scholarly journals Female-Specific Role of Progranulin to Suppress Bone Formation

Endocrinology ◽  
2019 ◽  
Vol 160 (9) ◽  
pp. 2024-2037 ◽  
Author(s):  
Liping Wang ◽  
Theresa Roth ◽  
Mary C Nakamura ◽  
Robert A Nissenson
Keyword(s):  
Bone Resorption ◽  
Bone Formation ◽  
Microglial Cells ◽  
Treatment Of Osteoporosis ◽  
Female Mice ◽  
Diet Induced Obesity ◽  
Skeletal Effects ◽  
Female Specific ◽  
Osteogenic Factors

Abstract Progranulin (PGRN) is best known as a glial protein for which deficiency leads to the most common inherited form of frontotemporal dementia. Recently, PGRN has been found to be an adipokine associated with diet-induced obesity and insulin resistance. Therefore, PGRN may have homeostatic effects on bone because PGRN is reported to promote the differentiation of bone-resorbing osteoclasts. We investigated the actions of PGRN on bone using PGRN gene (Grn) knockout (KO) mice and transgenic mice with PGRN mutation and surprisingly found that loss of PGRN prevented the bone loss in female mice induced by aging and estrogen deficiency, whereas it had no effect on male bones during aging. Strikingly, bone formation was increased in female (but not male) PGRN KO mice. We also found that loss of PGRN inhibited bone resorption and osteoclastogenesis in both male and female mice and promoted the production of osteogenic factors in osteoclast lineage cells. These results indicate that PGRN serves to uncouple bone turnover in female mice by promoting bone resorption and suppressing bone formation. Furthermore, we demonstrated that microglial cells/macrophages, but not adipocytes, are an important source of PGRN in producing negative skeletal effects in females. Targeting PGRN production by microglial cells/macrophage-lineage cells may provide a therapeutic approach for the treatment of osteoporosis in females.

scholarly journals Role of Biomolecules in Osteoclasts and Their Therapeutic Potential for Osteoporosis

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 747
Author(s):  
Xin Zhao ◽  
Suryaji Patil ◽  
Fang Xu ◽  
Xiao Lin ◽  
Airong Qian
Keyword(s):  
Transcription Factors ◽  
Bone Resorption ◽  
Bone Formation ◽  
Bone Metabolism ◽  
Therapeutic Potential ◽  
Bone Microarchitecture ◽  
Treatment Of Osteoporosis ◽  
Non Coding Rnas ◽  
And Function

Osteoclasts (OCs) are important cells that are involved in the regulation of bone metabolism and are mainly responsible for coordinating bone resorption with bone formation to regulate bone remodeling. The imbalance between bone resorption and formation significantly affects bone metabolism. When the activity of osteoclasts exceeds the osteoblasts, it results in a condition called osteoporosis, which is characterized by reduced bone microarchitecture, decreased bone mass, and increased occurrences of fracture. Molecules, including transcription factors, proteins, hormones, nucleic acids, such as non-coding RNAs, play an important role in osteoclast proliferation, differentiation, and function. In this review, we have highlighted the role of these molecules in osteoclasts regulation and osteoporosis. The developed therapeutics targeting these molecules for the treatment of osteoporosis in recent years have also been discussed with challenges faced in clinical application.

scholarly journals Dual targeting of salt inducible kinases and CSF1R uncouples bone formation and bone resorption

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Cheng-Chia Tang ◽  
Christian D Castro ◽  
Maureen J O'Meara ◽  
Sung-Hee Yoon ◽  
Tadatoshi Sato ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Formation ◽  
Bone Mass ◽  
Kinase Inhibitor ◽  
Bone Destruction ◽  
Anabolic Agents ◽  
Female Mice ◽  
New Class ◽  
Dual Targeting

Bone formation and resorption are typically coupled, such that the efficacy of anabolic osteoporosis treatments may be limited by bone destruction. The multi-kinase inhibitor YKL-05-099 potently inhibits salt inducible kinases (SIKs) and may represent a promising new class of bone anabolic agents. Here we report that YKL-05-099 increases bone formation in hypogonadal female mice without increasing bone resorption. Postnatal mice with inducible, global deletion of SIK2 and SIK3 show increased bone mass, increased bone formation, and, distinct from the effects of YKL-05-099, increased bone resorption. No cell-intrinsic role of SIKs in osteoclasts was noted. In addition to blocking SIKs, YKL-05-099 also binds and inhibits CSF1R, the receptor for the osteoclastogenic cytokine M-CSF. Modeling reveals that YKL-05-099 binds to SIK2 and CSF1R in a similar manner. Dual targeting of SIK2/3 and CSF1R induces bone formation without concomitantly increasing bone resorption and thereby may overcome limitations of most current anabolic osteoporosis therapies.

