Mitigating Critical Peripheral Nerve Deficit Therapy with Reactive Oxygen Species/Ca2+-Responsive Dynamic Hydrogel-Mediated mRNA Delivery.

Critical peripheral nerve deficiencies present as one of the most formidable conundrums in the realm of clinical medicine, frequently culminating in structural degradation and derangement of the neuromuscular apparatus. Engineered extracellular vesicles (EVs) exhibit the potential to ameliorate nerve impairments. However, the advent of Wallerian degeneration (WD), an inexorable phenomenon that ensues post peripheral nerve injury, serves as an insurmountable impediment to the direct therapeutic efficacy of EVs. In this investigation, we have fashioned a dynamic network for the conveyance of PTEN-induced kinase 1 (PINK1) mRNA (E-EV-P@HPCEP) using an adaptive hydrogel with reactive oxygen species (ROS)/Ca2+ responsive ability as the vehicle, bearing dual-targeted, engineered EVs. This intricate system is to precisely deliver PINK1 to senescent Schwann cells (SCs) while concurrently orchestrating a transformation in the inflammatory-senescent milieu following injury, thereby stymying the progression of WD in peripheral nerve fibers through the stimulation of autophagy within the mitochondria of the injured cells and the maintenance of mitochondrial mass equilibrium. WD, conventionally regarded as an inexorable process, E-EV-P@HPCEP achieved functionalized EV targeting, orchestrating a dual-response dynamic release mechanism via boronate ester bonds and calcium chelation, effectuating an enhancement in the inflammatory-senescent microenvironment, which expedites the therapeutic management of nerve deficiencies and augments the overall reparative outcome.

Prognosis and diagnosis of prostate cancer based on hypergraph regularization sparse least partial squares regression algorithm.

BACKGROUND: Prostate cancer (PCa) is a malignant tumor of the male reproductive system, and its incidence has increased significantly in recent years. This study aimed to further identify candidate biomarkers with prognostic and diagnostic significance by integrating gene expression and DNA methylation data from PCa patients through association analysis. MATERIAL AND METHODS: To this end, this paper proposes a sparse partial least squares regression algorithm based on hypergraph regularization (HR-SPLS) by integrating and clustering two kinds of data. Next, module 2, with the most significant weight, was selected for further analysis according to the weight of each module related to DNA methylation and mRNAs. Based on the DNA methylation sites in module 2, this paper uses multiple machine learning methods to construct a PCa diagnosis-related model of 10-DNA methylation sites. RESULTS: The results of Receiver Operating Characteristic (ROC) analysis showed that the DNA methylation-related diagnostic model we constructed could diagnose PCa patients with high accuracy. Subsequently, based on the mRNAs in module 2, we constructed a prognostic model for 7-mRNAs (MYH11, ACTG2, DDR2, CDC42EP3, MARCKSL1, LMOD1, and MYLK) using multivariate Cox regression analysis. The prognostic model could predict the disease free survival of PCa patients with moderate to high accuracy (area under the curve (AUC) =0.761). In addition, Gene Set EnrichmentAnalysis (GSEA) and immune analysis indicated that the prognosis of patients in the risk group might be related to immune cell infiltration. CONCLUSIONS: Our findings may provide new methods and insights for identifying disease-related biomarkers by integrating DNA methylation and gene expression data.

FeS2-modified MXene nanocomposite platform for efficient PTT/CDT/TDT integration through enhanced GSH consumption.

