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Central nervous system (CNS) lesions become surrounded by neuroprotective borders of newly proliferated reactive astrocytes; however, fundamental features of these cells are poorly understood. Here we show that following spinal cord injury or stroke, 90% and 10% of border-forming astrocytes derive, respectively, from proliferating local astrocytes and oligodendrocyte progenitor cells in adult mice of both sexes. Temporal transcriptome analysis, single-nucleus RNA sequencing and immunohistochemistry show that after focal CNS injury, local mature astrocytes dedifferentiate, proliferate and become transcriptionally reprogrammed to permanently altered new states, with persisting downregulation of molecules associated with astrocyte-neuron interactions and upregulation of molecules associated with wound healing, microbial defense and interactions with stromal and immune cells. These wound repair astrocytes share morphologic and transcriptional features with perimeningeal limitans astrocytes and are the predominant source of neuroprotective borders that re-establish CNS integrity around lesions by separating neural parenchyma from stromal and immune cells as occurs throughout the healthy CNS., (© 2024. The Author(s).)

Addressing the limitations of existing landslide displacement prediction models in capturing the dynamic characteristics of data changes, this study introduces a novel dynamic displacement prediction model for landslides. The proposed method combines Variational Mode Decomposition (VMD) with Sparrow Search Optimization (SSO) and Long Short-Term Memory (LSTM) techniques to formulate a comprehensive VMD-SSO-LSTM model. Through the application of VMD, the method dissects cumulative displacement and rainfall data, thereby extracting distinct components such as trend, periodicity, and fluctuation components for displacement, as well as low-frequency and high-frequency components for rainfall. Furthermore, leveraging Gray Correlational Analysis, the interrelationships between the periodic component of displacement and the low-frequency component of rainfall, as well as the fluctuation component of displacement and the high-frequency component of rainfall, are established. Building upon this foundation, the SSO-LSTM model dynamically predicts the interrelated displacement components, synthesizing the predicted values of each component to generate real-time dynamic forecasts. Simulation results underscore the effectiveness of the proposed VMD-SSO-LSTM model, indicating root-mean-square error (RMSE) and mean absolute percentage error (MAPE) values of 1.2329 mm and 0.1624%, respectively, along with a goodness of fit (R 2 ) of 0.9969. In comparison to both back propagation (BP) prediction model and LSTM prediction model, the VMD-SSO-LSTM model exhibits heightened predictive accuracy., (© 2024. The Author(s).)

Rheumatoid arthritis (RA) is a common autoimmune disease that can lead to severe joint damage and disability. And early diagnosis and treatment of RA can avert or substantially slow the progression of joint damage in up to 90% of patients, thereby preventing irreversible disability. Previous research indicated that 50% of the risk for the development of RA is attributable to genetic factors, but the pathogenesis is not well understood. Thus, it is urgent to identify biomarkers to arrest RA before joints are irreversibly damaged. Here, we first use the Robust Rank Aggregation method (RRA) to identify the differentially expressed genes (DEGs) between RA and normal samples by integrating four public RA patients' mRNA expression data. Subsequently, these DEGs were used as the input for the weighted gene co-expression network analysis (WGCNA) approach to identify RA-related modules. The function enrichment analysis suggested that the RA-related modules were significantly enriched in immune-related actions. Then the hub genes were defined as the candidate genes. Our analysis showed that the expression levels of candidate genes were significantly associated with the RA immune microenvironment. And the results indicated that the expression of the candidate genes can use as predictors for RA. We hope that our method can provide a more convenient approach for the early diagnosis of RA., (© 2023. The Author(s).)

Astrocytes become reactive in response to insults to the central nervous system by adopting context-specific cellular signatures and outputs, but a systematic understanding of the underlying molecular mechanisms is lacking. In this study, we developed CRISPR interference screening in human induced pluripotent stem cell-derived astrocytes coupled to single-cell transcriptomics to systematically interrogate cytokine-induced inflammatory astrocyte reactivity. We found that autocrine-paracrine IL-6 and interferon signaling downstream of canonical NF-κB activation drove two distinct inflammatory reactive signatures, one promoted by STAT3 and the other inhibited by STAT3. These signatures overlapped with those observed in other experimental contexts, including mouse models, and their markers were upregulated in human brains in Alzheimer's disease and hypoxic-ischemic encephalopathy. Furthermore, we validated that markers of these signatures were regulated by STAT3 in vivo using a mouse model of neuroinflammation. These results and the platform that we established have the potential to guide the development of therapeutics to selectively modulate different aspects of inflammatory astrocyte reactivity., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Saliva is rich in proteins, DNA, RNA and microorganisms, and can be regarded as a biomarker library. In order to explore a noninvasive and simple means of early screening for liver cancer, proteomics was used to screen salivary markers of hepatitis B associated liver cancer. We used mass spectrometry coupled isobaric tags for relative and absolute quantitation (iTRAQ)-technology to identify differentially expressed proteins (DEPs). Western blot, immunohistochemistry and enzyme linked immunosorbent assay were used to detect marker expression of in tissues and saliva. Statistical analysis was used to analyze the diagnostic efficacy of the markers was analyzed through statistical analyses. By comparing the hepatocellular carcinoma (HCC) group with non-HCC groups, we screened out 152 salivary DEPs. We found orosomucoid 1(ORM1) had significantly higher expression in saliva of HCC patients compared with non-HCC groups (p < 0.001) and the expression of ORM1 in liver cancer tissues was significantly higher than that in adjacent normal tissues (p < 0.001). The combination of salivary ORM1 and alpha-fetoprotein (AFP) showed reasonable specificities and sensitivities for detecting HCC. In a word, salivary ORM1 as a new biomarker of hepatitis B associated hepatocellular carcinoma, combination of salivary ORM1 and AFP as an improved diagnostic tool for hepatocellular carcinoma., (© 2022. The Author(s).)

