Identification and Verification of Endoplasmic Reticulum Stress-Related Genes as Novel Signatures for Osteoarthritis Diagnosis and Therapy: A Bioinformatics Analysis-Oriented Pilot Study.

BACKGROUND AND PURPOSE: Endoplasmic reticulum stress (ERS) has been reported to be closely associated with the development of osteoarthritis (OA), but the underlying mechanisms are not fully delineated. The present study was designed to investigate the involvement of ERS-related genes in regulating OA progression. METHODS: The expression profiles of OA patients and normal people were downloaded from the gene expression omnibus (GEO) database. The differentially expressed genes (DEGs) in datasets GSE55457 and GSE55235 were screened and identified by R software with the construction of the protein-protein interaction (PPI) networks. Through the STRING and Venn diagram analysis, hub ERS-related genes were obtained. Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses were performed. Biomarkers with high diagnostic values of osteoarthritis (OA) were studied. The hematoxylin and eosin (H&E) staining and micro-CT were applied to evaluate the establishment of the OA model. The expression levels of biomarkers were validated with the use of reverse transcription­quantitative polymerase chain reaction (RT-qPCR) and western blot. Finally, we evaluated the correlations of hub ERS-related genes with the immune infiltration cells via the CIBERSORT algorithm. RESULTS: A total of 60 downregulated and 52 upregulated DEGs were identified, and the following GO and KEGG pathway analyses verified that those DEGs were mainly enriched in biological process (BP), cellular component (CC), molecular function (MF), and inflammation-associated signal pathways. Interestingly, among all the DEGs, six ER stress-associated genes, including activating transcription factor 3 (ATF3), DEAD-Box Helicase 3 X-Linked (DDX3X), AP-1 transcription factor subunit (JUN), eukaryotic initiation factor 4 (EIF4A1), KDEL endoplasmic reticulum protein retention receptor 3 (KDELR3), and vascular endothelial growth factor A (VEGFA), were found to be closely associated with OA progression, and the following RT-qPCR and Western Blot analysis confirmed that DDX3X, JUN, and VEGFA were upregulated, whereas KDELR3, EIF4A1, and ATF3 were downregulated in OA rats tissues compared to the normal tissues, which were in accordance with our bioinformatics findings. Furthermore, our receiver operating characteristic (ROC) curve analysis verified that the above six ER stress-associated genes could be used as ideal biomarkers for OA diagnosis and those genes also potentially regulated immune responses by influencing the biological functions of mast cells and macrophages. CONCLUSION: Collectively, the present study firstly identified six ER stress-associated genes (ATF3, DDX3X, JUN, EIF4A1, KDELR3, and VEGFA) that may play critical role in regulating the progression of OA.

FGF1 reduces cartilage injury in osteoarthritis via regulating AMPK/Nrf2 pathway.

Osteoarthritis (OA) is a systemic joint degenerative disease involving a variety of cytokines and growth factors. In this study, we investigated the protective effect of fibroblast growth factor 1 (FGF1) knockdown on OA and its underlying mechanisms in vitro. In addition, we evaluated the effect of FGF1 knockout on the destabilization of the medial meniscus (DMM) and examined the anterior and posterior cruciate ligament model in vivo. FGF1 affects OA cartilage destruction by increasing the protein expression of Nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1), which is associated with the phosphorylation of AMPK and its substrates. Our study showed that FGF1 knockdown could reverse the oxidative damage associated with osteoarthritis. Nrf2 knockdown eliminated the antioxidant effect of FGF1 knockdown on chondrocytes. Furthermore, AMPK knockdown could stop the impact of FGF1 knockdown on osteoarthritis. These findings suggested that FGF1 knockdown could effectively prevent and reverse osteoarthritis by activating AMPK and Nrf2 in articular chondrocytes.

Meglumine cyclic adenylate improves cardiovascular hemodynamics and motor-function in a rat model of acute T4 thoracic spinal cord injury.

