Bone marrow derived stem cells (BMSCs) transplantation are viewed as a promising therapeutic candidate for spinal cord injury (SCI). However, the inflammatory microenvironment in the spinal cord ...following SCI limits the survival and efficacy of transplanted BMSCs. In this study, we investigate whether injured neuronal cells derived exosomes would influence the survival of transplanted BMSCs after SCI. In order to mimic the microenvironment in SCI that the neuronal cells or transplanted BMSCs suffer in vivo, PC12 cells conditioned medium and PC12 cell's exosomes collected from H
O
-treated PC12 cell's culture medium were cultured with BMSCs under oxidative stress in vitro. PC12 cells conditioned medium and PC12 cell's exosomes significantly accelerated the apoptosis of BMSCs induced by H
O
. Moreover, the cleaved caspase-3, cytochrome (Cyt) C, lactate dehydrogenase (LDH) releases, and apoptotic percentage were increased, and the ratio of Bcl-2/Bax and cell viability were decreased. Inhibition of exosome secretion via Rab27a small interfering RNA prevented BMSCs apoptosis in vitro. In addition, hypoxia-preconditioned promoted the survival of BMSCs under oxidative stress both in vivo after SCI and in vitro. Our results also indicate that HIF-1α plays a central role in the survival of BMSCs in hypoxia pretreatment under oxidative stress conditions. siRNA-HIF-1α increased apoptosis of BMSCs; in contrast, HIF-1α inducer FG-4592 attenuated apoptosis of BMSCs. Taken together, we found that the injured PC12 cells derived exosomes accelerate BMSCs apoptosis after SCI and in vitro, hypoxia pretreatment or activating expression of HIF-1α to be important in the survival of BMSCs after transplantation, which provides a foundation for application of BMSCs in therapeutic potential for SCI.
We demonstrate single molecule conductance as a sensitive and atomically precise probe of binding configurations of adenine and its biologically relevant variants on gold. By combining experimental ...measurements and density functional theory (DFT) calculations of single molecule-metal junction structures in aqueous conditions, we determine for the first time that robust binding of adenine occurs in neutral or basic pH when the molecule is deprotonated at the imidazole moiety. The molecule binds through the donation of the electron lone pairs from the imidazole nitrogen atoms, N7 and N9, to the gold electrodes. In addition, the pyrimidine ring nitrogen, N3, can bind concurrently and strengthen the overall metal-molecule interaction. The amine does not participate in binding to gold in contrast to most other amine-terminated molecular wires due to the planar geometry of the nucleobase. DFT calculations reveal the importance of interface charge transfer in stabilizing the experimentally observed binding configurations. We demonstrate that biologically relevant variants of adenine, 6-methyladenine and 2'-deoxyadenosine, have distinct conductance signatures. These results lay the foundation for biosensing on gold using single molecule conductance readout.
China's universal medical insurance system (UMIS) is designed to promote social fairness through improving access to medical services and reducing out-of-pocket (OOP) costs for all Chinese. However, ...it is still not known whether UMIS has a significant impact on the accessibility of medical service supply and the affordability, as well as the seeking-care choice, of patients in China.
Segmented time-series regression analysis, as a powerful statistical method of interrupted time series design, was used to estimate the changes in the quantity and quality of medical service supply before and after the implementation of UMIS. The rates of catastrophic payments and seeking-care choices for UMIS beneficiaries were selected to measure the affordability and medical service flow of patients after the implementation of UMIS.
