Xiaojuan He

Aptamer-functionalized lipid nanoparticles targeting osteoblasts as a novel RNA interference–based bone anabolic strategy

Currently, major concerns about the safety and efficacy of RNA interference (RNAi)-based bone anabolic strategies still exist because of the lack of direct osteoblast-specific delivery systems for osteogenic siRNAs. Here we screened the aptamer CH6 by cell-SELEX, specifically targeting both rat and human osteoblasts, and then we developed CH6 aptamer–functionalized lipid nanoparticles (LNPs) encapsulating osteogenic pleckstrin homology domain-containing family O member 1 (Plekho1) siRNA (CH6-LNPs-siRNA). Our results showed that CH6 facilitated in vitro osteoblast-selective uptake of Plekho1 siRNA, mainly via macropinocytosis, and boosted in vivo osteoblast-specific Plekho1 gene silencing, which promoted bone formation, improved bone microarchitecture, increased bone mass and enhanced mechanical properties in both osteopenic and healthy rodents. These results indicate that osteoblast-specific aptamer-functionalized LNPs could act as a new RNAi-based bone anabolic strategy, advancing the targeted delivery selectivity of osteogenic siRNAs from the tissue level to the cellular level.

Osteoclast-derived exosomal miR-214-3p inhibits osteoblastic bone formation.

Emerging evidence indicates that osteoclasts direct osteoblastic bone formation. MicroRNAs (miRNAs) have a crucial role in regulating osteoclast and osteoblast function. However, whether miRNAs mediate osteoclast-directed osteoblastic bone formation is mostly unknown. Here, we show that increased osteoclastic miR-214-3p associates with both elevated serum exosomal miR-214-3p and reduced bone formation in elderly women with fractures and in ovariectomized (OVX) mice. Osteoclast-specific miR-214-3p knock-in mice have elevated serum exosomal miR-214-3p and reduced bone formation that is rescued by osteoclast-targeted antagomir-214-3p treatment. We further demonstrate that osteoclast-derived exosomal miR-214-3p is transferred to osteoblasts to inhibit osteoblast activity in vitro and reduce bone formation in vivo. Moreover, osteoclast-targeted miR-214-3p inhibition promotes bone formation in ageing OVX mice. Collectively, our results suggest that osteoclast-derived exosomal miR-214-3p transfers to osteoblasts to inhibit bone formation. Inhibition of miR-214-3p in osteoclasts may be a strategy for treating skeletal disorders involving a reduction in bone formation.

Inhibitory effect of Astragalus polysaccharides on lipopolysaccharide-induced TNF-a and IL-1β production in THP-1 cells.

Astragalus polysaccharides (APS), one of main bioactive components in Astragalus membranaceus Bunge, has been reported to possess anti-inflammatory activities, but the molecular mechanisms behind this activity are largely unknown. This study aimed to investigate expression of inflammatory cytokines and the MAPK/NF-κB pathway in human THP-1 macrophages induced by lipopolysaccharide (LPS). The results showed that the concentrations of TNF-α and IL-1β released from LPS stimulated THP-1 cells increased significantly compared to control (p < 0.01). After treatment with APS, the TNF-α and IL-1β levels were significantly lower than those in the LPS group (p < 0.05). The mRNA expression of TNF-α and IL-1β were also inhibited. Mechanistic studies indicated that APS strongly suppressed NF-κB activation and down-regulated the phosphorylation of ERK and JNK, which are important signaling pathways involved in the production of TNF-α and IL-1β, demonstrating that APS could suppress the production of TNF-α and IL-1β by LPS stimulated macrophages by inhibiting NF-κB activation and ERK and JNK phosphorylation.

Anti-oxidative and TNF-α suppressive activities of puerarin derivative (4AC) in RAW264.7 cells and collagen-induced arthritic rats

Puerarin is a major active ingredient extracted from the root of P. lobata, a traditional Chinese herb, and possesses anti-oxidative and anti-inflammatory activities. However, the low oral bioavailability of puerarin limits its further application. Therefore, we synthesized tetraacetyl puerarin (4AC) through acetylation to improve its liposolubility and bioavailability. In the present investigations, we tested the anti-oxidative and TNF-α suppressive activity of 4AC in lipopolysaccharide (LPS)-induced RAW264.7 macrophages and bovine type II collagen-induced arthritic (CIA) rats. The results showed that 4AC retained the bioactivity of puerarin. And 4AC significantly increased the activity of SOD and reduced the level of MDA both in vitro and in vivo. It also improved the level of GSH-PX and the total antioxidant capacity in vivo. Furthermore, it dramatically decreased TNF-α level in the cultured supernatant of RAW264.7 cells treated with LPS and in the serum of CIA rats. These initial results indicated that 4AC had a potential therapeutic effect on CIA rats through an anti-oxidative and TNF-α suppressive activity. In addition, the molecular mechanism of anti-oxidation of 4AC was explored by testing the MAPKs/NF-κB signaling pathway. The results showed that 4AC significantly inhibited NF-κB expression and down-regulated the levels of p-ERK and p-JNK in LPS-activated RAW264.7 cells. These results indicated that 4AC had bioactive anti-oxidative effects and suggest the potential value of 4AC for the treatment of rheumatoid arthritis.