Astrocytes respond to injury and disease in the central nervous system with reactive changes that influence the outcome of the disorder 1-4 . These changes include differentially expressed genes (DEGs) whose contextual diversity and regulation are poorly understood. Here we combined biological and informatic analyses, including RNA sequencing, protein detection, assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) and conditional gene deletion, to predict transcriptional regulators that differentially control more than 12,000 DEGs that are potentially associated with astrocyte reactivity across diverse central nervous system disorders in mice and humans. DEGs associated with astrocyte reactivity exhibited pronounced heterogeneity across disorders. Transcriptional regulators also exhibited disorder-specific differences, but a core group of 61 transcriptional regulators was identified as common across multiple disorders in both species. We show experimentally that DEG diversity is determined by combinatorial, context-specific interactions between transcriptional regulators. Notably, the same reactivity transcriptional regulators can regulate markedly different DEG cohorts in different disorders; changes in the access of transcriptional regulators to DNA-binding motifs differ markedly across disorders; and DEG changes can crucially require multiple reactivity transcriptional regulators. We show that, by modulating reactivity, transcriptional regulators can substantially alter disorder outcome, implicating them as therapeutic targets. We provide searchable resources of disorder-related reactive astrocyte DEGs and their predicted transcriptional regulators. Our findings show that transcriptional changes associated with astrocyte reactivity are highly heterogeneous and are customized from vast numbers of potential DEGs through context-specific combinatorial transcriptional-regulator interactions., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

The variation of brain functions as healthy ageing has been discussed widely using resting-state brain imaging. Previous conclusions may be misinterpreted without considering the effects of global signal (GS) on local brain activities. Up to now, the variation of GS with ageing has not been estimated. To fill this gap, we defined the GS as the mean signal of all voxels in the gray matter and systematically investigated correlations between age and indices of GS fluctuations. What's more, these tests were replicated with data after hemodynamic response function (HRF) de-convolution and data without noise regression as well as head motion data to verify effects of non-neural information on age. The results indicated that GS fluctuations varied as ageing in three ways. First, GS fluctuations were reduced with age. Second, the GS power transferred from lower frequencies to higher frequencies with age. Third, the GS power was more evenly distributed across frequencies in ageing brain. These trends were partly influenced by HRF and physiological noise, indicating that the age effects of GS fluctuations are associated with a variety of physiological activities. These results may indicate the temporal dedifferentiation hypothesis of brain ageing from the global perspective., (© 2022. The Author(s).)

In order to analyze the influence of meso-structure and meso-parameters on deep granite characteristics, a construction method of variable radius proportional clump model was proposed with particle flow method. The clump particle flow structure was constructed which suited the mechanical characteristics of granite. The deep cavern numerical calculation model of gradual particle density was constructed using the variable radius proportional clump model construction method, and the macroscopic fracture law of deep cavern surrounding rock was analyzed. The results show that meso parameters have lower effects on the compressive and tensile ratios of particle structures in the ball and clump models. It is also found that clump structure is greatly influenced by particle proportion and size while ball model is only slightly influenced by particle size. Furthermore, the compressive and tensile strength curves and fracture modes of numerical simulations and laboratory tests are in good agreement. In addition, the calculated results of the tunnel after simulated excavation are very close to the engineering practice. There are obvious shear failure areas on the right vault and left wall of the tunnel, and the shape and depth of the fracture area are basically the same., (© 2022. The Author(s).)

The hub role of the right anterior insula (AI) has been emphasized in cognitive neurosciences and been demonstrated to be frequency-dependently organized. However, the functional organization of left AI (LAI) has not been systematically investigated. Here we used 100 unrelated datasets from the Human Connectome Project to study the frequency-dependent organization of LAI along slow 6 to slow 1 bands. The broadband functional connectivity of LAI was similar to previous findings. In slow 6-slow 3 bands, both dorsal and ventral seeds in LAI were correlated to the salience network (SN) and language network (LN) and anti-correlated to the default mode network (DMN). However, these seeds were only correlated to the LAI in slow 2-slow 1 bands. These findings indicate that broadband and narrow band functional connections reflect different functional organizations of the LAI. Furthermore, the dorsal seed had a stronger connection with the LN and anti-correlation with DMN while the ventral seed had a stronger connection within the SN in slow 6-slow 3 bands. In slow 2-slow 1 bands, both seeds had stronger connections with themselves. These observations indicate distinctive functional organizations for the two parts of LAI. Significant frequency effect and frequency by seed interaction were also found, suggesting different frequency characteristics of these two seeds. The functional integration and functional segregation of LDAI and LVAI were further supported by their cognitive associations. The frequency- and seed-dependent functional organizations of LAI may enlighten future clinical and cognitive investigations.