scholarly journals Dual targeting of salt inducible kinases and CSF1R uncouples bone formation and bone resorption

2021 ◽  
Author(s):  
Cheng-Chia Tang ◽  
Christian Castro ◽  
Maureen J O'Meara ◽  
Sung-Hee Yoon ◽  
Daniel J Brooks ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Formation ◽  
Bone Mass ◽  
Kinase Inhibitor ◽  
Bone Destruction ◽  
Anabolic Agents ◽  
Female Mice ◽  
New Class ◽  
Dual Targeting

Bone formation and resorption are typically coupled, such that the efficacy of anabolic osteoporosis treatments may be limited by bone destruction. The multi-kinase inhibitor YKL-05-099 potently inhibits salt inducible kinases (SIKs) and may represent a promising new class of bone anabolic agents. Here we report that YKL-05-099 increases bone formation in hypogonadal female mice without increasing bone resorption. Postnatal mice with inducible, global deletion of SIK2 and SIK3 show increased bone mass, increased bone formation, and, distinct from the effects of YKL-05-099, increased bone resorption. No cell-intrinsic role of SIKs in osteoclasts was noted. In addition to blocking SIKs, YKL-05-099 also binds and inhibits CSF1R, the receptor for the osteoclastogenic cytokine M-CSF. Modeling reveals that YKL-05-099 binds to SIK2 and CSF1R in a similar manner. Dual targeting of SIK2/3 and CSF1R induces bone formation without concomitantly increasing bone resorption and thereby may overcome limitations of most current anabolic osteoporosis therapies.

scholarly journals Lumican Inhibits Osteoclastogenesis and Bone Resorption by Suppressing Akt Activity

2021 ◽  
Vol 22 (9) ◽  
pp. 4717
Author(s):  
Jin-Young Lee ◽  
Da-Ae Kim ◽  
Eun-Young Kim ◽  
Eun-Ju Chang ◽  
So-Jeong Park ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Formation ◽  
Map Kinases ◽  
Osteoclast Differentiation ◽  
Dependent Manner ◽  
Dual Action ◽  
Dose Dependent ◽  
Resorptive Activity

Lumican, a ubiquitously expressed small leucine-rich proteoglycan, has been utilized in diverse biological functions. Recent experiments demonstrated that lumican stimulates preosteoblast viability and differentiation, leading to bone formation. To further understand the role of lumican in bone metabolism, we investigated its effects on osteoclast biology. Lumican inhibited both osteoclast differentiation and in vitro bone resorption in a dose-dependent manner. Consistent with this, lumican markedly decreased the expression of osteoclastogenesis markers. Moreover, the migration and fusion of preosteoclasts and the resorptive activity per osteoclast were significantly reduced in the presence of lumican, indicating that this protein affects most stages of osteoclastogenesis. Among RANKL-dependent pathways, lumican inhibited Akt but not MAP kinases such as JNK, p38, and ERK. Importantly, co-treatment with an Akt activator almost completely reversed the effect of lumican on osteoclast differentiation. Taken together, our findings revealed that lumican inhibits osteoclastogenesis by suppressing Akt activity. Thus, lumican plays an osteoprotective role by simultaneously increasing bone formation and decreasing bone resorption, suggesting that it represents a dual-action therapeutic target for osteoporosis.

scholarly journals Brown Fat Dnmt3b Deficiency Ameliorates Obesity in Female Mice

Life ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1325
Author(s):  
Fenfen Li ◽  
Xin Cui ◽  
Jia Jing ◽  
Shirong Wang ◽  
Huidong Shi ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Energy Expenditure ◽  
Knockout Mice ◽  
Dna Methyltransferase ◽  
De Novo ◽  
Brown Fat ◽  
Chow Diet ◽  
Female Mice ◽  
Diet Induced Obesity