Hypoxic microenvironment and glutathione (GSH) accumulation in tumours limit the efficacy of cytotoxic reactive oxygen species (ROS) anti-tumour therapy. To address this challenge, we increased the consumption of GSH and the production of ROS through a novel nanoplatform with the action of inorganic nanoenzymes. In this study, we prepared mesoporous FeS2 using a simple template method, efficiently loaded AIPH, and assembled Ti3C2/FeS2-AIPH@BSA (TFAB) nanocomposites through self-assembly with BSA and 2D Ti3C2. The constructed TFAB nanotherapeutic platform enhanced chemodynamic therapy (CDT) by generating toxic hydroxyl radicals (˙OH) via FeS2, while consuming GSH to reduce the loss of generated ˙OH via glutathione oxidase-like (GSH-OXD). In addition, TFAB is able to stimulate the decomposition of AIPH under 808 nm laser irradiation to produce oxygen-independent biotoxic alkyl radicals (˙R) for thermodynamic therapy (TDT). In conclusion, TFAB represents an innovative nanoplatform that effectively addresses the limitations of free radical-based treatment strategies. Through the synergistic therapeutic strategy of photothermal therapy (PTT), CDT, and TDT within the tumor microenvironment, TFAB nanoplatforms achieve controlled AIPH release, ROS generation, intracellular GSH consumption, and precise temperature elevation, resulting in enhanced intracellular oxidative stress, significant apoptotic cell death, and notable tumor growth inhibition. This comprehensive treatment strategy shows great promise in the field of tumor therapy.

Microenvironment-responsive smart hydrogels with antibacterial activity and immune regulation for accelerating chronic wound healing.

Current therapeutic strategies for chronic refractory wounds remain challenge owing to their unfavorable wound microenvironment and poor skin regeneration ability. Thus far, a regimen for effective chronic refractory wounds management involves bacterial elimination, alleviation of oxidative stress, inhibition of inflammatory response, and promotion of angiogenesis. In this work, an injectable glycopeptide hydrogel based on phenylboronic acid-grafted ϵ-polylysine (EPBA) and poly (vinyl alcohol) (PVA) with pH/reactive oxygen species (ROS) dual-responsive properties was prepared, which exerted intrinsic antibacterial and antioxidant properties. ROS-responsive micelles (MIC) loaded with herb-derived Astragaloside IV (AST) are introduced into the hydrogel before gelation. Attributed to the acidic condition and oxidative stress microenvironment of wound bed, the hydrogel gradually disintegrates, and the released EPBA could help to eliminate bacterial. Meanwhile, the subsequential release of AST could help to achieve anti-oxidation, anti-inflammatory, proangiogenic effects, and regulation of macrophage polarization to accelerate chronic wound healing. In addition, the wound repair mechanism of composite hydrogel accelerating skin regeneration was assessed by RNA-sequencing, exploring a range of potential targets and pathway for further study. Collectively, this multifunctional hydrogel dressing, matching different healing stages of tissue remodeling, holds a great potential for the treatment of chronic refractory wounds.

Multifunctional Hydrogel Enhances Inflammatory Control, Antimicrobial Activity, and Oxygenation to Promote Healing in Infectious Wounds.

Chronic infected wounds often fail to heal through normal repair mechanisms, and the persistent response of reactive oxygen species (ROS) and inflammation is a major contributing factor to the difficulty in their healing. In this context, we developed an ROS-responsive injectable hydrogel. This hydrogel is composed of ε-polylysine grafted (EPL) with caffeic acid (CA) and hyaluronic acid (HA) grafted with phenylboronic acid (PBA). Before the gelation process, a mixture CaO2@Cur-PDA (CCP) consisting of calcium peroxide (CaO2) coated with polydopamine (PDA) and curcumin (Cur) is embedded into the hydrogel. Under the conditions of chronic refractory wound environments, the hydrogel gradually dissociates. HA mimics the function of the extracellular matrix, while the released caffeic acid-grafted ε-polylysine (CE) effectively eliminates bacteria in the wound vicinity. Additionally, released CA also clears ROS and influences macrophage polarization. Subsequently, CCP further decomposes, releasing Cur, which promotes angiogenesis. This multifunctional hydrogel accelerates the repair of diabetic skin wounds infected with Staphylococcus aureus in vivo and holds promise as a candidate dressing for the healing of chronic refractory wounds.

Highly Bioadaptable Hybrid Conduits with Spatially Bidirectional Structure for Precision Nerve Fiber Regeneration via Gene Therapy.

