Effects of rapamycin on osteosarcoma cell proliferation and apoptosis by inducing autophagy

OBJECTIVE

To investigate the influences of rapamycin on proliferation and apoptosis of human osteosarcoma MG-63 cells and the mechanisms of action.

MATERIALS AND METHODS

The human osteosarcoma MG-63 cells were randomly divided into Control group, Rapamycin group, and Rapamycin + Beclin-1 plasmid transfection group. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was adopted to detect the viability of MG-63 cells in each group, and the 5-Ethynyl-2'-deoxyuridine (EdU) staining and Hoechst staining were applied to determine the proliferation and apoptosis, respectively, of MG-63 cells in each group. The levels of B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax) were measured using enzyme-linked immunosorbent assay (ELISA) kits, and the protein expression levels of Beclin-1 and Vps34 in each group of MG-63 cells were tested using the Western blotting.

RESULTS

Compared with the Control group, Rapamycin group, and Rapamycin + Beclin-1 plasmid transfection group had markedly weakened the viability of MG-63 cells, inhibited cell proliferation, remarkably increased cell apoptosis rate, elevated Bax level, notably declined Bcl-2 level, and significantly raised the levels of Beclin-1 and Vps34 proteins in MG-63 cells. Besides, the effects in Beclin-1 plasmid transfection group were stronger.

CONCLUSIONS

Rapamycin may decrease the viability, inhibit the proliferation, and promote the apoptosis of MG-63 cells by activating autophagy.

MiR-155-5p accelerates cerebral ischemia-reperfusion injury via targeting DUSP14 by regulating NF-κB and MAPKs signaling pathways

OBJECTIVE

This study aimed to explore the role of miR-155-5p in middle cerebral artery occlusion/reperfusion (MCAO/R) model in rats and oxygen-glucose deprivation/reoxygenation (OGD/R)-induced SH-SY5Y cells. In addition, this study also aimed to explore the underlying mechanisms to expect that miR-155-5p may be investigated as a new and effective diagnostic and therapeutic target for ischemic stroke.

MATERIALS AND METHODS

The in vivo MCAO/R rat model and in vitro OGD/R cell model were established. The miR-155-5p mRNA expression was detected by quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR). Dual specificity ATPase (DUSP) 14 was predicted to be a potential target of miR-155-5p by TargetScan. The targeting relationship was confirmed by Luciferase assay. The cell viability was determined using the Cell Counting Kit-8 (CCK-8). The expression level of inflammatory cytokines, including tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) levels were detected by Enzyme-Linked Immunosorbent Assay (ELISA). Western blot was used to detect the protein expression of DUSP14, the apoptotic protein Cleaved cysteine-aspartic acid protease (caspase)-3, and Cleaved PARP, as well as nuclear factor kappa B (NF-κB) and MAPKs signaling pathways related proteins.

RESULTS

MiR-155-5p was upregulated in both MCAO/R rats and OGD/R-induced SH-SY5Y cells. MiR-155-5p knockdown inhibited OGD/R-induced cell injury and inflammation, as well as MCAO/R-induced brain injury. MiR-155-5p regulated the NF-κB and MAPKs signaling pathways by targeting DUSP14. DUSP14 knockdown partially reversed the protective effect of miR-155-5p knockdown on OGD/R-induced SH-SY5Y cell injury and inflammation.

CONCLUSIONS

MiR-155-5p accelerates cerebral I/R injury via targeting DUSP14 by regulating NF-κB and MAPKs signaling pathways. Inhibition of miR-155-5p significantly reduces apoptosis and brain injury. These results indicated that miR-155-5p plays a key role in cerebral I/R injury and has the potential to be explored as a new target for ischemic stroke.