Colorectal cancer is the third most frequently diagnosed malignancies among both men and women, which has an increased mortality but a poor prognosis. Targeting mTOR becomes an effective approach that shows promising antitumor activities in various cancers including colonic carcinoma. However, the potential mechanism against colon cancer remains incompletely understood. Here, we demonstrated that the anti-cancer effect of AZD8055 and OSI-027 is at least in part modulated by the gradual process of apoptosis initiation, progressing from mTOR suppression, 4EBP1 dephosphorylation, or EZH2 suppression, thereby leading to PUMA-dependent apoptosis via the intrinsic mitochondrial pathway. Furthermore, AZD8055 inhibited colorectal cancer tumor growth in mice significantly. PUMA deletion caused resistance of dual mTOR inhibitors, suggesting PUMA mediated carcinogenesis in vitro and in vivo. Collectively, these findings established a vital status of PUMA in driving the antineoplastic efficacy of targeting mTOR by AZD8055 and OSI-027 and offered the rationales for the current clinical assessment.

Fecal DNA metabarcoding is currently used in various fields of ecology to determine animal diets. Contamination of non-food DNA from complex field environments is a considerable challenge to the reliability of this method but has rarely been quantified. We evaluated plant DNA contamination by sequencing the chloroplast trnL P6 loop region from food-controlled geese feces. The average percentage of contaminant sequences per sample was 1.86%. According to the results of generalized linear models, the probability of contamination was highest in samples placed in wet soil. The proportion of contaminant sequences was lowest at the earliest sampling point and was slightly higher in samples placed in open conditions. Exclusion of rare OTUs (operational taxonomic units) was effective for obtaining reliable dietary data from the obtained sequences, and a 1% cutoff reduced the percentage of contaminated samples to less than 30%. However, appropriate interpretation of the barcoding results considering inevitable contamination is an important issue to address. We suggest the following procedures for fecal sampling and sequence data treatment to increase the reliability of DNA metabarcoding diet analyses: (i) Collect samples as soon as possible after deposition, (ii) avoid samples from deposits on wet soil, and (iii) exclude rare OTUs from diet composition estimations.

Transected axons fail to regrow across anatomically complete spinal cord injuries (SCI) in adults. Diverse molecules can partially facilitate or attenuate axon growth during development or after injury 1-3 , but efficient reversal of this regrowth failure remains elusive 4 . Here we show that three factors that are essential for axon growth during development but are attenuated or lacking in adults-(i) neuron intrinsic growth capacity 2,5-9 , (ii) growth-supportive substrate 10,11 and (iii) chemoattraction 12,13 -are all individually required and, in combination, are sufficient to stimulate robust axon regrowth across anatomically complete SCI lesions in adult rodents. We reactivated the growth capacity of mature descending propriospinal neurons with osteopontin, insulin-like growth factor 1 and ciliary-derived neurotrophic factor before SCI 14,15 ; induced growth-supportive substrates with fibroblast growth factor 2 and epidermal growth factor; and chemoattracted propriospinal axons with glial-derived neurotrophic factor 16,17 delivered via spatially and temporally controlled release from biomaterial depots 18,19 , placed sequentially after SCI. We show in both mice and rats that providing these three mechanisms in combination, but not individually, stimulated robust propriospinal axon regrowth through astrocyte scar borders and across lesion cores of non-neural tissue that was over 100-fold greater than controls. Stimulated, supported and chemoattracted propriospinal axons regrew a full spinal segment beyond lesion centres, passed well into spared neural tissue, formed terminal-like contacts exhibiting synaptic markers and conveyed a significant return of electrophysiological conduction capacity across lesions. Thus, overcoming the failure of axon regrowth across anatomically complete SCI lesions after maturity required the combined sequential reinstatement of several developmentally essential mechanisms that facilitate axon growth. These findings identify a mechanism-based biological repair strategy for complete SCI lesions that could be suitable to use with rehabilitation models designed to augment the functional recovery of remodelling circuits.

Individuals who received anterior cruciate ligament (ACL) reconstruction surgeries demonstrated lower extremity movement asymmetries. The purpose of this study was to determine if psychological impairment was a contributor to lower extremity movement asymmetries in walking for individuals who received ACL reconstruction surgeries. Three-dimensional videographic and force plate data were collected for 25 males after unilateral ACL reconstruction performing walking without (single-task condition) and with the concurrent cognitive task (dual-task condition). Both uninjured and injured legs had significantly smaller peak knee flexion angle and peak knee extension moment during loading response and mid-stance phases in dual-task condition compared to single task condition (P ≤ 0.012). Walking condition and leg had significant interaction effects on peak hip adduction angle during mid-stance phase (P = 0.042) and peak hip abduction moment during loading response phase (P = 0.048). The inter-leg difference of peak hip adduction angle during mid-stance (P = 0.038) and terminal stance (P = 0.036) phases, and peak hip abduction moment during loading response phase (P = 0.024) were significantly decreased in dual-task condition compared to single-task condition. Psychological factors have significant effects on post-operative movements of both injured and uninjured knees of individuals who received ACL reconstruction surgery. Although physical factors may be primary contributors to the post-operative lower extremity movement asymmetries, psychological factors also contribute to the post-operative hip movement asymmetries.