China's UMIS was established in 2008. After that, the trending increase of the expenditure of the UMIS was higher than that of increase in revenue compared to previous years. Up to 2014, the UMIS had covered 97.5% of the entire population in China. After introduction of the UMIS, there were significant increases in licensed physicians, nurses, and hospital beds per 1000 individuals. In addition, hospital outpatient visits and inpatient visits per year increased compared to the pre-UMIS period. The average fatality rate of inpatients in the overall hospital and general hospital and the average fatality rate due to acute myocardial infarction (AMI) in general hospitals was significantly decreased. In contrast, no significant and prospective changes were observed in rural physicians per 1000 individuals, inpatient visits and inpatient fatality rate in the community centers and township hospitals compared to the pre-UMIS period. After 2008, the rates of catastrophic payments for UMIS inpatients at different income levels were declining at three levels of hospitals. Whichever income level, the rate of catastrophic payments for inpatients of Urban Employee's Basic Medical Insurance was the lowest. For the low-income patients, a single hospitalization at a tertiary hospital can lead to catastrophic payments. It is needless to say what the economic burden could be if patients required multiple hospitalizations within a year. UMIS beneficiaries showed the intention of growth to seek hospitalization services in tertiary hospitals.
Introduction of the UMIS contributed to an increase in available medical services and the use thereof, and a decrease in fatality rate. The affordability of UMIS beneficiaries for medical expenses was successfully ameliorated. The differences in patients' affordability are mainly manifested in different medical insurance schemes and different seeking-care choices. The ability of the poor patients covered by UMIS to resist catastrophic medical payments is still relatively weak. Therefore, the current UMIS should reform the insurance payment model to promote the integration of medical services and the formation of a tiered treatment system. UMIS also should establish supplementary medical insurance packages for the poor.
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•Matrine attenuates heterotopic ossification.•Matrine suppresses TGF-β induced mesenchymal stromal cells migration.•Matrine suppresses TGF-β induced osteogenic differentiation.
...Heterotopic ossification (HO) is a debilitating disease characterized by extraskeletal bone formation. Active TGF-β recruits mesenchymal stromal cells (MSCs), which contribute to trauma-induced HO. Inhibiting TGF-β induced MSC migration and osteogenic differentiation could be a promising treatment for HO. Matrine is an alkaloid from the genus Sophora that can suppress pancreatic and hepatic fibrosis by regulating TGF-β/Smad signaling. We conducted this study to evaluate the effects of matrine on HO and explore the mechanisms, we carried out this study.
Achilles tendon puncture was performed in C57BL/6J male mice to establish the HO model. Following treatment with matrine for 3, 6, 9, and 15 weeks, mice were sacrificed and tendons were collected. In vivo, micro-CT, hematoxylin and eosin staining, CD73 and CD90 immunofluorescence, and osteocalcin staining were used to evaluate the development of HO. In vitro, a transwell migration assay was used to evaluate MSC migration. Immunohistochemistry, immunofluorescence and western blotting were used to evaluate the TGF-β/Smad2/3 pathway. Real-time PCR was conducted to analyze the transcription of alkaline phosphatase (Alp), runt-related transcription factor-2 (Runx2), osteocalcin (Ocn), osteopontin (Opn), and type I collagen (Col1). ALP activity and alizarin red staining were used to assess MSC osteogenic differentiation.
In vivo, matrine significantly reduced ossification and inhibited HO progression. In vitro, matrine significantly suppressed MSC migration, ALP activity, and mineralization of MSCs. Mechanistically, matrine inhibited TGF-β induced Smad2/3 phosphorylation and transcription of Runx2, Alp, and Ocn after osteoinduction.
Matrine inhibited HO by suppressing the migration and osteogenic differentiation of TGF-β-induced-MSCsin mice.
Purpose
The optimal technique for arthroscopic rotator cuff repair is still controversial. The aim of this study was to compare modified arthroscopic double-pulley suture-bridge (DPSB) technique with ...medial knot tying to those without tying, considering clinical and radiological outcomes.
Methods
This study included 292 patients with large full-thickness rotator cuff tears treated with modified DPSB technique. The patients were divided into 158 cases with medial knot tying (knot-tying group) and 134 without tying (knotless group). At follow-up, clinical outcome was assessed by the Constant score, American Shoulder and Elbow Surgeons (ASES) score, and Shoulder Rating Scale of the University of California at Los Angeles (UCLA) score. The assessment of tendon healing was performed with magnetic resonance imaging (MRI) at a minimum of 12 months postoperatively.
