scholarly journals Regulation of Osteoclast Differentiation and Activity by Lipid Metabolism

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 89
Author(s):  
Haemin Kim ◽  
Brian Oh ◽  
Kyung-Hyun Park-Min
Keyword(s):  
Lipid Metabolism ◽  
Molecular Mechanisms ◽  
Bone Cells ◽  
Critical Role ◽  
Osteoclast Differentiation ◽  
Bone Diseases ◽  
Metabolic Reprogramming ◽  
Lipid Lowering ◽  
Metabolic Bone Diseases ◽  
Increased Risk

Bone is a dynamic tissue and is constantly being remodeled by bone cells. Metabolic reprogramming plays a critical role in the activation of these bone cells and skeletal metabolism, which fulfills the energy demand for bone remodeling. Among various metabolic pathways, the importance of lipid metabolism in bone cells has long been appreciated. More recent studies also establish the link between bone loss and lipid-altering conditions—such as atherosclerotic vascular disease, hyperlipidemia, and obesity—and uncover the detrimental effect of fat accumulation on skeletal homeostasis and increased risk of fracture. Targeting lipid metabolism with statin, a lipid-lowering drug, has been shown to improve bone density and quality in metabolic bone diseases. However, the molecular mechanisms of lipid-mediated regulation in osteoclasts are not completely understood. Thus, a better understanding of lipid metabolism in osteoclasts can be used to harness bone cell activity to treat pathological bone disorders. This review summarizes the recent developments of the contribution of lipid metabolism to the function and phenotype of osteoclasts.

scholarly journals MicroRNA-277 targetsinsulin-like peptides 7and8to control lipid metabolism and reproduction inAedes aegyptimosquitoes

2017 ◽  
Vol 114 (38) ◽  
pp. E8017-E8024 ◽  
Author(s):  
Lin Ling ◽  
Vladimir A. Kokoza ◽  
Changyu Zhang ◽  
Emre Aksoy ◽  
Alexander S. Raikhel
Keyword(s):  
Lipid Metabolism ◽  
Molecular Mechanisms ◽  
Fat Body ◽  
Critical Role ◽  
Target Prediction ◽  
Luciferase Reporter ◽  
Ovary Development ◽  
Mrna Levels ◽  
Essential Components ◽  
Energy Store

Hematophagous female mosquitoes transmit numerous devastating human diseases, including malaria, dengue fever, Zika virus, and others. Because of their obligatory requirement of a vertebrate blood meal for reproduction, these mosquitoes need a lot of energy; therefore, understanding the molecular mechanisms linking metabolism and reproduction is of particular importance. Lipids are the major energy store providing the fuel required for host seeking and reproduction. They are essential components of the fat body, a metabolic tissue that is the insect analog of vertebrate liver and adipose tissue. In this study, we found that microRNA-277 (miR-277) plays an important role in regulating mosquito lipid metabolism. The genetic disruption of miR-277 using the CRISPR-Cas9 system led to failures in both lipid storage and ovary development. miR-277 mimic injection partially rescued these phenotypic manifestations. Examination of subcellular localization of FOXO protein via CRISPR-assisted, single-stranded oligodeoxynucleotide-mediated homology-directed repair revealed that insulin signaling is up-regulated in response to miR-277 depletion. In silico target prediction identified that insulin-like peptides 7 and 8 (ilp7andilp8) are putative targets of miR-277; RNA immunoprecipitation and a luciferase reporter assay confirmed thatilp7andilp8are direct targets of this miRNA. CRISPR-Cas9 depletion ofilp7andilp8led to metabolic and reproductive defects. These depletions identified differential actions of ILP7 and ILP8 in lipid homeostasis and ovarian development. Thus, miR-277 plays a critical role in mosquito lipid metabolism and reproduction by targetingilp7andilp8, and serves as a monitor to control ILP7 and ILP8 mRNA levels.

scholarly journals Fucoidan Prevents RANKL-Stimulated Osteoclastogenesis and LPS-Induced Inflammatory Bone Loss via Regulation of Akt/GSK3β/PTEN/NFATc1 Signaling Pathway and Calcineurin Activity

Marine Drugs ◽  
2019 ◽  
Vol 17 (6) ◽  
pp. 345 ◽  
Author(s):  
Sheng-Hua Lu ◽  
Yi-Jan Hsia ◽  
Kuang-Chung Shih ◽  
Tz-Chong Chou
Keyword(s):  
Bone Loss ◽  
Molecular Mechanisms ◽  
Bone Erosion ◽  
Osteoclast Differentiation ◽  
Bone Diseases ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Calcineurin Activity

