The circUbqln1, regulated by XBP1s, interplays with 14-3-3ζ to inhibit collagen synthesis and promote osteoarthritis by controlling PRODH activity and proline metabolism.

INTRODUCTION: Osteoarthritis (OA) is a degenerative bone disease associated with ageing, characterized by joint pain, stiffness, swelling and deformation. Currently, pharmaceutical options for the clinical treatment of OA are very limited. Circular RNAs(cirRNAs) have garnered significant attention in OA and related drug development due to their unique RNA sequence characteristics.Therefore,exploring the role of cirRNAs in the occurrence and development of OA is of paramount importance for the development of effective medications for OA. OBJECTIVES: To identify a novel circRNA, circUbqln1, for treating osteoarthritis and elucidate its pathophysiological role and mechanisms in the treatment of OA. METHODS: The circUbqln1 expression and distribution were determined by qRT-PCR and FISH. XBP1 gene knockout(XBP1 cKO) spontaneous OA and DMM model and WT mouse CIOA model were used to explore the role of XBP1 and circUbqln1 in OA.Overexpression or knockdown of circUbqln1 lentivirus was used to observe the impacts of circUbqln1 on primary chondrocytes,C28/I2 and mice in vitro and in vivo.Chromatin immunoprecipitation,luciferase reporter assay,RNA pulldown,mass spectrometry,RNA immunoprecipitation,fluorescence in situ hybridization,and flow cytometry to explore the molecular mechanisms of circUbqln1. RESULTS: It was found that cartilage-specific XBP1 cKO mice exhibited a faster OA progression compared to normal's.Importantly,transcript factor XBP1s has the capacity to impede the biogenesis of circUbqln1,derived from Ubqln1. The circUbqln1 promotes cartilage catabolism and inhibits anabolism, therefore accelerates the occurrence of OA.Mechanismly,circUbqln1 can translocate to the chondrocyte nucleus with the assistance of phosphorylated 14-3-3ζ, upregulate the transcriptional activity of the proline dehydrogenase(Prodh) promoter and PRODH enzyme activity. Consequently, this leads to the promotion of proline degradation and the inhibition of collagen synthesis,ultimately culminating in the impairment of cartilage and its structural integrity. CONCLUSION: CircUbqln1 plays a crucial role in the occurrence and development of OA, indicating that the inhibition of circUbqln1 holds promise as a significant approach for treating OA in the future.

Gut-joint axis: Oral Probiotic ameliorates Osteoarthritis.

Osteoarthritis (OA) etiology is multifactorial, and its prevalence is growing globally. The Gut microbiota shapes our immune system and impacts all aspects of health and disease. The idea of utilizing probiotics to treat different conditions prevails. Concerning musculoskeletal illness and health, current data lack the link to understand the interactions between the host and microbiome. We report that S. thermophilus, L. pentosus (as probiotics), and γ-aminobutyric acid (GABA) harbour against osteoarthritis in vivo and alleviate IL-1ß induced changes in chondrocytes in vitro. We examined the increased GABA concentration in mice's serum and small intestine content followed by bacterial treatment. The treatment inhibited the catabolism of cartilage and rescued mice joints from degradation. Furthermore, the anabolic markers upregulated and decreased inflammatory markers in mice knee joints and chondrocytes. This study is the first to represent GABA's chondrogenic and chondroprotective effects on joints and human chondrocytes. This data provides a foundation for future studies to elucidate the role of GABA in regulating chondrocyte cell proliferation. These findings opened future horizons to understanding the gut-joint axis and OA treatment. Thus, probiotic/GABA therapy shields OA joints in mice and could at least serve as adjuvant therapy to treat osteoarthritis.

Identification and functional coordination analysis of gene co-expression networks in different tissues of XBP1 cartilage-specific deficient mice.