Peripheral nerve deficits give rise to motor and sensory impairments within the limb. The clinical restoration of extensive segmental nerve defects through autologous nerve transplantation often encounters challenges such as axonal mismatch and suboptimal functional recovery. These issues may stem from the limited regenerative capacity of proximal axons and the subsequent Wallerian degeneration of distal axons. To achieve the integration of sensory and motor functions, a spatially differential plasmid DNA (pDNA) dual-delivery nanohydrogel conduit scaffold is devised. This innovative scaffold facilitates the localized administration of the transforming growth factor ß (TGF-ß) gene in the proximal region to accelerate nerve regeneration, while simultaneously delivering nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2) to the distal region to mitigate Wallerian degeneration. By promoting autonomous and selective alignment of nerve fiber gap sutures via structure design, the approach aims to achieve a harmonious unification of nerve regeneration, neuromotor function, and sensory recovery. It is anticipated that this groundbreaking technology will establish a robust platform for gene delivery in tissue engineering.

Highly Biocompatible Polyester-Based Piezoelectric Elastomer with Antitumor and Antibacterial Activity for Ultrasound-Enhanced Piezoelectric Therapy.

Currently, the use of piezoelectric materials to provide sustainable and noninvasive bioelectric stimulation to eradicate tumor cells and accelerate wound healing has raised wide attention. The development of a multifunctional piezoelectric elastomer with the ability to perform in situ tumor therapy as well as wound repair is of paramount importance. However, current piezoelectric materials have a large elastic modulus and limited stretchability, making it difficult to match with the dynamic curvature changes of the wound. Therefore, by copolymerizing lactic acid, butanediol, sebacic acid, and itaconic acid to develop a piezoelectric elastomer (PLBSIE), we construct a new ultrasound-activated PLBSIE-based tumor/wound unified therapeutic platform. Excitedly, it showed outstanding piezoelectric performance and high stretchability, and the separated carrier could react with water to generate highly cytotoxic reactive oxygen species (ROS), contributing to effectively killing tumor cells and eliminating bacteria through piezoelectric therapy. In addition, ultrasound-triggered piezoelectric effects could promote the migration and differentiation of wound-healing-related cells, thus accelerating wound healing. Herein, such a piezoelectric elastomer exerted a critical role in postoperative tumor-induced wound therapy and healing with the merits of possessing multifunctional abilities. Taken together, the developed ultrasound-activated PLBSIE will offer a comprehensive treatment for postoperative osteosarcoma therapy.

Inhibition of IKKß via a DNA-Based In Situ Delivery System Improves Achilles Tendinopathy Healing in a Rat Model.

BACKGROUND: The inhibition of IKKß by the inhibitor 2-amino-6-[2-(cyclopropylmethoxy)-6-hydroxyphenyl]-4-(4-piperidinyl)-3-pyridine carbonitrile (ACHP) is a promising strategy for the treatment of Achilles tendinopathy. However, the poor water solubility of ACHP severely hinders its in vivo application. Moreover, the effective local delivery of ACHP to the tendon and its therapeutic effects have not been reported. PURPOSE: To investigate the therapeutic effects of IKKß inhibition via injection of ACHP incorporated into a DNA supramolecular hydrogel in a collagenase-induced tendinopathy rat model. STUDY DESIGN: Controlled laboratory study. METHODS: Dendritic DNA, a Y-shaped monomer, and a crosslinking monomer were mixed with ACHP and self-assembled into an ACHP-DNA supramolecular hydrogel (ACHP-Gel). The effects of ACHP-Gel in tendon stem/progenitor cells were investigated via RNA sequencing and validated using quantitative reverse transcription polymerase chain reaction (qRT-PCR). A total of 120 collagenase-induced rats were randomly assigned to 5 groups: blank, phosphate-buffered saline (PBS), DNA-Gel, ACHP, and ACHP-Gel. Healing outcomes were evaluated using biomechanic and histologic evaluations at 4 and 8 weeks. RESULTS: ACHP-Gel enhanced the solubility of ACHP and sustained its release for ≥21 days in vivo, which significantly increased the retention time of ACHP and markedly reduced the frequency of administration. RNA sequencing and qRT-PCR showed that ACHP effectively downregulated genes related to inflammation and extracellular matrix remodeling and upregulated genes related to tenogenic differentiation. The cross-sectional area (P = .024), load to failure (P = .002), stiffness (P = .039), and elastic modulus (P = .048) significantly differed between the ACHP-Gel and PBS groups at 8 weeks. The ACHP-Gel group had better histologic scores than the ACHP group at 4 (P = .042) and 8 weeks (P = .009). Type I collagen expression (COL-I; P = .034) and the COL-I/collagen type III ratio (P = .015) increased while interleukin 6 expression decreased (P < .001) in the ACHP-Gel group compared with the ACHP group at 8 weeks. CONCLUSION: DNA supramolecular hydrogel significantly enhanced the aqueous solubility of ACHP and increased its release-retention time. Injection frequency was markedly reduced. ACHP-Gel suppressed inflammation in Achilles tendinopathy and promoted tendon healing in a rat model. CLINICAL RELEVANCE: ACHP-Gel injection is a promising strategy for the treatment of Achilles tendinopathy in clinical practice.

