Large extracellular vesicles from induced pluripotent stem cell-marrow stem cells enhance limb angiogenesis via ERK/MAPK.

Aim: This study aims to investigate the effects of large extracellular vesicles (EVs) induced by pluripotent stem cell-derived mesenchymal stem cells on lower limb ischemic disease and explore its potential mechanisms. Materials & methods: The pathology of muscles was accessed by H&E staining and immunofluorescence staining. In vitro, we conducted wound-healing assay, tube formation assay, RT qPCR, ELISA, RNA sequencing and proteomic analysis. Results: iMSCs-lEVs alleviated the injury of ischemic lower limb and promoted the recovery of lower limb function. In vitro, iMSCs-lEVs promoted the proliferation, migration, and angiogenesis of HMEC-1 cells by regulating the ERK/MAPK signing pathway. Conclusion: This study demonstrated that iMSCs-lEVs promoted endothelial cell angiogenesis via the ERK/MAPK signaling pathway, thereby improving function after lower limb ischemic injury.

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Large extracellular vesicles secreted by human iPSC-derived MSCs ameliorate tendinopathy via regulating macrophage heterogeneity.

Tendinopathy is a common musculoskeletal disorder which results in chronic pain and reduced performance. The therapeutic effect of stem cell derived-small extracellular vesicles (sEVs) for tendinopathy has been validated in recent years. However, whether large extracellular vesicles (lEVs), another subset of extracellular vesicles, possesses the ability for the improvement of tendinopathy remains unknown. Here, we showed that lEVs secreted from iPSC-derived MSCs (iMSC-lEVs) significantly mitigated pain derived from tendinopathy in rats. Immunohistochemical analysis showed that iMSC-lEVs regulated the heterogeneity of infiltrated macrophages and several inflammatory cytokines in rat tendon tissue. Meanwhile, in vitro experiments revealed that the M1 pro-inflammatory macrophages were repolarized towards M2 anti-inflammatory macrophages by iMSC-lEVs, and this effect was mediated by regulating p38 MAPK pathway. Moreover, liquid chromatography-tandem mass spectrometry analysis identified 2208 proteins encapsulated in iMSC-lEVs, including 134 new-found proteins beyond current Vesiclepedia database. By bioinformatics and Western blot analyses, we showed that DUSP2 and DUSP3, the negative regulator of p38 phosphorylation, were enriched in iMSC-lEVs and could be transported to macrophages. Further, the immunomodulatory effect of iMSC-lEVs on macrophages was validated in explant tendon tissue from tendinopathy patients. Taken together, our results demonstrate that iMSC-lEVs could reduce inflammation in tendinopathy by regulating macrophage heterogeneity, which is mediated via the p38 MAPK pathway by delivery of DUSP2 and DUSP3, and might be a promising candidate for tendinopathy therapy.

Early Emergent and Progressive Aberrant Subchondral Bone Remodeling Coupled with Aggravated Cartilage Degeneration in Developmental Dysplasia of the Hip.

OBJECTIVE: Developmental dysplasia of the hip (DDH) is the most common skeletal development in children and could result in secondary osteoarthritis. This study aims to clarify the alternations of subchondral trabecular bone remodeling and microstructural properties during the development of DDH, and the potential influence of these alternations on the overlying cartilage degeneration and DDH progression. DESIGN: Traditional straight-leg swaddling method was adopted to establish DDH model in newborn Sprague Dawley rats. Hip joint specimens from normal or DDH rats were used. Typical features of DDH in radiological examination were observed by x-ray analysis. Micro-computed tomography analysis was applied to evaluate the microstructural properties of subchondral bone at postnatal weeks 2, 4, and 6. Histological and immunohistochemical analyses were adopted to appraise subchondral bone remodeling activity and cartilage degeneration. The associations among subchondral bone, articular cartilage, and DDH severity were analyzed via multiple linear regression analysis. RESULTS: Compared with control group, the subchondral bone in DDH group displayed a gradual trend of deteriorated microstructure and worsening biomechanical properties along with aberrant bone remodeling, which might be responsible for the inhibition of stress transmission from the articular cartilage to the subchondral bone and thus leading to the cartilage degeneration and accelerated DDH progression. CONCLUSIONS: Our findings indicate that alternations of subchondral trabecular bone in a time-dependent manner could contribute to the DDH progression and the amelioration on subchondral bone might be a favorable therapeutic candidate for DDH.

