摘要: Irritable bowel syndrome (IBS) is a widespread gastrointestinal disorder known for its multifaceted pathogenesis and varied extraintestinal manifestations, yet its implications for bone and muscle health are underexplored. Recent studies suggest a link between IBS and musculoskeletal disorders, but a comprehensive understanding remains elusive, especially concerning the role of bile acids (BAs) in this context. This study aimed to elucidate the potential contribution of IBS to bone and muscle deterioration via alterations in gut microbiota and BA profiles, hypothesizing that cholestyramine could counteract these adverse effects. We employed a mouse model to characterize IBS and analysed its impact on bone and muscle health. Our results revealed that IBS promotes bone and muscle loss, accompanied by microbial dysbiosis and elevated BAs. Administering cholestyramine significantly mitigated these effects, highlighting its therapeutic potential. This research not only confirms the critical role of BAs and gut microbiota in IBS-associated bone and muscle loss but also demonstrates the efficacy of cholestyramine in ameliorating these conditions, thereby contributing significantly to the field's understanding and offering a promising avenue for treatment. This study reveals that irritable bowel syndrome (IBS) contributes to bone and muscle loss through microbial dysbiosis and increased bile acid (BA) levels. Notably, administering cholestyramine ameliorates these effects by decreasing BA contents and modulating gut microbiota, underscoring its therapeutic potential in managing IBS-induced musculoskeletal deterioration. image

摘要: Breast cancer has overtaken lung cancer as the number one cancer worldwide. Paclitaxel (PTX) is a widely used first-line anti-cancer drug, but it is not very effective in clinical breast cancer therapy. It has been reported that triptolide (TPL) can enhance the anticancer effect of paclitaxel, and better synergistic therapeutic effects are seen with concomitant administration of PTX and TPL. In this study, we developed pH-responsive polymeric micelles for co-delivery of PTX and TPL, which disassembling in acidic tumour microenvironments to target drug release and effectively kill breast cancer cells. Firstly, we synthesized amphiphilic copolymer mPEG2000-PBAE through Michael addition reaction, confirmed by various characterizations. Polymer micelles loaded with TPL and PTX (TPL/PTX-PMs) were prepared by the thin film dispersion method. The average particle size of TPL/PTX-PMs was 97.29 +/- 1.63 nm, with PDI of 0.237 +/- 0.003 and Zeta potential of 9.57 +/- 0.80 mV, LC% was 6.19 +/- 0.21%, EE% was 88.67 +/- 3.06%. Carrier material biocompatibility and loaded micelle cytotoxicity were assessed using the CCK-8 method, demonstrating excellent biocompatibility. Under the same drug concentration, TPL/PTX-PMs were the most toxic to tumour cells and had the strongest proliferation inhibitory effect. Cellular uptake assays revealed that TPL/PTX-PMs significantly increased intracellular drug concentration and enhanced antitumor activity. Overall, pH-responsive micellar co-delivery of TPL and PTX is a promising approach for breast cancer therapy. Self-assembly of TPL/PTX-PPMs forpH-responsive drug release in tumor cells.image

摘要: Epigenetic modifications play critical roles during somatic cell nuclear transfer (SCNT) embryo development. Whether RNA N6-methyladenosine (m(6) A) affects the developmental competency of SCNT embryos remains unclear. Here, we showed that porcine bone marrow mesenchymal stem cells (pBMSCs) presented higher RNA m(6) A levels than those of porcine embryonic fibroblasts (pEFs). SCNT embryos derived from pBMSCs had higher RNA m(6) A levels, cleavage, and blastocyst rates than those from pEFs. Compared with pEFs, the promoter region of METTL14 presented a hypomethylation status in pBMSCs. Mechanistically, DNA methylation regulated METTL14 expression by affecting the accessibility of transcription factor SP1 binding, highlighting the role of the DNA methylation/SP1/METTL14 pathway in donor cells. Inhibiting the DNA methylation level in donor cells increased the RNA m(6) A level and improved the development efficiency of SCNT embryos. Overexpression of METTL14 significantly increased the RNA m(6) A level in donor cells and the development efficiency of SCNT embryos, whereas knockdown of METTL14 suggested the opposite result. Moreover, we revealed that RNA m(6) A-regulated TOP2B mRNA stability, translation level, and DNA damage during SCNT embryo development. Collectively, our results highlight the crosstalk between RNA m(6) A and DNA methylation, and the crucial role of RNA m(6) A during nuclear reprogramming in SCNT embryo development.