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.

scholarly journals Effects on Liver Lipid Metabolism of the Naturally Occurring Dietary Flavone Luteolin-7-glucoside

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Carla Sá ◽  
Ana Rita Oliveira ◽  
Cátia Machado ◽  
Marisa Azevedo ◽  
Cristina Pereira-Wilson
Keyword(s):  
Lipid Metabolism ◽  
Fatty Acid Synthase ◽  
Molecular Mechanisms ◽  
Metabolic Diseases ◽  
Regulatory Element ◽  
Lipid Lowering ◽  
Whole Body ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Hepatic Expression

Disruptions in whole-body lipid metabolism can lead to the onset of several pathologies such as nonalcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVDs). The present study aimed at elucidating the molecular mechanisms behind the lipid-lowering effects of the flavone luteolin-7-glucoside (L7G) which we previously showed to improve plasma lipid profile in rats. L7G is abundant in plant foods of Mediterranean diet such as aromatic plants used as herbs. Results show that dietary supplementation with L7G for one week induced the expression of peroxisome proliferator-activated receptor-alpha (PPAR-α) and of its target gene carnitine palmitoyl transferase 1 (CPT-1) in rat liver. L7G showed a tendency to decrease the hepatic expression of sterol regulatory element-binding protein-1 (SREBP-1), without affecting fatty acid synthase (FAS) protein levels. Although SREBP-2 and LDLr mRNA levels did not change, the expression of HMG CoA reductase (HMGCR) was significantly repressed by L7G. L7G also inhibited this enzyme’sin vitroactivity in a dose dependent manner, but only at high and not physiologically relevant concentrations. These results add new evidence that the flavone luteolin-7-glucoside may help in preventing metabolic diseases and clarify the mechanisms underlying the beneficial health effects of diets rich in fruits and vegetables.

scholarly journals Nur77 prevents excessive osteoclastogenesis by inducing ubiquitin ligase Cbl-b to mediate NFATc1 self-limitation

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Xiaoxiao Li ◽  
Wei Wei ◽  
HoangDinh Huynh ◽  
Hao Zuo ◽  
Xueqian Wang ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Critical Role ◽  
Osteoclast Differentiation ◽  
Feedback Mechanism ◽  
Bone Diseases ◽  
Orphan Nuclear Receptor ◽  
Low Bone Mass ◽  
Degenerative Disorders ◽  
Regulatory Loop

Osteoclasts are bone-resorbing cells essential for skeletal remodeling. However, over-active osteoclasts can cause bone-degenerative disorders. Therefore, the level of NFATc1, the master transcription factor of osteoclast, must be tightly controlled. Although the activation and amplification of NFATc1 have been extensively studied, how NFATc1 signaling is eventually resolved is unclear. Here, we uncover a novel and critical role of the orphan nuclear receptor Nur77 in mediating an NFATc1 self-limiting regulatory loop to prevent excessive osteoclastogenesis. Nur77 deletion leads to low bone mass owing to augmented osteoclast differentiation and bone resorption. Mechanistically, NFATc1 induces Nur77 expression at late stage of osteoclast differentiation; in turn, Nur77 transcriptionally up-regulates E3 ubiquitin ligase Cbl-b, which triggers NFATc1 protein degradation. These findings not only identify Nur77 as a key player in osteoprotection and a new therapeutic target for bone diseases, but also elucidate a previously unrecognized NFATc1→Nur77→Cblb—•NFATc1 feedback mechanism that confers NFATc1 signaling autoresolution.

scholarly journals SUN-052 Effects of Cross-Sex Hormone Therapy on Lipid Metabolism in Transgender Women and Men

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Carly Kelley ◽  
Andrea D Coviello
Keyword(s):  
Lipid Metabolism ◽  
Hormone Therapy ◽  
Transgender Women ◽  
Small Sample ◽  
Sex Hormone ◽  
Lipid Lowering ◽  
Lipid Lowering Therapy ◽  
Transgender Persons ◽  
Lipid Panel ◽  
Increased Risk