A meniscus tear often happens during active sports. It needs to be repaired or replaced surgically to avoid further damage to the articular cartilage. To address the shortage of autologous meniscal cells, we designed a co-culture system of synovial stem cells (SMSCs) and meniscal cells (MCs) to produce a large cell number and to maintain characteristics of MCs. Different ratios of SMSCs and MCs at 3:1, 1:1, and 1:3 were tested. Mono-culture of SMSCs or MCs served as control groups. Proliferation and differentiation abilities were compared. The expression of extracellular matrix (ECM) genes in MCs was assessed using an ECM array to reveal the mechanism at the gene level. The co-culture system of SMSCs/MCs at the ratio of 1:3 showed better results than the control groups or those at other ratios. This co-culture system may be a promising strategy for meniscus repair with tissue engineering.

At present, PANI/MWNT composites have been paid more attention as promising electrode materials in supercapacitors. Yet some shortcomings still limit the widely application of PANI/MWNT electrolytes. In this work, in order to improve capacitance ability and long-term stability of electrode, a multi-amino dendrimer (PAMAM) had been covalently linked onto multi-walled carbon nanotubes (MWNT) as a bridge to facilitating covalent graft of polyaniline (PANI), affording P-MWNT/PANI electrode composites for supercapacitor. Surprisingly, ordered arrays of PANI nanowires on MWNT (setaria-like morphology) had been observed by scanning electron microscopy (SEM). Electrochemical properties of P-MWNT/PANI electrode had been characterized by cyclic voltammetry (CV) and galvanostatic charge-discharge technique. The specific capacitance and long cycle life of P-MWNT-PANI electrode material were both much higher than MWNT/PANI. These interesting results indicate that multi-amino dendrimer, PAMAM, covalently linked on MWNT provides more reaction sites for in-situ polymerization of ordered PANI, which could efficiently shorten the ion diffusion length in electrolytes and lead to making fully use of conducting materials.

This study is intended to find more effective and robust clinical diagnostic indices to characterize muscle strength and coordination alternation following anterior cruciate ligament (ACL) rupture. To evaluate angle-specific moments and hamstring (H)/quadriceps (Q) ratios, 46 male subjects with unilateral chronic ACL-rupture performed isokinetic concentric (c), eccentric (e) quadriceps and hamstring muscle tests respectively at 60°/s. Normalized moments and H/Q ratios were calculated for peak moment (PM) and 30°, 40°, 50°, 60°, 70°, 80° knee flexion angles. Furthermore, we introduced single-to-arithmetic-mean (SAM) and single-to-root-mean-square (SRMS) muscle co-contraction ratios, calculating them for specific angles and different contraction repetitions. Normalized PM and 40° specific concentric quadriceps, concentric hamstring strength in the ACL-deficient knee were reduced significantly (P ≤ 0.05). Concentric angle-specific moments together with Qe/Qc ratios at 40° (d = 0.766 vs. d = 0.654) identify more obvious differences than peak values in ACL ruptured limbs. Furthermore, we found SRMS-QeQc deficits at 40° showed stronger effect than Qe/Qc ratios (d = 0.918 vs. d = 0.766), albeit other ratio differences remained basically the same effect size as the original H/Q ratios. All the newly defined SAM and SRMS indices could decrease variance. Overall, 40° knee moments and SAM/SRMS ratios might be new potential diagnosis indices for ACL rupture detection.

Since transplantation of meniscal allograft or artificial menisci is limited by graft sources and a series of adverse events, substitution for meniscus reconstruction still needs to be explored. Natural biomaterials, which can provide a unique 3-D microenvironment, remain a promising alternative for tissue engineering. Among them, autograft is a preferred option for its safety and excellent biocompatibility. In this study, we utilized semitendinosus tendon autograft in meniscus reconstruction to investigate its fibrochondrogenic metaplasticity potential and chondroprotective effect. Tendon-derived stem cells (TDSCs) and synovial-derived mesenchymal stem cells (SMSCs), two most important stem cell sources in our strategy, exhibited excellent viability, distribution, proliferation and fibrochondrogenic differentiation ability in decellularized semitendinosus tendon (DST) scaffolds in vitro. Histologic evaluation of the tendon grafts in vivo suggested endogenous stem cells differentiated into fibrochondrocytes, synthesized proteoglycan, type II collagen and radial type I collagen at 12 weeks and 24 weeks post-surgery. As for elastic modulus and hardness of the grafts, there were no significant differences between native meniscus and regenerated meniscus at 24 weeks. The protection of condylar cartilage from degeneration was significantly better in the reconstruction group comparing to control group. Overall, semitendinosus tendon autograft seems to be a promising substitution in meniscus reconstruction.