Results
The Constant score, ASES score and UCLA score in the knot-tying and knotless groups all improved significantly from before surgery to 12 months postoperatively (
P
< 0.05, respectively). No significant differences were observed between groups for each phase evaluated (n.s.). Tendon healing was categorised according to Sugaya’s classification. The retearing rate was 27/158 (17.0%) in the knot-tying group and 20/134 (14.9%) in the knotless group, with no statistically significant difference between groups (n.s.). Additionally, the retear was classified using the Cho’s classification. When comparing the retear rates of different types independently, no statistically significant differences were found between groups (n.s.).
Conclusions
The knotless modified DPSB technique showed comparable short-term functional outcomes to those of the knot tying method in large full-thickness rotator cuff tears. Additionally, no significant differences in repair integrity were observed between the two methods. Both techniques can be considered effective treatments for patients with large-sized full-thickness rotator cuff tears.
Level of evidence
III.
Osteoarthritis (OA) is a chronic degenerative disease of the joints characterized by articular cartilage damage, subchondral bone remodeling, osteophyte formation, and inflammatory changes. This work ...aims to investigate the protective role of long non-coding RNA (lncRNA) maternally expressed 3 (MEG3) against the apoptosis of chondrocytes.
Chondrocyte cell lines, CHON-001, and ATDC5 were treated with different doses of interleukin-1β (IL-1β) to mimic the inflammatory response during OA pathogenesis. Quantitative real-time polymerase chain reaction was performed to measure MEG3, miR-9-5p, and Krüppel-like factor 4 (KLF4) mRNA expression levels. MEG3 and KLF4 overexpression plasmids, MEG3 shRNA, miR-9-5p mimics, and miR-9-5p inhibitors were transfected into the cells. Cell counting kit-8, wound healing assay, and flow cytometry were conducted to determine cell viability, migration, and apoptotic rate. Dual-luciferase reporter assay was adopted to verify the targeting relationships among MEG3, miR-9-5p, and KLF4. Western blot was used to detect KLF4 protein expression. Enzyme-linked immunosorbent assay was employed to measure the levels of inflammatory factors.
MEG3 expression in chondrocytes was down-regulated by the stimulation of IL-1β, and MEG3 negatively regulated miR-9-5p expression but positively regulated KLF4 expression. MEG3 overexpression strengthened the viability and migration of CHON-001 and ATDC5 cells but restrained the apoptosis and inflammatory response, while MEG3 knockdown had opposite effects. miR-9-5p inhibition or KLF4 overexpression could counteract the effects of MEG3 knockdown on chondrocytes. Besides that, MEG3 was proved to be a molecular sponge for miR-9-5p, and KLF4 was verified as the target of miR-9-5p.
MEG3 can promote chondrocyte proliferation and migration and inhibit apoptosis and inflammation by sponging miR-9-5p to induce KLF4 expression, which provides a promising therapy target for OA treatment.
Pigmented villonodular synovitis (PVNS) is a rare, benign, proliferative neoplastic process that commonly affects synovial-lined anatomic spaces. The diffuse type (DPVNS) is characterized by invasion ...of the entire joint synovium, while the localized type (LPVNS) is characterized by a relatively normal synovial appearance. This report describes a unique case of massive intraarticular LPVNS with an extraarticular extension through the lateral patellar retinaculum. No similar cases have been found in the literature.
A 58-year-old woman had a history of hyperuricemia and knee trauma and presented with unilateral knee acute swelling and pain symptoms with sudden onset. Recent expansion of the LPVNS caused the development of a tender palpable soft tissue mass in the anterolateral aspect of the knee and acute reduced mobility. Preoperative magnetic resonance imaging of the knee revealed the presence of only the soft tissue mass and mild degenerative changes. Open synovectomy was performed successfully to excise the mass. Intraoperatively, macroscopic features of the bright brown inflamed synovium suggested LPVNS, which was confirmed histopathologically. Postoperatively, the symptoms of limited mobility and pain were appreciably relieved. Recurrence was not observed during the clinical follow-up at 1, 6 or 18 months after surgery.
