Transcription directionality is licensed by Integrator at active human promoters.

A universal characteristic of eukaryotic transcription is that the promoter recruits RNA polymerase II (RNAPII) to produce both precursor mRNAs (pre-mRNAs) and short unstable promoter upstream transcripts (PROMPTs) toward the opposite direction. However, how the transcription machinery selects the correct direction to produce pre-mRNAs is largely unknown. Here, through multiple acute auxin-inducible degradation systems, we show that rapid depletion of an RNAPII-binding protein complex, Integrator, results in robust PROMPT accumulation throughout the genome. Interestingly, the accumulation of PROMPTs is compensated by the reduction of pre-mRNA transcripts in actively transcribed genes. Consistently, Integrator depletion alters the distribution of polymerase between the sense and antisense directions, which is marked by increased RNAPII-carboxy-terminal domain Tyr1 phosphorylation at PROMPT regions and a reduced Ser2 phosphorylation level at transcription start sites. Mechanistically, the endonuclease activity of Integrator is critical to suppress PROMPT production. Furthermore, our data indicate that the presence of U1 binding sites on nascent transcripts could counteract the cleavage activity of Integrator. In this process, the absence of robust U1 signal at most PROMPTs allows Integrator to suppress the antisense transcription and shift the transcriptional balance in favor of the sense direction.

Preoperative multimodal ultrasonic imaging in a case of Peutz-Jeghers syndrome complicated by atypical lobular endocervical glandular hyperplasia: a case report and literature review.

BACKGROUND: Peutz-Jeghers syndrome (PJS), an autosomal dominant multiple cancerous disorder, is clinically characterized by mucocutaneous macules and multiple gastrointestinal hamartomatous polyps. Gastric-type endocervical adenocarcinoma (G-EAC), a special subtype of cervical adenocarcinoma with non-specific symptoms and signs, is known to occur in approximately 11% of female patients with PJS. CASE PRESENTATION: Here, we report a case of PJS in a 24-year-old female with multiple mucocutaneous black macules who complained of vaginal discharge and menorrhagia. Moreover, we first described the multimodal ultrasonographical manifestations of PJS-correlated G-EAC. The three-dimensional reconstructed view of G-EAC on 3D realisticVue exhibited a distinctive "cosmos pattern" resembling features on magnetic resonance imaging, and the contrast-enhanced ultrasound displayed a "quick-up and slow-down" pattern of the solid components inside the mixed cervical echoes. We reported the multimodal ultrasonographical characteristics of a case of PJS-related G-EAC, as well as reviewed PJS-related literature and medical imaging features and clinical characteristics of G-EAC to provide insight into the feasibility and potential of utilizing multimodal ultrasonography for the diagnosis of G-EAC. CONCLUSIONS: Multimodal ultrasound can visualize morphological features, solid components inside, and blood supplies of the G-EAC lesion and distinguish the G-EAC lesion from normal adjacent tissues. This facilitates preoperative diagnosis and staging of PJS-related G-EAC, thereby aiding subsequent health and reproductive management for patients with PJS.

SYNOPSIS: We reported multimodal ultrasonographical characteristics of a case of Peutz-Jeghers syndrome-related gastric-type endocervical adenocarcinoma (G-EAC), indicating the potential use of multimodal ultrasonography for G-EAC diagnosis.

Ribosomal frameshifting at normal codon repeats recodes functional chimeric proteins in human.

Ribosomal frameshifting refers to the process that ribosomes slip into +1 or -1 reading frame, thus produce chimeric trans-frame proteins. In viruses and bacteria, programmed ribosomal frameshifting can produce essential trans-frame proteins for viral replication or regulation of other biological processes. In humans, however, functional trans-frame protein derived from ribosomal frameshifting is scarcely documented. Combining multiple assays, we show that short codon repeats could act as cis-acting elements that stimulate ribosomal frameshifting in humans, abbreviated as CRFS hereafter. Using proteomic analyses, we identified many putative CRFS events from 32 normal human tissues supported by trans-frame peptides positioned at codon repeats. Finally, we show a CRFS-derived trans-frame protein (HDAC1-FS) functions by antagonizing the activities of HDAC1, thus affecting cell migration and apoptosis. These data suggest a novel type of translational recoding associated with codon repeats, which may expand the coding capacity of mRNA and diversify the regulation in human.