Abnormal differentiation and proliferation of chondrocytes leads to various diseases related to growth and development. The process of chondrocyte differentiation involves a series of complex cellular and molecular interactions. X-box binding protein 1 (XBP1), an essential molecule of the unfolded protein response (UPR) in Endoplasmic Reticulum (ER) stress, participated in cartilage development and causes other related diseases. We previously reported that XBP1 deficiency in cartilage impacts the function and associated diseases of many different tissues including cartilage. However, how differential expression of genes modulates the roles of cartilage and other tissues when XBP1 is lack of in chondrocytes remains unclear. We aimed to screen for differentially expressed (DE) genes in cartilage, brain, heart, and muscle by high-throughput sequencing in XBP1 cartilage-specific knockout (CKO) mice. Further, gene co-expression networks were constructed by weighted gene co-expression network analysis (WGCNA) algorithm and pivot genes were identified in the above four tissues. Protein detection, Hematoxylin-eosin (HE) staining and immunohistochemistry (IHC) experiments have proved that these differentially co-expressed genes participate in the downstream regulatory pathway of different tissues and affect tissue function.Significantly differentially expressed mRNAs [differentially expressed genes (DEGs)] were identified between XBP1 CKO mice and controls in cartilage, brain, heart, and muscle tissues, including 610, 126, 199 and 219 DEGs, respectively. 39 differentially co-expressed genes were identified in the above four tissues, and they were important pivot genes. Comprehensive analysis discovered that XBP1 deficiency in cartilage influences the difference of co-expressed genes between cartilage and other different tissues. These differentially co-expressed genes participate in downstream regulatory pathways of different tissues and affect tissue functions. Collectively, our conclusions may contribute potential biomarkers and molecular mechanisms for the mutual modulation between cartilage and different tissues and the diagnosis and treatment of diseases caused by abnormalities in different tissues. The analysis also provides meaningful insights for future genetic discoveries.

Improving the Anti-washout Property of Acrylate Grouting Material by Bentonite: Its Characterization, Improving Mechanism, and Practical Application.

Acrylate is a popular polymer grouting material that has been widely used to control groundwater seepage. However, the vulnerability of acrylate slurry to dynamic water washout restricts its application in groundwater environments characterized by high flow velocity and water pressures. In this paper, lithium bentonite (Li-B) was used to modify the traditional magnesium acrylate (AC) grouting material. The influence of Li-B to AC ratios on the modified materials' washout resistance was explored, and the modification mechanism was analyzed using X-ray diffraction (XRD), infrared spectroscopy (IR), and scanning electron microscopy (SEM). Finally, the anti-washout ability of the modified slurry was verified through engineering applications. Results revealed that LiB-AC grout had adjustable setting times (10.5 to 395.6 s), minimal bleeding (0.1%), higher viscosity (65 mPa·s) and expansibility (350%), stronger anti-water dispersibility (24 times that of pure AC slurry), higher mechanical strength (compressive strength is 0.386 MPa, tensile strength is 0.088 MPa), and better impermeability (2.23 × 10-8 m/s). The lithium bentonite was beneficial to the setting time, bleeding, viscosity, slurry retention rate, impermeability, and mechanical strength of the acrylate grout. However, it diminished the expansibility of the acrylate grout. At the optimal acrylate content (20%), the mechanical strength and impermeability of the LiB-AC grout were the highest. The better performance of LiB-AC grout was attributed to the formation of a more stable and dense interlaced spatial network structure after the modification by Li-B. The LiB-AC grout was used in the dynamic water grouting project of a metro shield tunnel segment and achieved better anti-washout performance than cement-water glass and pure AC slurry.

Progranulin regulation of autophagy contributes to its chondroprotective effect in osteoarthritis.

Progranulin (PGRN) is a multifunctional growth factor involved in many physiological processes and disease states. The apparent protective role of PGRN and the importance of chondrocyte autophagic function in the progression of osteoarthritis (OA) led us to investigate the role of PGRN in the regulation of chondrocyte autophagy. PGRN knockout chondrocytes exhibited a deficient autophagic response with limited induction following rapamycin, serum starvation, and IL-1ß-induced autophagy. PGRN-mediated anabolism and suppression of IL-1ß-induced catabolism were largely abrogated in the presence of the BafA1 autophagy inhibitor. Mechanistically, during the process of OA, PGRN and the ATG5-ATG12 conjugate form a protein complex; PGRN regulates autophagy in chondrocytes and OA through, at least partially, the interactions between PGRN and the ATG5-ATG12 conjugate. Furthermore, the ATG5-ATG12 conjugate is critical for cell proliferation and apoptosis. Knockdown or knockout of ATG5 reduces the expression of ATG5-ATG12 conjugate and inhibits the chondroprotective effect of PGRN on anabolism and catabolism. Overexpression of PGRN partially reversed this effect. In brief, the PGRN-mediated regulation of chondrocyte autophagy plays a key role in the chondroprotective role of PGRN in OA. Such studies provide new insights into the pathogenesis of OA and PGRN-associated autophagy in chondrocyte homeostasis.