Here, we report the unique case of localized pigmented villonodular synovitis of the knee in a misdiagnosed patient with intra- and extraarticular lesion, which might be attributed to the history of knee trauma and the focal defect of the lateral patellar retinaculum. Open synovectomy effectively relieved the symptoms of limited mobility and pain and no recurrence was observed prior to 18 months postoperatively. To reduce misdiagnosis, MRI examinations are recommended for all patients suspected of having PVNS, including those who have a history of hyperuricemia.
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•Nanozymes mitigate ROS-driven bone disorders.•Diverse applications in bone health.•Challenges in orthopedic applications.
Bone-related disorders, such as osteoporosis, ...osteoarthritis, and osteosarcoma, have complex origins. Genetic, environmental factors, and significantly, oxidative stress due to Reactive Oxygen Species (ROS) play pivotal roles in these disorders. With their profound implications on global health, it becomes imperative to seek innovative therapeutic solutions. Nanozymes, known for their superior stability, cost-effectiveness, and tunable properties, present themselves as a prospective answer in mitigating ROS-driven bone ailments. This review explores the diverse applications and mechanisms of nanozymes in the context of bone health. They show potential in not only counteracting ROS-induced oxidative stress but also in modulating angiogenesis and showcasing antibacterial effects. We systematically analyze the effects of nanozymes on conditions such as osteonecrosis of the femoral head, skin flap transplantation, osteomyelitis, osteoarthritis, intervertebral disc disease, osteoporosis, and osteosarcoma, highlighting their potential roles in modulating disease processes. In addition, we discuss the challenges of applying nanozymes to orthopedic diseases. It offers insights into the transformative potential of nanozymes in bone therapeutics, underscoring the need to address challenges and capitalize on opportunities for their broader application in orthopedics.
Reversible lysine methylation is essential for regulating histones and emerges to critically regulate non-histone proteins as well. Here we show that the master transcription factor OCT4 in ...pluripotent stem cells (PSCs) was methylated at multiple lysine residues. LSD1 that is highly expressed in PSCs can directly interact with and demethylate OCT4 at lysine 222 (K222) in the flexible linker region. Reduced LSD1 activity led to the methylation of OCT4-K222 that diminished the differentiation potential of PSCs while facilitating proteasome-independent degradation of OCT4 proteins. Furthermore, site-specifically replacing K222 with phenylalanine to mimic the constitutively methylated lysine promoted the 'locked-in' mode engagement of the OCT4 PORE-homodimers that tightly bind to and block the transcription of multiple PORE-motif-containing target genes regulating cell fate determination and cell junction organization, and thereby reducing the pluripotency of PSCs. Thus, LSD1-mediated demethylation of OCT4 plays a crucial role in restricting the 'locked-in' mode binding of OCT4 PORE-homodimers to the PORE-motif-containing genes and thereby maintaining their transcription to safeguard the pluripotency of PSCs.
Biogeographical variation in herbivore communities may drive invasive plants to evolve lower defense against specialist herbivores but higher defense against generalist herbivores (shifting defense ...hypothesis, SDH). However, empirical tests on this topic have been strongly biased toward examining constitutive resistance and less is known about the evolution of induced resistance and tolerance. We examined constitutive and induced resistance and tolerance of the invasive plant,
Alternanthera philoxeroides
(alligator weed, Centrospermae: Amaranthaceae) against the specialist herbivore
Agasicles hygrophila
(Coleoptera, Chrysomelidae) and the generalist herbivore
Spodoptera litura
(Lepidoptera, Noctuidae), using genotypes from its introduced and native ranges. We found that introduced genotypes, compared to native genotypes, had higher constitutive resistance to the generalist herbivore, but similar constitutive resistance to the specialist herbivore. Furthermore, introduced genotypes, compared to native genotypes, had lower induced resistance to the generalist herbivore, but similar induced resistance to the specialist herbivore. Moreover, although introduced and native genotypes did not differ in their tolerance to the generalist, the introduced genotypes exhibited lower tolerance to the specialist than native ones. Therefore, while individual defense strategy does not indicate a shift from defense against the specialist to defense against the generalist, the results for the different defense strategies jointly support the SDH.
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