scholarly journals Osteocyte apoptosis: the roles and key molecular mechanisms in resorption-related bone diseases

2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Jiang-ying Ru ◽  
Yan-fen Wang

Abstract Vital osteocytes have been well known to function as an important orchestrator in the preservation of robustness and fidelity of the bone remodeling process. Nevertheless, some key pathological factors, such as sex steroid deficiency and excess glucocorticoids, and so on, are implicated in inducing a bulk of apoptotic osteocytes, subsequently resulting in resorption-related bone loss. As much, osteocyte apoptosis, under homeostatic conditions, is in an optimal state of balance tightly controlled by pro- and anti-apoptotic mechanism pathways. Importantly, there exist many essential signaling proteins in the process of osteocyte apoptosis, which has a crucial role in maintaining a homeostatic environment. While increasing in vitro and in vivo studies have established, in part, key signaling pathways and cross-talk mechanism on osteocyte apoptosis, intrinsic and complex mechanism underlying osteocyte apoptosis occurs in various states of pathologies remains ill-defined. In this review, we discuss not only essential pro- and anti-apoptotic signaling pathways and key biomarkers involved in these key mechanisms under different pathological agents, but also the pivotal role of apoptotic osteocytes in osteoclastogenesis-triggered bone loss, hopefully shedding new light on the attractive and proper actions of pharmacotherapeutics of targeting apoptosis and ensuing resorption-related bone diseases such as osteoporosis and fragility fractures.

Marine Drugs ◽  
2019 ◽  
Vol 17 (6) ◽  
pp. 345 ◽  
Author(s):  
Sheng-Hua Lu ◽  
Yi-Jan Hsia ◽  
Kuang-Chung Shih ◽  
Tz-Chong Chou

Excessive osteoclast differentiation and/or function plays a pivotal role in the pathogenesis of bone diseases such as osteoporosis and rheumatoid arthritis. Here, we examined whether fucoidan, a sulfated polysaccharide present in brown algae, attenuates receptor activator of nuclear factor-κB ligand (RANKL)-stimulated osteoclastogenesis in vitro and lipopolysaccharide (LPS)-induced bone resorption in vivo, and investigated the molecular mechanisms involved. Our results indicated that fucoidan significantly inhibited osteoclast differentiation in RANKL-stimulated macrophages and the bone resorbing activity of osteoclasts. The effects of fucoidan may be mediated by regulation of Akt/GSK3β/PTEN signaling and suppression of the increase in intracellular Ca2+ level and calcineurin activity, thereby inhibiting the translocation of nuclear factor-activated T cells c1 (NFATc1) into the nucleus. However, fucoidan-mediated NFATc1 inactivation was greatly reversed by kenpaullone, a GSK3β inhibitor. In addition, using microcomputer tomography (micro-CT) scanning and bone histomorphometry, we found that fucoidan treatment markedly prevented LPS-induced bone erosion in mice. Collectively, we demonstrated that fucoidan was capable of inhibiting osteoclast differentiation and inflammatory bone loss, which may be modulated by regulation of Akt/GSK3β/PTEN/NFATc1 and Ca2+/calcineurin signaling cascades. These findings suggest that fucoidan may be a potential agent for the treatment of osteoclast-related bone diseases.


2021 ◽  
Vol 12 ◽  
Author(s):  
Mengbo Zhu ◽  
Wenbin Xu ◽  
Jiuzhou Jiang ◽  
Yining Wang ◽  
Yanjing Guo ◽  
...  