Programmable DNA Hydrogel Provides Suitable Microenvironment for Enhancing TSPCS Therapy in Healing of Tendinopathy.

Tendon stem/progenitor cells (TSPCs) therapy is a promising strategy for enhancing cell matrix and collagen synthesis, and regulating the metabolism of the tendon microenvironment during tendon injury repair. Nevertheless, the barren microenvironment and gliding shear of tendon cause insufficient nutrition supply, damage, and aggregation of injected TSPCs around tendon tissues, which severely hinders their clinical application in tendinopathy. In this study, a TSPCs delivery system is developed by encapsulating TSPCs within a DNA hydrogel (TSPCs-Gel) as the DNA hydrogel offers an excellent artificial extracellular matrix (ECM) microenvironment by providing nutrition for proliferation and protection against shear forces. This delivery method restricts TSPCs to the tendons, significantly extending their retention time. It is also found that TSPCs-Gel injections can promote the healing of rat tendinopathy in vivo, where cross-sectional area and load to failure of injured tendons in rats are significantly improved compared to the free TSPCs treatment group at 8 weeks. Furthermore, the potential healing mechanism of TSPCs-Gel is investigated by RNA-sequencing to identify a series of potential gene and signaling pathway targets for further clinical treatment strategies. These findings suggest the potential pathways of using DNA hydrogels as artificial ECMs to promote cell proliferation and protect TSPCs in TSPC therapy.

Comparison of femoral neck system vs. dynamic hip system blade for the treatment of femoral neck fracture in young patients: A retrospective study.

Background: Femoral neck fracture is a common fracture in orthopedic practice. This study aimed to compare the clinical outcomes between the femoral neck system and dynamic hip system blade for the treatment of femoral neck fracture in young patients. Methods: This retrospective study included 43 and 52 patients who underwent treatment for femoral neck fracture with the femoral neck system and dynamic hip system blade, respectively, between August 2019 and August 2020. Operative indexes, including operation duration, blood loss, incision length, postoperative complications (femoral neck shortening, non-union, screw pull-out, femoral head necrosis), and Harris scale scores were recorded and analyzed. Results: Compared to that with the dynamic hip system blade, the femoral neck system showed significantly less operation duration (femoral neck system vs. dynamic hip system blade: 47.09 ± 9.19 vs. 52.90 ± 9.64, P = 0.004), less blood loss (48.53 ± 10.69 vs. 65.31 ± 17.91, P < 0.001), and shorter incision length (4.04 ± 0.43 vs. 4.93 ± 0.53, P < 0.001). Femoral neck shortening was significantly lower with the femoral neck system than with the dynamic hip system blade (3.93 ± 2.40, n = 39 vs. 5.22 ± 2.89, n = 44, P = 0.031). No statistical differences were observed between the two groups in nonunion, screw pull-out, and femoral head necrosis. In addition, the latest follow-up Harris scale score was significantly higher with the femoral neck system than with the dynamic hip system blade (92.3 ± 4.5 vs. 89. 9 ± 4.9, P = 0.015). Conclusion: The femoral neck system results in less trauma, less femoral neck shortening, and better hip joint function than the dynamic hip system blade for the treatment of femoral neck fracture in young patients.

