Latest ArticlesWhile mesenchymal stem cell (MSC) shows great potentials in treating intervertebral disc degeneration, most MSC die soon after intradiscal transplantation, resulting in inferior therapeutic efficacy. Currently, bulk hydrogels are the common solution to improve MSC survival in tissues, although hydrogel encapsulation impairs MSC migration and disrupts extracellular microenvironment. Cell hydrogel encapsulation has been proposed to overcome the limitation of traditional bulk hydrogels, yet this technique has not been used in treating disc degeneration. Using a layer-by-layer self-assembly technique, we fabricated alginate and gelatin microgel to encapsulate individual MSC for treating disc degeneration. The small size of microgel allowed intradiscal injection of coated MSC. We demonstrated that pyroptosis was involved in MSC death under oxidative stress stimulation, and microgel coating suppressed pyroptosis activation by maintaining mitochondria homeostasis. Microgel coating protected MSC in the harsh disc microenvironment, while retaining vital cellular functions such as migration, proliferation, and differentiation. In a rat model of disc degeneration, coated MSC exhibits prolonged retention in the disc and better efficacy of attenuating disc degeneration, as compared with bare MSC treatment alone. Further, microgel-coated MSC exhibited improved therapeutic effects in treating disc degeneration via suppressing the activation of pyroptosis in the disc. For the first time, microgel-encapsulated MSC was used to treat disc degeneration and obtain encouraging outcomes. The developed biocompatible single-cell hydrogel is an effective strategy to protect MSC and maintain cellular functions and may be an efficacious approach to improving the efficacy of MSC therapy in treating disc degeneration. The objective of this study is to improve the efficacy of cell therapy for treating disc degeneration using single-cell hydrogel encapsulation and further to understand related cytoprotective mechanisms.
Facile fabrication of highly conductive and self-encapsulated graphene electronics is in urgent demand for carbon-based integrated circuits, field effect transistors, optoelectronic devices, and flexible sensors. The current fabrication of these electronic devices is mainly based on layer-by-layer techniques (separate circuit preparation and encapsulation procedures), which show multistep fabrication procedures, complicated renovation/repair procedures, and poor electrical property due to graphene oxidation and exfoliation. Here, we propose a laser-guided interfacial writing (LaserIW) technique based on self-confined, nickel-catalyzed graphitization to directly fabricate highly conductive, embedded graphene electronics inside multilayer structures. The doped nickel is used to induce chain carbonization, which firstly enhances the photothermal effect to increase the confined temperature for initial carbonization, and the generated carbon further increases the light-absorption capacity to fabricate high-quality graphene. Meanwhile, the nickel atoms contribute to the accelerated connection of carbon atoms. This interfacial carbonization inherently avoids the exfoliation and oxidation of the as-formed graphene, resulting in an 8-fold improvement in electrical conductivity (~20,000 S/m at 7,958 W/cm2 and 2 mm/s for 20% nickel content). The LaserIW technique shows excellent stability and reproducibility, with ±2.5% variations in the same batch and ±2% variations in different batches. Component-level wireless light sensors and flexible strain sensors exhibit excellent sensitivity (665 kHz/(W/cm2) for passive wireless light sensors) and self-encapsulation (<1% variations in terms of waterproof, antifriction, and antithermal shock). Additionally, the LaserIW technique allows for one-step renovation of in-service electronics and nondestructive repair of damaged circuits without the need to disassemble encapsulation layers. This technique reverses the layer-by-layer processing mode and provides a powerful manufacturing tool for the fabrication, modification, and repair of multilayer, multifunctional embedded electronics, especially demonstrating the immense potential for in-space manufacturing.
