scholarly journals Theaflavin-3,3′-Digallate Promotes the Formation of Osteoblasts Under Inflammatory Environment and Increases the Bone Mass of Ovariectomized Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Gaoran Ge ◽  
Sen Yang ◽  
Zhenyang Hou ◽  
Minfeng Gan ◽  
Huaqiang Tao ◽  
...  

Postmenopausal osteoporosis is a disease of bone mass reduction and structural changes due to estrogen deficiency, which can eventually lead to increased pain and fracture risk. Chronic inflammatory microenvironment leading to the decreased activation of osteoblasts and inhibition of bone formation is an important pathological factor that leads to osteoporosis. Theaflavin-3,3′-digallate (TFDG) is an extract of black tea, which has potential anti-inflammatory and antiviral effects. In our study, we found that TFDG significantly increased the bone mass of ovariectomized (OVX) mice by micro-CT analysis. Compared with OVX mice, TFDG reduced the release of proinflammatory cytokines and increased the expression of osteogenic markers in vivo. In vitro experiments demonstrated that TFDG could promote the formation of osteoblasts in inflammatory environment and enhance their mineralization ability. In this process, TFDG activated MAPK, Wnt/β-Catenin and BMP/Smad signaling pathways inhibited by TNF-α, and then promoted the transcription of osteogenic related factors including Runx2 and Osterix, promoting the differentiation and maturation of osteoblasts eventually. In general, our study confirmed that TFDG was able to promote osteoblast differentiation under inflammatory environment, enhance its mineralization ability, and ultimately increase bone mass in ovariectomized mice. These results suggested that TFDG might have the potential to be a more effective treatment of postmenopausal osteoporosis.

2019 ◽  
Vol 10 (10) ◽  
pp. 6556-6567 ◽  
Author(s):  
Haiming Jin ◽  
Zhenxuan Shao ◽  
Qingqing Wang ◽  
Jiansen Miao ◽  
Xueqin Bai ◽  
...  

Postmenopausal osteoporosis (PMO) is a progressive disease occurring in elderly postmenopausal women that is characterized by low bone mass and impaired bone quality.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Gyhye Yoo ◽  
Ji-Hye Park ◽  
Yang-Ju Son ◽  
Chang Ho Lee ◽  
Chu Won Nho

Abstract Objectives Postmenopausal osteoporosis, a condition of low bone density consequent to decreased estrogen levels after menopause in women, is generally treated with hormone replacement therapy. However, long-term hormone use may cause critical side effects including breast cancer. Alternatively, phytoestrogens, which have similar structures to steroid hormones, are reported to cure postmenopausal symptoms with fewer side effects. Here, we investigated the effects of EtOH extract of Circaea mollis Siebold & Zucc. (EECM), a traditional herbal medicine in Asia that exhibits anti-arthritic activities, on postmenopausal osteoporosis. Methods In vitro model: MCF7 breast cancer cells and MC3T3-E1 pre-osteoblast cells were utilized to estimate estrogenic and osteogenic activity. Osteoblastic markers were measured by western blot and real-time PCR. In vivo model: Female mature C57BL/6 mice were ovariectomized and oral administrated with 10 mg/kg and 40 mg/kg of EECM respectively. Results EECM increased alkaline phosphatase activity and osteoblastic markers including osteoprotegerin at day 6 during mouse preosteoblast differentiation. EECM inhibited osteoclast differentiation and bone resorption in an osteoblast-osteoclast primary co-culture system via osteoprotegerin-mediated RANK/RANKL signaling. In ovariectomized mice, EECM prevented bone mineral density decrease and recovered osteoblastic molecules. Conclusions EECM enhanced the differentiation of osteoblasts via osteogenic markers and modulated RANK/RANKL signaling via an elevation of OPG from osteoblasts in vitro and in vivo. Therefore, EECM may be effective in preventing bone loss and offers a promising alternative for the nutritional management of postmenopausal osteoporosis. Funding Sources This work was supported by the Center Project for the Korea-Mongolia Science and Technology Cooperation (2U06170). Supporting Tables, Images and/or Graphs


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Xuekun Fu ◽  
Bo Zhou ◽  
Qinnan Yan ◽  
Chu Tao ◽  
Lei Qin ◽  
...  