Osteoclasts (OCs) play an important role in osteoporosis, a disease that is mainly characterized by bone loss. In our research, we aimed to identify novel approach for regulating osteoclastogenesis and thereby treating osteoporosis. Previous studies have set a precedent for screening traditional Chinese herbal extracts for effective inhibitors. Peiminine is an alkaloid extracted from the bulb of Fritillaria thunbergii Miq that reportedly has anticancer and anti-inflammatory effects. Thus, the potential inhibitory effect of peiminine on OC differentiation was investigated via a series of experiments. According to the results, peiminine downregulated the levels of specific genes and proteins in vitro and consequently suppressed OC differentiation and function. Based on these findings, we further investigated the underlying molecular mechanisms and identified the NF-κB and ERK1/2 signaling pathways as potential targets of peiminine. In vivo, peiminine alleviated bone loss in an ovariectomized mouse model.


Author(s):  
Maryam Muhammad Mailafiya ◽  
Mohamad Aris Mohd Moklas ◽  
Kabeer Abubakar ◽  
Abubakar Danmaigoro ◽  
Samaila Musa Chiroma ◽  
...  

Background: Cockle shell-derived calcium carbonate nanoparticles (CSCaCO3NP) are natural biogenic inorganic material that is used in drug delivery mainly as a bone-remodeling agent as well as a delivery agent for various therapeutics against bone diseases. Curcumin possess wide safety margin and yet puzzled with the problem of poor bioavailability due to insolubility. Propounding in vitro and in vivo studies on toxicity assessments of newly synthesized nanoparticles are ongoing to overcome some crucial challenges regarding their safety administration. Nanotoxicology has paved ways for concise test protocols to monitor sequential events with regards to possible toxicity of newly synthesized nanomaterials. The development of nanoparticle with no or less toxic effect has gained tremendous attentions. Objective: This study aimed at evaluating the in vitro cytotoxic effect of curcumin-loaded cockle shell-derived calcium carbonate nanoparticles (Cur-CSCaCO3NP) and assessing its biocompatibility on normal cells using standard techniques of WST’s assay. Method: Standard techniques of WST’s assay was used for the evaluation of the biocompatibility and cytotoxicity. Result: The result showed that CSCaCO3NP and Cur-CSCaCO3NP possess minimal toxicity and high biocompatibility on normal cells even at higher dose of 500 µg/ml and 40 µg/ml respectively. Conclusion: CSCaCO3NP can be termed an excellent non-toxic nanocarrier for curcumin delivery. Hence, curcumin loaded cockle shell derived calcium carbonate nanoparticles (Cur-CSCaCO3NP) could further be assessed for various in vivo and in vitro therapeutic applications against various bone related ailments.


Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3169
Author(s):  
Kevin Doello ◽  
Cristina Mesas ◽  
Francisco Quiñonero ◽  
Gloria Perazzoli ◽  
Laura Cabeza ◽  
...  

Sodium selenite acts by depleting enzymes that protect against cellular oxidative stress. To determine its effect alone or in combination with gemcitabine (GMZ) in pancreatic cancer, we used PANC-1 and Pan02 cell lines and C57BL mice bearing a Pan02-generated tumor. Our results demonstrated a significant inhibition of pancreatic cancer cell viability with the use of sodium selenite alone and a synergistic effect when associated with GMZ. The molecular mechanisms of the antitumor effect of sodium selenite alone involved apoptosis-inducing factor (AIF) and the expression of phospho-p38 in the combined therapy. In addition, sodium selenite alone and in association with GMZ significantly decreased the migration capacity and colony-forming ability, reduced tumor activity in multicellular tumor spheroids (MTS) and decreased sphere formation of cancer stem cells. In vivo studies demonstrated that combined therapy not only inhibited tumor growth (65%) compared to the untreated group but also relative to sodium selenite or GMZ used as monotherapy (up to 40%), increasing mice survival. These results were supported by the analysis of C57BL/6 albino mice bearing a Pan02-generated tumor, using the IVIS system. In conclusion, our results showed that sodium selenite is a potential agent for the improvement in the treatment of pancreatic cancer and should be considered for future human clinical trials.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Lingyu Yang ◽  
Dehai Xian ◽  
Xia Xiong ◽  
Rui Lai ◽  
Jing Song ◽  
...  