Small extracellular vesicles from iPSC-derived mesenchymal stem cells ameliorate tendinopathy pain by inhibiting mast cell activation.

Aim: This study aimed to explore the effect of small extracellular vesicles from induced pluripotent stem cell-derived mesenchymal stem cells (iMSC-sEVs) on acute pain and investigate the underlying mechanisms. Materials & methods: The pathology of tendons was accessed by hematoxylin and eosin staining, immunohistochemical and immunofluorescent staining. The pain degree was measured by pain-related behaviors. In vitro, we performed ß-hexosaminidase release assay, RT-qPCR, toluidine blue staining, ELISA and RNA sequencing. Results: iMSC-sEVs effectively alleviated acute pain in tendinopathy as well as inhibiting activated mast cell infiltration and interactions with nerve fibers in vivo. In vitro, iMSC-sEVs reduced the degranulation of mast cells and the expression of proinflammatory cytokines and genes involved in the HIF-1 signaling pathway. Conclusion: This study demonstrated that iMSC-sEVs relieved tendinopathy-related pain through inhibiting mast cell activation via the HIF-1 signaling pathway.

Machine Learning Algorithm Guiding Local Treatment Decisions to Reduce Pain for Lung Cancer Patients with Bone Metastases, a Prospective Cohort Study.

INTRODUCTION: As life expectancy increases for lung cancer patients with bone metastases, the need for personalized local treatment to reduce pain is expanding. METHODS: Patients were treated by a multidisciplinary team (MDT), and local treatment including surgery, percutaneous osteoplasty, or radiation. Visual analog scale (VAS) and quality of life (QoL) scores were analyzed. VAS at 12 weeks after treatment was the main outcome. We developed and tested machine learning models to predict which patients should receive local treatment. Model discrimination was evaluated by the area under curve (AUC), and the best model was used for prospective decision-making accuracy validation. RESULTS: Under the direction of MDT, 161 patients in the training set, 32 patients in the test set, and 36 patients in the validation set underwent local treatment. VAS in surgery, percutaneous osteoplasty, and radiation groups decreased significantly to 4.78 ± 1.28, 4.37 ± 1.36, and 5.39 ± 1.31 at 12 weeks, respectively (p < 0.05), with no significant differences among the three datasets, and improved QoL was also observed (p < 0.05). A decision tree (DT) model that included VAS, bone metastases character, Frankel classification, Mirels score, age, driver gene, aldehyde dehydrogenase 2, and enolase 1 expression had a best AUC in predicting whether patients would receive local treatment of 0.92 (95% CI 0.89-0.94) in the training set, 0.85 (95% CI 0.77-0.94) in the test set, and 0.88 (95% CI 0.81-0.96) in the validation set. CONCLUSION: Local treatment provided significant pain relief and improved QoL. There were no significant differences in reducing pain and improving QoL among training, test, and validation sets. The DT model was best at determining whether patients should receive local treatment. Our machine learning model can help guide clinicians to make local treatment decisions to reduce pain. TRIAL REGISTRATION: Trial registration number ChiCRT-ROC-16009501.

Mesenchymal stem cells-derived exosomes ameliorate intervertebral disc degeneration through inhibiting pyroptosis.