Can a structured home-based rehabilitation program reduce dorsal central wrist pain?

OBJECTIVES: Dorsal central wrist pain, often a consequence of peri-scapholunate ligament injury, can result in a decline in functional performance. There is a scarcity of clinical data evaluating the effectiveness of conservative management on peri-scapholunate ligament injury. Conservative management includes education, immobilization with orthotic devices, scapholunate-stabilizing muscle strengthening, and proprioception training. The identification of the ligamento-muscular reflex and scapholunate-stabilizing muscles formed the rationale for a rehabilitation training program. We have devised an innovative standardized 16-week treatment program for patients with dorsal central wrist pain associated with acute peri-SL ligament injury. We hypothesized that the program can effectively reduce dorsal wrist pain and improve functional performance. MATERIALS AND METHODS: Recruited subjects underwent the 16-week home-based program, which included immobilization and rehabilitation exercises, to improve their wrist stability. Follow-up was arranged every 4 weeks for progress monitoring. The Short-Form 12 item questionnaire version 2, power grip, pinch grip, wrist range of motion, total performance score and total pain score when performing activities of daily living were used to evaluate the effectiveness of the program. An exercise adherence questionnaire was used to evaluate adherence to the home rehabilitation program. RESULTS: Twenty-three subjects (26 wrists) completed the program. Pain on visual analog scale improved by 5.1 cm and total pain score improved from 14.4/20 to 19.5/20. Total performance score reached 39/40, which indicated near-normal wrist function. Power grip and pinch grip increased by 22.3% and 17.8%, respectively. The physical component scale of the Short-Form 12 item questionnaire showed significant improvement, while the mental component scale did not. Overall adherence was fair. DISCUSSION: Conservative management, including immobilization and rehabilitation training, can provide significant clinical improvement in patients with dorsal central wrist pain associated with acute peri-scapholunate ligament injury. CONCLUSION: Standardized wrist rehabilitation can be taken as a reference treatment modality. It is an evidence-based non-invasive treatment option for clinicians and therapists.

PRAME induces genomic instability in uveal melanoma.

PRAME is a CUL2 ubiquitin ligase subunit that is normally expressed in the testis but becomes aberrantly overexpressed in many cancer types in association with aneuploidy and metastasis. Here, we show that PRAME is expressed predominantly in spermatogonia around the time of meiotic crossing-over in coordination with genes mediating DNA double strand break repair. Expression of PRAME in somatic cells upregulates pathways involved in meiosis, chromosome segregation and DNA repair, and it leads to increased DNA double strand breaks, telomere dysfunction and aneuploidy in neoplastic and non-neoplastic cells. This effect is mediated at least in part by ubiquitination of SMC1A and altered cohesin function. PRAME expression renders cells susceptible to inhibition of PARP1/2, suggesting increased dependence on alternative base excision repair pathways. These findings reveal a distinct oncogenic function of PRAME that can be targeted therapeutically in cancer.

Combining MSC Exosomes and Cerium Oxide Nanocrystals for Enhanced Dry Eye Syndrome Therapy.

Dry eye syndrome (DES) is a prevalent ocular disorder involving diminishe·d tear production and increased tear evaporation, leading to ocular discomfort and potential surface damage. Inflammation and reactive oxygen species (ROS) have been implicated in the pathophysiology of DES. Inflammation is one core cause of the DES vicious cycle. Moreover, there are ROS that regulate inflammation in the cycle from the upstream, which leads to treatment failure in current therapies that merely target inflammation. In this study, we developed a novel therapeutic nanoparticle approach by growing cerium oxide (Ce) nanocrystals in situ on mesenchymal stem cell-derived exosomes (MSCExos), creating MSCExo-Ce. The combined properties of MSCExos and cerium oxide nanocrystals aim to target the "inflammation-ROS-injury" pathological mechanism in DES. We hypothesized that this approach would provide a new treatment option for patients with DES. Our analysis confirmed the successful in situ crystallization of cerium onto MSCExos, and MSCExo-Ce displayed excellent biocompatibility. In vitro and in vivo experiments have demonstrated that MSCExo-Ce promotes corneal cell growth, scavenges ROS, and more effectively suppresses inflammation compared with MSCExos alone. MSCExo-Ce also demonstrated the ability to alleviate DES symptoms and reverse pathological alterations at both the cellular and tissue levels. In conclusion, our findings highlight the potential of MSCExo-Ce as a promising therapeutic candidate for the treatment of DES.