The ALPK1 (alpha-kinase 1)-TIFA (TRAF-interacting protein with fork head-associated domain)-TRAF6 signaling pathway plays a pivotal role in regulating inflammatory processes, with TIFA and TRAF6 serving as key molecules in this cascade. Despite its significance, the functional mechanism of TIFA-TRAF6 remains incompletely understood. In this study, we unveil that TIFA undergoes liquid–liquid phase separation (LLPS) induced by ALPK1 in response to adenosine diphosphate (ADP)-β-D-manno-heptose (ADP-Hep) recognition. The phase separation of TIFA is primarily driven by ALPK1, the pT9-FHA domain, and the intrinsically disordered region segment. Simultaneously, TRAF6 exhibits phase separation during ADP-Hep-induced inflammation, a phenomenon observed consistently across various inflammatory signal pathways. Moreover, TRAF6 is recruited within the TIFA condensates, facilitating lysine (K) 63-linked polyubiquitin chain synthesis. The subsequent recruitment, enrichment, and activation of downstream effectors within these condensates contribute to robust inflammatory signal transduction. Utilizing a novel chemical probe (compound 22), our analysis demonstrates that the activation of the ALPK1-TIFA-TRAF6 signaling pathway in response to small molecules necessitates the phase separation of TIFA. In summary, our findings reveal TIFA as a sensor for upstream signals, initiating the LLPS of itself and downstream proteins. This process results in the formation of membraneless condensates within the ALPK1-TIFA-TRAF6 pathway, suggesting potential applications in therapeutic biotechnology development.
Mitochondrial fission promotes glioma progression. The function and regulation mechanisms of lncRNAs in glioma mitochondrial fission are unclear. The expression of LINC00475 and its correlation with clinical parameters in glioma were analyzed using bioinformatics. Then, in vitro and in vivo assays were performed to explore the function of spliced variant LINC00475 (LINC00475-S) in gliomas. To explore the mechanisms, RNA-seq, MeRIP, RIP, pulldown-IP, dCas9-ALKBH5 editing system, LC/MS, and Western blotting were utilized. LINC00475 was confirmed to be overexpressed and with higher frequencies of AS events in gliomas compared to normal brain tissue and was associated with worse prognosis. In vitro and animal tumor formation experiments demonstrated that the effect of LINC00475-S on proliferation, metastasis, autophagy, and mitochondrial fission of glioma cells was significantly stronger than that of LINC00475. Mechanistically, METTL3 induced the generation of LINC00475-S by splicing LINC00475 through m6A modification and subsequently promotes mitochondrial fission in glioma cells by inhibiting the expression of MIF. Pull-down combined LC/MS and RIP assays identified that the m6A recognition protein HNRNPH1 bound to LINC00475 within GYR and GY domains and promoted LINC00475 splicing. METTL3 facilitated HNRNPH1 binding to LINC00475 in an m6A-dependent manner, thereby inducing generation of LINC00475-S. METTL3 facilitated HNRNPH1-mediated AS of LINC00475, which promoted glioma progression by inducing mitochondrial fission. Targeting AS of LINC00475 and m6A editing could serve as a therapeutic strategy against gliomas.
The activation of pro-inflammatory M1-type macrophages by overexpression of reactive oxygen species (ROS) and reactive nitrogen species (RONS) in synovial membranes contributes to osteoarthritis (OA) progression and cartilage matrix degradation. Here, combing Pt and Se with potent catalytic activities, we developed a hybrid Pt–Se nanozymes as ROS and RONS scavengers to exert synergistic effects for OA therapy. As a result, Pt–Se nanozymes exhibited efficient scavenging effect on ROS and RONS levels, leading to repolarization of M1-type macrophages. Furthermore, the polarization of synovial macrophages to the M2 phenotype inhibited the expression of pro-inflammatory factors and salvaged mitochondrial function in arthritic chondrocytes. In vivo results also suggest that Pt–Se nanozymes effectively suppress the early progression of OA with an Osteoarthritis Research International Association score reduction of 68.21% and 82.66% for 4 and 8 weeks, respectively. In conclusion, this study provides a promising strategy to regulate inflammatory responses by macrophage repolarization processes for OA therapeutic.
Recent studies have highlighted the pivotal roles of circular RNAs (circRNAs) in cardiovascular diseases. Through high-throughput circRNA sequencing of both normal myocardial tissues and hypertrophic patients, we unveiled 32,034 previously undiscovered circRNAs with distinct cardiac expression patterns. Notably, circITGa9, a circRNA derived from integrin-α9, exhibited substantial up-regulation in cardiac hypertrophy patients. This elevation was validated across extensive sample pools from cardiac patients and donors. In vivo experiments revealed heightened cardiac fibrosis in mice subjected to transverse aortic constriction (TAC) after circITGa9 injection. We identified circITGa9 binding proteins through circRNA precipitation followed by liquid chromatography tandem-mass spectrometry. Furthermore, circRNA pull-down/precipitation assays demonstrated that increased circITGa9 expression facilitated binding with tropomyosin 3 (TPM3). Specific binding sites between circITGa9 and TPM3 were identified through computational algorithms and further validated by site-directed mutagenesis. We further showed that circITGa9 induced actin polymerization, characteristic of tissue fibrosis. Finally, we developed approaches that improved cardiac function and decreased fibrosis by delivering small interfering RNA targeting circITGa9 or blocking oligo inhibiting the interaction of circITGa9 and TPM3 into TAC mice, which is amenable for further preclinical and translational development. We conclude that elevated circITGa9 levels drive cardiac remodeling and fibrosis. By pinpointing circITGa9 as a therapeutic target, we open doors to innovative interventions for mitigating cardiac remodeling and fibrosis.