Progranulin, a moderator of estrogen/estrogen receptor α binding, regulates bone homeostasis through PERK/p-eIF2 signaling pathway.

Under normal conditions, the human body employs the synergistic action of osteoblasts and osteoclasts to maintain a dynamic balance between bone formation and resorption. Bone homeostasis plays a very important role in the process of bone formation. Various bone diseases can occur if bone homeostasis is disrupted. In this study, the serum estrogen levels were significantly increased in the granulin (GRN)-deficient mice and PGRN regulates the binding of estrogen and estrogen receptor α (ERα) and then affects estrogen's ability to regulate bone formation and resorption. In addition, this study also explored the role that PGRN plays in regulating bone homeostasis by affecting the binding of estrogen and estrogen receptors through the protein kinase R-like endoplasmic reticulum kinase/phosphorylation of the eukaryotic initiation factor 2 signaling pathway. In summary, we confirmed the important role of PGRN in regulating the estrogen (E2)/ERα signal in maintaining bone homeostasis. Our findings may provide a new strategy for the treatment of osteoporosis and maintaining bone homeostasis. KEY MESSAGES: PGRN is a molecular regulator of the binding of E2 and ERα signal in maintaining bone homeostasis. PGRN plays in regulating bone homeostasis through the PERK/p-eIF2α signaling pathway. The best therapeutic effect of PGRN in osteoporosis is associated with different concentration of E2.

Numerical Study of the Optimum Fiber Content of Sealing Grease Using Discrete Element Method.

A sealing grease plays a crucial role in the sealing of shield tails. Its pumpability and pressure sealing resistant sealing performance are greatly affected by the fiber content. In this study, discrete element method models were used to simulate the pressure-resistant tests of sealing grease in order to investigate the influence of viscosity grade and fiber's aspect ratio on the optimum fiber content of sealing grease. Meanwhile, the rationality of the optimum fiber number determined based on the sealing performance was verified with the unbalanced force and fiber area proportion obtained in the simulation, of which the variation curves with the increasing fiber number were practically identical. The simulation results elucidated that the viscosity of grease had little effect on the optimum fiber content for sealing grease. However, the increase in viscosity can improve the sealing effect, and increasing the fiber's aspect ratio can reduce the fiber number to reach a specific seal state. Based on the analysis of the total number of fiber spheres for the models with different fiber's respect ratios, it can be concluded that the sealing grease sample made of the same fiber material and quality can reach the same seal state and seal effect, independent on fiber's aspect ratio.

Effect Of XBP1 Deficiency In Cartilage On The Regulatory Network Of LncRNA/circRNA-miRNA-mRNA.

X-box binding protein 1(XBP1) is a critical component for unfolded protein response (UPR) in ER stress. According to previous studies performed with different XBP1-deficient mice, the XBP1 gene affects mouse cartilage development and causes other related diseases. However, how the complete transcriptome, including mRNA and ncRNAs, affects the function of cartilage and other tissues when XBP1 is deficient in chondrocytes is unclear. In this study, we aimed to screen the differentially expressed (DE) mRNAs, circRNAs, lncRNAs and miRNAs in XBP1 cartilage-specific knockout (CKO) mice using high throughput sequencing and construct the circRNA-miRNA-mRNA and lncRNA-miRNA-mRNA regulatory networks. DE LncRNAs (DE-LncRNAs), circRNAs (DE-circRNAs), miRNAs (DE-miRNAs), and mRNAs [differentially expressed genes (DEGs)] between the cartilage tissue of XBP1 CKO mice and controls were identified, including 441 DE-LncRNAs, 15 DE-circRNAs, 6 DE-miRNAs, and 477 DEGs. Further, 253,235 lncRNA-miRNA-mRNA networks and 1,822 circRNA-miRNA-mRNA networks were constructed based on the correlation between lncRNAs/circRNAs, miRNAs, mRNAs. The whole transcriptome analysis revealed that XBP1 deficiency in cartilage affects the function of cartilage and other different tissues, as well as associated diseases. Overall, our findings may provide potential biomarkers and mechanisms for the diagnosis and treatment of cartilage and other related diseases.