Umbilical artery thrombosis and maternal positive autoimmune antibodies: two case reports and a literature review.

Background: Previous studies have shown that abnormal increases in autoimmune antibodies in pregnant women may increase the risk of maternal thrombosis. However, at our hospital, two pregnant women presented with umbilical artery thrombosis and positive maternal autoantibodies were detected in both, which led us to consider whether maternal autoantibodies also played a role in umbilical artery thrombosis. Case presentation: Case 1: Fetal ultrasound of a 34-year-old pregnant woman at 30+4 weeks gestation showed two umbilical arteries, with an inner diameter of approximately 0.15 cm for the smaller was artery. However, only a single umbilical artery blood flow signal was detected. Due to fetal distress, which was noted on abnormal cardiotocography and Doppler ultrasound, an emergency cesarean section was performed at 31+1 weeks gestation. The Apgar score of the newborn was 3-8-8. Umbilical cord examination detected thrombosis in the two umbilical arteries. Moreover, blood test results during pregnancy showed nRNP/Sm antibody (+) and SS antibody (+++). Case 2: The first systematic ultrasound of a 33-year-old twin pregnancy at 24+3 weeks gestation was normal, but routine fetal ultrasound at 27+1 weeks gestation showed only one umbilical artery between fetus A and the placenta. Blood test results showed that the patient was anti-nRNP/Sm antibody (+) in the rheumatoid immune activity test at 27+3 weeks gestation. An emergency cesarean section was performed at 34+6 weeks gestation because of the single umbilical artery and abnormal maternal coagulation. Both umbilical cords of fetus A and B blood test results showed anti-nRNP/Sm antibody (++). The pathological examination of the umbilical cord and placenta showed the presence of old thrombosis in one of the umbilical arteries of fetus A. Conclusions: Abnormal maternal autoantibodies may be a risk factor for umbilical artery thrombosis. For these pregnant women, conducting more detailed ultrasound monitoring might get early detection of UAT formation and avoid the occurrence of adverse pregnancy outcomes.

A structured non-operative treatment program for traumatic triangular fibrocartilage complex tear: A quasi-experimental study.

OBJECTIVES: Triangular fibrocartilage complex (TFCC) injury is a common cause of ulnar-sided wrist pain. However, treatment protocols vary across clinical settings and a standardized treatment protocol is needed to improve quality of care. We devised a rehabilitation regime which comprised both orthoses and exercises. We hypothesized that the program can effectively reduce pain and improve functional performance. MATERIALS AND METHODS: Thirty-two subjects participated in the 5-phase rehabilitation program. Progress was monitored every 3 weeks. Outcome measures comprised numeric pain rating scale (NPRS), activities of daily living (ADL) pain score, wrist range of motion (ROM), ADL performance score, patient-rated wrist evaluation (PRWE), power grip and distal radioulnar joint (DRUJ) instability grade. RESULTS: NPRS decreased from 5.3/10 to 0.5/10 while the ADL pain score improved from 10/20 to 19.1/20. ROM in flexion/extension and supination/pronation improved by 35%. Functional performance on ADL performance score and PRWE improved from 21/40 to 38/40 and 49.5/100 to 14.6/100, respectively. Power grip increased by 59.5%, and DRUJ stability improved. DISCUSSION: The combination of orthoses and progressive strengthening and proprioception training was effective in re-establishing DRUJ stability, and improving wrist strength and functional performance. CONCLUSIONS: This study provided insight for the development of a rehabilitation protocol for patients with TFCC injury.

The Metabolism and Immune Environment in Diffuse Large B-Cell Lymphoma.

Cells utilize different metabolic processes to maintain their growth and differentiation. Tumor cells have made some metabolic changes to protect themselves from malnutrition. These metabolic alterations affect the tumor microenvironment and macroenvironment. Developing drugs targeting these metabolic alterations could be a good direction. In this review, we briefly introduce metabolic changes/regulations of the tumor macroenvironment and microenvironment and summarize potential drugs targeting the metabolism in diffuse large B-cell lymphoma.