AbstractIn vertebrates, the type 1 parathyroid hormone receptor (PTH1R) is a critical regulator of skeletal development and homeostasis; however, how it is modulated is incompletely understood. Here we report that deleting Kindlin-2 in osteoblastic cells using the mouse 10-kb Dmp1-Cre largely neutralizes the intermittent PTH-stimulated increasing of bone volume fraction and bone mineral density by impairing both osteoblast and osteoclast formation in murine adult bone. Single-cell profiling reveals that Kindlin-2 loss increases the proportion of osteoblasts, but not mesenchymal stem cells, chondrocytes and fibroblasts, in non-hematopoietic bone marrow cells, with concomitant depletion of osteoblasts on the bone surfaces, especially those stimulated by PTH. Furthermore, haploinsufficiency of Kindlin-2 and Pth1r genes, but not that of either gene, in mice significantly decreases basal and, to a larger extent, PTH-stimulated bone mass, supporting the notion that both factors function in the same genetic pathway. Mechanistically, Kindlin-2 interacts with the C-terminal cytoplasmic domain of PTH1R via aa 474–475 and Gsα. Kindlin-2 loss suppresses PTH induction of cAMP production and CREB phosphorylation in cultured osteoblasts and in bone. Interestingly, PTH promotes Kindlin-2 expression in vitro and in vivo, thus creating a positive feedback regulatory loop. Finally, estrogen deficiency induced by ovariectomy drastically decreases expression of Kindlin-2 protein in osteocytes embedded in the bone matrix and Kindlin-2 loss essentially abolishes the PTH anabolic activity in bone in ovariectomized mice. Thus, we demonstrate that Kindlin-2 functions as an intrinsic component of the PTH1R signaling pathway in osteoblastic cells to regulate bone mass accrual and homeostasis.


Author(s):  
Jiongwei Pan ◽  
Gang Huang ◽  
Zhangyong Yin ◽  
Xiaoping Cai ◽  
Enhui Gong ◽  
...  

AbstractSignificantly high-expressed circFLNA has been found in various cancer cell lines, but not in lung cancer. Therefore, this study aimed to explore the role of circFLNA in the progression of lung cancer. The target gene of circFLNA was determined by bioinformatics and luciferase reporter assay. Viability, proliferation, migration, and invasion of the transfected cells were detected by CCK-8, colony formation, wound-healing, and transwell assays, respectively. A mouse subcutaneous xenotransplanted tumor model was established, and the expressions of circFLNA, miR-486-3p, XRCC1, CYP1A1, and related genes in the cancer cells and tissues were detected by RT-qPCR, Western blot, or immunohistochemistry. The current study found that miR-486-3p was low-expressed in lung cancer. MiR-486-3p, which has been found to target XRCC1 and CYP1A1, was regulated by circFLNA. CircFLNA was located in the cytoplasm and had a high expression in lung cancer cells. Cancer cell viability, proliferation, migration, and invasion were promoted by overexpressed circFLNA, XRCC1, and CYP1A1 but inhibited by miR-486-3p mimic and circFLNA knockdown. The weight of the xenotransplanted tumor was increased by circFLNA overexpression yet reduced by miR-486-3p mimic. Furthermore, miR-486-3p mimic reversed the effect of circFLNA overexpression on promoting lung cancer cells and tumors and regulating the expressions of miR-486-3p, XRCC1, CYP1A1, and metastasis/apoptosis/proliferation-related factors. However, overexpressed XRCC1 and CYP1A1 reversed the inhibitory effect of miR-486-3p mimic on cancer cells and tumors. In conclusion, circFLNA acted as a sponge of miR-486-3p to promote the proliferation, migration, and invasion of lung cancer cells in vitro and in vivo by regulating XRCC1 and CYP1A1.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 987
Author(s):  
Eric J. O’Neill ◽  
Deborah Termini ◽  
Alexandria Albano ◽  
Evangelia Tsiani

Cancer is a disease characterized by aberrant proliferative and apoptotic signaling pathways, leading to uncontrolled proliferation of cancer cells combined with enhanced survival and evasion of cell death. Current treatment strategies are sometimes ineffective in eradicating more aggressive, metastatic forms of cancer, indicating the need to develop novel therapeutics targeting signaling pathways which are essential for cancer progression. Historically, plant-derived compounds have been utilized in the production of pharmaceuticals and chemotherapeutic compounds for the treatment of cancer, including paclitaxel and docetaxel. Theaflavins, phenolic components present in black tea, have demonstrated anti-cancer potential in cell cultures in vitro and in animal studies in vivo. Theaflavins have been shown to inhibit proliferation, survival, and migration of many cancer cellswhile promoting apoptosis. Treatment with theaflavins has been associated with increased levels of cleaved poly (ADP-ribose) polymerase (PARP) and cleaved caspases-3, -7, -8, and -9, all markers of apoptosis, and increased expression of the proapoptotic marker Bcl-2-associated X protein (Bax) and concomitant reduction in the antiapoptotic marker B-cell lymphoma 2 (Bcl-2). Additionally, theaflavin treatment reduced phosphorylated Akt, phosphorylated mechanistic target of rapamycin (mTOR), phosphatidylinositol 3-kinase (PI3K), and c-Myc levels with increased expression of the tumour suppressor p53. This review summarizes the current in vitro and in vivo evidence available investigating the anti-cancer effects of theaflavins across various cancer cell lines and animal models.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1602
Author(s):  
Anna Elizarova ◽  
Alexey Sokolov ◽  
Valeria Kostevich ◽  
Ekaterina Kisseleva ◽  
Evgeny Zelenskiy ◽  
...  