Proanthocyanidins (PCs) are naturally occurring polyphenolic compounds abundant in many vegetables, plant skins (rind/bark), seeds, flowers, fruits, and nuts. Numerousin vitroandin vivostudies have demonstrated myriad effects potentially beneficial to human health, such as antioxidation, anti-inflammation, immunomodulation, DNA repair, and antitumor activity. Accumulation of prooxidants such as reactive oxygen species (ROS) exceeding cellular antioxidant capacity results in oxidative stress (OS), which can damage macromolecules (DNA, lipids, and proteins), organelles (membranes and mitochondria), and whole tissues. OS is implicated in the pathogenesis and exacerbation of many cardiovascular, neurodegenerative, dermatological, and metabolic diseases, both through direct molecular damage and secondary activation of stress-associated signaling pathways. PCs are promising natural agents to safely prevent acute damage and control chronic diseases at relatively low cost. In this review, we summarize the molecules and signaling pathways involved in OS and the corresponding therapeutic mechanisms of PCs.


Antioxidants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 916 ◽  
Author(s):  
Salman Ul Islam ◽  
Muhammad Bilal Ahmed ◽  
Haseeb Ahsan ◽  
Mazharul Islam ◽  
Adeeb Shehzad ◽  
...  

Human skin is continuously subjected to environmental stresses, as well as extrinsic and intrinsic noxious agents. Although skin adopts various molecular mechanisms to maintain homeostasis, excessive and repeated stresses can overwhelm these systems, leading to serious cutaneous damage, including both melanoma and non-melanoma skin cancers. Phytochemicals present in the diet possess the desirable effects of protecting the skin from damaging free radicals as well as other benefits. Dietary phytochemicals appear to be effective in preventing skin cancer and are inexpensive, widely available, and well tolerated. Multiple in vitro and in vivo studies have demonstrated the significant anti-inflammatory, antioxidant, and anti-angiogenic characteristics of dietary phytochemicals against skin malignancy. Moreover, dietary phytochemicals affect multiple important cellular processes including cell cycle, angiogenesis, and metastasis to control skin cancer progression. Herein, we discuss the advantages of key dietary phytochemicals in whole fruits and vegetables, their bioavailability, and underlying molecular mechanisms for preventing skin cancer. Current challenges and future prospects for research are also reviewed. To date, most of the chemoprevention investigations have been conducted preclinically, and additional clinical trials are required to conform and validate the preclinical results in humans.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1232
Author(s):  
Stefania D’Adamo ◽  
Silvia Cetrullo ◽  
Veronica Panichi ◽  
Erminia Mariani ◽  
Flavio Flamigni ◽  
...  

Osteoarthritis (OA) is a disease associated to age or conditions that precipitate aging of articular cartilage, a post-mitotic tissue that remains functional until the failure of major homeostatic mechanisms. OA severely impacts the national health system costs and patients’ quality of life because of pain and disability. It is a whole-joint disease sustained by inflammatory and oxidative signaling pathways and marked epigenetic changes responsible for catabolism of the cartilage extracellular matrix. OA usually progresses until its severity requires joint arthroplasty. To delay this progression and to improve symptoms, a wide range of naturally derived compounds have been proposed and are summarized in this review. Preclinical in vitro and in vivo studies have provided proof of principle that many of these nutraceuticals are able to exert pleiotropic and synergistic effects and effectively counteract OA pathogenesis by exerting both anti-inflammatory and antioxidant activities and by tuning major OA-related signaling pathways. The latter are the basis for the nutrigenomic role played by some of these compounds, given the marked changes in the transcriptome, miRNome, and methylome. Ongoing and future clinical trials will hopefully confirm the disease-modifying ability of these bioactive molecules in OA patients.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Andressa V. B. Nogueira ◽  
Marjan Nokhbehsaim ◽  
Sema Tekin ◽  
Rafael S. de Molon ◽  
Luis C. Spolidorio ◽  
...  