Mesenchymal stem cell (MSCs)-based therapies have shown a promised result for intervertebral disc degeneration (IVDD) treatment. However, its molecular mechanisms remain unclear. Exosomes involve cell-cell communication via transference of its contents among different cells, and the present potential effect on cell death regulation. This study aimed to investigate the role of MSCs-derived exosomes on IVDD formation. Here, we first found the NLRP3-mediated nucleus pulposus cell (NP cell) pyroptosis was activated in the IVDD mice model and lipopolysaccharide (LPS)-induced model. However, MSCs treatment could inhibit NP cell pyroptosis in vitro. We then isolated MSCs-derived exosomes by differential centrifugation and identified the characteristics. Secondly, we investigated the function of MSCs-derived exosomes on LPS-induced NP cell pyroptosis. Finally, we presented evidence that MSCs-derived exosomal miR-410 was a crucial regulator of pyroptosis. Results showed that MSCs-derived exosomes play an anti-pyroptosis role by suppressing the NLRP3 pathway. Moreover, it suggested that this effect was attributed to miR-410, which was derived from MSCs-exosomes and could directly bind to NLRP3mRNA. In conclusion, for the first time, we demonstrated that MSCs-exosome treatment may inhibit pyroptosis and could be a promising therapeutic strategy for IVDD.

Small extracellular vesicles secreted by human iPSC-derived MSC enhance angiogenesis through inhibiting STAT3-dependent autophagy in ischemic stroke.

BACKGROUND: Small extracellular vesicles (sEV) secreted by mesenchymal stem cells (MSC) derived from human induced pluripotent stem cells (iPSC, iMSC-sEV) are considered to have great potential in treating ischemic diseases. Angiogenesis play an important role in post-stroke recovery. However, no studies have yet been conducted to systemically examine the effect and the underlying mechanism of iMSC-sEV on angiogenesis under brain ischemia conditions. METHODS: Ischemic stroke model was performed in rats induced by middle cerebral artery occlusion (MCAO), and the pro-angiogenic capacity of iMSC-sEV was measured. The in vitro effects of iMSC-sEV on the migration and tube formation of endothelial cells were investigated, respectively. Autophagy and autophagy-related signaling pathway were detected in vivo and in vitro. RESULTS: We found that iMSC-sEV significantly reduced infarct volume, enhanced angiogenesis, and alleviated long-term neurological deficits in rats after stroke. We also demonstrated that iMSC-sEV increased migration and tube formation of endothelial cells in vitro. A further mechanism study revealed that the pro-angiogenic effect of iMSC-sEV was correlated with a reduction in autophagy. Furthermore, iMSC-sEV significantly activated signal transducer and activator of transcription 3 (STAT3), and suppression of STAT3 abolished iMSC-sEV-induced inhibition of autophagy and promotion of angiogenesis in vivo and in vitro. CONCLUSIONS: Taken together, our data indicate that iMSC-sEV promote angiogenesis after ischemic stroke, potentially, by inhibiting autophagy, a process that is partially dependent on STAT3 activation.

ESC-sEVs Rejuvenate Senescent Hippocampal NSCs by Activating Lysosomes to Improve Cognitive Dysfunction in Vascular Dementia.

Vascular dementia (VD) is one of the most common types of dementia, however, the intrinsic mechanism is unclear and there is still lack of effective medications. In this study, the VD rats exhibit a progressive cognitive impairment, as well as a time-related increasing in hippocampal neural stem cells (H-NSCs) senescence, lost and neurogenesis decline. Then, embryonic stem cell-derived small extracellular vesicles (ESC-sEVs) are intravenously injected into VD rats. ESC-sEVs treatment significantly alleviates H-NSCs senescence, recovers compromised proliferation and neuron differentiation capacity, and reverses cognitive impairment. By microarray analysis and RT-qPCR it is identified that several miRNAs including miR-17-5p, miR-18a-5p, miR-21-5p, miR-29a-3p, and let-7a-5p, that can inhibit mTORC1 activation, exist in ESC-sEVs. ESC-sEVs rejuvenate H-NSCs senescence partly by transferring these miRNAs to inhibit mTORC1 activation, promote transcription factor EB (TFEB) nuclear translocation and lysosome resumption. Taken together, these data indicate that H-NSCs senescence cause cell depletion, neurogenesis reduction, and cognitive impairment in VD. ESC-sEVs treatment ameliorates H-NSCs senescence by inhibiting mTORC1 activation, and promoting TFEB nuclear translocation and lysosome resumption, thereby reversing senescence-related neurogenesis dysfunction and cognitive impairment in VD. The application of ESC-sEVs may be a novel cell-free therapeutic tool for patients with VD, as well as other aging-related diseases.