PRAME induces genomic instability in uveal melanoma.

PRAME is a CUL2 ubiquitin ligase subunit that is normally expressed in the testis but becomes aberrantly overexpressed in many cancer types in association with aneuploidy and metastasis. Here, we show that PRAME is expressed predominantly in spermatogonia around the time of meiotic crossing-over in coordination with genes mediating DNA double strand break repair. Expression of PRAME in somatic cells upregulates pathways involved in meiosis, chromosome segregation and DNA repair, and it leads to increased DNA double strand breaks, telomere dysfunction and aneuploidy in neoplastic and non-neoplastic cells. This effect is mediated at least in part by ubiquitination of SMC1A and altered cohesin function. PRAME expression renders cells susceptible to inhibition of PARP1/2, suggesting increased dependence on alternative base excision repair pathways. These findings reveal a distinct oncogenic function of PRAME than can be targeted therapeutically in cancer.

Clinical Effects and Safety of Auricular Acupressure as an Adjunct Therapy on Postoperative Pain among Patients with Hip Fracture: A Meta-Analysis.

Objectives: To evaluate the short-term outcome of treatment by auricular acupressure (AA) on postoperative pain among hip fracture (HF) patients. Methods: A systematic search for randomized controlled trials on this topic was conducted through May 2022 by searching multiple English and Chinese databases. The methodological quality of the included trails was assessed by the Cochrane Handbook tool, and relevant data were extracted and statistically analyzed by RevMan 5.4.1 software. The quality of the evidence supporting each outcome was evaluated by GRADEpro GDT. Results: Fourteen trials with a total of 1390 participants were included in this study. Compared with conventional treatment (CT) alone, the combination of AA and CT had a significantly greater effect on the visual analog scale at 12 h (MD -0.53, 95% CI -0.77 to -0.30), 24 h (MD -0.59, 95% CI -0.92 to -0.25), 36 h (MD -0.07, 95% CI -0.13 to -0.02), 48 h (MD -0.52, 95% CI -0.97 to -0.08), and 72 h (MD -0.72, 95% CI -1.02 to -0.42), amount of analgesics used (MD -12.35, 95% CI -14.21 to -10.48), Harris Hip Score (MD 6.58, 95% CI 3.60 to 9.56), effective rate (OR 6.37, 95% CI 2.68 to 15.15), and adverse events (OR 0.35, 95% CI 0.17 to 0.71). Conclusions: Compared with CT alone, the combination of AA and CRT had a significantly greater effect on postoperative pain in HF patients. However, trails with a rigorous methodology, including standard protocols for AA and multiethnic subjects, are still needed.

SiO2/hyaluronic acid nanoparticles carry CaO2, DOX and p53 plasmid to effectively achieve ion interference/chemical/gene multimodal therapy of lung cancer.

Monotherapy of lung cancer shows limited therapeutic effects due to its poorly targeted enrichment and low bioavailability. Using nanomaterials as carriers to form drug delivery systems has become a popular method to improve the targeting of anticancer drug therapy and patients' safety. However, the uniformity of the loaded drugs and the unsatisfactory effects are still the bottleneck in this field up to now. This study aims to construct a novel nanocomposite carrying 3 different types of anticancer drugs to enhance treatment efficacy. Herein, mesoporous silica (MSN) with high loading rate was constructed by dilute sulfuric acid thermal etching as the framework. Hyaluronic acid (HA) was loaded with CaO2, p53 and DOX to construct nanoparticle complexes-SiO2@CaO2@DOX@P53-HA. First, MSN was proved to be a porous sorbent with a mesoporous structure through BET analysis. The images obtained from the uptake experiment clearly show the gradual enrichment of the DOX and Ca2+ within the target cell. For in vitro experiments, the pro-apoptotic effects of SiO2@CaO2@DOX@P53-HA significantly increased compared to that of the single-agent group at different time points. Furthermore, in the tumor-bearing mouse experiment, the tumor volume was remarkably inhibited in the SiO2@CaO2@DOX@P53-HA group compared to that in the single-agent group. By observing the pathological sections of the euthanized mice, it is obvious that the tissues of the mice treated with the nanoparticles were more intact. Based on these beneficial results, it is believed that multimodal therapy is a meaningful treatment strategy for lung cancer.