The carboxyl-functionalised task-specific ionic liquid of 1-carboxymethyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl)imide ([HOOCmim][NTf 2 ]) was used as solvent and extractant for UO 2 2+ extraction from aqueous solution. A homogeneous phase of [HOOCmim][NTf 2 ]-H 2 O system could be achieved at 75 °C, and 86.8 ± 4.8% of UO 2 2+ was separated from the aqueous solution after vibrating for only 1 min. Furthermore, nearly 97.3 ± 2.9% of UO 2 2+ was stripped from [HOOCmim][NTf 2 ] phase by 1 M HNO 3 solution. K + , Na + , Mg 2+ , Dy 3+ , La 3+ , and Eu 3+ have little influence on the homogeneous extraction of UO 2 2+ , and the extraction efficiency of UO 2 2+ still remained at ca. 80%. Experimental and theoretical study on the selectivity of [HOOCmim][NTf 2 ]-H 2 O system were performed for the first time. Density functional theory calculation indicates that the solvent effect plays a significant role on the selectivity of [HOOCmim][NTf 2 ]-H 2 O.

Ependyma have been proposed as adult neural stem cells that provide the majority of newly proliferated scar-forming astrocytes that protect tissue and function after spinal cord injury (SCI). This proposal was based on small, midline stab SCI. Here, we tested the generality of this proposal by using a genetic knock-in cell fate mapping strategy in different murine SCI models. After large crush injuries across the entire spinal cord, ependyma-derived progeny remained local, did not migrate and contributed few cells of any kind and less than 2%, if any, of the total newly proliferated and molecularly confirmed scar-forming astrocytes. Stab injuries that were near to but did not directly damage ependyma, contained no ependyma-derived cells. Our findings show that ependymal contribution of progeny after SCI is minimal, local and dependent on direct ependymal injury, indicating that ependyma are not a major source of endogenous neural stem cells or neuroprotective astrocytes after SCI.

Previous studies proposed various hypotheses to the formation of the mega-dunes and water recharge of the lakes in the Badain Jaran Desert but left the coexistence of lake-dune pattern unsolved. This research found that the local circulation, generated from the differences of thermodynamic properties and the unique landscape settings between lakes and mega-dunes, can be applied to interpret the pattern.

Mechanical factors play a key role in regulating the development of cartilage degradation in osteoarthritis. This study aimed to identify the influence of mechanical stress in cartilage and chondrocytes. To explore the effects of mechanical stress on cartilage morphology, we observed cartilages in different regions by histological and microscopic examination. Nanoindentation was performed to assess cartilage biomechanics. To investigate the effects of mechanical stress on chondrocytes, cyclic tensile strain (CTS, 0.5 Hz, 10%) was applied to monolayer cultures of human articular chondrocytes by using Flexcell-5000. We quantified the mechanical properties of chondrocytes by atomic force microscopy. Chondrocytes were stained with Toluidine blue and Alcian blue after exposure to CTS. The expression of extracellular matrix (ECM) molecules was detected by qPCR and immunofluorescence analyses in chondrocytes after CTS. Our results demonstrated distinct morphologies and mechanical properties in different cartilage regions. In conclusion, mechanical stress can affect the chondrocyte phenotype, thereby altering the expression of chondrocyte ECM.

Though many surgical animal models have been used to induce osteoarthritis (OA) of the knee joint, they always open the capsule of the joint. Any surgical procedures that incises the capsule may cause inflammation, pain, and possibly altered gait. One common disadvantage of these surgically induced animal models is that they may affect the initial structures and synovial fluid in joint. These animal models may not be suitable for research into synovial fluid changes during early OA. This study aimed to create an animal model of early OA by resecting the medial collateral ligament (MCL) outside of the capsule. At 1, 2, 3, 4, 5 and 6 weeks after surgery, eight knees from each group were harvested. The joint gap was measured on posteroanterior radiographs after MCL-transection (MCLT). Gross examination and histological analysis were performed to evaluate cartilage damage to the medial femoral condyles, and knee joints were scanned using a Micro-CT system. The MCLT group experienced early stage OA from 3 to 6 weeks according to the histological scores. IL-6, MMP-1 and MMP-13 content in the synovial fluid were higher after MCLT than anterior cruciate ligament transection (ACLT) at 1 and 2 weeks.