Abstract Sex hormone therapy in cisgender persons (i.e. postmenopausal women and hypogonadal men and women) leads to changes in lipid metabolism and weight, but it is unclear to what extent this occurs in transgender persons receiving higher doses of cross-sex hormone therapy (CSHT) for the purpose of gender transition.Objective: To determine changes in lipid metabolism among transgender women (TW) and transgender men (TM) on CSHT.Methods: We conducted a retrospective chart review of patients identified at a transgender-specific clinic within an academic medical center. Data were collected on age, ethnicity, hormone therapies, lipid lowering therapy (LLT), surgical status, lipid panel, A1C, LFTs, BMI, and weight before and after initiation of HT. Patients on stable LLT were included but those with LLT initiated after baseline observation were excluded. Changes from baseline to post CSHT in TW and TM groups were evaluated with paired t-tests.Results: We identified 18 TW and 22 TM for whom laboratory data were available. Mean±SD age of TW was 33±13 years and for TM was 28±12 years; the majority (78%) were Caucasian. Mean±SD duration of HT in TW was 10.1±4.5 months and in TM 6.7±4.4 months. No patients had undergone gonadectomy at any time prior to or during the data collection period. One TW and one TM were on stable LLT during the observation period. All TW were treated with estradiol (78% oral, 11% patch) and spironolactone. In TW, there was a significant 10% increase in HDL from 48±17 mg/dl to 53±15 mg/dl (p=0.02) but there were no significant changes in other lipid fractions, A1c, or weight/BMI. The majority of TM (82%) were treated with weekly intramuscular testosterone-esters injections and the remainder with daily testosterone gel. More substantial and unfavorable metabolic changes occurred in the TM with a 15% decrease in HDL from 55±15 mg/dl to 47±10 mg/dl (p=0.004), increase in A1c from 5.07±0.45% to 5.22 ± 0.39%(p=0.04), increase in BMI from 29±10 kg/m2 to 31±10 kg/m2 (p=0.002), and a trend toward increased triglycerides (96±64 mg/dl to 110±80 mg/dl, p=0.07). Hemoglobin and hematocrit significantly increased in TM but there was no significant change in LFT in either group. Limitations include lack of data on body composition to determine relative changes in adipose tissue or muscle mass in relation to weight changes and small sample size.Conclusion: Our study suggests that CSHT has a neutral to slightly favorable impact on lipid metabolism in TW and a negative impact on lipids and glucose in TM. Larger, prospective studies are needed to determine whether these changes persist over the longer duration of CSHT and whether this translates to an increased risk of cardiovascular disease and mortality. Clinicians should inform TM patients about these potential negative effects of CSHT on lipid metabolism so that their patients can adopt healthy lifestyle interventions early on to optimize their cardiovascular risk.

Abstract P001: HDAC1 Plays an Important Role in the Differentiation of Embryonic Stem Cells and Induced Pluripotent Stem Cells into Cardiovascular Lineages

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Eneda Hoxha ◽  
Erin Lambers ◽  
Veronica Ramirez ◽  
Prasanna Krishnamurthy ◽  
Suresh Verma ◽  
...  
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Es Cells ◽  
Critical Role ◽  
Embryonic Stem ◽  
Ips Cells ◽  
Full Potential ◽  
Early Differentiation ◽  
Increased Risk ◽  
Mes Cells

Despite advancements in the treatment of myocardial infarction (MI), the majority of patients are at increased risk for developing heart failure due to the loss of cardiomyocytes and microvasculature. Some of the main obstacles in the realization of the full potential of iPS/ES cells arise from incomplete and poorly understood molecular mechanisms and epigenetic modifications that govern their pluripotency and directed differentiation. Real-time array experiments revealed that HDAC1 is highly expressed in pluripotent cells. Additionally the lack of this molecule is embryonic lethal, suggesting it plays a key role in development. Thus, we hypothesized that HDAC1 plays a critical role in directing cardiovascular differentiation of mES and iPS cells in vitro. HDAC1 was knocked down in mES cells (C57BL/6) and iPS cells using a shRNA vector. Differentiation through embryoid body (EB) was induced in wild type mES cells and iPS cells and in their HDAC1-null counterparts and the ability of these cells to differentiate into three early embryonic lineages and more specifically cardiovascular lineage was monitored. EBs lacking HDAC1 differentiated slower and showed delayed suppression of pluripotent genes such as Oct4 and Sox2. ChiP experiments revealed high histone acetylation levels at the promoter regions of these genes during early differentiation. In addition cells lacking HDAC1 showed reduced expression of early markers for all three germ layers. HDAC1-null EBs also showed delayed and reduced spontaneous beating. Expression of cardiomyocite markers as well as markers of other cardiovascular lineages was repressed in HDAC1 -null cells. However, supplementation with BMP2 during early differentiation recovered the ability in the HDAC1-null cells to differentiate into endodermal and mesodermal lineages, but not ectodermal. We propose that HDAC1 plays a critical role in early development and cardiovascular differentiation of mES and iPS cells by repressing pluripotent genes and allowing for expression of early developmental genes such as SOX17 and BMP2. Further research in the molecular mechanisms involved in this process will greatly aid our understanding of the epigenetic circuitry of pluripotency and differentiation in ES and iPS cells.