Bathymetric gradient shapes the community composition rather than the species richness of deep-sea benthic ciliates

The bathymetric gradient is one of the most important factors that regulate the distribution of life. However, community variations of benthic ciliates along bathymetric gradients in the deep sea remain rather unexplored. In this study, we hypothesize that in the deep sea, the bathymetric gradient shapes the benthic ciliate community composition rather than the species richness. Here, we evaluated the distribution patterns and drivers of benthic ciliate communities of an abyssal plain, a seamount, and a trench with water depths ranging from 800 m down to 6600 m by high throughput eDNA sequencing and statistical analyses. We observed no significant correlation between ciliate operated taxonomic unit (OTU) richness and water depth. A meta-analysis, which combined our previously published data from the neritic habitats, supports the notion that water depth exceeding 800 m has little effect on the richness of benthic ciliate species. In contrast, the composition of deep-sea ciliate communities was significantly distinct in different habitats along the bathymetric gradients. A SourceTracker analysis revealed extremely low connectivity among ciliate communities along the bathymetric gradients. More than 95% of the community dissimilarity in the deep-sea floor was attributed to species replacement, which might be caused by environmental sorting or historical constraints. Furthermore, the observed community variations could be ascribed more to water depth than to geographic distance. The findings imply that the strong force of environmental sorting along the bathymetric gradients and the low connectivity among the ciliate communities might lead to an isolated evolution. This could shape the community composition rather than the species richness, which is mainly determined by the limited nutrient availability and the extreme environmental conditions in the deep sea.

Alterations in leaf photosynthetic electron transport in Welsh onion (Allium fistulosum L.) under different light intensity and soil water conditions

Welsh onions (Allium fistulosum L.) are often affected by stressful environments, such as high light and drought, during summer cultivation, which hinders their growth. We used CO₂ assimilation, OJIP transient and MR curves to analyse the photosynthetic characteristics of Welsh onion. The results showed that single high light stress caused a decrease in the net photosynthesis rate through stomatal limitation, while the single drought treatment and the combined stress induced nonstomatal limitation. F_O and F_J increased, F_m decreased, and a distinct K-phase was induced. High light and drought stress blocked MR transients, leading to a gradual decrease in V_PSI and V_PSII-PSI . In general, photosynthesis of Welsh onion was inhibited by high light and drought, which destroyed the receptor and donor side of PSII and reduced electron transport capacity of PSII and PSI.

Morphology and phylogenetic analysis of five deep-sea golden gorgonians (Cnidaria, Octocorallia, Chrysogorgiidae) in the Western Pacific Ocean, with the description of a new species

Explorations of seamounts in the Western Pacific Ocean and South China Sea resulted in collecting 18 specimens of golden gorgonians. Based on the morphology and the genetic analysis of mtMutS, they are described as one new species, Chrysogorgiacarolinensissp. nov., and four known species, including Chrysogorgiadendritica Xu, Zhan & Xu, 2020, Metallogorgiamelanotrichos (Wright & Studer, 1889), Metallogorgiamacrospina Kükenthal, 1919, and Pseudochrysogorgiabellona Pante & France, 2010. Chrysogorgiacarolinensis belongs to the Chrysogorgia “group A, Spiculosae” with rods or spindles distributed in the polyp-body wall and tentacles, and differs from all of its congeners except C.dendritica by the 1/3L branching sequence and amoeba-shaped sclerites at the basal polyp body. The mtMutS sequence of C.carolinensissp. nov. has six deletion mutations compared to those of its congeners, supporting the establishment of the new species. Although no genetic variability was observed between the closely related species C.dendritica and C.abludo Pante & Watling, 2012, the former is different from the latter by the apparently irregular sclerites in the polyp body wall. The two specimens of Metallogorgiamelanotrichos match well with the original description except for relatively larger polyps, while the M.macrospina specimens have slightly smaller polyps than the holotype. The juvenile of Metallogorgia has an obvious morphological difference with the adults in the colony shape and branches, but they can be unified by the same polyps and sclerites as well as mitochondrial MutS sequences. Thus, the generic diagnosis of Metallogorgia is slightly extended to include the morphology of juveniles. The morphology of Pseudochrysogorgiabellona Pante & France, 2010, as a new record for the South China Sea, matches well with that of the original description. In the phylogenetic trees, the Chrysogorgia species are separated into two clades, and while Metallogorgia and Pseudochrysogorgia formed a sister clade.