Down-regulation of LINC00472 promotes osteosarcoma tumorigenesis by reducing FOXO1 expressions via miR-300.

BACKGROUND: Osteosarcoma (OS) is one of the most common types of primary bone tumors which poses negative effects on the bones of both young children and adolescents. LncRNA LINC00472 has been reported to be involved with poor prognostics in breast cancer and ovarian cancer. As a new lncRNA, its role in OS remains to be elusive. Herein, we are focused to explore its regulatory mechanism in the development of OS. METHODS: qRT-PCR was utilized to examine the expressions of LINC00472 and miR-300 in OS tissues and cell lines. OS cell lines of U2OS and MG63 were used to investigate the biological function of LINC00472. Xenograft tumor model was built in nude mice with MG63 cells. RESULTS: The expressions of LINC00472 were inhibited in OS tissues and cells, and were negatively related to the expressions of miR-300. LINC00472 directly targeted miR-300. FOXO1 was inhibited in OS tissues and its expressions were negatively related to the expressions of miR-300. LINC00472 over-expressions decreased cell proliferation abilities and colony formation abilities. These effects were mediated by miR-300. The silence of LINC00472 and over-expressions of miR-300 suppressed FOXO1 expressions. LINC00472 greatly reduced tumor growth in vivo and this effect was attenuated by miR-300 mimic. CONCLUSIONS: From all the experiments and observations, we demonstrated that LINC00472 could be a potential tumor suppressor in OS through interacting with miR-300 and FOXO1.

Interleukin-6 Serum Levels Are Elevated in Individuals with Degenerative Cervical Myelopathy and Are Correlated with Symptom Severity.

BACKGROUND Few studies have investigated systemic inflammation levels in degenerative cervical myelopathy (DCM). This study evaluated the concentration of inflammatory cytokines in DCM patients and assessed whether they can predict symptom severity. MATERIAL AND METHODS A total of 40 consecutive DCM patients and 10 healthy volunteers were included in this study. Concentrations of interleukin (IL)-1ß, IL-6, interferon-γ, and tumor necrosis factor-α were compared between DCM patients and normal controls. Spearman's correlation coefficient was used to examine relationships of cytokines with age, body mass index (BMI), symptom duration, and symptom severity. A DCM compression rat model was established to examine the levels of inflammatory cytokines in serum and cerebrospinal fluid (CSF). RESULTS Serum level of IL-6 is significantly higher in DCM patients compared with normal people (0.8±0.5 pg/ml vs. 0.5±0.3 pg/ml, P=0.036). Positive correlations were found between IL-6 levels with BMI (r=0.519; P=0.001) and symptom severity (ρ=-0.556, P<0.001). In DCM compression model rats, IL-6 was elevated in CSF (40.5±3.3 vs. 13.2±2.4 pg/ml, P<0.001) and serum (7.1±1.7 vs. 2.9±1.6 pg/ml, P<0.001) samples from rats in the compression operation group compared with the sham operation group. Infusion of IL-6 in rats receiving the sham operation also led to motor function damage and mechanical allodynia threshold decline. CONCLUSIONS Serum IL-6 level was elevated in DCM patients and its concentration can predict symptom severity. Local infusion of IL-6 led to myelopathy symptoms in model rats, which suggests that anti-inflammation can effectively treat DCM.

CPNE1 silencing inhibits the proliferation, invasion and migration of human osteosarcoma cells.