Treating Autoimmune Inflammatory Diseases with an siERN1-Nanoprodrug That Mediates Macrophage Polarization and Blocks Toll-like Receptor Signaling.

The clinical application of small interfering RNA (siRNA) drugs provides promising opportunities to develop treatment strategies for autoimmune inflammatory diseases. In this study, siRNAs targeting the endoplasmic reticulum to nucleus signaling 1 (ERN1) gene (siERN1) were screened. Two cationic polymers, polyethylenimine (PEI) and poly(ß-amino amine) (PBAA), which can improve the efficiency of the siRNA transfection, were used as siERN1 delivery carriers. They were implemented to construct a nanodrug delivery system with macrophage-targeting ability and dual responsiveness for the treatment of autoimmune inflammatory diseases. In terms of the mechanism, siERN1 can regulate the intracellular calcium ion concentration by interfering with the function of inositol 1,4,5-trisphosphate receptor 1/3 (IP3R1/3) and thus inducing M2 polarization of macrophages. Furthermore, siERN1-nanoprodrug [FA (folic acid)-PEG-R(RKKRRQRRR)-NPs(ss-PBAA-PEI)@siERN1] acts as a conductor of macrophage polarization by controlling the calcium ion concentration and is an inhibitor of MyD88-dependent Toll-like receptor signaling. The results revealed that the FA-PEG-R-NPs@siERN1 has universal biocompatibility, long-term drug release responsiveness, superior targeting properties, and therapeutic effects in mouse collagen-induced arthritis and inflammatory bowel disease models. In conclusion, this study reveals a potential strategy to treat autoimmune inflammatory disorders.

Comparative Study on Mechanical Properties of Sealing Grease Composed of Different Base Oils for Shield Tunnel.

This study proposes a novel sealing grease with improved mechanical properties and environmental performance. A series of sealing grease samples were made with different base oils, including mineral oil and renewable oil (vegetable oil and lard). In this study, thermogravimetric analysis (TGA) was conducted to study the adsorption capacity of the thickener to the base oil. The fluidity of the sealing grease was also tested at different temperatures. Furthermore, an exponential function was proposed for the flow rate of the sealing grease and the temperature. Moreover, a cone penetration test was conducted to study the consistency of the sealing grease. The results indicated that the capacity of the thickener to adsorb vegetable oil was greater than that of mineral oil, but less than that of lard. Additionally, the flow rate of the sealing grease increased with an increase in temperature. At a fixed temperature, the flow rate of the sealing grease increased with the base oil content. According to the exponential function, the composition of the base oil is the key factor that determines the temperature sensitivity of the sealing grease. In addition, the sealing grease made of vegetable oil has the minimum temperature sensitivity coefficient.

Understanding Free Volume Characteristics of Ethylene-Propylene-Diene Monomer (EPDM) through Molecular Dynamics Simulations.

Understanding the underlying processes associated with the viscoelasticity performance of ethylene-propylene-diene monomer (EPDM) during its service life is essential for assessing and predicting its waterproofing performance in underground infrastructure. The viscoelasticity of the polymer is closely related to its free volume, and both of these properties depend on multiple factors, such as temperature, stress magnitude, and strain level. To explore the fundamental viscoelastic behavior of EPDM using free volume as a proxy for viscoelasticity, this article investigates the influence of temperature, stress magnitude, and strain level, as well as their combined effect, on the free volume through molecular dynamics (MD) simulations. An EPDM cross-linked molecular model was built and verified by comparing the simulation values of glass transition temperature, mechanical properties, and gas diffusivity with the experimental results reported in the literature. Then, the dependence of EPDM's fractional free volume on temperature, strain, and their combined effect was investigated via MD simulations, on the basis of which the applicability of various superposition principles was also evaluated.