Predictors of and predictive nomogram for cut-out of proximal femur nail anti-rotation device in intertrochanteric fractures.

PURPOSE: This study determined independent predictors and developed a predictive nomogram for failed correction of intertrochanteric fractures due to cut-out of the proximal femur nail anti-rotation (PFNA) device. METHODS: Demographic and radiological data of 592 adult patients with intertrochanteric fractures (AO 31A) treated by PFNA were collected retrospectively. Independent predictors of cut-out were obtained through univariate and multivariate analyses, and a predictive nomogram was established. The discrimination, calibration, and clinical utility of the nomogram were based on receiver operating characteristic curve (AUC), concordance index (C-index), calibration curve, and decision curve analysis, respectively. RESULTS: Overall, 18 (3.04%) cases of cut-out occurred. Independent predictors according to the multivariate analysis were body mass index (BMI), poor-to-acceptable quality of reduction, PFNA blade position, and tip-apex distance (TAD). AUC of the nomogram was 0.849, and C-index was 0.849 (95% CI [0.844-0.854]). Bootstrapping yielded a corrected C-index of 0.849. The calibration and decision curves indicated good agreement and clinical benefit of the nomogram. CONCLUSION: A reliable predictive nomogram was developed for cut-out of the PFNA in intertrochanteric fractures, based on BMI, quality of reduction, blade position, and TAD.

Lysosomal-Associated Transmembrane Protein 5 Promotes Proliferation, Migration, and Invasion of Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) is the most aggressive and deadly cancer of the urinary system and is regulated by multiple signaling pathways. However, the specific molecular mechanisms underlying ccRCC have not been fully studied or demonstrated. This study aimed to elucidate the function of lysosomal-associated transmembrane protein 5 (LAPTM5) in ccRCC cell lines and animal models and determine the potential underlying mechanisms. Our results demonstrated that LAPTM5 expression in patients with ccRCC was significantly higher in the tumor group than that in the adjacent nontumor group. Moreover, LAPTM5 promoted proliferation, migration, and invasion of ccRCC cells through the gain and loss of the function of LAPTM5 in 786-0 and Caki-1 cell lines. Similar results regarding LAPTM5 overexpression were obtained in BALB/c nude mice. In addition, LAPTM5 activated the Jun N-terminal kinase (JNK)/p38 signaling cascade by interacting with Ras-related C3 botulinum toxin substrate 1 (RAC1). Treatment with an RAC1 inhibitor eliminated the effects of LAPTM5 in ccRCC. In conclusion, these results indicate that LAPTM5 may be a new therapeutic target for ccRCC via activation of the RAC1-JNK/p38 axis.

[Circular RNA expression pattern and competing endogenous RNA network involved in rotator cuff tendinopathy].