PEAR1 rs12041331 polymorphisms and the risk of adverse cardiovascular outcomes in patients with acute coronary syndrome and/or percutaneous coronary intervention: a systematic review and meta-analysis

Background

Platelet endothelial aggregation receptor-1 (PEAR1), expressed in endothelium, platelets, and other tissues, is a platelet transmembrane tyrosine kinase receptor involved in platelet aggregation and platelet-platelet contact. The minor allele (A) in intron 1 of the PEAR1 gene (rs12041331, G>A) is associated with an reduced PEAR1 protein expression and suppressed platelet aggregation response toward multiple agonists. But current evidences on the association between PEAR1 rs12041331 polymorphisms and cardiovascular outcomes in patients with acute coronary syndrome (ACS) and/or percutaneous coronary intervention (PCI) are discordant.

Purpose

To characterize and quantify the association between PEAR1 rs12041331 polymorphisms and cardiovascular outcomes in patients with ACS and/or PCI.

Methods

We conducted a systematic review and meta-analysis by searching MEDLINE via PubMed, EMBASE, Cochrane Central Register of Controlled Trials, SinoMed, CNKI, and Wanfang Data before Dec 7, 2019 to identify studies evaluating the association between PEAR1 rs12041331 polymorphisms and cardiovascular outcomes in patients with ACS and/or PCI. The primary outcome was the major adverse cardiovascular outcomes (MACEs) defined by each study. We adopted the Mantel-Haenszel method to calculate the relative risks (RRs) with 95% confidence intervals (CIs) and the corresponding P values using the random effect model. To assess the effect of ethnicity, we performed the subgroup analyses per ethnic population using the fix effect model.

Results

Among 542 citations identified along with 1 from additional sources, we included 4 studies, which documented 218 MACEs in 8180 patients. The A allele frequency in each study was comparable with that reported in the 1000 Genome Project, but varied among ethnic populations, that is 45.8% in East Asians, 46.5% in American Africans, and 9.2% in Caucasians, adopted from the 1000 Genome Project. A-allele carriers are associated with a 54% increase in MACEs than non-A-carriers (RR, 1.54; 95% CI, 1.10–2.16; P=0.01) with a low but non-significant heterogeneity. Subgroup analyses showed that A-allele carriers tend to have more MACEs than non-A-allele carriers despite of ethnicity, that is 1.32-fold increase in East Asians (RR, 1.32; 95% CI, 0.99–1.77; P=0.06), 2.43-fold in Caucasians (RR, 2.43; 95% CI, 0.99–5.98; P=0.05), and 3.56-fold (RR, 3.56; 95% CI, 1.08–11.70; P=0.04) in American Africans.

Conclusions

Our study indicates that the PEAR1 rs12041331 is prognostic in patients with ACS and/or PCI and treated with DAPT, which might be not caused by the associations with pharmacological response to antiplatelet agents. Further investigations are thus required to address the unrevealing mechanisms of PEAR1, especially on the development of atherosclerosis and the occurrence of acute adverse ischemic events.

Figure 1

Funding Acknowledgement

Type of funding source: None

Genetic polymorphisms and cardiovascular outcomes in Chinese patients undergoing PCI and treated with clopidogrel and aspirin

Background

Genetic polymorphisms of key proteins involved in clopidogrel absorption, metabolism, and action may contribute to variability in platelet inhibition in patients undergoing percutaneous coronary intervention (PCI), but their impacts on cardiovascular outcomes remain unclear.

Purpose

To examine the associations between genetic polymorphisms and cardiovascular outcomes in Chinese patients undergoing PCI and treated with clopidogrel and aspirin.

Methods

This prospective cohort study consecutively enrolled 2,453 post-PCI patients treated with clopidogrel and aspirin. Adenosine diphosphate-induced platelet aggregation was measured by light transmission aggregometry. A total of 40 single nucleotide polymorphisms (SNPs) of 18 genes selected according to published studies were investigated using an improved multiplex ligation detection reaction technique. The primary outcome was major adverse cardiovascular event (MACE), the composite of cardiovascular death, non-fatal myocardial infarction (MI), and ischemic stroke within one year after PCI.