Fe (hydr)oxides have a substantial impact on the structure and stability of soil organic carbon (SOC) pools and also drive organic carbon turnover processes via reduction–oxidation reactions. Currently, many studies have paid much attention to organic matter–Fe mineral–microbial interactions on SOC turnover, while there is few research on how exogenous carbon addition abiotically regulates the intrinsic mechanisms of Fe-mediated organic carbon conversion. The study investigated the coupling process of artificial humic acid (A-HA) and Fe(hydr)oxide, the mechanism of inner-sphere ligands, and the capacity for carbon sequestration using transmission electron microscopy, thermogravimetric, x-ray photoelectron spectroscopy, and wet-chemical disposal. Furthermore, spherical aberration-corrected scanning transmission electron microscopy–electron energy loss spectroscopy and Mössbauer spectra have been carried out to demonstrate the spatial heterogeneity of A-HA/Fe (hydr)oxides and reveal the relationship between the increase in Fe-phase crystallinity and redox sensitivity and the accumulation of organic carbon. Additionally, the dynamics of soil structures on a microscale, distribution of carbon–iron microdomains, and the cementing-gluing effect can be observed in the constructing nonliving anthropogenic soils, confirming that the formation of stable aggregates is an effective approach to achieving organic carbon indirect protection. We propose that exogenous organic carbon inputs, specifically A-HA, could exert a substantial but hitherto unexplored effect on the geochemistry of iron–carbon turnover and sequestration in anoxic water/solid soils and sediments.
The progression of numerous malignancies has been linked to N6-methyladenosine (m6A) alteration. However, the opposite trend of m6A levels in the development and metastasis of cancer has not been reported. This study aimed to evaluate the biological function and mechanism of fat mass and obesity-associated protein (FTO) in regulating m6A modification in prostate cancer development and epithelial–mesenchymal transition (EMT). An EMT model of LNCaP and PC-3 cells was established with transforming growth factor-β treatment, and FTO knockout cell line was established in prostate cancer cells using the CRISPR/Cas9 gene editing technology. The level of m6A modification in tumor tissues was higher than that in normal prostate tissues; m6A levels were decreased after EMT. FTO deletion increased m6A expression and enhanced PC-3 cell motility, invasion, and EMT both in vitro and in vivo. RNA sequencing and functional investigations suggested that DDIT4, a novel EMT target gene, plays a role in m6A-regulated EMT, which was recognized and stabilized by the m6A effector IGF2BP2/3. Decreased FTO expression was an independent indicator of worse survival, and the level of DDIT4 was considerably elevated in patients with bone metastasis. Thus, this study revealed that the m6A demethylase FTO can play different roles in prostate cancer as a regulator of EMT and an inhibitor of m6A modification. Moreover, DDIT4 can be suggested as a possible biomarker for prostate cancer metastasis prediction.
Males and females display dimorphic behaviors that often involve sex-specific locomotor patterns. How the sexually dimorphic locomotion is mediated is poorly understood. In this study, we identify a neuropeptide that oppositely regulates locomotion for efficient sexual behaviors in Drosophila males and females. We find that males are less active than females if isolated. However, when sexually aroused through activating homologous but sexually dimorphic pC1 neurons, males exhibit higher activity levels than females. We discover diuretic hormone 44 (DH44) that functions in pC1 neurons in a sex-specific way to inhibit male locomotion and promote female locomotion. Surprisingly, DH44 exerts opposite effects in sexually aroused flies to promote male locomotion and suppress female locomotion, which is crucial for successful male courtship and female receptivity. These findings demonstrate sexually dimorphic and state-dependent control of locomotor activity by pC1 neuronal activity and DH44 modulation.