摘要: Gene-edited (GE) pig-to-human xenotransplantation continues to make breakthroughs, but which kind of gene combination is suitable for organ-specific transplantation remains unclear. In this study, we utilised CRISPR/Cas9 gene editing technology, PiggyBac transposon system, and serial somatic cell cloning technology to develop GTKO/CMAHKO/beta 4GalNT2KO/hCD46/hCD55/hCD59/hCD39/hTBM 8 gene-edited cloned (GEC) donor pigs and performed pig-to-non-human primate (NHP) transplantation to evaluate the effectiveness of these GEC pigs. The 8-GEC pigs were obtained by recloning with a 33-day-old 8-GEC fetus with O blood type, which was generated after cell transfection, screening of cell colonies, and somatic cell cloning. Molecular identification at DNA, mRNA, and protein levels confirmed successful 8-gene editing. Three copies of transgenes were identified by droplet digital polymerase chain reaction and whole genome sequencing, which were inserted into the introns of pig RFTN1 and MYO10 genes, as well as the intergenic region between PRLR and LOC110257300 genes of these 8-GEC pigs. The 8-GEC pigs also exhibited the ability of germline transmission when mated with our previously generated 4-GEC male pigs. Moreover, antigen-antibody binding assay and complement-dependent cytotoxicity assay demonstrated that 8-gene editing effectively reduced the immune incompatibility and kidney xenograft from 8-GEC pigs survived for 15 and 17 days in two NHPs, respectively. Postoperatively, the recipient serum antibodies IgA, IgG and IgM, complements C3 and C4, coagulation indicators PT, APTT, TT and FIB, as well as most electrolytes and liver function indicators remained relatively stable. Serum creatinine was normal within 10 days post operation. However, the kidney xenograft developed active antibody-mediated rejection at necropsy, characterised by the deposition of antibodies IgG and IgM, as well as complements C4d, C3c and C5b-C9, infiltration of CD68+ macrophages, and micro-thrombotic embolism of glomerular capillaries, etc. In conclusion, we successfully developed fertile 8-GEC pigs, which effectively alleviated immune rejection and exerted life-supporting kidney function in the recipients.

摘要: The keystone pathogen Porphyromonas gingivalis (P.g.) is responsible for cementum resorption in periodontitis; however, the mechanism involved in it remains unclear. Sirtuin 3 (Sirt3) is a NAD(+)-dependent protein deacetylase contributing to mitochondrial homeostasis and various cell functions. In this study, the expression of Sirt3 in cementoblasts was found to be increased during cementoblast mineralisation and cementum development, while it decreased gradually under P.g. infection in a multiplicity of infection-dependent manner. Compared with wild type mice, the Sirt3 knockout mice showed less cellular cementum and lower mineralisation capacity with decreased expression of Runx2 and OCN in cementoblasts. Sirt3 inhibition by 3-TYP or Sirt3 silencing by lentivirus infection both confirmed the impaired cementogenesis. Conversely, honokiol (HKL) was simulated to bind Sirt3 and was applied to activate Sirt3 in cementoblasts. HKL-mediated Sirt3 activation facilitated cementoblast mineralisation and rescued P.g.-suppressed cementoblast mineralisation markedly. Superoxide dismutase 2 (SOD2), the downstream molecule of Sirt3, showed a similar expression pattern to Sirt3 under different conditions. Silencing of SOD2 was demonstrated to restrain cementoblast mineralisation. The pan acetylation was detected to decrease under Sirt3-upregulating conditions and increase under Sirt3-downregulating conditions. The binding of Sirt3 and SOD2 in cementoblasts was also verified. Furthermore, SOD2 acetylation and specific SOD2-K68 acetylation were found to be upregulated under P.g. or Sirt3 silencing conditions and downregulated by HKL stimulation. Moreover, K68Q mutation simulating acetylation decreased cementoblast mineralisation, while K68R mutation simulating deacetylation increased it. Altogether, Sirt3 deacetylates SOD2 via K68 to orchestrate P.g.-perturbed cementogenesis, and HKL is a Sirt3-targeted treatment candidate.