Results

We restricted the analyses to the first 1,452 patients who had finished one-year follow-up and complete data on genotyping and platelet aggregation. 44 (3.03%) patients suffered MACE. Among the 40 SNPs, only the A-allele carriers of CYP2C19*2 had a significant higher risk of MACE (adjusted HR 2.05; 95% CI, 1.01–4.19; p=0.048) and platelet aggregation than non-A-carriers after adjusting age, sex, MI presentation, and left ventricular ejection fraction. CYP2C19*3, CYP2B6 rs3745274, and PEAR1 rs12041331 variants were also significantly associated with platelet aggregation (all p<0.05) but not with MACE at 1 year.

Conclusion

About 54.2% of Chinese patients with PCI were A-allele carriers of CYP2C19*2, who face a two-fold higher risk of MACE than non-A-allele carriers in Chinese patients after PCI. It would help identify low clopidogrel responders and optimize antiplatelet therapy before drug administration.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Natural Science Funding of China

Electrocardiographic (ECG) predictors of major adverse cardiac events in women with ischemia and no obstructive coronary artery disease (INOCA)

Introduction

The Women's Ischemia Syndrome Evaluation (WISE) studies observed that majority of women undergoing coronary angiography for symptoms/signs of ischemia have no obstructive coronary artery disease (INOCA) but have an increased risk of major adverse cardiac events (MACE) exceeding 2.5% yearly by 5 years. Identifying modifiable and non-modifiable factors that help predict or contribute to adverse outcomes in this population is important.

Purpose

Identifying electrocardiographic predictors of MACE in women with INOCA.

Methods

In a cohort of women referred for coronary angiography between 1996–2001 for symptoms and/or signs of ischemia, 944 underwent a resting 12-lead ECG at baseline read at core lab. No obstructive CAD was found in 567/944 (60%), (mean age 55.6±11 years). Complete follow up information for MACE as (first occurrence of all-cause death, nonfatal myocardial infarction (MI), nonfatal stroke, or hospitalization for heart failure) or angina was available in 425 women.

Results

At follow up (median 5.9 years) MACE had occurred in 17.6% with angina hospitalization in 22.8% of these women. Women who experienced MACE were older (mean age 59±11 vs 55±10 years, P=0.02) and had longer corrected QT interval (mean QTc 437±29.7 vs 425±26.7 ms, P=0.001) vs. women without MACE. Diabetes, hypertension and history of smoking did not differ between MACE groups. Predictors of MACE by univariate analysis were: age at presentation (P=0.013), baseline heart rate (P=0.03), and QTc (P=0.0005). Baseline ST-T wave changes, QTc and waist circumference predicted angina hospitalization (P=0.003, 0.003 and 0.013 respectively). After adjusting for other risk factors in the multivariate analysis (see Figure) QTc, peripheral arterial disease (PAD) and current smoking were found to be independent predictors for MACE. ST-T wave changes and QTc independently predicted angina hospitalizations.

Conclusion

Among ECG findings in women with INOCA, QTc was a significant predictor of MACE and this was driven by hospitalization with angina. Ongoing ischemia likely contributes to these baseline ECG signals which could prove useful to better select subgroups for more intense anti-ischemic management.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Heart, Lung, and Blood Institute (NHLBI)

Proximal Type - Epithelioid Sarcoma- A Rare And Aggressive Soft Tissue Neoplasm

Introduction/Objective

Epithelioid Sarcoma is a rare malignant soft tissue neoplasm that is well known for local recurrence, regional lymph node involvement, and metastasis. It accounts for less than one percent of all sarcomas. Two subtypes of epithelioid sarcoma are described: the conventional or classic subtype and the proximal subtype, with the classic type being more common than the proximal type. We present a case of proximal epithelioid sarcoma involving the inguinal region, in which the patient presented with the history of weight loss for one year and a slow- growing inguinal mass for the last few months. The biopsy was done in an outside hospital and showed carcinoma of unknown origin. Imaging also failed to reveal any clear source of this mass.

Methods

The mass was resected and sent to pathology, where H&E staining and immunohistochemistry was done for diagnosis.