Obesity results from a chronic energy imbalance due to energy intake exceeding energy expenditure. Activation of brown fat thermogenesis has been shown to combat obesity. Epigenetic regulation, including DNA methylation, has emerged as a key regulator of brown fat thermogenic function. Here we aimed to study the role of Dnmt3b, a DNA methyltransferase involved in de novo DNA methylation, in the regulation of brown fat thermogenesis and obesity. We found that the specific deletion of Dnmt3b in brown fat promotes the thermogenic and mitochondrial program in brown fat, enhances energy expenditure, and decreases adiposity in female mice fed a regular chow diet. With a lean phenotype, the female knockout mice also exhibit increased insulin sensitivity. In addition, Dnmt3b deficiency in brown fat also prevents diet-induced obesity and insulin resistance in female mice. Interestingly, our RNA-seq analysis revealed an upregulation of the PI3K-Akt pathway in the brown fat of female Dnmt3b knockout mice. However, male Dnmt3b knockout mice have no change in their body weight, suggesting the existence of sexual dimorphism in the brown fat Dnmt3b knockout model. Our data demonstrate that Dnmt3b plays an important role in the regulation of brown fat function, energy metabolism and obesity in female mice.

scholarly journals Free Fatty Acid Receptor 4 (GPR120) Stimulates Bone Formation and Suppresses Bone Resorption in the Presence of Elevated n-3 Fatty Acid Levels

Endocrinology ◽  
2016 ◽  
Vol 157 (7) ◽  
pp. 2621-2635 ◽  
Author(s):  
Seong Hee Ahn ◽  
Sook-Young Park ◽  
Ji-Eun Baek ◽  
Su-Youn Lee ◽  
Wook-Young Baek ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Bone Resorption ◽  
Bone Loss ◽  
Bone Formation ◽  
High Fat Diet ◽  
Wild Type ◽  
High Fat ◽  
Free Fatty Acid Receptor

Free fatty acid receptor 4 (FFA4) has been reported to be a receptor for n-3 fatty acids (FAs). Although n-3 FAs are beneficial for bone health, a role of FFA4 in bone metabolism has been rarely investigated. We noted that FFA4 was more abundantly expressed in both mature osteoclasts and osteoblasts than their respective precursors and that it was activated by docosahexaenoic acid. FFA4 knockout (Ffar4−/−) and wild-type mice exhibited similar bone masses when fed a normal diet. Because fat-1 transgenic (fat-1Tg+) mice endogenously converting n-6 to n-3 FAs contain high n-3 FA levels, we crossed Ffar4−/− and fat-1Tg+ mice over two generations to generate four genotypes of mice littermates: Ffar4+/+;fat-1Tg−, Ffar4+/+;fat-1Tg+, Ffar4−/−;fat-1Tg−, and Ffar4−/−;fat-1Tg+. Female and male littermates were included in ovariectomy- and high-fat diet-induced bone loss models, respectively. Female fat-1Tg+ mice decreased bone loss after ovariectomy both by promoting osteoblastic bone formation and inhibiting osteoclastic bone resorption than their wild-type littermates, only when they had the Ffar4+/+ background, but not the Ffar4−/− background. In a high-fat diet-fed model, male fat-1Tg+ mice had higher bone mass resulting from stimulated bone formation and reduced bone resorption than their wild-type littermates, only when they had the Ffar4+/+ background, but not the Ffar4−/− background. In vitro studies supported the role of FFA4 as n-3 FA receptor in bone metabolism. In conclusion, FFA4 is a dual-acting factor that increases osteoblastic bone formation and decreases osteoclastic bone resorption, suggesting that it may be an ideal target for modulating metabolic bone diseases.

Romosozumab: A first-in-class sclerostin inhibitor for osteoporosis

2020 ◽  
Vol 77 (23) ◽  
pp. 1949-1956
Author(s):  
Caitlin Prather ◽  
Erin Adams ◽  
Whitney Zentgraf
Keyword(s):  
Clinical Trials ◽  
High Risk ◽  
Bone Resorption ◽  
Bone Formation ◽  
English Language ◽  
Safety Concern ◽  
Osteoporotic Fractures ◽  
Mineral Density ◽  
Treatment Of Osteoporosis ◽  
Poster Presentations

