative family in Cornales, the earliest branching lineage in the Asterids on the life tree of angiosperms. This family includes the only genus Cornus, a group of ~55 species. These species occur widely in Northern Hemisphere and have been used as resources for horticultural ornaments, medicinal and industrial manufacturing. However, no any genome sequences are available for this family. Here, we reported a chromosome­level genome for Cornus controversa. This was generated using high-fidelity plus Hi–C sequencing, and totally ~771.80 Mb assembled sequences and 39,886 protein-coding genes were obtained. We provided evidence for a whole-genome duplication event (WGD) unique to C. controversa. The evolutionary features of this genome indicated that the expanded and unique genes might have contributed to response to stress, stimulus and defense. By using chromosome-level syntenic blocks shared between eight living genomes, we found high degrees of genomic diversification from the ancestral core-eudicot genome to the present-day genomes, suggesting an important role of WGD in genomic plasticity that leads to speciation and diversification. These results provide foundational insights on the evolutionary history of Cornaceae, as well as on the Asterids diversification.     

Stabilization of IGF2BP1 by USP10 promotes breast cancer metastasis via CPT1A in an m6A-dependent manner

Metastasis leads to the vast majority of breast cancer mortality. Increasing evidence has shown that N6-methyladenosine (m6A) modification and its associated regulators play a pivotal role in breast cancer metastasis. Here, we showed that overexpression of the m6A reader IGF2BP1 was clinically correlated with metastasis in breast cancer patients. Moreover, IGF2BP1 promoted distant metastasis in vitro and in vivo. Mechanistically, we first identified USP10 as the IGF2BP1 deubiquitinase. USP10 can bind to, deubiquitinate, and stabilize IGF2BP1, resulting in its higher expression level in breast cancer. Furthermore, by MeRIP-seq and experimental verification, we found that IGF2BP1 directly recognized and bound to the m6A sites on CPT1A mRNA and enhanced its stability, which ultimately mediated IGF2BP1-induced breast cancer metastasis. In clinical samples, USP10 levels correlated with IGF2BP1 and CPT1A levels, and breast cancer patients with high levels of USP10, IGF2BP1, and CPT1A had the worst outcome. Therefore, these findings suggest that the USP10/IGF2BP1/CPT1A axis facilitates breast cancer metastasis, and this axis may be a promising prognostic biomarker and therapeutic target for breast cancer.     

Neuropeptide Y protects kidney from acute kidney injury by inactivating M1 macrophages via the Y1R-NF-κB-Mincle-dependent mechanism

Neuropeptide Y (NPY) is produced by the nerve system and may contribute to the progression of CKD. The present study found the new protective role for NPY in AKI in both patients and animal models. Interestingly, NPY was constitutively expressed in blood and resident kidney macrophages by co-expressing NPY and CD68+ markers, which was lost in patients and mice with AKI-induced by cisplatin. Unexpectedly, NPY was renoprotective in AKI as mice lacking NPY developed worse renal necroinflammation and renal dysfunction in cisplatin and ischemic-induced AKI. Importantly, NPY was also a therapeutic agent for AKI because treatment with exogenous NPY dose-dependently inhibited cisplatin-induced AKI. Mechanistically, NPY protected kidney from AKI by inactivating M1 macrophages via the Y1R-NF-κB-Mincle-dependent mechanism as deleting or silencing NPY decreased Y1R but increased NF-κB-Mincle-mediated M1macrophage activation and renal necroinflammation, which were reversed by addition of NPY or by silencing Mincle but promoted by blocking Y1R with BIBP 3226. Thus, NPY is renoprotective and may be a novel therapeutic agent for AKI. NPY may act via Y1R to protect kidney from AKI by blocking NF-κB-Mincle-mediated M1 macrophage activation and renal necroinflammation.     

An Overview: The Diversified Role of Mitochondria in Cancer Metabolism

Mitochondria are intracellular organelles involved in energy production, cell metabolism and cell signaling. They are essential not only in the process of ATP synthesis, lipid metabolism and nucleic acid metabolism, but also in tumor development and metastasis. Mutations in mtDNA are commonly found in cancer cells to promote the rewiring of bioenergetics and biosynthesis, various metabolites especially oncometabolites in mitochondria regulate tumor metabolism and progression. And mutation of enzymes in the TCA cycle leads to the unusual accumulation of certain metabolites and oncometabolites. Mitochondria have been demonstrated as the target for cancer treatment. Cancer cells rely on two main energy resources: oxidative phosphorylation (OXPHOS) and glycolysis. By manipulating OXPHOS genes or adjusting the metabolites production in mitochondria, tumor growth can be restrained. For example, enhanced complex I activity increases NAD⁺/NADH to prevent metastasis and progression of cancers. In this review, we discussed mitochondrial function in cancer cell metabolism and specially explored the unique role of mitochondria in cancer stem cells and the tumor microenvironment. Targeting the OXPHOS pathway and mitochondria-related metabolism emerging as a potential therapeutic strategy for various cancers.     

Associations of serum high-sensitivity C-reactive protein and prealbumin with coronary vessels stenosis determined by coronary angiography and heart failure in patients with myocardial infarction

BackgroundTo explore the associations of serum high-sensitivity C-reactive protein (hs-CRP) and prealbumin (PAB) with the number of diseased coronary vessels, degree of stenosis and heart failure in patients with myocardial infarction (MI).MethodsA total of 39 MI patients treated in the Cardiology were selected as the observation group, and another 41 patients with normal results of coronary angiography during the same period were selected as the control group. The general data of patients were recorded in detail, the content of serum hs-CRP and PAB in the peripheral blood was detected, and the number of diseased coronary vessels and the degree of stenosis were detected via coronary angiography.ResultsCompared with those in control group, the blood pressure and heart rate significantly rose, the content of indexes related to the severity of MI were significantly increased, the content of hs-CRP was significantly increased, and the content of PAB was significantly decreased in observation group. Hs-CRP was positively correlated with the number of diseased coronary vessels, degree of stenosis and heart failure in patients, but PAB was negatively correlated with the above factors. The survival rate of MI patients with high content of hs-CRP was obviously lower than that of patients with low content of hsCRPConclusionsSerum hs-CRP and PAB are closely associated with the number of diseased coronary vessels, degree of stenosis and heart failure in MI patients.