A cement paste-tail sealant interface modified with a silane coupling agent for enhancing waterproofing performance in a concrete lining system.

Although hydrophobic surface coating of concrete is currently used to enhance waterproofing performance of underground structures, the chemical and mechanical incompatibility between an inorganic cement and organic coating makes it a challenge to ensure long-term waterproofing properties of underground facilities, especially for tunnel lining systems. This study explores the feasibility of using a silane coupling agent to improve compatibility between the cement and tail sealant interface, which aims to reduce the water leakage risk of lining systems. The enhanced waterproofing performance of the cement-tail sealant interface modified with the silane agent was confirmed by its hydrophobicity (i.e. reduced wetting ability) and reduced permeability, which was evaluated by static water-contact angle and impermeability pressure measurements. The processes underlying the enhanced waterproofing performance of the cement-tail sealant interface were revealed by chemical bonding, microstructure and porosity characterization. Fourier transform infrared spectroscopy (FTIR) results of the cement-tail sealant interface confirm the reactions between the silane agent and cement hydration products, while both microstructure and porosity results reveal that the cement-tail sealant interface is denser and less porous, relative to the control cement grout.

A Preliminary Study about the Potential Effects of Heavy Metals on the Human Male Reproductive Parameters in HIV-Infected Population in China.

Due to the inconsistent effects of human immunodeficiency virus (HIV) on the human male reproduction in previous studies and the impacts of environmental exposures, such as heavy metals, on male reproduction receiving little attention in HIV-infected population, the aim of present study was to investigate whether heavy metals have potential effects on reproductive parameters in HIV-infected men. The current study assessed the associations between semen quality or serum hormone and concentration of the three heavy metal toxicants (lead (Pb), cadmium (Cd), and zinc (Zn)) in seminal, urine, and serum, and 50 HIV-infected men were recruited in the present study. Concentrations of Pb, Cd, and Zn were measured in three fluids by graphite furnace atomic absorption spectrophotometer. Semen analyses were performed according to World Health Organization criteria. Serum samples were analyzed for follicle-stimulating hormone, luteinizing hormone, and testosterone. HIV RNA viral load was determined by HIV virus loads kit. Spearman's rank correlations were used for correlation analyses. The results showed that the concentrations of Pb, Cd, and Zn were significantly correlated with semen quality and serum hormone. HIV-1 virus loads were significantly associated with increased seminal Pb. However, HIV-1 virus loads were not statistically associated with semen quality and serum hormone. Our findings suggested that environmental heavy metals had potential effects on reproductive parameters in HIV-infected men in China.

The Protective Effects of Melatonin Against Oxidative Stress and Inflammation Induced by Acute Cadmium Exposure in Mice Testis.

Cadmium (Cd) is widely used in daily life and was recently recognized as a possible source of human toxicity due to its ability to accumulate in organs. Previous studies have shown that Cd exposure may cause testicular toxicity through oxidative stress and an inflammatory effect. Melatonin has been demonstrated to be an effective anti-oxidant and has an anti-inflammatory effect. The aim of the present study was to investigate the toxicological effects of Cd on reproduction in male mice and the potential protective action of melatonin against these adverse effects. Adult male mice were injected intraperitoneally with Cd at a dose of 2 mg/kg body weight per day for seven consecutive days with or without melatonin pretreatment. Sex organ weight, sperm parameters including sperm quality, apoptosis, acrosome integrity, mitochondrial membrane potential, testicular morphology, serum sex hormone, inflammatory status, and oxidative stress were evaluated. The results showed that significant adverse effects were observed in the male reproductive system after Cd exposure, including alterations in sperm parameters, increased DNA damage, and sex hormone disturbance. Acute Cd exposure also significantly increased malondialdehyde (MDA) contents, decreased glutathione (GSH) and superoxide dismutase (SOD) activities, and upregulated levels of the pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α), and interleukin-1beta (IL-1ß), in the testis. In contrast, melatonin pretreatment significantly alleviated these toxic effects, and its mechanism may involve inhibiting MDA level, restoring GSH and SOD activities, and reducing the upregulation of TNF-α and IL-1ß. Our data suggest that oxidative stress and inflammation are involved in Cd-induced toxicity in the male reproductive system and that co-administration of melatonin exerts a protective effect against Cd-induced male reproductive toxicity.