Osteoarthritis (OA) is a common debilitating joint disorder, there's still no available disease-modifying drug for OA currently. This study aims to explore the role of TAK1 in OA pathogenesis and therapeutic efficiency of TAK1 inhibition for OA. The contribution of TAK1 to OA pathogenesis was investigated by intra-articular injection of TAK1-encoding adenovirus in rats. TAK1 inhibitor 5Z-7-induced expression changes of extracellular matrix (ECM)-related genes were detected by real-time PCR. The protective effect of 5Z-7 against OA progression was evaluated in a post-traumatic OA rat model. Our results showed that intra-articular injection of Ad-Tak1 induced cartilage destruction and OA-related cytokine secretion in rat joints. TAK1 inhibition by 5Z-7 efficiently blocked NF-κB, JNK and p38 pathways activation in OA chondrocytes and synoviocytes, Meanwhile, 5Z-7 significantly decreased the expression of matrix-degrading enzymes and pro-inflammatory cytokine, while increased ECM protein expression, which are all crucial components in OA. 5Z-7 also ameliorated ECM loss in OA cartilage explants. More importantly, 5Z-7 significantly protected against cartilage destruction in a rat model of OA. In conclusion, our findings provide the first in vivo evidence that TAK1 contributes to OA by disrupting cartilage homeostasis, thus represents an ideal target for OA treatment, with 5Z-7 as a candidate therapeutic.

Transected axons fail to regrow in the mature central nervous system. Astrocytic scars are widely regarded as causal in this failure. Here, using three genetically targeted loss-of-function manipulations in adult mice, we show that preventing astrocyte scar formation, attenuating scar-forming astrocytes, or ablating chronic astrocytic scars all failed to result in spontaneous regrowth of transected corticospinal, sensory or serotonergic axons through severe spinal cord injury (SCI) lesions. By contrast, sustained local delivery via hydrogel depots of required axon-specific growth factors not present in SCI lesions, plus growth-activating priming injuries, stimulated robust, laminin-dependent sensory axon regrowth past scar-forming astrocytes and inhibitory molecules in SCI lesions. Preventing astrocytic scar formation significantly reduced this stimulated axon regrowth. RNA sequencing revealed that astrocytes and non-astrocyte cells in SCI lesions express multiple axon-growth-supporting molecules. Our findings show that contrary to the prevailing dogma, astrocyte scar formation aids rather than prevents central nervous system axon regeneration., Competing Interests: The authors declare no competing financial interests.

Circular RNAs (circRNAs) are involved in the development of various diseases, but there is little knowledge of circRNAs in osteoarthritis (OA). The aim of study was to identify circRNA expression in articular cartilage and to explore the function of chondrocyte extracellular matrix (ECM)-related circRNAs (circRNA-CER) in cartilage. To identify circRNAs that are specifically expressed in cartilage, we compared the expression of circRNAs in OA cartilage with that in normal cartilage. Bioinformatics was employed to predict the interaction of circRNAs and mRNAs in cartilage. Loss-of-function and rescue experiments for circRNA-CER were performed in vitro. A total of 71 circRNAs were differentially expressed in OA and normal cartilage. CircRNA-CER expression increased with interleukin-1 and tumor necrosis factor levels in chondrocytes. Silencing of circRNA-CER using small interfering RNA suppressed MMP13 expression and increased ECM formation. CircRNA-CER could compete for miR-136 with MMP13. Our results demonstrated that circRNA-CER regulated MMP13 expression by functioning as a competing endogenous RNA (ceRNA) and participated in the process of chondrocyte ECM degradation. We propose that circRNA-CER could be used as a potential target in OA therapy.

Runx2 is a powerful osteo-inductive factor and adipose-derived stem cells (ADSCs) are multipotent. However, it is unknown whether Runx2-overexpressing ADSCs (Runx2-ADSCs) could promote anterior cruciate ligament (ACL) reconstruction. We evaluated the effect of Runx2-ADSCs on ACL reconstruction in vitro and in vivo. mRNA expressions of osteocalcin (OCN), bone sialoprotein (BSP) and collagen I (COLI) increased over time in Runx2-ADSCs. Runx2 overexpression inhibited LPL and PPARγ mRNA expressions. Runx2 induced alkaline phosphatase activity markedly. In nude mice injected with Runx2-ADSCs, promoted bone formation was detected by X-rays 8 weeks after injection. The healing of tendon-to-bone in a rabbit model of ACL reconstruction treated with Runx2-ADSCs, fibrin glue only and an RNAi targeting Runx2, was evaluated with CT 3D reconstruction, histological analysis and biomechanical methods. CT showed a greater degree of new bone formation around the bone tunnel in the group treated with Runx2-ADSCs compared with the fibrin glue group and RNAi Runx2 group. Histology showed that treatment with Runx2-ADSCs led to a rapid and significant increase at the tendon-to-bone compared with the control groups. Biomechanical tests demonstrated higher tendon pullout strength in the Runx2-ADSCs group at early time points. The healing of the attachment in ACL reconstruction was enhanced by Runx2-ADSCs.

Articular cartilage injury is still a significant challenge because of the poor intrinsic healing potential of cartilage. Stem cell-based tissue engineering is a promising technique for cartilage repair. As cartilage defects are usually irregular in clinical settings, scaffolds with moldability that can fill any shape of cartilage defects and closely integrate with the host cartilage are desirable. In this study, we constructed a composite scaffold combining mesenchymal stem cells (MSCs) E7 affinity peptide-modified demineralized bone matrix (DBM) particles and chitosan (CS) hydrogel for cartilage engineering. This solid-supported composite scaffold exhibited appropriate porosity, which provided a 3D microenvironment that supports cell adhesion and proliferation. Cell proliferation and DNA content analysis indicated that the DBM-E7/CS scaffold promoted better rat bone marrow-derived MSCs (BMMSCs) survival than the CS or DBM/CS groups. Meanwhile, the DBM-E7/CS scaffold increased matrix production and improved chondrogenic differentiation ability of BMMSCs in vitro. Furthermore, after implantation in vivo for four weeks, compared to those in control groups, the regenerated issue in the DBM-E7/CS group exhibited translucent and superior cartilage-like structures, as indicated by gross observation, histological examination, and assessment of matrix staining. Overall, the functional composite scaffold of DBM-E7/CS is a promising option for repairing irregularly shaped cartilage defects.