Results

The H&E sections of the left inguinal mass showed proliferation of large epithelioid cells with a moderate amount of cytoplasm, vesicular nuclear chromatin and prominent nucleoli. Mitosis was also seen. Necrosis was not identified. Immunohistochemical staining was done and revealed that the tumor cells were immunoreactive for epithelial marker cytokeratin AE1/AE3 and showed loss of INI-1. Tumor cells were also negative for Myogenin, ERG, HMB-45, MART-1, Myo-D1, S100, and SMA. Considering the cytomorphology and immunophenotypic findings the diagnosis of epithelioid sarcoma, proximal type was made.

Conclusion

Epithelioid sarcoma is a malignant mesenchymal neoplasm with epithelioid cytomorphology and phenotype. Among the two types of epithelioid sarcoma, the proximal type is reported about 50% less than the classic type and is associated with aggressive behavior and worse prognosis. The classic cytomorphology and immunohistochemistry findings helped us in making the diagnosis in this case.

A Comparative Analysis of Immunohistochemical Profile of Primary and Metastatic Endometrial Endometrioid Carcinoma

Introduction/Objective

Beta catenin plays an important role in cancer tumorigenesis and have been found to be associated with metastasis in a variety of tumors. Analyzing TCGA data, we found that 30% of endometrial endometrioid carcinoma cases have beta-catenin mutations. We hypothesize that beta-catenin mutation may be associated with metastasis of endometrial endometrioid carcinoma. ER and PR expression was also compared to determine any changes after metastasis.

Methods

Retrospective institutional review of all endometrial endometrioid carcinoma (192 cases) between 2011 to 2018 was performed, including 149 cases of FIGO grade I, 38 cases of FIGO grade II and 5 cases of FIGO grade III. 19 cases with paired primary and metastatic specimen were identified. Immunohistochemistry staining (IHC) was carried out for ER, PR and beta-catenin.

Results

Median patient age was 56 years. The most common metastatic site was vagina, accounting for 68% of metastasis (14/19), followed by bladder (3/19), lung (2/19) and rectum (1/19). The primary and metastatic carcinoma of all 19 cases exhibit very similar morphology. All of those cases were positive and concordant for ER and PR in primary and metastatic endometrioid carcinoma. On the other hand, nuclear beta-catenin staining caused by mutation was positive in 5 metastatic carcinoma but not in primary carcinoma.

Conclusion

IHC expression of ER and PR remains unchanged between primary and metastatic carcinoma, demonstrating the reliability of ER and PR to confirm the origin of metastatic carcinoma. 26% of the metastatic carcinoma (5/19) exhibit nuclear beta-catenin staining but not in primary carcinoma, suggesting the possible role of beta-catenin in metastasis of endometrial endometrioid carcinoma.

Structural exercise-based intervention for health problems in individuals with autism spectrum disorders: a pilot study

OBJECTIVE

Exercise-based intervention promises to be more effective in a structured framework for individuals with autism spectrum disorders (ASD). The aim of this study was to observe changes in behavior of individuals with ASD by investigating their physical status after the structured exercise-based intervention.

PATIENTS AND METHODS

The exercise intervention integrated an 8-week exercise program that included aerobic, resistive, and neuromuscular exercises. Body composition and the Autism Treatment Evaluation Checklist (ATEC) were evaluated to assess changes after the exercise-based intervention.

RESULTS

After the exercise intervention, the fat mass of individuals with ASD were significantly reduced, and their behavior improved markedly.

CONCLUSIONS

This pilot study demonstrated that individuals with ASD require long-term, structured exercise-based intervention, and that such exercise-based intervention is effective for improving their health.

[Lung cancer combined with connective tissue disease-related interstitial lung disease: CT features]

Objective: To investigate the CT features and dynamic changes of new developed lung cancer in patients with connective tissue disease-related interstitial lung disease (CTD-ILD). Methods: A series of chest CT images of 58 CTD-ILD patients during follow-up were collected. The CT features of interstitial lung disease, the initial appearance time of lung cancer, the time of diagnosis of lung cancer, the morphological characteristics (location, shape, size) of lung cancer lesions and the dynamic changes of CT features were analyzed. Results: Among 58 patients, rheumatoid arthritis was the most common (31 cases). Chest CT images showed coexistence of two or more interstitial CT signs. During the follow-up, a total of 59 lung cancer lesions were found. The median time of lung cancer lesion occurred was 289 days. The median delay in diagnosis was 43 days. There were 44 cases of non-small cell lung cancer (including 23 cases of squamous cell carcinoma and 19 cases of adenocarcinoma), 12 cases of small cell lung cancer. Forty-three (72.9%) lesions were located in the lower lobes and 41 (69.5%) lesions were located in the area of pulmonary interstitial fibrosis. According to CT morphological characteristics of lung cancer, nodular type (37 cases), inflammatory consolidation (12 cases) and intra-honeycomb type (10 cases) were identified. Conclusions: The chest CT features of patients with CTD-ILD are complex. New developed lung cancer is easily missed or misdiagnosed in the early stage. Pay attention to the special CT characteristics of CTD-ILD with lung cancer is helpful for early diagnosis.