LncRNA-WAKMAR2 regulates expression of CLDN1 to affect skin barrier through recruiting c-Fos.

BACKGROUND: Chronic actinic dermatitis (CAD) is an immune-mediated photo-allergic skin disease. In the clinic, the treatment of this disease is hampered by the lack of proper understanding of the skin barrier dysfunction mechanism. OBJECTIVE: To illuminate the mechanism of skin barrier dysfunction in CAD. METHODS: Transcriptome sequencing and protein profiling were used to detect skin barrier injury-related genes. RNA pull down, a promoter-reporter gene assay, and chromatin isolation by RNA purification-sequencing were used to elucidate the effect of WAKMAR2 in skin barrier functionality. RESULTS: Transcriptome sequencing from patient's tissues showed a significantly decreased expression of WAKMAR2. Down-regulation of WAKMAR2 destroyed the keratinocyte barrier. Moreover, WAKMAR2 can directly bind to the c-Fos protein. This novel long non-coding RNA (LncRNA)-protein complexes were targeted to the CLDN1 promotor. Overexpression of WAKMAR2 enhanced the promoter activity of CLDN1, while the addition of AP-1 inhibitor could reverse this phenomenon. Furthermore, our in vivo results suggested that expression of WAKMAR2 was required for the repair of skin damage in mice induced by ultraviolet irradiation. CONCLUSIONS: We identified a crucial LncRNA (WAKMAR2) for the protection of the skin barrier in vitro and in vivo. Mechanically, it can specifically interact with c-Fos protein for the regulation of CLDN1, a finding which could be applied for CAD treatment.

Optimal diagnostic fever thresholds using non-contact infrared thermometers under COVID-19.

Fever screening is an effective method to detect infectors associated with different variants of coronavirus disease 2019 (COVID-19) based on the fact that most infectors with COVID-19 have fever symptoms. Non-contact infrared thermometers (NCITs) are widely used in fever screening. Nevertheless, authoritative data is lacking in defining "fever" at different body surface sites when using NCITs. The purpose of this study was to determine the optimal diagnostic threshold for fever screening using NICTs at different body surface sites, to improve the accuracy of fever screening and provide theoretical reference for healthcare policy. Participants (n = 1860) who were outpatients or emergency patients at Chengdu Women's and Children's Central Hospital were recruited for this prospective investigation from March 1 to June 30, 2021. NCITs and mercury axillary thermometers were used to measure neck, temple, forehead and wrist temperatures of all participants. Receiver operating characteristic curves were used to reflect the accuracy of NCITs. Linear correlation analysis was used to show the effect of age on body temperature. Multilinear regression analysis was used to explore the association between non-febrile participant's covariates and neck temperature. The mean age of participants was 3.45 ± 2.85 years for children and 28.56 ± 7.25 years for adults. In addition 1,304 (70.1%) participants were children (≤12), and 683 (36.7%) were male. The neck temperature exhibited the highest accuracy among the four sites. Further the optimal fever diagnostic thresholds of NCITs at the four body surface measurement sites were neck (36.75 °C, sensitivity: 0.993, specificity: 0.858); temple (36.55 °C, sensitivity: 0.974, specificity: 0.874); forehead (36.45 °C, sensitivity: 0.961, specificity: 0.813); and wrist (36.15 °C, sensitivity: 0.951, specificity: 0.434). Based on the findings of our study, we recommend 36.15, 36.45, 36.55, and 36.75 °C as the diagnostic thresholds of fever at the wrist, forehead, temple and neck, respectively. Among the four surface sites, neck temperature exhibited the highest accuracy.

Multitask Deep Neural Network for the Fully Automatic Measurement of the Angle of Progression.