Resistin, a proinflammatory adipokine, is elevated in many inflammatory diseases. However, little is known about its performance in periodontitis. The present study is aimed at evaluating resistin expression and synthesis in periodontal cells and tissues under inflammatory/microbial stress in addition to its effects on the periodontium. In vivo, 24 male rats were randomly divided into two groups: control and ligature-induced periodontal disease. After 6 and 12 days, animals were sacrificed to analyze gene expression of adipokines, bone loss, inflammation, and resistin synthesis. In vitro, human periodontal ligament (PDL) fibroblasts were used to evaluate the expression of resistin after inflammatory stimuli. In addition, PDL fibroblasts were exposed to resistin to evaluate its role on soft and hard tissue metabolism markers. The periodontitis group demonstrated significant bone loss, an increase in the number of inflammatory cells and vascular structures, an increase in resistin expression and synthesis, and a decrease in the expression of adiponectin, leptin, and its functional receptor. PDL fibroblasts showed a significant increase in resistin expression and synthesis in response to the inflammatory stimulus by IL-1β. Resistin induced an increase in cytokine expression and a decrease in the regulation of some hard tissue and matrix formation genes in PDL fibroblasts. These data indicate that resistin is produced by periodontal cells and tissues, and this effect is enhanced by inflammatory stimuli. Moreover, resistin seems to interfere with soft and hard tissue metabolism during periodontitis by reducing markers related to matrix formation and bone tissue.


Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 596 ◽  
Author(s):  
María del Carmen Villegas-Aguilar ◽  
Álvaro Fernández-Ochoa ◽  
María de la Luz Cádiz-Gurrea ◽  
Sandra Pimentel-Moral ◽  
Jesús Lozano-Sánchez ◽  
...  

Dietary phenolic compounds are considered as bioactive compounds that have effects in different chronic disorders related to oxidative stress, inflammation process, or aging. These compounds, coming from a wide range of natural sources, have shown a pleiotropic behavior on key proteins that act as regulators. In this sense, this review aims to compile information on the effect exerted by the phenolic compounds and their metabolites on the main metabolic pathways involved in energy metabolism, inflammatory response, aging and their relationship with the biological properties reported in high prevalence chronic diseases. Numerous in vitro and in vivo studies have demonstrated their pleiotropic molecular mechanisms of action and these findings raise the possibility that phenolic compounds have a wide variety of roles in different targets.


Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 672 ◽  
Author(s):  
Zain Akram ◽  
Ishtiaq Ahmed ◽  
Heike Mack ◽  
Ramandeep Kaur ◽  
Richard C. Silva ◽  
...  

The budding yeast Saccharomyces cerevisiae has an actin cytoskeleton that comprises a set of protein components analogous to those found in the actin cytoskeletons of higher eukaryotes. Furthermore, the actin cytoskeletons of S. cerevisiae and of higher eukaryotes have some similar physiological roles. The genetic tractability of budding yeast and the availability of a stable haploid cell type facilitates the application of molecular genetic approaches to assign functions to the various actin cytoskeleton components. This has provided information that is in general complementary to that provided by studies of the equivalent proteins of higher eukaryotes and hence has enabled a more complete view of the role of these proteins. Several human functional homologues of yeast actin effectors are implicated in diseases. A better understanding of the molecular mechanisms underpinning the functions of these proteins is critical to develop improved therapeutic strategies. In this article we chose as examples four evolutionarily conserved proteins that associate with the actin cytoskeleton: (1) yeast Hof1p/mammalian PSTPIP1, (2) yeast Rvs167p/mammalian BIN1, (3) yeast eEF1A/eEF1A1 and eEF1A2 and (4) yeast Yih1p/mammalian IMPACT. We compare the knowledge on the functions of these actin cytoskeleton-associated proteins that has arisen from studies of their homologues in yeast with information that has been obtained from in vivo studies using live animals or in vitro studies using cultured animal cell lines.


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