STUDY DESIGN: Animal experimental study. OBJECTIVES: Spinal cord injury (SCI) at or above the T6 level causes cardiovascular dysfunction. Maintaining cAMP levels with cAMP analogs can facilitate neurological recovery. In the present study, the effects of meglumine cyclic adenylate (MCA), a cAMP analog and approved cardiovascular drug, on cardiovascular and neurological recovery in acute T4-SCI in rats were investigated. SETTING: Hospital in Kunming, China. METHODS: Eighty rats were randomly allocated to five groups, and groups A-D received SCI: (A) a group administered MCA at 2 mg/kg/d iv qd, (B) a group administered dopamine at 2.5 to 5 µg/kg/min iv to maintain mean arterial pressure above 85 mm Hg, (C) a group administered atropine at 1 mg/kg iv bid, (D) a group receiving an equal volume of saline iv qd for 3 weeks after SCI and (E) a group undergoing laminectomy only. The cardiovascular and behavioral parameters of the rats were examined, and spinal cord tissues were processed for hematoxylin and eosin staining, Nissl staining, electron microscopy, and analysis of cAMP levels. RESULTS: Compared with dopamine or atropine, MCA significantly reversed the decrease in cAMP levels in both myocardial cells and the injured spinal cord; improved hypotension, bradycardia and behavioral parameters at 6 weeks; and improved spinal cord blood flow and histological structure at 7 days post-SCI. The regression analysis suggested spinal cord motor-function improved as decreased heart rate and mean arterial pressure were stopped post-SCI. CONCLUSIONS: MCA may be an effective treatment for acute SCI by sustaining cAMP-dependent reparative processes and improving post-SCI cardiovascular dysfunction. SPONSORSHIP: N/A.

Efficient near-infrared broadband garnet phosphor for pc-LED and its application to vascular visualization and night vision.

Ultra-broadband near-infrared (NIR) spectroscopy has unparalleled application prospects in intelligent detection and phosphor-converted light-emitting diodes (pc-LED), which are most likely to become the next generation of NIR light sources, has become a hot spot for research nowadays. To cope with the demand for more NIR spectroscopy applications, more efficient NIR phosphors need to be developed. Here, by screening the subject with a smaller band gap and by screening the suitable ion electronegativity of the lattice position where the Cr3+ is located, and then through the energy transfer, a series of Gd3Zn2GaGe2O12:xCr3+, yYb3+ (GZGG:Cr3+/Yb3+) NIR broadband garnet phosphors were found for the first time. By controlling the energy transfer process, the internal quantum yield (IQY) (54.9%), external quantum yield (EQY) (24.65%), bandwidth (260 nm), and thermal stability (60% at 150 °C) of NIR emission were substantially improved. The obtained phosphors are packaged with blue light chips into pc-LED, which can be applied in different fields such as vascular visualization and night vision.

Near-Infrared Broadband ZnTa2O6:Cr3+ Phosphor for pc-LEDs and Its Application to Nondestructive Testing.

Broadband near-infrared (NIR) phosphors are necessary materials for developing portable NIR light sources. Moreover, exploiting an NIR phosphor with a main peak located beyond a wavelength of 900 nm remains a challenge because this spectral range has great potential in biological nondestructive testing and solution testing. In this study, a range of Cr3+-doped ZnTa2O6 (ZTO) phosphors were completely synthesized by a solid-state method, which show broadband Cr3+ emission centered at 935 nm with a large full width at half maximum (FWHM) of 185 nm due to two distorted octahedral sites. A packaged phosphor-converted light-emitting diode (pc-LED) device is used to penetrate a 5-cm-thick chicken breast and identify diverse solutions based on differences in the measured transmission spectra. The results indicate broad application prospects in the field of biological tissue penetration and solution analysis.

Chromium(III)-Doped Phosphors of High-Efficiency Two-Site Occupation Broadband Infrared Emission for Vessel Visualization Applications.

The exploration of efficient broadband near-infrared (NIR) emitting materials is essential to establishing new NIR applications. In this work, an excellent NIR phosphor Mg7Ga2GeO12:Cr3+, with an emission band of 650-1350 nm and a full width at half maximum of 266 nm, was successfully prepared. When Ga3+ ions were replaced by In3+ ions, its emission intensity increased 4 times, and the internal and external quantum efficiency reached 86 and 37%, respectively. A NIR phosphor-converted light-emitting diode (pc-LED) component was made by combining a synthetic Mg7Ga1.84In0.07GeO12:0.09Cr3+ phosphor with a 450 nm blue luminescent chip. The vascular and skeletal distribution on human fingers and the back of the hand can be seen under the display of a commercial NIR camera, indicating that Mg7Ga1.84In0.07GeO12:0.09Cr3+ phosphors have promising applications in the field of the blood vessel and bone visualization.

Ultra-sensitive luminescence ratiometric thermometry from 2E→4A2 transitions of AlTaO4:Cr3.