Serum Metabolic Signatures of Four Types of Human Arthritis

Similar symptoms of the different types of arthritis have continued to confound the clinical diagnosis and represent a clinical dilemma making treatment choices with a more personalized or generalized approach. Here we report a mass spectrometry-based metabolic phenotyping study to identify the global metabolic defects associated with arthritis as well as metabolic signatures of four major types of arthritis--rheumatoid arthritis (n = 27), osteoarthritis (n = 27), ankylosing spondylitis (n = 27), and gout (n = 33)--compared with healthy control subjects (n = 60). A total of 196 metabolites were identified from serum samples using a combined gas chromatography coupled with time-of-flight mass spectrometry (GC-TOF MS) and ultraperformance liquid chromatography quadrupole-time-of-flight mass spectrometry (UPLC-QTOF MS). A global metabolic profile is identified from all arthritic patients, suggesting that there are common metabolic defects resulting from joint inflammation and lesion. Meanwhile, differentially expressed serum metabolites are identified constituting an unique metabolic signature of each type of arthritis that can be used as biomarkers for diagnosis and patient stratification. The results highlight the applicability of metabonomic phenotyping as a novel diagnostic tool for arthritis complementary to existing clinical modalities.

Present Advances and Future Perspectives of Molecular Targeted Therapy for Osteosarcoma

Osteosarcoma (OS) is a bone cancer mostly occurring in pediatric population. Current treatment regime of surgery and intensive chemotherapy could cure about 60%–75% patients with primary osteosarcoma, however only 15% to 30% can be cured when pulmonary metastasis or relapse has taken place. Hence, novel precise OS-targeting therapies are being developed with the hope of addressing this issue. This review summarizes the current development of molecular mechanisms and targets for osteosarcoma. Therapies that target these mechanisms with updated information on clinical trials are also reviewed. Meanwhile, we further discuss novel therapeutic targets and OS-targeting drug delivery systems. In conclusion, a full insight in OS pathogenesis and OS-targeting strategies would help us explore novel targeted therapies for metastatic osteosarcoma.

Progress and Challenges in Developing Aptamer-Functionalized Targeted Drug Delivery Systems

Aptamers, which can be screened via systematic evolution of ligands by exponential enrichment (SELEX), are superior ligands for molecular recognition due to their high selectivity and affinity. The interest in the use of aptamers as ligands for targeted drug delivery has been increasing due to their unique advantages. Based on their different compositions and preparation methods, aptamer-functionalized targeted drug delivery systems can be divided into two main categories: aptamer-small molecule conjugated systems and aptamer-nanomaterial conjugated systems. In this review, we not only summarize recent progress in aptamer selection and the application of aptamers in these targeted drug delivery systems but also discuss the advantages, challenges and new perspectives associated with these delivery systems.

Triptolide Modulates TREM-1 Signal Pathway to Inhibit the Inflammatory Response in Rheumatoid Arthritis

Triptolide (TP), an active component isolated from Tripterygiumwilfordii Hook F, has therapeutic potential against rheumatoid arthritis (RA). However, the underlying molecular mechanism has not been fully elucidated. The aim of this study is to investigate the mechanisms of TP acting on RA by combining bioinformatics analysis with experiment validation. The human protein targets of TP and the human genes of RA were found in the PubChem database and NCBI, respectively. These two dataset were then imported into Ingenuity Pathway Analysis (IPA) software online, and then the molecular network of TP on RA could be set up and analyzed. After that, both in vitro and in vivo experiments were done to further verify the prediction. The results indicated that the main canonical signal pathways of TP protein targets networks were mainly centered on cytokine and cellular immune signaling, and triggering receptors expressed on myeloid cells (TREM)-1 signaling was searched to be the top one shared signaling pathway and involved in the cytokine and cellular immune signaling. Further in vitro experiments indicated that TP not only remarkably lowered the levels of TREM-1 and DNAX-associated protein (DAP)12, but also significantly suppressed the activation of janus activating kinase (JAK)2 and signal transducers and activators of transcription (STAT)3. The expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 in lipopolysaccharides (LPS)-stimulated U937 cells also decreased after treatment with TP. Furthermore, TREM-1 knockdown was able to interfere with the inhibition effects of TP on these cytokines production. In vivo experiments showed that TP not only significantly inhibited the TREM-1 mRNA and DAP12 mRNA expression, and activation of JAK2 and STAT3 in ankle of rats with collagen-induced arthritis (CIA), but also remarkably decreased production of TNF-α, IL-1β and IL-6 in serum and joint. These findings demonstrated that TP could modulate the TREM1 signal pathway to inhibit the inflammatory response in RA.