OBJECTIVE: To detect the differentially expressed circular RNA (circRNA) in rotator cuff tendinopathy and analyze the potential molecular mechanism of these parental genes. METHODS: Ten supraspinatus tendons donated from patients who underwent tendon repair surgery between June 2018 and June 2019 were used for RNA-sequence. All rotator cuff tendinopathy and normal tendon samples were confirmed by MRI, histological staining, and observation by arthroscopy. All pathological tendons were matched with tendon samples for patients' age, gender, body mass index, and Bonar score. The bioinformatic analysis was performed based on the differentially expressed circRNA and their parental genes, including gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and competing endogenous RNA (ceRNA) network construction. RESULTS: There were 94 differentially expressed circRNAs, including 31 up-regulated and 63 down-regulated, detected between the rotator cuff tendinopathy and normal tendon samples with |log2 fold change (FC)| >2, P<0.05. GO analysis showed that the genes were mostly enriched in response to cyclic adenosine monophosphate (cAMP). KEGG pathway analysis showed that the most genes were enriched in extracellular matrix-receptor interaction, protein digestion and absorption, cell cycle, and nuclear factor κB signaling pathway. ceRNA networks showed the interactions among circRNAs, mRNAs, and miRNAs. And circRNA.8951-has-miR-6089-DNMT3B was the most sum max energy. CONCLUSION: This bioinformatic study reveals several potential therapeutic targets for rotator cuff tendinopathy, which paves the way to better treatment and prevention of this disorder.

Conjoint analysis of lncRNA and mRNA expression in rotator cuff tendinopathy.

BACKGROUND: Rotator cuff tendinopathy (RCT) is a common musculoskeletal disorder in the shoulder, whose underlying mechanism is unknown. Long non-coding RNAs (lncRNAs) are involved in the development of various diseases, but little is known about their potential roles in RCT. METHODS: In this study, we profiled lncRNAs and mRNAs involved in RCT in comparison with the normal tendon (NT) by RNA sequencing (RNA-Seq), to identify potential therapeutic targets. Gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG) pathway, competing endogenous RNA (ceRNA), and co-expression network construction were used to identify the potential functions of these RNAs. Three lncRNAs and three mRNAs were validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: In total, 419 lncRNAs and 1,541 mRNAs were differentially expressed between the RCT and NT groups with a fold change of >2 and P of <0.01. The GO and KEGG pathway analyses showed that the differentially expressed mRNAs were mainly enriched in complement activation and involved in the citrate cycle. The ceRNA network showed the interaction of differentially expressed RNAs, comprising 139 lncRNAs, 126 mRNAs, and 35 miRNAs. NONHSAT209114.1, ENST00000577806, NONHSAT168464.1, PLK2, TMEM214, and IGF2 were validated by PCR. We constructed a co-expressed network of these validated RNAs. CONCLUSIONS: We preliminarily analyzed the profile of lncRNAs and mRNAs in RCT. The bioinformatic analysis revealed several potential therapeutic targets for RCT.

Comparison of dorsal closing wedge calcaneal osteotomy versus posterosuperior prominence resection for the treatment of Haglund syndrome.

BACKGROUND: Haglund syndrome is a common disease that causes posterior heel pain. This study compared the clinical outcomes of dorsal closing wedge calcaneal osteotomy (DCWCO) and posterosuperior prominence resection (PPR) for the treatment of Haglund syndrome. METHODS: This retrospective study included 12 patients who underwent DCWCO and 32 patients who underwent PPR from January 2010 to August 2016. Patients were evaluated using the American Orthopedic Foot Ankle Society ankle-hindfoot scale (AOFAS), Victorian Institute of Sport Assessment Scale for Achilles tendinopathy (VISA-A), Fowler-Philip angle, Bohler's angle, and calcaneal pitch angle preoperatively and postoperatively (at 3 months, 6 months, 1 year, and the latest follow-up). RESULTS: Both groups exhibited a significant increase in their AOFAS and VISA-A scores after surgery. The DCWCO group had lower AOFAS scores than the PPR group at 6 months (77.6 ± 5.1 vs. 82.8 ± 7.8; P = 0.037) but had higher scores at the latest follow-up (98.2 ± 2.3 vs. 93.4 ± 6.1; P = 0.030). The DCWCO group had lower VISA-A scores at 3 months (56.9 ± 13.9 vs. 65.2 ± 11.0; P = 0.044) but higher scores at the latest follow-up (98.2 ± 2.6 vs. 94.3 ± 5.0; P = 0.010) than the PPR group. Both groups exhibited significant changes in the Fowler-Philip angle and Bohler's angle after surgery. The postoperative Fowler-Philip angle of the DCWCO group was greater than that of the PPR group (35.9° ± 4.9° vs. 31.4° ± 6.2°; P = 0.026). However, there was no statistically significant difference in any other angle of the two groups postoperatively. CONCLUSIONS: Compared to the PPR group, the DCWCO group had poorer short-term clinical outcomes but provide better long-term function and symptom remission. This method can be a good option for those patients with higher functional expectations.