In recent years, non-contact ratiometric luminescence thermometry has continued to gain popularity among researchers, owing to its compelling features, such as high accuracy, fast response, and convenience. The development of novel optical thermometry with ultrahigh relative sensitivity (Sr) and temperature resolution has become a frontier topic. In this work, we present a novel, to the best of our knowldege, luminescence intensity ratio (LIR) thermometry method that relies on AlTaO4:Cr3+ materials, based on the fact that they possess both anti-Stokes phonon sideband emission and R-line emission at the 2E→4A2 transitions and have been confirmed to follow the Boltzmann distribution. In the temperature range 40-250 K, the emission band of the anti-Stokes phonon sideband shows an upward trend, while the bands of the R-lines show the opposite downward trend. Relying on this fascinating feature, the newly proposed LIR thermometry achieves a maximum relative sensitivity of 8.45%K-1 and a temperature resolution of 0.038 K. Our work is expected to provide guiding insights for optimizing the sensitivity of Cr3+-based LIR thermometers and provide some novel entry points for designing excellent and reliable optical thermometers.

LINC01534 Promotes the Aberrant Metabolic Dysfunction and Inflammation in IL-1ß-Simulated Osteoarthritic Chondrocytes by Targeting miR-140-5p.

OBJECTIVE: Long non-coding RNA 01534 (LINC01534) is highly expressed in the tissues of patients with osteoarthritis (OA). This study investigated the mechanism of LINC01534 on abnormal metabolic dysfunction in OA chondrocytes induced by interleukin-1ß (IL-1ß). METHODS: The quantitative real-time polymerase chain reaction (qRT-PCR) was used to determine the expressions of LINC01534, aggrecan, collagen II, and matrix metalloproteinase (MMPs) in OA cartilage tissue or OA chondrocyte model induced by IL-1ß. The expressions of aggrecan and collagen II in the chondrocyte were detected by Western blot. The levels of tumor necrosis factor-α (TNF-α), IL-8, IL-6, MMP-13, MMP-9, MMP-3, and prostaglandin E2 (PGE2) in chondrocyte were determined by enzyme-linked immunosorbernt assay. Bioinformatics, dual luciferin gene reporting, RNA pulldown, and Northern blot were used to determine the interaction between LINC01534 and miR-140-5p. RESULTS: The results showed that LINC01534 was upregulated in both OA cartilage tissue and OA chondrocyte model. In addition, silencing LINC01534 significantly alleviated the inhibitory effect of IL-1ß on expressions of aggrecan and collagen II in chondrocytes, and significantly downregulated the expression of matrix metalloproteinases in IL-1ß-induced chondrocytes. Meanwhile, silencing LINC01534 also significantly inhibited the productions of proinflammatory factors NO, PGE2, TNF-α, IL-6, and IL-8 in the IL-1ß-induced chondrocytes. Furthermore, miR-140-5p was confirmed to be a direct target of LINC01534. More importantly, inhibition of miR-140-5p significantly reversed the inhibitory effect of silencing LINC01534 on abnormal matrix degradation in the IL-1ß-induced chondrocyte model of OA. CONCLUSION: Therefore, LINC01534 could promote the abnormal matrix degradation and inflammatory response of OA chondrocytes through the targeted binding of miR-140-5p.

MicroRNA-92a-3p enhances functional recovery and suppresses apoptosis after spinal cord injury via targeting phosphatase and tensin homolog.

Spinal cord injury (SCI) is a neurological disease commonly caused by traumatic events on spinal cords. MiRNA-92a-3p is reported to be down-regulated after SCI. Our study investigated the effects of up-regulated miR-92a-3p on SCI and the underlying mechanisms. SCI mice model was established to evaluate the functional recovery of hindlimbs of mice through open-field locomotion and scored by Basso, Beattie, and Bresnahan (BBB) locomotion scale. Apoptosis of spinal cord cells was determined by flow cytometry. The effects of miR-92a-3p on SCI were detected by intrathecally injecting miR-92a-3p agomiR (agomiR-92) into the mice prior to the establishment of SCI. Phosphatase and tensin homolog (PTEN) was predicted as a target of miR-29a-3p by TargetScan. We further assessed the effects of agomiR-92 or/and overexpressed PTEN on apoptosis rates and apoptotic protein expressions in SCI mice. Moreover, the activation of protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling was determined by Western blot. The results showed that compared with the sham-operated mice, SCI mice had much lower BBB scores, and theapoptosis rate of spinal cord cells was significantly increased. After SCI, the expression of miR-92a-3p was down-regulated, and increased expression of miR-92a-3p induced by agomiR-92 further significantly increased the BBB score and decreased apoptosis. PTEN was specifically targeted by miR-92a-3p. In addition, the phosphorylation levels of Akt and mTOR were up-regulated under the treatment of agomiR-92. Our data demonstrated that the neuroprotective effects of miR-92a-3p on spinal cord safter SCI were highly associated with the activation of the PTEN/AKT/mTOR pathway.