Down-regulation of Treg cells and up-regulation of TH1/TH2 cytokine ratio were induced by polysaccharide from Radix Glycyrrhizae in H22 hepatocarcinoma bearing mice

Radix Glycyrrhizae polysaccharide (GP) possesses multiple pharmacological activities. However, the effect of GP on CD4+CD25+ regulatory T (Treg) cells has not been elucidated. This study aimed to investigate the effects of GP on Treg cells and Th1/Th2 cytokines in H22 hepatocarcinoma tumor-bearing mice. The results demonstrated that GP inhibits tumor progression. In the lymph nodes of the tumor microenvironment and spleen, the proportion of Treg cells was significantly higher in the tumor-bearing mice. GP administration down-regulated the population of Treg cells (P < 0.01) and decreased lymph node Foxp3 and IL-10 mRNA expression (P < 0.01). In addition, GP treatment decreased IL-10 and TGF-β level (P < 0.01) and increased IL-2 and IL-12p70 level in serum (P < 0.01). In conclusion, GP reduced the proportion of Treg cells and Foxp3 lowered expression in Treg cells, and up-regulated Th1/Th2 cytokine ratio in serum in the tumor bearing mice, which might partially cause the inhibition of tumor growth.

Comparison of toxic reaction of Tripterygium wilfordii multiglycoside in normal and adjuvant arthritic rats.

AIM OF THE STUDY Tripterygium wilfordii multiglycoside (GTW), an authorized Chinese patent drug, is used for treatment of rheumatoid arthritis and other immune disease. This study was to determine whether GTW induced different toxic reactions in adjuvant arthritis rats (AA rats) compared to those in normal rats. MATERIALS AND METHODS To prepare arthritic rat model, male Sprague-Dawley (SD) rats were immunized by injecting complete Freunds Adjuvant into right hind footpad. And then, GTW was given to rats intragastrically at dosage of 7 or 105 mg kg(-1)day(-1) from day 15 to day 28 after immunization. Routine clinical parameters and histopathologic changes of liver, kidney and testis were examined. Metabolic profiling in serum of groups was analyzed by LC-MS. A principal component analysis (PCA) and partial-least-squares discriminate analysis (PLS-DA) were carried out combined with mass spectrometry (MS) data set. All the quantitative data were performed by two-way ANOVA analysis following Students t-test. RESULTS AND CONCLUSIONS Treatment with GTW at both doses could diminish the right and left hind paws swelling. There was slight lipoid degeneration in hepatic tissue of normal rats treated by high dose of GTW, but there were not distinctly pathological changes in hepatic tissue of AA rats treated by GTW. Compared normal rats administered with GTW, no statistically significant difference in the serum alanine aminotransferase (ALT), creatinine (CRE), and blood urea nitrogen (BUN) levels were observed. However, the serum aspartate aminotransferase (AST) level was significant decreased in AA rats under exposure GTW compared with normal rats in the same conditions (p<0.05), which indicated that GTW could offer a different liver toxic reaction in normal and AA rats. The metabolic analysis showed that a clear separation of PCA and PLS-DA score spot in normal rats, but not separation was seen in AA rats perturbed with low dosage GTW. The result indicated low dosage GTW might arouse a general toxic in normal rats but not in AA rats. The biomarker analysis showed that the level of lysophosphatidylcholines (LPCs) was down-regulated, but the level of ursodeoxycholic acid (UDCA) and chenodexycholic acid (CDCA) was up-regulated in AA rats compared with normal rats under exposure GTW. According to pathway analysis of metabolic markers, we conceived that LPC, UDCA and CDCA were the critical intermediates of choline and fatty acid metabolism. And the lipid metabolism was a correlative outcome of GTW induced toxicity in the liver in physiological condition animals. Taken together, GTW could induce different toxic reactions between normal and AA rats, and the lipid metabolism might be part of the mechanism for the hepatic lipidosis or the other liver injury.