Cellular Communication in Bone Homeostasis and the Related Anti-osteoporotic Drug Development

2020 ◽  
Vol 27 (7) ◽  
pp. 1151-1169 ◽  
Author(s):  
Yi Zhang ◽  
Guojing Luo ◽  
Xijie Yu
Keyword(s):  
Drug Development ◽  
Bone Remodeling ◽  
Bone Cells ◽  
Bone Diseases ◽  
Cellular Communication ◽  
New Drugs ◽  
Complex Signal ◽  
Bone Homeostasis ◽  
Metabolic Bone Diseases ◽  
Signal Network

Background: Intercellular crosstalk among osteoblast, osteoclast, osteocyte and chondrocyte is involved in the precise control of bone homeostasis. Disruption of this cellular and molecular signaling would lead to metabolic bone diseases such as osteoporosis. Currently a number of anti-osteoporosis interventions are restricted by side effects, complications and long-term intolerance. This review aims to summarize the bone cellular communication involved in bone remodeling and its usage to develop new drugs for osteoporosis. Methods: We searched PubMed for publications from 1 January 1980 to 1 January 2018 to identify relevant and latest literatures, evaluation and prospect of osteoporosis medication were summarized. Detailed search terms were ‘osteoporosis’, ‘osteocyte’, ‘osteoblast’, ‘osteoclast’, ‘bone remodeling’, ‘chondrocyte’, ‘osteoporosis treatment’, ‘osteoporosis therapy’, ‘bisphosphonates’, ‘denosumab’, ‘Selective Estrogen Receptor Modulator (SERM)’, ‘PTH’, ‘romosozumab’, ‘dkk-1 antagonist’, ‘strontium ranelate’. Results: A total of 170 papers were included in the review. About 80 papers described bone cell interactions involved in bone remodeling. The remaining papers were focused on the novel advanced and new horizons in osteoporosis therapies. Conclusion: There exists a complex signal network among bone cells involved in bone remodeling. The disorder of cell-cell communications may be the underlying mechanism of osteoporosis. Current anti-osteoporosis therapies are effective but accompanied by certain drawbacks simultaneously. Restoring the abnormal signal network and individualized therapy are critical for ideal drug development.

scholarly journals C-terminal truncated HBx initiates hepatocarcinogenesis by downregulating TXNIP and reprogramming glucose metabolism

Oncogene ◽  
2020 ◽  
Author(s):  
Yu Zhang ◽  
Qian Yan ◽  
Lanqi Gong ◽  
Hang Xu ◽  
Beilei Liu ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Genetic Alterations ◽  
Metabolic Reprogramming ◽  
Mice Model ◽  
Activated T Cells ◽  
Chronic Hepatitis B Virus

AbstractChronic hepatitis B virus (HBV) infection is strongly associated with the initiation and development of hepatocellular carcinoma (HCC). However, the genetic alterations and pathogenesis mechanisms remain significantly unexplored, especially for HBV-induced metabolic reprogramming. Analysis of integration breakpoints in HBV-positive HCC samples revealed the preferential clustering pattern within the 3′-end of X gene in the HBV genome, leading to the production of C-terminal truncated X protein (Ct-HBx). In this study, we not only characterized the oncogenic role of two Ct-HBx (HBx-120 and HBx-134) via in vitro and in vivo functional assays but also deciphered their underlying molecular mechanisms. Gene expression profiling by transcriptome sequencing identified potential targets of Ct-HBx and novel malignant hallmarks such as glycolysis, cell cycle, and m-TORC1 signaling in Ct-HBx-expressing cells. TXNIP, a well-established regulator of glucose metabolism, was shown to be downregulated by Ct-HBx and play a pivotal role in Ct-HBx-mediated HCC progression. Suppression of TXNIP is frequently observed in HCC patients with Ct-HBx expression and significantly (P = 0.015) correlated to a poorer prognosis. Re-introduction of TXNIP attenuated the metabolic reprogramming induced by the Ct-HBx and inhibited the tumor growth in the mice model. Further study suggested that Ct-HBx could downregulate TXNIP via a transcriptional repressor nuclear factor of activated T cells 2 (NFACT2). Collectively, our findings indicate that TXNIP plays a critical role in Ct-HBx-mediated hepatocarcinogenesis, serving as a novel therapeutic strategy in HCC treatment.