MiR-217 Inhibits Proliferation, Migration, and Invasion by Targeting SIRT1 in Osteosarcoma.

Purpose: Many studies have revealed that microRNAs (miRNAs) play crucial roles in cancer development and progression. miRNA-217 (miR-217) has been implicated in various cancers. However, the role of miR-217 in osteosarcoma (OS) remains unclear. In this study, the authors examined the role of miR-217 in development of OS. Materials and Methods: Using quantitative real-time PCR, they assessed expression levels of miR-217 in cultured cells and patient samples and examined the proliferation, migration, and invasion of cultured cells by MTT cell proliferation assays, cell scratch test, and cell transwell test. The proliferation, migration, and invasion were examined for MG63 and U2OS transfected by miR-217. Silent information regulator 2 homolog 1 (SIRT1) overexpression plasmid was designed. Results: Expression of miR-217 was downregulated in samples of OS tissue and cultured cells. Proliferation, migration, and invasion were inhibited by ectopic overexpression of miR-217. SIRT1 was identified as targets of miR-217. Expression levels of SIRT1 were inhibited by miR-217 expression in cultured cells, and the expression levels of miR-217 and SIRT1 were inversely correlated in patients with OS. Conclusion: MiR-217 acts as a tumor suppressor in the development of OS. The tumor-suppressive function of miR-217 in OS suggests inhibition of SIRT1.

A tyrosine aminotransferase involved in rosmarinic acid biosynthesis in Prunella vulgaris L.

Rosmarinic acid (RA) and its derivants are medicinal compounds that comprise the active components of several therapeutics. We isolated and characterised a tyrosine aminotransferase of Prunella vulgaris (PvTAT). Deduced PvTAT was markedly homologous to other known/putative plant TATs. Cytoplasmic localisation of PvTAT was observed in tobacco protoplasts. Recombinantly expressed and purified PvTAT had substrates preference for L-tyrosine and phenylpyruvate, with apparent K m of 0.40 and 0.48 mM, and favoured the conversion of tyrosine to 4-hydroxyphenylpyruvate. In vivo activity was confirmed by functional restoration of the Escherichia coli tyrosine auxotrophic mutant DL39. Agrobacterium rhizogenes-mediated antisense/sense expression of PvTAT in hairy roots was used to evaluate the contribution of PvTAT to RA synthesis. PvTAT were reduced by 46-95% and RA were decreased by 36-91% with low catalytic activity in antisense transgenic hairy root lines; furthermore, PvTAT were increased 0.77-2.6-fold with increased 1.3-1.8-fold RA and strong catalytic activity in sense transgenic hairy root lines compared with wild-type counterparts. The comprehensive physiological and catalytic evidence fills in the gap in RA-producing plants which didn't provide evidence for TAT expression and catalytic activities in vitro and in vivo. That also highlights RA biosynthesis pathway in P. vulgaris and provides useful information to engineer natural products.

Artemisia dominant species succession relating to the soil moisture decrease in abandoned land of the Loess Plateau (China): comparative study of drought-adaptive characteristics.

Artemisia scoparia, Artemisia sacrorum and Artemisia giraldii were three dominant Artemisia species which successive grew in the secondary succession on abandoned land of the Loess Plateau. The succession accompanied the soil moisture steady decrease with field age after their abandonment. To elucidate the relationship between the Artemisia species succession and their drought-adaptation, three dominant species and a contrastive species Artemisia annua (mesophyte), were selected to compare their drought-resistant characteristics, including morphological and anatomical traits of leaf and root. Then physiological responses were investigated in mature plants after drought treatment. The results indicated that three dominant species leaf presented drought-adaptive structures, such as bushy trichomes, transitional or isolateral leaf cells, thick cuticles and epidermal cells. However, A. annua had no leaf traits involved in drought-adaptation. In addition, A. sacrorum and A. giraldii contained large root systems, while A. scoparia and A. annua utilized succulent roots. The physiological responses to drought suggested that A. giraldii had strong regulation in water using strategy, growth, as well as superoxide dismutase and catalase activity. A. sacrorum and A. giraldii could maintain high ascorbate peroxidase activity and malondialdehyde content, while A. scoparia and A. giraldii presented higher peroxidase activity, ascorbate and soluble sugar content. A. annua exhibited high proline and carotenoid contents under drought. The drought-resistant of the four Artemisia species presented the order of A. giraldii > A. sacrorum > A. scoparia > A. annua, which was consistent with their succession on abandoned land.