摘要: The phosphatidylinositol 3-kinase/Protein Kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signalling pathway is pivotal in various cancers, including T-cell acute lymphoblastic leukaemia (T-ALL), a particularly aggressive type of leukaemia. This study investigates the effects of Neosetophomone B (NSP-B), a meroterpenoid fungal metabolite, on T-ALL cell lines, focusing on its anti-cancer mechanisms and therapeutic potential. NSP-B significantly inhibited the proliferation of T-ALL cells by inducing G0/G1 cell cycle arrest and promoting caspase-dependent apoptosis. Additionally, NSP-B led to the dephosphorylation and subsequent inactivation of the PI3K/AKT/mTOR signalling pathway, a critical pathway in cell survival and growth. Molecular docking studies revealed a strong binding affinity of NSP-B to the active site of AKT, primarily involving key residues crucial for its activity. Interestingly, NSP-B treatment also induced apoptosis and significantly reduced proliferation in phytohemagglutinin-activated primary human CD3+ T cells, accompanied by a G0/G1 cell cycle arrest. Importantly, NSP-B did not affect normal primary T cells, indicating a degree of selectivity in its action, targeting only T-ALL cells and activated T cells. In conclusion, our findings highlight the potential of NSP-B as a novel therapeutic agent for T-ALL, specifically targeting the aberrantly activated PI3K/AKT/mTOR pathway and being selective in action. These results provide a strong basis for further investigation into NSP-B's anti-cancer properties and potential application in T-ALL clinical therapies.

摘要: The bone marrow (BM) niches are the complex microenvironments that surround cells, providing various external stimuli to regulate a range of haematopoietic stem cell (HSC) behaviours. Recently, it has been proposed that the fate decision of HSCs is often correlated with significantly altered biophysical signals of BM niches. To thoroughly elucidate the effect of mechanical microenvironments on cell fates, we constructed 2D and 3D cell culture hydrogels using polyacrylamide to replicate the mechanical properties of heterogeneous sub-niches, including the inherent rigidity of marrow adipose tissue (2 kPa), perivascular tissue (8 kPa) and endosteum region (35 kPa) in BM. Our observations suggest that HSCs can respond to the mechanical heterogeneity of the BM microenvironment, exhibiting diversity in cell mechanics, haematopoietic pool maintenance and differentiated lineages. Hydrogels with higher stiffness promote the preservation of long-term repopulating HSCs (LT-HSCs), while those with lower stiffness support multi-potent progenitors (MPPs) viability in vitro. Furthermore, we established a comprehensive transcriptional profile of haematopoietic subpopulations to reflect the multipotency of haematopoietic stem and progenitor cells (HSPCs) that are modulated by niche-like stiffness. Our findings demonstrate that HSPCs exhibit completely distinct downstream differentiated preferences within hydrogel systems of varying stiffness. This highlights the crucial role of tissue-specific mechanical properties in HSC lineage decisions, which may provide innovative solutions to clinical challenges. HSPCs respond to the mechanical microenvironment of the BM. 3D hydrogels with higher stiffness promote LT-HSC maintenance, whereas those with lower stiffness support MPP viability. A comprehensive transcriptional profile and fate trajectory of HSPCs suggest that niche-like stiffness leads to differences in the components and lineage decision of heterogeneous HSPCs. image