[The clinical features and prognosis of 32 cases of pulmonary actinomycosis]

Objectives: To describe the clinical features and prognosis of pulmonary actinomycosis in a tertiary Chinese hospital. Methods: We conducted a retrospective analysis of 32 patients diagnosed with pulmonary actinomycosis between January 2013 and December 2019. General characteristics, clinical manifestations, lab data, chest CT imaging, treatment and follow-up information were reviewed and analyzed. Results: This study consisted of 19 males and 13 females, with a mean age of (58±12) years, ranging from 16 to 76 years. There were 26 cases with co-morbidities. Among them, there were 16 cases with pulmonary co-morbidity. Sixteen cases had a smoking history. Eight cases, 5 men and 3 women, with a mean age of (48±8) years, ranging from 41 to 58 years, received thoracic surgery for diagnosis. The remaining 24 cases who did not receive thoracic surgery consisted of 14 males and 8 females, with a mean age of (54±14)years, ranging from 16 to 76 years. Cough (25cases), expectoration (21 cases) and fever (16 cases) were the common clinical manifestations. The erythrocyte sedimentation rate (ESR) ranged from 2 to 114 mm/1 h, with a mean value of (28±31) mm/1 h. The ESR was elevated (>20 mm/1 h) in 15 cases. The C-reactive protein (CRP) ranged from 1 to 116 mg/L, with a mean value of (28±45) mg/L. The CRP was elevated (>8 mg/L) in 16 cases. Localized air-space consolidation (18 cases), pulmonary mass or nodules (16 cases) were the common chest CT manifestations. When compared with non-surgical cases, fever was the sole characteristic that was less common in cases with thoracic surgery (1 case in surgical group vs 11 cases in non-surgical group, P<0.05). Actinomyces spp. was found in 7 cases (87.5%) who received thoracic surgery, in 16 (61.5%) specimens collected through bronchoscopy and in 10 (55.6%) sputum samples of good quality. All of our enrolled cases were administrated with oral antibiotics, and 14 cases were prescribed with intravenous antibiotics initially. Among them, 27 cases were administrated with more than one antibiotic. Penicillin, ampicillin and amoxillin were prescribed for 25 cases. Finally, 30 cases showed improvement or cure in our hospital. Conclusions: Pulmonary actinomycosis tended to develop in aged patients with co-morbidities. Cough, expectoration, fever and localized air-space consolidation were the common clinical and radiological manifestations, respectively. Actinomyces spp. could be found more easily in the surgically resected tissues than other specimens. The prognosis of our enrolled cases was good after treatment with combined antibiotics.

MFN2 contributes to metabolic disorders and inflammation in the aging of rat chondrocytes and osteoarthritis

OBJECTIVE

Metabolic disorders and inflammation of chondrocytes are major pathological changes in aging cells and osteoarthritis (OA). Recent studies demonstrated age-related mitochondrial dysfunction may be a key contributing factor in the development of OA. Mitofusin 2 (MFN2) is a key regulator of mitochondrial fusion, cell metabolism, autophagy and apoptosis. This study was performed to ascertain whether MFN2 was involved in the aging of chondrocytes and OA.

METHODS

Metabolic measurements were taken in rat chondrocytes between different ages (3-week, 5-month, 12-month). MFN2 activity was detected in both human and rat chondrocytes during aging and OA. Then, knockdown of MFN2 with small interfering RNA (siRNA) was performed to confirm whether MFN2 contributes to metabolic changes. Lentiviruses were used to establish MFN2-overexpression/knockdown OA models both in vivo and in vitro to confirm whether MFN2 contributes to OA progress. Further, regulatory mechanism of MFN2 was assessed and interaction between MFN2 and PARKIN was performed.