Osteosarcoma (OS) is the most common primary malignancy of the bone affecting children and adolescents. Copine 1 (CPNE1) is a highly conserved calcium-dependent phospholipid-binding protein and may function in regulating signal transduction and membrane trafficking. In the present study, we investigated CPNE1 expression in osteosarcoma tissues and cells, and studied the effects of small interfering RNA (siRNA)-targeting CPNE1 on proliferation, metastasis and chemosensitivity of the osteosarcoma cells. The results demonstrated that CPNE1 was highly expressed in the osteosarcoma tissues and cell lines. Moreover, functional investigations confirmed that CPNE1 knockdown significantly inhibited cell proliferation, colony formation, invasion and metastasis in Saos-2 and HOS cells. Western blot analysis indicated that CPNE1 silencing downregulated the expression of many proteins associated with tumorigenesis and development, including Ras, MEK-1/2, WNT1, ß-catenin, cyclin A1, IRAK2 and cIAP2. In addition, CPNE1 downregulation enhanced the sensitivity of Saos-2 cells towards cisplatin and adriamycin. The present study provides deep insight into the clinical use of lentiviral-mediated CPNE1 silencing for osteosarcoma therapy.

Stem Cell-Derived Extracellular Vesicles as a Novel Potential Therapeutic Tool for Tissue Repair.

Stem cells, with their therapeutic potential in tissue repair and regeneration, have been widely used in translational medicine. Recent evidence suggests that the beneficial effects are mediated largely by their paracrine actions rather than the engraftment and differentiation at the injured sites. Extracellular vesicles (EVs), actively released from cells, play important roles in cell-to-cell communication and display multiple functions in tissue regeneration. In the present report, we will briefly review the current knowledge related to the therapeutic potential of EVs, particularly stem cell or progenitor cell-derived ones for promoting tissue repair and regeneration, and focus on the restorative properties of exosomes/microvesicles in cutaneous wound healing, bone regeneration, hindlimb ischemia, and vascular injury repair. Stem Cells Translational Medicine 2017;6:1753-1758.

An in situ photocrosslinkable platelet rich plasma - Complexed hydrogel glue with growth factor controlled release ability to promote cartilage defect repair.

The repair of articular cartilage injury is a great clinical challenge. Platelet-rich plasma (PRP) has attracted much attention for the repair of articular cartilage injury, because it contains various growth factors that are beneficial for wound repair. However, current administration methods of PRP have many shortcomings, such as unstable biological fixation and burst release of growth factors, all of which complicate its application in the repair of articular cartilage and compromise its therapeutic efficacy. In this study, based on our previously reported photoinduced imine crosslinking (PIC) reaction, we developed an in situ photocrosslinkable PRP hydrogel glue (HNPRP) through adding a photoresponsive hyaluronic acid (HA-NB) which could generate aldehyde groups upon light irradiation and subsequently react with amino groups, into autologous PRP. Our study showed that HNPRP hydrogel glue was cytocompatible and could be conveniently and rapidly prepared in situ, forming a robust hydrogel scaffold. In addition, our results demonstrated that HNPRP hydrogel not only achieved controlled release of growth factors, but also showed strong tissue adhesive ability. Therefore, HNPRP hydrogel was quite suitable for cartilage defect regeneration. Our further in vitro experiment showed that HNPRP hydrogel could promote the proliferation and migration of chondrocytes and bone marrow stem cells (BMSCs). In vivo testing using a rabbit full-thickness cartilage defect model demonstrated that HNPRP hydrogel could achieve integrative hyaline cartilage regeneration and its therapeutic efficacy was better than thrombin activated PRP gel. STATEMENT OF SIGNIFICANCE: In this study, we have developed a photocrosslinkable platelet rich plasma (PRP) - complexed hydrogel glue (HNPRP) for cartilage regeneration. The in situ formed HNPRP hydrogel glue showed not only the controlled release ability of growth factors, but also strong tissue adhesiveness, which could resolve the current problems in clinical application of PRP. Furthermore, HNPRP hydrogel glue could promote integrative hyaline cartilage regeneration, and its reparative efficacy for cartilage defect was better than thrombin activated PRP gel. This study provided not only an effective repair material for cartilage regeneration, but also developed an advanced method for PRP application.