Downregulation of type I collagen expression in the Achilles tendon by dexamethasone: a controlled laboratory study.

BACKGROUND: Spontaneous Achilles tendon rupture associated with long-term dexamethasone (Dex) use has been reported. However, few studies have investigated the potential mechanism. The aim of this study was to evaluate the effects of oral Dex on type I collagen in humans and rats and its association with tendon rupture. METHODS: First, six Achilles tendons from patients who received long-term Dex treatment, and another six normal tendons were harvested for histological evaluation. Secondly, 8-week-old rats (n = 72) were randomly assigned to a Dex group or a control group. Type I collagen was studied at the mechanical, histological, and molecular levels after 3 and 5 weeks. Tenocytes isolated from normal human and rat tendon were used to investigate the effect of Dex on cellular scale. RESULTS: Histological analysis of human and rat tendon tissue revealed an irregular, disordered arrangement of type I collagen in the Dex group compared with the control group. In addition, In the Dex+ group, type I collagen expression decreased in comparison with the Dex- group in both human and rat tenocytes. The mechanical strength of tendons was significantly reduced in the Dex group (68.87 ± 11.07 N) in comparison with the control group (81.46 ± 7.62 N, P = 0.013) after 5 weeks. Tendons in the Dex group were shorter with smaller cross-sectional areas (10.71 ± 0.34 mm2, 1.44 ± 0.22 mm2, respectively) after 5 weeks than those in the control group (11.13 ± 0.50 mm2, P = 0.050, 2.74 ± 0.34 mm2, P < 0.001, respectively). CONCLUSIONS: This finding suggests long-term use of Dex that decreases the expression of type I collagen at molecular and tissue levels both in human and rat Achilles tendons. Furthermore, Dex decreases the mechanical strength of the tendon, thereby increasing the risk of Achilles tendon rupture.

Aspirin inhibits adipogenesis of tendon stem cells and lipids accumulation in rat injury tendon through regulating PTEN/PI3K/AKT signalling.

Tendon injury repairs are big challenges in sports medicine, and fatty infiltration after tendon injury is very common and hampers tendon injury healing process. Tendon stem cells (TSCs), as precursors of tendon cells, have shown promising effect on injury tendon repair for their tenogenesis and tendon extracellular matrix formation. Adipocytes and lipids accumulation is a landmark event in pathological process of tendon injury, and this may induce tendon rupture in clinical practice. Based on this, it is important to inhibit TSCs adipogenesis and lipids infiltration to restore structure and function of injury tendon. Aspirin, as the representative of non-steroidal anti-inflammatory drugs (NSAIDs), has been widely used in tendon injury for its anti-inflammatory and analgesic actions, but effect of aspirin on TSCs adipogenesis and fatty infiltration is still unclear. Under adipogenesis conditions, TSCs were treated with concentration gradient of aspirin. Oil red O staining was performed to observe changes of lipids accumulation. Next, we used RNA sequencing to compare profile changes of gene expression between induction group and aspirin-treated group. Then, we verified the effect of filtrated signalling on TSCs adipogenesis. At last, we established rat tendon injury model and compared changes of biomechanical properties after aspirin treatment. The results showed that aspirin decreased lipids accumulation in injury tendon and inhibited TSCs adipogenesis. RNA sequencing filtrated PTEN/PI3K/AKT signalling as our target. After adding the signalling activators of VO-Ohpic and IGF-1, inhibited adipogenesis of TSCs was reversed. Still, aspirin promoted maximum loading, ultimate stress and breaking elongation of injury tendon. In conclusion, by down-regulating PTEN/PI3K/AKT signalling, aspirin inhibited adipogenesis of TSCs and fatty infiltration in injury tendon, promoted biomechanical properties and decreased rupture risk of injury tendon. All these provided new therapeutic potential and medicine evidence of aspirin in treating tendon injury and tendinopathy.