Hypoxia-inducible factor-2α (Hif-2α) is a potential therapeutic target for osteoarthritis (OA), but the application of this target in the delivery of therapeutic agents to chondrocytes remains a challenge. A chondrocyte-targeting vector was constructed in a previous study to enhance transfection efficiency and specificity of chondrocytes in vivo. This study used vectors to deliver small-interfering RNA (siRNA) and silenced Hif-2α expression to prevent cartilage degeneration in OA-affected mice. After siRNA transfection was conducted by cartilage-targeting nanoparticles, the protein levels of Hif-2α, matrix metalloproteinases (MMP-13, -9), a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS-4, -5), vascular endothelial growth factor (VEGF), type X collagen and nuclear factor (NF)-κB in interleukin-1-beta (IL-1β)-stimulated chondrocytes were determined. Chondrocyte-targeting ability was also determined by fluorescein isothiocyanate (FITC)-labeled siRNA tracking under a confocal microscope. OA model was established by surgically destabilizing the knee joints of a mouse. Hif-2α siRNA was then delivered intra-articularly with nanoparticles in vivo. Cartilage degeneration and synovium inflammation in the knee joints were analyzed by histomorphometry. IL-1β levels in the synovial fluid were also measured by enzyme-linked immunosorbent assay. In vitro assay results showed that catabolic factors, including Hif-2α, MMP-13 and -9, ADAMTS-4, VEGF, collagen type X and NF-κB, were downregulated after Hif-2α-siRNA transfection by chondrocyte-targeting nanoparticles. In vivo assay results with FITC-labeled siRNA tracking also confirmed that nanoparticles promoted the local concentration and prolonged the retention time of siRNA in the cartilage. Histological analysis results confirmed that nanoparticle-mediated siRNA maintained cartilage integrity and alleviated synovium inflammation. IL-1β levels decreased after siRNA was silenced by nanoparticles. Thus, chondrocyte-targeting nanoparticles could deliver Hif-2α siRNA to cartilage and specifically inhibit the expression of catabolic proteins.

Huntington's disease (HD) is characterized by striatal medium spiny neuron (MSN) dysfunction, but the underlying mechanisms remain unclear. We explored roles for astrocytes, in which mutant huntingtin is expressed in HD patients and mouse models. We found that symptom onset in R6/2 and Q175 HD mouse models was not associated with classical astrogliosis, but was associated with decreased Kir4.1 K(+) channel functional expression, leading to elevated in vivo striatal extracellular K(+), which increased MSN excitability in vitro. Viral delivery of Kir4.1 channels to striatal astrocytes restored Kir4.1 function, normalized extracellular K(+), ameliorated aspects of MSN dysfunction, prolonged survival and attenuated some motor phenotypes in R6/2 mice. These findings indicate that components of altered MSN excitability in HD may be caused by heretofore unknown disturbances of astrocyte-mediated K(+) homeostasis, revealing astrocytes and Kir4.1 channels as therapeutic targets.

Rare-earth Yb(3+) and Ho(3+) co-doped fluorapatite (FA:Yb(3+)/Ho(3+)) crystals were prepared by hydrothermal synthesis, and their structure, upconversion properties, cell proliferation and imaging were investigated. The synthesized crystals, with a size of 16 by 286 nm, have a hexagonal crystal structure of classic FA and a Ca/Yb/Ho molar ratio of 100/16/2.1. Several reasonable Yb(3+)/Ho(3+) -embedding lattice models along the fluorine channel of the FA crystal cell are proposed for the first time, such as models for (Ca7YbHo©)(PO4)6F2 and (Ca6YbHoNa2)(PO4)6F2. The activated FA:Yb(3+)/Ho(3+) crystals were found to exhibit distinct upconversion fluorescence. The 543- and 654-nm signals in the emission spectra could be assigned, respectively, to the (5)F4 ((5)S2) - (5)I8 and (5)F5 - (5)I8 transitions of holmium via 980-nm near-infrared excitation and the energy transfer of ytterbium. After the surfaces were grafted with hydrophilic dextran, the crystals displayed clear fluorescent cell imaging. Thus, the prepared novel FA:Yb(3+)/Ho(3+) upconversion fluorescent crystals have potential applications in the biomedical field.