Comparison of exosomes secreted by induced pluripotent stem cell-derived mesenchymal stem cells and synovial membrane-derived mesenchymal stem cells for the treatment of osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is the most common joint disease worldwide. In the past decade, mesenchymal stem cells (MSCs) have been used widely for the treatment of OA. A potential mechanism of MSC-based therapies has been attributed to the paracrine secretion of trophic factors, in which exosomes may play a major role. In this study, we aimed to compare the effectiveness of exosomes secreted by synovial membrane MSCs (SMMSC-Exos) and exosomes secreted by induced pluripotent stem cell-derived MSCs (iMSC-Exos) on the treatment of OA. METHODS: Induced pluripotent stem cell-derived MSCs and synovial membrane MSCs were characterized by flow cytometry. iMSC-Exos and SMMSC-Exos were isolated using an ultrafiltration method. Tunable resistive pulse-sensing analysis, transmission electron microscopy, and western blots were used to identify exosomes. iMSC-Exos and SMMSC-Exos were injected intra-articularly in a mouse model of collagenase-induced OA and the efficacy of exosome injections was assessed by macroscopic, histological, and immunohistochemistry analysis. We also evaluated the effects of iMSC-Exos and SMMSC-Exos on proliferation and migration of human chondrocytes by cell-counting and scratch assays, respectively. RESULTS: The majority of iMSC-Exos and SMMSC-Exos were approximately 50-150 nm in diameter and expressed CD9, CD63, and TSG101. The injection of iMSC-Exos and SMMSC-Exos both attenuated OA in the mouse OA model, but iMSC-Exos had a superior therapeutic effect compared with SMMSC-Exos. Similarly, chondrocyte migration and proliferation were stimulated by both iMSC-Exos and SMMSC-Exos, with iMSC-Exos exerting a stronger effect. CONCLUSIONS: The present study demonstrated that iMSC-Exos have a greater therapeutic effect on OA than SMMSC-Exos. Because autologous iMSCs are theoretically inexhaustible, iMSC-Exos may represent a novel therapeutic approach for the treatment of OA.

Integration of stem cell-derived exosomes with in situ hydrogel glue as a promising tissue patch for articular cartilage regeneration.

The regeneration of articular cartilage, which scarcely shows innate self-healing ability, is a great challenge in clinical treatment. Stem cell-derived exosomes (SC-Exos), an important type of extracellular nanovesicle, exhibit great potential for cartilage regeneration to replace stem cell-based therapy. Cartilage regeneration often takes a relatively long time and there is currently no effective administration method to durably retain exosomes at cartilage defect sites to effectively exert their reparative effect. Therefore, in this study, we exploited a photoinduced imine crosslinking hydrogel glue, which presents excellent operation ability, biocompatibility and most importantly, cartilage-integration, as an exosome scaffold to prepare an acellular tissue patch (EHG) for cartilage regeneration. It was found that EHG can retain SC-Exos and positively regulate both chondrocytes and hBMSCs in vitro. Furthermore, EHG can integrate with native cartilage matrix and promote cell deposition at cartilage defect sites, finally resulting in the promotion of cartilage defect repair. The EHG tissue patch therefore provides a novel, cell-free scaffold material for wound repair.

Exosomes/tricalcium phosphate combination scaffolds can enhance bone regeneration by activating the PI3K/Akt signaling pathway.