Association between polymorphisms in IL27 and risk for CHD in a Chinese population.

BACKGROUND: IL-27, a member of the IL-12 family, has been involved in maternal tolerance to the foetus and successful pregnancy. Growing evidences indicate that IL-27 plays a crucial role in pregnancy. Aim We carried out the present study in order to investigate whether polymorphisms in the IL27 are associated with the risk for CHDs, including atrial septal defect and ventricular septal defect. Patients and methods We conducted this case-control study among 247 atrial septal defect patients, 150 ventricular septal defect patients, and 368 healthy controls in a Chinese population using polymerase chain reaction-restriction fragment length polymorphism assay. RESULTS: Significantly increased risk for atrial septal defect (p=0.001, OR=1.490, 95% CI=1.178-1.887) and ventricular septal defect (p=0.004, OR=1.502, 95% CI=1.139-1.976) was observed to be associated with the allele G of rs153109. In a dominant model, we have also observed that increased susceptibilities for atrial septal defect (p<0.01, OR=1.89, 95% CI=1.35-2.63) and ventricular septal defect (p<0.01, OR=2.50, 95% CI=1.67-3.85) were statistically associated with rs153109; however, no association was found between CHD risk and rs17855750 in the IL27 gene. CONCLUSION: The 153109 of the IL27 gene may be associated with the susceptibility to CHD, including atrial septal defect and ventricular septal defect.

Developing a multiplex mtSNP assay for forensic application in Han Chinese based on mtDNA phylogeny and hot spot.

We designed one multiplex assay with a reduced number of SNPs from whole mitochondrial genome as a screening approach for forensic purposes and developed a multiplex SNaPshot assay with 26 mitochondrial SNPs (mtSNPs). This assay included 16 target mtSNPs that defined the main haplogroups in Chinese population and ten hot-spot mtSNPs found by pyrosequencing. To validate our multiplex mtSNP assay, we not only analyzed a Chinese Han population sample, but also sequenced the complete control region of same set of individuals. Fifty-one haplotypes were observed in 204 individuals using our multiplex mtSNP assay and the haplotype diversity was estimated to be 0.9626. Our multiplex mtSNP assay could also distinguish some individuals sharing the same control region sequences. The same mtSNP profiles were obtained from the bloodstain, hair shaft, and salivary swab from same individuals. A good profile could be obtained with 50 pg of DNA. It was evident that our multiplex mtSNP assay not only improved the discrimination power, but also allowed allocating mitochondrial DNA profiles to particular haplogroups not clearly defined with the control region alone. We highlight the importance of the balance of target mtSNPs for haplogroup assignment and hot-spot mtSNPs for increasing discrimination power.

Analysis of face stability during excavation of Double-O-Tube shield tunnel.

This paper focuses on the face stability analysis of Double-O-Tube shield tunnel. This kind of analysis is significant to ensure the safety of workers and reduce the influence on the surrounding environment. The key point of the stability analysis is to determine the supporting pressure applied to the face by the shield. A collapse failure will occur when the supporting pressure is not sufficient to prevent the movement of the soil mass towards the tunnel. A three-dimensional collapse failure mechanism was presented in this paper. Based on the mechanism of a single circular shield tunnel, the mechanism of Double-O-Tube shield tunnel was established by using the fact that both of the mechanisms are symmetrical. Then by means of the kinematic theorem of limit analysis, the numerical results were obtained, and a design chart was provided. The finite difference software FLAC3D was applied to investigate the face failure mechanism of DOT shield tunnel established in this paper; the critical supporting pressures of the collapse failure mechanism in different strata (sand and silt) were calculated. Through comparative analysis, the theoretical values were very close to the numerical values. This shows that the face failure mechanism of DOT shield tunnel is reasonable, and it can be applied to the sand and silt strata.