摘要: Oral squamous cell carcinoma (OSCC), a type of malignant tumour that primarily occurs in the oral mucosa, has drawn considerable attention owing to its aggressive growth and potentially high metastatic rate. Surgical resection is the primary treatment method for OSCC and is typically combined with radiation therapy and chemotherapy. microRNA-149-3p (miR-149) is a negative regulator of the Pi3k/Akt pathway and can effectively inhibit the proliferation of tumour cells. However, the application of miR-149 is limited owing to its relatively low efficiency of cellular uptake and poor stability when used alone. To overcome these challenges, this study adopted a novel nucleic acid nanostructured material, tetrahedral framework nucleic acids (tFNAs). The use of tFNAs as carriers to assemble the T-miR-149 complex reduced the expression of Pi3k and Akt involved in tumorigenesis and alterations in proteins related to cell apoptosis. The results indicated that the bionic drug delivery system has an effective tumour suppressive effect on OSCC in mice, revealing its potential clinical value in the treatment of OSCC.

摘要: Cell fate determination in mammalian development is complex and precisely controlled and accumulating evidence indicates that epigenetic mechanisms are crucially involved. N-4-acetylcytidine (ac(4)C) is a recently identified modification of messenger RNA (mRNA); however, its functions are still elusive in mammalian. Here, we show that N-acetyltransferase 10 (NAT10)-mediated ac(4)C modification promotes ectoderm differentiation of human embryonic stem cells (hESCs) by acetylating nuclear receptor subfamily 2 group F member 1 (NR2F1) mRNA to enhance translation efficiency (TE). Acetylated RNA immunoprecipitation sequencing (acRIP-seq) revealed that levels of ac(4)C modification were higher in ectodermal neuroepithelial progenitor (NEP) cells than in hESCs or mesoendoderm cells. In addition, integrated analysis of acRIP-seq and ribosome profiling sequencing revealed that NAT10 catalysed ac(4)C modification to improve TE in NEP cells. RIP-qRT-PCR analysis identified an interaction between NAT10 and NR2F1 mRNA in NEP cells and NR2F1 accelerated the nucleus-to-cytoplasm translocation of yes-associated protein 1, which contributed to ectodermal differentiation of hESCs. Collectively, these findings point out the novel regulatory role of ac(4)C modification in the early ectodermal differentiation of hESCs and will provide a new strategy for the treatment of neuroectodermal defects diseases.

摘要: Glaucoma and other optic neuropathies lead to progressive and irreversible vision loss by damaging retinal ganglion cells (RGCs) and their axons. Cell replacement therapy is a potential promising treatment. However, current methods to obtain RGCs have inherent limitations, including time-consuming procedures, inefficient yields and complex protocols, which hinder their practical application. Here, we have developed a straightforward, rapid and efficient approach for directly inducing RGCs from mouse embryonic fibroblasts (MEFs) using a combination of triple transcription factors (TFs): ASCL1, BRN3B and PAX6 (ABP). We showed that on the 6th day following ABP induction, neurons with molecular characteristics of RGCs were observed, and more than 60% of induced neurons became iRGCs (induced retinal ganglion cells) in the end. Transplanted iRGCs had the ability to survive and appropriately integrate into the RGC layer of mouse retinal explants and N-methyl-D-aspartic acid (NMDA)-damaged retinas. Moreover, they exhibited electrophysiological properties typical of RGCs, and were able to regrow dendrites and axons and form synaptic connections with host retinal cells. Together, we have established a rapid and efficient approach to acquire functional RGCs for potential cell replacement therapy to treat glaucoma and other optic neuropathies. The transcription factor (TF) combination ASCL1 + BRN3B + PAX6 could efficiently reprogram mouse embryonic fibroblasts (MEFs) into induced retinal ganglion cells (iRGCs). These iRGCs not only expressed several molecular markers of native RGCs, but also exhibited typical RGC electrophysiological properties. Upon transplantation into mouse retinal explants or NMDA-damaged retinas, iRGCs could integrate into the ganglion cell layer, survive for a prolonged period, grow long neuron fibres, form synapses with host cells, and exhibit electrophysiological functions.image