Interleukin-15 facilitates muscle regeneration through modulation of fibro/adipogenic progenitors.

BACKGROUND: Chronic muscle injury is characteristics of fatty infiltration and fibrosis. Recently, fibro/adipogenic progenitors (FAPs) were found to be indispensable for muscular regeneration while were also responsible for fibrosis and fatty infiltration in muscle injury. Many myokines have been proven to regulate the adipose or cell proliferation. Because the fate of FAPs is largely dependent on microenvironment and the regulation of myokines on FAPs is still unclear. We screened the potential myokines and found Interleukin-15 (IL-15) may regulate the fatty infiltration in muscle injury. In this study, we investigated how IL-15 regulated FAPs in muscle injury and the effect on muscle regeneration. METHODS: Cell proliferation assay, western blots, qRT-PCR, immunohistochemistry, flow cytometric analysis were performed to investigate the effect of IL-15 on proliferation and adipogensis of FAPs. Acute muscle injury was induced by injection of glycerol or cardiotoxin to analyze how IL-15 effected on FAPs in vivo and its function on fatty infiltration or muscle regeneration. RESULTS: We identified that the expression of IL-15 in injured muscle was negatively associated with fatty infiltration. IL-15 can stimulate the proliferation of FAPs and prevent the adipogenesis of FAPs in vitro and in vivo. The growth of FAPs caused by IL-15 was mediated through JAK-STAT pathway. In addition, desert hedgehog pathway may participate in IL-15 inhibiting adipogenesis of FAPs. Our study showed IL-15 can cause the fibrosis after muscle damage and promote the myofiber regeneration. Finally, the expression of IL-15 was positively associated with severity of fibrosis and number of FAPs in patients with chronic rotator cuff tear. CONCLUSIONS: These findings supported the potential role of IL-15 as a modulator on fate of FAPs in injured muscle and as a novel therapy for chronic muscle injury.

Activated ClC-2 Inhibits p-Akt to Repress Myelination in GDM Newborn Rats.

This study aims to investigate the effect and mechanism of type 2 voltage-gated chloride channel (ClC-2) on myelin development of newborn rats' cerebral white matter with gestational diabetes mellitus (GDM). In this study, GDM model was induced in late pregnant rat model. The alteration of ClC-2 expression in various developmental stages of cerebral white matter with/without being exposed to high glucose was analyzed using RT-PCR, active oxygen detection, TUNEL staining, Western Blot as well as immuno-histochemical staining. Our results showed that ClC-2 mRNA and protein expressions in GDM group were significantly increased in white matter of fetal rats after E18 stage, and elevated the level of TNF-α and iNOS in white matter at P0 and P3 stage of newborn rats. Meanwhile, In GDM group, reactive oxygen species (ROS) levels of the white matter at E18, P0, and P3 stage were significantly higher than control group. Furthermore, the expression level of myelin transcription factor Olig2 at P0 stage and CNPase at P3 stage were strikingly lower than that of the control group. In GDM group, ClC-2 expression in the corpus callosum (CC) and cingulate gyrus (CG) regains, and TUNEL positive cell number were increased at P0 and P3 stage. However, PDGFα positive cell number at P0 stage and CNPase expression at P3 stage were significantly decreased. Caspase-3 was also increased in those white matter regions in GDM group, but p-Akt expression was inhibited. While DIDS (a chloride channel blocker) can reverse these changes. In conclusion, ClC-2 and caspase-3 were induced by GDM, which resulted in apoptosis and myelination inhibition. The effect was caused by repressing PI3K-Akt signaling pathway. Application of ClC-2 inhibitor DIDS showed protective effects on cerebral white matter damage stimulated by high glucose concentration.