RESULTS

A metabolic shift to mitochondrial respiration was confirmed in rat chondrocytes during aging. MFN2 expression was elevated in both human and rat chondrocytes during aging and OA. Knockdown of MFN2 with siRNA reversed the age-related metabolic changes in rat chondrocytes. Overexpression of MFN2 exacerbated inflammation and OA progress, while knockdown of MFN2 ameliorated inflammation and OA progress. Further, MFN2 could be ubiquitinated by PARKIN, declined PARKIN expression during aging and OA might result in elevated MFN2 expression.

CONCLUSIONS

Elevated MFN2 contributes to metabolic changes and inflammation during aging of rat chondrocytes and osteoarthritis.

MiR-663a, regulated by lncRNA GAS5, contributes to osteosarcoma development through targeting MYL9

Osteosarcoma is characterized by high malignancy and high metastasis rate, resulting in high mortality and disability. MiR-663a has been reported in a variety of tumors to promote tumorigenesis. However, miR-663a has not been reported in the pathogenesis of osteosarcoma. Bioinformatics analysis and experiments including real-time quantitative polymerase chain reaction (RT-qPCR), luciferase reporter, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Western blot, RNA immunoprecipitation, and flow cytometry assay were applied to explore the function and mechanism of miR-663a in MG63, U2OS, Saos-2, SF-86, and hFOB1.19 cells. In this study, we found that miR-663a is highly expressed in osteosarcoma. At the same time, we discovered that miR-663a facilitates cell proliferation and migration, whereas suppresses cell apoptosis in osteosarcoma. Through a series of biological experiments, it was found that miR-663a regulates the cellular process in osteosarcoma by modulating the expression of MYL9. In addition, we also found that long noncoding RNA (lncRNA) GAS5 serves as a molecular sponge for miR-663a and regulates the progression of osteosarcoma via the ceRNA mechanism. We uncover that miR-663a promotes osteosarcoma development through targeting MYL9, which was regulated by lncRNA GAS5.

New Insights Into the Virus-to-Prokaryote Ratio (VPR) in Marine Sediments

The virus-to-prokaryote ratio (VPR), which reflects the numerical dominance of viruses over their hosts, has been proposed as a proxy for assessing the relationship between viruses and prokaryotes. Previous studies showed that VPR values fluctuate over six orders of magnitude within and across various benthic ecosystems, with an average value of approximately 10. We hypothesize that this high VPR value is largely due to the inaccurate enumeration of viruses and prokaryotes (e.g., centrifugation treatments may lead to a three-fourfold overestimation of VPR). In this study, we evaluated the impact of processing methods on the determination of VPR values. Using an optimized procedure, we investigated the marine benthic VPR at 31 sites, from intertidal zones through continental shelves to abyssal plains, and assessed its monthly variation in two contrasting intertidal habitats (muddy-sand and sandy). By compiling 135 VPR data points of surface sediments from 37 publications, we reveal the effect of centrifugation on published VPR values and describe the spatial distribution of VPR values on a larger scale based on reliable data. The results showed that the commonly used centrifugation method may result in an overestimation of VPR values that are approximately one order of magnitude higher than those obtained using the dilution method, while other processing steps had a limited impact on the VPR. Our analysis indicates that the benthic VPR value is low and less varied across temporal and spatial scales, fluctuating mostly within 10, and the average VPR is approximately 2 in both marine and freshwater habitats. An insignificant seasonal pattern in the VPR was observed in the intertidal zone, with lower VPR values occurring at high temperatures. The VPR spatial distribution was primarily associated with sediment phaeophytin a, suggesting that the trophic conditions of the upper water column and the sedimentation of organic matter to the bottom are the key factors affecting VPR values. The mean VPR in benthic habitats is approximately one order of magnitude lower and much less varied than that observed in pelagic habitats, indicating that the virus-host relationship and the ecological function of viruses in the two ecosystems may be very different.