Abstract Purpose The purpose of this article is to review the pharmacology, efficacy, and safety of the sclerostin inhibitor romosozumab for the treatment of osteoporosis, including data from clinical trials of the drug. Summary A review of the literature was performed by searching PubMed and MEDLINE for all relevant articles published between January 2014 and February 2020 using the keywords romosozumab, romosozumab-aqqg, osteoporosis, and fracture. All relevant English-language articles evaluating the pharmacology, efficacy, or safety of romosozumab for the treatment of osteoporosis in humans were included; poster presentations were excluded. Romosozumab has been approved by the Food and Drug Administration and is considered both safe and effective for the treatment of osteoporosis in high-risk postmenopausal females. Phase 2 and phase 3 clinical trials have shown a statistically significant decrease in new vertebral fractures and an increase in bone mineral density with romosozumab use, as compared with both placebo use and use of alternative osteoporosis therapies. The primary safety concern is a potential risk of cardiovascular events; additionally, hypocalcemia must be corrected prior to initiation. Romosozumab is the first anabolic medication that both increases bone formation and decreases bone resorption. Data suggest that romosozumab is more effective than oral bisphosphonates in preventing osteoporotic fractures, though cost and safety concerns must be considered. Conclusion Romosozumab is a novel, 12-month treatment option for postmenopausal women at high risk for osteoporotic fracture that both increases bone formation and decreases bone resorption.

Role of parathyroid hormone in regulation of main calcium fluxes in rats.

1977 ◽  
Vol 232 (6) ◽  
pp. E535
Author(s):  
B Haldimann ◽  
J P Bonjour ◽  
H Fleisch
Keyword(s):  
Parathyroid Hormone ◽  
Bone Resorption ◽  
Bone Formation ◽  
Bone Turnover ◽  
Linear Correlation ◽  
Constant Amount ◽  
Calcium Fluxes ◽  
Growing Rats

The effect of calcium deprivation on the various calcium fluxes was studied in growing rats either sham-operated (SHAM), thyroparathyroidectomized (TPTX), or thyroparathyroidectomized and supplemented with parathyroid hormone (PTH) (TPTX + PTH). In SHAM rats a decrease in the net absorption of calcium (Vna) has no influence on calcemia or on bone formation (Vo+), but leads to an increase in bone resorption (Vo-). In TPTX rats a decrease in Vna induces a decrease in calcemia and in Vo+ but still causes an increase in Vo-. The same is true in TPTX + PTH rats although all the variables measured are increased. In TPTX rats, both without and with PTH, a linear correlation exists between calcemia and Vo+ suggesting that calcemia influences bone formation. Furthermore, it appears that PTH is important in regulating bone turnover, but that the adaptation of Vo- to a change in Vna can occur in the absence or in the presence of a constant amount of this hormone. The mechanism of regulating this adaptation of bone resorption is still unknown.

A Comparison of Osteoclast-Rich and Osteoclast-Poor Osteopetrosis in Adult Mice Sheds Light on the Role of the Osteoclast in Coupling Bone Resorption and Bone Formation

2014 ◽  
Vol 95 (1) ◽  
pp. 83-93 ◽  
Author(s):  
Christian S. Thudium ◽  
Ilana Moscatelli ◽  
Carmen Flores ◽  
Jesper S. Thomsen ◽  
Annemarie Brüel ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Formation ◽  
Adult Mice

scholarly journals SIKs control osteocyte responses to parathyroid hormone

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Marc N. Wein ◽  
Yanke Liang ◽  
Olga Goransson ◽  
Thomas B. Sundberg ◽  
Jinhua Wang ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Bone Resorption ◽  
Bone Formation ◽  
Small Molecule ◽  
Nuclear Translocation ◽  
Rna Seq ◽  
Once Daily ◽  
Skeletal Effects ◽  
Stimulation Of

Abstract Parathyroid hormone (PTH) activates receptors on osteocytes to orchestrate bone formation and resorption. Here we show that PTH inhibition of SOST (sclerostin), a WNT antagonist, requires HDAC4 and HDAC5, whereas PTH stimulation of RANKL, a stimulator of bone resorption, requires CRTC2. Salt inducible kinases (SIKs) control subcellular localization of HDAC4/5 and CRTC2. PTH regulates both HDAC4/5 and CRTC2 localization via phosphorylation and inhibition of SIK2. Like PTH, new small molecule SIK inhibitors cause decreased phosphorylation and increased nuclear translocation of HDAC4/5 and CRTC2. SIK inhibition mimics many of the effects of PTH in osteocytes as assessed by RNA-seq in cultured osteocytes and following in vivo administration. Once daily treatment with the small molecule SIK inhibitor YKL-05-099 increases bone formation and bone mass. Therefore, a major arm of PTH signalling in osteocytes involves SIK inhibition, and small molecule SIK inhibitors may be applied therapeutically to mimic skeletal effects of PTH.

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