Sympathetic hyperactivity has an important role in cardiovascular mortality in patients with type 2 diabetes (T2D). Thyrotropin-releasing hormone (TRH)-containing fibers innervate autonomic motor and premotor nuclei of the brainstem and spinal cord that regulate cardiovascular functions. We compared cardiovascular responses to application of TRH-analog in the brainstem of Wistar and T2D Goto-Kakizaki (GK) rats. GK rats exhibited basal systolic hypertension (152±2 mm Hg) and had a significantly potentiated, dose-related hypertensive response to intracisternal (i.c.) injection of the TRH-analog RX77368 (10-60 ng). In GK rats only, i.c. RX77368 (30-60 ng) markedly increased heart rate (HR; +88 b.p.m.) and induced acute cardiac mortality (100%), concurrent with extreme hyperglycemia (>26 mmol l(-1)), increased plasma H(2)O(2) and 8-isoprostane, and enhanced heart expression of NADPH oxidase 4 and vascular cell adhesion molecule-1 mRNAs. GK rats also had elevated basal plasma epinephrine, higher adrenal gene expression of tyrosine hydroxylase and dopamine β-hydroxylase (DβH), and greater plasma catecholamine and adrenal DβH responses to i.c. TRH-analog, compared with Wistar rats. In GK rats, hexamethonium blocked i.c. RX77368-induced hypertensive and tachycardic responses, and reduced mortality by 86%, whereas phentolamine abolished the hypertensive response but enhanced tachycardia (+160 b.p.m.), and reduced mortality by 50%. The angiotensin II type 1 receptor antagonist irbesartan prevented i.c. RX77368-induced increases in blood pressure, HR and mortality. In conclusion, sympathetic overactivation triggered by brainstem TRH contributes to the mechanism of cardiovascular morbidity and mortality in T2D, which involves heightened cardiac inflammation and peripheral oxidative stress responses to sympathetic drive, and a mediating role of the renin-angiotensin system.

After complete spinal cord transections that removed all supraspinal inputs in adult rats, combinations of serotonergic agonists and epidural electrical stimulation were able to acutely transform spinal networks from nonfunctional to highly functional and adaptive states as early as 1 week after injury. Using kinematics, physiological and anatomical analyses, we found that these interventions could recruit specific populations of spinal circuits, refine their control via sensory input and functionally remodel these locomotor pathways when combined with training. The emergence of these new functional states enabled full weight-bearing treadmill locomotion in paralyzed rats that was almost indistinguishable from voluntary stepping. We propose that, in the absence of supraspinal input, spinal locomotion can emerge from a combination of central pattern-generating capability and the ability of these spinal circuits to use sensory afferent input to control stepping. These findings provide a strategy by which individuals with spinal cord injuries could regain substantial levels of motor control.

Aim: To examine whether isoliquiritigenin (ISL) can attenuate myocardial ischemiareperfusion (MI/R) injury in rats by inducing metallothionein (MT) through activation of janus kinase 2 (JAK 2)/signal transducers and activators of transcription 3 (STAT 3) pathway., Methods: The experimental model of MI/R in rats was generated by 30 min of ischemia and reperfusion for 2 h. The mRNA expression of MT, COX-2, and iNOS were measured by RT-PCR. The protein expressions of MT, JAK/STAT, extracellular signal-regulated kinase (ERK), and Akt were determined by Western blotting in the absence or presence of a JAK kinase inhibitor, tyrphostin AG490 (1.0 mg/kg, iv, 1 h before ischemia)., Results: Pretreatment with ISL markedly decreased the severity of reperfusion-induced arrhythmias and myocardial infarct size. In the ISL 20 mg/kg group, the activities of lactate dehydrogenase (LDH) and creatinine phosphokinase (CPK) were reduced by 38.4% and 51.3% when compared with the vehicle group. Increased JAK 2/STAT 3 phosphorylation was accompanied by increased synthesis of MT but not of COX-2 or iNOS in ISL-treated groups. AG490 can significantly weaken ISL-induced cardioprotection and prevent the increase of MT expression and JAK 2/STAT 3 phosphorylation., Conclusion: ISL protected MI/R injury through activation of JAK 2/STAT 3 signal transduction pathway, which might be involved in mediating the upregulation of MT expression.

53BP2 was initially identified as a protein interacting with p53 in a yeast two-hybrid screen and subsequently shown to enhance p53 transcriptional transactivation and induce apoptosis when transiently overexpressed in cell lines. In order to further study the biologically relevant effects of 53BP2, we have constructed HEK293 stable cell lines where 53BP2 expression can be regulated using an ecdysone inducible expression system. Our results indicate that the response of cells is dependent on the amount of 53BP2 that is expressed. High levels of 53BP2 expression (>or=140-fold above endogenous) impede cell cycle progression and induce apoptosis. Lower levels of 53BP2 expression (6-11-fold above endogenous) suppress colony formation but do not lead to detectable perturbations in the cell cycle or apoptosis. Lower levels of 53BP2 expression sensitized cells to apoptosis induced by DNA damaging chemotherapy agents doxorubicin, ara-C and VP16, but not microtubule active agents paclitaxel and vinblastine. Our results demonstrate that high levels of 53BP2 expression have profound biological effects ultimately leading to apoptosis, whereas lower levels of 53BP2 expression have more subtle effects on growth and sensitize cells to some chemotherapy agents.