BACKGROUND: Recently, accumulating evidence has shown that exosomes, the naturally secreted nanocarriers of cells, can exert therapeutic effects in various disease models in the absence of parent cells. However, application of exosomes in bone defect repair and regeneration has been rarely reported, and little is known regarding their underlying mechanisms. METHODS: Exosomes derived from human-induced pluripotent stem cell-derived mesenchymal stem cells (hiPS-MSC-Exos) were combined with tricalcium phosphate (ß-TCP) to repair critical-sized calvarial bone defects, and the efficacy was assessed by histological examination. We evaluated the in vitro effects of hiPSC-MSC-Exos on the proliferation, migration, and osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs) by cell-counting, scratch assays, and qRT-PCR, respectively. Gene expression profiling and bioinformatics analyses were also used to identify the underlying mechanisms in the repair. RESULTS: We found that the exosome/ß-TCP combination scaffolds could enhance osteogenesis as compared to pure ß-TCP scaffolds. In vitro assays showed that the exosomes could release from ß-TCP and could be internalized by hBMSCs. In addition, the internalization of exosomes into hBMSCs could profoundly enhance the proliferation, migration, and osteogenic differentiation of hBMSCs. Furthermore, gene expression profiling and bioinformatics analyses demonstrated that exosome/ß-TCP combination scaffolds significantly altered the expression of a network of genes involved in the PI3K/Akt signaling pathway. Functional studies further confirmed that the PI3K/Akt signaling pathway was the critical mediator during the exosome-induced osteogenic responses of hBMSCs. CONCLUSIONS: We propose that the exosomes can enhance the osteoinductivity of ß-TCP through activating the PI3K/Akt signaling pathway of hBMSCs, which means that the exosome/ß-TCP combination scaffolds possess better osteogenesis activity than pure ß-TCP scaffolds. These results indicate that naturally secreted nanocarriers-exosomes can be used as a bioactive material to improve the bioactivity of the biomaterials, and that hiPS-MSC-Exos combined with ß-TCP scaffolds can be potentially used for repairing bone defects.

Optimization and Biodistribution of [(11)C]-TKF, An Analog of Tau Protein Imaging Agent [(18)F]-THK523.

The quantification of neurofibrillary tangles (NFTs) using specific PET tracers can facilitate the diagnosis of Alzheimer's disease (AD) and allow monitoring of disease progression and treatment efficacy. [(18)F]-THK523 has shown high affinity and selectivity for tau pathology. However, its high retention in white matter, which makes simple visual inspection difficult, may limit its use in research or clinical settings. In this paper, we optimized the automated radiosynthesis of [(11)C]-TKF and evaluated its biodistribution and toxicity in C57 mice. [(11)C]-TKF can be made by reaction precursor with [(11)C]MeOTf or (11)CH3I, but [(11)C]MeOTf will give us higher labeling yields and specific activity. [(11)C]-TKF presented better brain uptake in normal mouse than [(18)F]-THK523 (3.23% ± 1.25% ID·g(-1) vs. 2.62% ± 0.39% ID·g(-1) at 2 min post-injection). The acute toxicity studies of [(11)C]-TKF were unremarkable.

Ligustrazine Inhibits Cartilage Endplate Hypertrophy via Suppression of TGF-ß1.

CEP hypertrophy is one of the characteristics of intervertebral disc degeneration (IDD). LIG exerts a protective effect on IDD in animal model. The effect of LIG on CEP hypertrophy is further investigated in the present study. Cells were isolated from hypertrophic samples obtained from patients during vertebral fusion surgery. Cellular proliferation and the expression of type I collagen (Col I) and TGF-ß1 were tested. In the bipedal rats, the edges of the CEP and the sizes of noncartilaginous outgrowth, as well as the expression of osteogenic markers, Col1a, ALP, Runx2, and TGF-ß1, were detected. Within two passages, the condensed hypertrophic CEP cells exhibited osteogenic capacity by bony-like nodules and ALP positive staining, along with increased expression of Col I and TGF-ß1. LIG inhibited proliferation of CEP cells and downregulated the expression of Col I and TGF-ß1 in vitro. Furthermore, LIG attenuated CEP hypertrophy on the lumbar spine of bipedal rats by reducing Col1a, ALP, Runx2, and TGF-ß1 mRNA expression and TGF-ß1 distribution in vivo. We concluded LIG exerted a preventive effect on CEP hypertrophy via suppression of TGF-ß1 levels. This information could be used to develop alternative therapeutic methods to treat spinal CEP hypertrophy.