The angle of progression (AoP) for assessing fetal head (FH) descent during labor is measured from the standard plane of transperineal ultrasound images as the angle between a line through the long axis of pubic symphysis (PS) and a second line from the right end of PS tangentially to the contour of the FH. This paper presents a multitask network with a shared feature encoder and three task-special decoders for standard plane recognition (Task1), image segmentation (Task2) of PS and FH, and endpoint detection (Task3) of PS. Based on the segmented FH and two endpoints of PS from standard plane images, we determined the right FH tangent point that passes through the right endpoint of PS and then computed the AoP using the above three points. In this paper, the efficient channel attention unit is introduced into the shared feature encoder for improving the robustness of layer region encoding, while an attention fusion module is used to promote cross-branch interaction between the encoder for Task2 and that for Task3, and a shape-constrained loss function is designed for enhancing the robustness to noise based on the convex shape-prior. We use Pearson's correlation coefficient and the Bland-Altman graph to assess the degree of agreement. The dataset includes 1964 images, where 919 images are nonstandard planes, and the other 1045 images are standard planes including PS and FH. We achieve a classification accuracy of 92.26%, and for the AoP calculation, an absolute mean (STD) value of the difference in AoP (∆AoP) is 3.898° (3.192°), the Pearson's correlation coefficient between manual and automated AoP was 0.964 and the Bland-Altman plot demonstrates they were statistically significant (P < 0.05). In conclusion, our approach can achieve a fully automatic measurement of AoP with good efficiency and may help labor progress in the future.

VEGF promotes tendon regeneration of aged rats by inhibiting adipogenic differentiation of tendon stem/progenitor cells and promoting vascularization.

Studies have shown that the stem cell microenvironment is a key factor for stem cell maintenance or differentiation. In this study, we compared the expression of 23 cytokines such as IL-6, IL-10, and TNFα between young and aged rats during patellar tendon repair by cytokine microarray, and found that significant difference between IL-10, G-CSF, and VEGF at 3, 7, or 14 days post-operatively. The effects of these factors on adipogenic differentiation of TPSCs were examined through western blot and oil red O experiments. It was shown that VEGF had an inhibitive effect on the adipogenic differentiation of TPSCs. SPP-1 was figured out as our target by RNA sequencing and confirmed by western blot in vitro. Further in vivo studies showed that adipocyte accumulation was also decreased in the tendons of aged rats after injection of VEGF and the histological score and biomechanical property were also improved via targeting SPP-1. Furthermore, histochemical results showed that vascularization of the injury sites was significantly elevated. In conclusion, VEGF not only plays an important role in decreasing adipocyte accumulation but also improves vascularization of the tendon during aged tendon healing. We believe active regulation of VEGF may improve the treatment of age-related tendon diseases and tendon injuries.

Reliability of Non-Contact Infrared Thermometers for Fever Screening Under COVID-19.

Purpose: Fever is one of the most typical clinical symptoms of coronavirus disease 2019 (COVID-19), and non-contact infrared thermometers (NCITs) are commonly used to screen for fever. However, there is a lack of authoritative data to define a "fever" when an NCIT is used and previous studies have shown that NCIT readings fluctuate widely depending on ambient temperatures and the body surface site screened. The aim of this study was to establish cut-off points for normal temperatures of different body sites (neck, forehead, temples, and wrist) and investigate the accuracy of NCITs at various ambient temperatures to improve the standardization and accuracy of fever screening. Patients and Methods: A prospective investigation was conducted among 904 participants in the outpatient and emergency departments of Chengdu Women's and Children's Central Hospital. Body temperature was measured using NCITs and mercury axillary thermometers. A receiver operating characteristic curve was used to determine the accuracy of body temperature detection at the four body surface sites. Data on participant characteristics were also collected. Results: Among the four surface sites, the neck temperature detection group had the highest accuracy. When the neck temperature was 37.35°C as the optimum fever diagnostic threshold, the sensitivity was 0.866. The optimum fever diagnostic thresholds for forehead, temporal, and wrist temperature were 36.65°C, 36.65°C, and 36.75°C, respectively. Moreover, triple neck temperature detection had the highest sensitivity, up to 0.998, whereas the sensitivity of triple wrist temperature detections was 0.949. Notably, the accuracy of NCITs significantly reduced when the temperature was lower than 18°C. Conclusion: Neck temperature had the highest accuracy among the four NCIT temperature measurement sites, with an optimum fever diagnostic threshold of 37.35°C. Considering the findings reported in our study, we recommend triple neck temperature detection with NCITs as the fever screening standard for COVID-19.