scholarly journals Lipoprotein(a) – Link between Atherogenesis and Thrombosis

2019 ◽  
Vol 120 (2-3) ◽  
pp. 39-51 ◽  
Author(s):  
Danica Labudovic ◽  
Irena Kostovska ◽  
Katerina Tosheska Trajkovska ◽  
Svetlana Cekovska ◽  
Julijana Brezovska Kavrakova ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Vascular System ◽  
Plasma Concentrations ◽  
Lipid Lowering ◽  
Coagulation Cascade ◽  
Lipoprotein A ◽  
Cellular Effects ◽  
Apolipoprotein A ◽  
Increased Risk ◽  
Circulating Levels

Lipoprotein(a) – Lp(a) – is an independent risk factor for cardiovascular disease (CVD). Indeed, individuals with plasma concentrations of Lp(a) > 200 mg/l carry an increased risk of developing CVD. Circulating levels of Lp(a) are remarkably resistant to common lipid lowering therapies, currently available treatment for reduction of Lp(a) is plasma apheresis, which is costly and labour intensive. The Lp(a) molecule is composed of two parts: LDL/apoB-100 core and glycoprotein, apolipoprotein(a) – Apo(a), both of them can interact with components of the coagulation cascade, inflammatory pathways and blood vessel cells (smooth muscle cells and endothelial cells). Therefore, it is very important to determine the molecular pathways by which Lp(a) affect the vascular system in order to design therapeutics for targeting the Lp(a) cellular effects. This paper summarises the cellular effects and molecular mechanisms by which Lp(a) participate in atherogenesis, thrombogenesis, inflammation and development of cardiovascular diseases.

Alpinetin Inhibits RANKL-Induced Osteoclastogenesis and Ovariectomy-Induced Bone Loss by Modulating NFATc1 Transcription and Lysosomal Function

2020 ◽  
Author(s):  
Rongxin He ◽  
Jinwei Lu ◽  
Yazhou Chen ◽  
Yong Li ◽  
Chenyi Ye ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Bone Matrix ◽  
Osteoclast Differentiation ◽  
Estrogen Deficiency ◽  
Bone Diseases ◽  
Dependent Manner ◽  
Metabolic Bone Diseases ◽  
Lysosomal Function ◽  
Metabolic Bone

Abstract BackgroundPostmenopausal osteoporosis is a chronic metabolic bone disease caused by excessive osteoclast activation, and osteoclasts are considered to be the sole participants in the degeneration and resorption of bone matrix for controlling bone integrity and continuity. The biological functions of osteoclasts depend critically on the number and activity of fused polykaryon. Hence, targeting osteoclast differentiation and activity can modulate bone resorption and alleviate osteoporosis. Alpinetin is widely used for excellent anti-inflammatory activities and little side-effect, but its role in osteoporosis remains unknown.ResultsIn this study, we investigated for the first time the ability of alpinetin to inhibit estrogen deficiency-induced bone loss. Alpinetin significantly reduced the expression levels of NFATc1 and its downstream genes, thereby inhibiting osteoclast differentiation in a concentration- and time-dependent manner. Additionally, alpinetin inhibited F-actin ring formation and bone resorption, as well as reduced the activation levels of NF-κB, ERK, and AKT signaling cascades. In mature osteoclasts, alpinetin remarkably inhibited integrin-mediated migration and lysosomal biogenesis and trafficking by modulating the PKCβ/TFEB and ATG5/LC3 axes. Importantly, alpinetin treatment in mice alleviated ovariectomy-induced bone volume loss. ConclusionOur findings strongly suggest that alpinetin plays a significant role in the regulation of NFATc1 production for the differentiation of osteoclasts and inhibits integrin-mediated cell migration and lysosomal function in mature osteoclasts, thus weaken the increased osteolytic ability due to estrogen deficiency. Alpinetin may represent a promising agent for the treatment of osteoporosis and other metabolic bone diseases.

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