As shown recently, oleic acid (OA) in complex with lactoferrin (LF) causes the death of cancer cells, but no mechanism(s) of that toxicity have been disclosed. In this study, constitutive parameters of the antitumor effect of LF/OA complex were explored. Complex LF/OA was prepared by titrating recombinant human LF with OA. Spectral analysis was used to assess possible structural changes of LF within its complex with OA. Structural features of apo-LF did not change within the complex LF:OA = 1:8, which was toxic for hepatoma 22a cells. Cytotoxicity of the complex LF:OA = 1:8 was tested in cultured hepatoma 22a cells and in fresh erythrocytes. Its anticancer activity was tested in mice carrying hepatoma 22a. In mice injected daily with LF-8OA, the same tumor grew significantly slower. In 20% of animals, the tumors completely resolved. LF alone was less efficient, i.e., the tumor growth index was 0.14 for LF-8OA and 0.63 for LF as compared with 1.0 in the control animals. The results of testing from 48 days after the tumor inoculation showed that the survival rate among LF-8OA-treated animals was 70%, contrary to 0% rate in the control group and among the LF-treated mice. Our data allow us to regard the complex of LF and OA as a promising tool for cancer treatment.


Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 320
Author(s):  
Thaís Pereira da Silva ◽  
Fernando Jacomini de Castro ◽  
Larissa Vuitika ◽  
Nayanne Louise Costacurta Polli ◽  
Bruno César Antunes ◽  
...  

Phospholipases-D (PLDs) found in Loxosceles spiders’ venoms are responsible for the dermonecrosis triggered by envenomation. PLDs can also induce other local and systemic effects, such as massive inflammatory response, edema, and hemolysis. Recombinant PLDs reproduce all of the deleterious effects induced by Loxosceles whole venoms. Herein, wild type and mutant PLDs of two species involved in accidents—L. gaucho and L. laeta—were recombinantly expressed and characterized. The mutations are related to amino acid residues relevant for catalysis (H12-H47), magnesium ion coordination (E32-D34) and binding to phospholipid substrates (Y228 and Y228-Y229-W230). Circular dichroism and structural data demonstrated that the mutant isoforms did not undergo significant structural changes. Immunoassays showed that mutant PLDs exhibit conserved epitopes and kept their antigenic properties despite the mutations. Both in vitro (sphingomyelinase activity and hemolysis) and in vivo (capillary permeability, dermonecrotic activity, and histopathological analysis) assays showed that the PLDs with mutations H12-H47, E32-D34, and Y228-Y229-W230 displayed only residual activities. Results indicate that these mutant toxins are suitable for use as antigens to obtain neutralizing antisera with enhanced properties since they will be based on the most deleterious toxins in the venom and without causing severe harmful effects to the animals in which these sera are produced.


1997 ◽  
Vol 8 (2) ◽  
pp. 175-200 ◽  
Author(s):  
H.F. Jenkinson ◽  
RJ Lamont

Streptococci express arrays of adhesins on their cell surfaces that facilitate adherence to substrates present in their natural environment within the mammalian host. A consequence of such promiscuous binding ability is that streptococcal cells may adhere simultaneously to a spectrum of substrates, including salivary glycoproteins, extracellular matrix and serum components, host cells, and other microbial cells. The multiplicity of streptococcal adherence interactions accounts, at least in part, for their success in colonizing the oral and epithelial surfaces of humans. Adhesion facilitates colonization and may be a precursor to tissue invasion and immune modulation, events that presage the development of disease. Many of the streptococcal adhesins and virulence-related factors are cell-wall-associated proteins containing repeated sequence blocks of amino acids. Linear sequences, both within the blocks and within non-repetitive regions of the proteins, have been implicated in substrate binding. Sequences and functions of these proteins among the streptococci have become assorted through gene duplication and horizontal transfer between bacterial populations. Several adhesins identified and characterized through in vitro binding assays have been analyzed for in vivo expression and function by means of animal models used for colonization and virulence. Information on the molecular structure of adhesins as related to their in vivo function will allow for the rational design of novel acellular vaccines, recombinant antibodies, and adhesion agonists for the future control or prevention of streptococcal colonization and streptococcal diseases.


2021 ◽  
Vol 17 (7) ◽  
pp. 1293-1304
Author(s):  
Zhuofei Zhao ◽  
Xiaona Lin ◽  
Lulu Zhang ◽  
Xia Liu ◽  
Qingwen Wang ◽  
...  

De novo designed lipidated methotrexate was synthesized and self-assembled into microbubbles for targeted rheumatoid arthritis theranostic treatment. Controlled lipidatedmethotrexate delivery was achieved by ultrasound-targetedmicrobubble destruction technique. Methotrexate was dissociated inflammatory microenvironment of synovial cavity, owing to representive low pH and enriched leucocyte esterase. We first manipulated methotrexate controlled release with RAW 264.7 cell line in vitro and further verified with rheumatoid arthritis rabbits in vivo. Results showed that lipidated methotrexate microbubbles precisely affected infection focus and significantly enhanced rheumatoid arthritis curative effect comparing with dissociative methotrexate. This study indicates that lipidated methotrexate microbubbles might be considered as a promising rheumatoid arthritis theranostics medicine.


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