Effects of aging on the histology and biochemistry of rat tendon healing.

INTRODUCTION: Tendon diseases and injuries are a serious problem for the aged population, often leading to pain, disability and a significant decline in quality of life. The purpose of this study was to determine the influence of aging on biochemistry and histology during tendon healing and to provide a new strategy for improving tendon healing. METHOD: A total of 24 Sprague-Dawley rats were equally divided into a young and an aged group. A rat patellar tendon defect model was used in this study. Tendon samples were collected at weeks 2 and 4, and hematoxylin-eosin, alcian blue and immunofluorescence staining were performed for histological analysis. Meanwhile, reverse transcription-polymerase chain reaction (RT-PCR) and western blot were performed to evaluate the biochemical changes. RESULTS: The histological scores in aged rats were significantly lower than those in young rats. At the protein level, collagen synthesis-related markers Col-3, Matrix metalloproteinase-1 and Metallopeptidase Inhibitor 1(TIMP-1) were decreased at week 4 in aged rats compared with those of young rats. Though there was a decrease in the expression of the chondrogenic marker aggrecan at the protein level in aged tendon, the Micro-CT results from weeks 4 samples showed no significant difference(p>0.05) on the ectopic ossification between groups. Moreover, we found more adipocytes accumulated in the aged tendon defect with the Oil Red O staining and at the gene and protein levels the markers related to adipogenic differentiation. CONCLUSIONS: Our findings indicate that tendon healing is impaired in aged rats and is characterized by a significantly lower histological score, decreased collagen synthesis and more adipocyte accumulation in patellar tendon after repair.

Adipogenic differentiation was inhibited by downregulation of PPARγ signaling pathway in aging tendon stem/progenitor cells.

BACKGROUND: Tendon stem/progenitor cells (TSPCs) play a vital role in tendon repair and regeneration. Previously we found more adipocytes accumulated in the patellar tendon injury sites in aging rats compared with the young ones, of which the mechanism is still unknown. Here, we want to identify whether erroneous differentiation of TSPCs by aging accounts for the adipocyte accumulation. METHODS: TSPCs from young and aging rats were isolated and propagated. Both young and aging TSPCs were induced to differentiate into adipocytes, and Oil red O staining, quantitative real-time polymerase chain reaction (qRT-PCR), western-blot and immunofluorescent staining were used to evaluate the capability of TSPCs. RNA sequencing was utilized to screen out different genes and signaling pathways related to adipogenesis between young and aging TSPCs. RESULTS: The Oil red O staining showed there were more adipocytes formed in young TSPCs. Besides, adipogenic markers perilipin, peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding proteins alpha (C/EBPα) and Fatty acid-binding protein 4 (FABP4) were elevated both at gene and protein level. PPARγ signaling pathway was selected as our target via RNA sequencing. After adding the signaling activators, Rosiglitazone maleate (RM), inhibited adipogenesis of aging TSCs was reversed. CONCLUSIONS: In conclusion, aging inhibited adipogenesis of TSPCs by down-regulating PPARγ signaling. It is not likely that the adipocyte accumulation in aging tendon during repair was due to the aging of TSPCs. This may provide new targets for curing aging tendon injuries or tendinopathies.

Mesoporous Zn/MgO Hexagonal Nano-Plates as a Catalyst for Camelina Oil Biodiesel Synthesis.

A novel mesoporous Zn/MgO hexagonal-nano-plate catalyst was synthesized by a simple template-free hydrothermal method and applied in the base-catalyzed transesterification of Camelina oil for biodiesel synthesis. The Zn/MgO catalyst calcinated at 873 K exhibited the highest catalytic activity with a yield of 88.7%. This catalytic reaction was performed using 3% w/w of the catalyst with a methanol-to-oil molar ratio of 24:1 at 393 K in 8 h. The excellent catalytic performance is possibly attributed to its favorable textural features with relatively high surface area (69.1 m2 g-1) and appropriate size of the mesopores (10.4 nm). In addition, the as-synthesized catalyst demonstrated a greater basic sites density than single mesoporous MgO, which might have been promoted by the addition of Zn, leading to a synergetic interaction that enhanced its catalytic activity. This catalytic system demonstrated high stability for five catalytic runs and catalytic activity with over 84% yield.