Publications by authors named "Yakar S"

Several mouse lines with congenital growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis disruption have shown improved health and extended lifespan. The current study investigated how inactivating this axis, specifically during aging, impacts the healthspan. We used a tamoxifen-inducible global GH receptor (GHR) knockout mouse model starting at 12 months and followed the mice until 24 months of age (iGHRKO mice).

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Canagliflozin (CANA) is a sodium glucose cotransporter-2 inhibitor that reduces blood glucose levels. Sodium glucose cotransporter-2 is primarily expressed in the kidney, but not in any bone cells, therefore effects on the skeleton are likely to be non-cell autonomous. Originally developed to treat type II diabetes, CANA use has expanded to treat cardiovascular and renovascular disease.

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Absent in melanoma (AIM) 2, a gene induced by interferon, acts as a cytosolic sensor for double-stranded (ds) DNA. It forms the AIM2 inflammasome, producing interleukin (IL)-1β and IL-18. Our previous study demonstrated that mice lacking AIM2 exhibit spontaneous obesity, insulin resistance, and inflammation in adipose tissue.

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Background: Primary osteoarthritis (OA) occurs without identifiable underlying causes such as previous injuries or specific medical conditions. Age is a major contributing factor to OA, and as one ages, various joint tissues undergo gradual change, including degeneration of the articular cartilage, alterations in subchondral bone (SCB) morphology, and inflammation of the synovium.

Methods: We investigated the prevalence of primary OA in aged, genetically diverse UM-HET3 mice.

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Methylene blue (MB) is a well-established antioxidant that has been shown to improve mitochondrial function in both and settings. Mitoquinone (MitoQ) is a selective antioxidant that specifically targets mitochondria and effectively reduces the accumulation of reactive oxygen species. To investigate the effect of long-term administration of MB on skeletal morphology, we administered MB to aged (18 months old) female C57BL/J6 mice, as well as to adult male and female mice with a genetically diverse background (UM-HET3).

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Article Synopsis
  • Primary osteoarthritis (OA) is a common age-related condition characterized by joint tissue degeneration, notably in articular cartilage and subchondral bone, without any obvious underlying causes.
  • The study focused on the prevalence of primary OA in aged UM-HET3 mice, assessing joint health through established scoring systems and examining the impact of agents like methylene blue (MB) and mitoquinone (MitoQ) on OA progression.
  • Findings revealed a high occurrence of OA, with significant correlations between joint inflammation, deterioration of cartilage, and inflammatory markers, alongside sex-specific responses to the treatments affecting the disease's development.
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Absent in Melanoma (AIM) 2 is a gene that is induced by interferon and acts as a cytosolic sensor for double-stranded (ds) DNA. It forms the AIM2 inflammasome, leading to the production of interleukin (IL)-1β and IL-18. Our previous research demonstrated that mice lacking AIM2 exhibit spontaneous obesity, insulin resistance, and inflammation in adipose tissue.

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This study investigated the prevalence and progression of primary osteoarthritis (OA) in aged UM-HET3 mice. Using the Osteoarthritis Research Society International (OARSI) scoring system, we assessed articular cartilage (AC) integrity in 182 knee joints of 22-25 months old mice. Aged UM-HET3 mice showed a high prevalence of primary OA in both sexes.

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Article Synopsis
  • SGLT2 inhibitors like Canagliflozin (CANA) help lower blood sugar and are commonly prescribed for type 2 diabetes, but there's concern about their impact on bone health.* -
  • Research conducted on mice showed that CANA treatment led to significant thinning of bone structures, particularly in male mice, affecting bone density and mineral composition.* -
  • The study indicates that long-term use of CANA could negatively affect bone integrity, potentially increasing the risk of fractures due to changes in bone morphology and mineral content.*
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Growth hormone (GH) is a key mediator of skeletal growth. In humans, excess GH secretion due to pituitary adenoma, seen in patients with acromegaly, results in severe arthropathies. This study investigated the effects of long-term excess GH on the knee joint tissues.

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Excess in growth hormone (GH) levels, seen in patients with acromegaly, is associated with increases in fractures. This happens despite wider bones and independent of bone mineral density. We used the bovine GH (bGH) transgenic mice, which show constitutive excess in GH and insulin-like growth factor 1 (IGF-1) in serum and tissues, to study how lifelong increases in GH and IGF-1 affect skeletal integrity.

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  • Fsp27 is a protein linked to lipid droplet regulation in fat cells, but its role in muscle function was previously unknown.
  • This study found that mice lacking Fsp27 showed significantly reduced muscle endurance and strength compared to normal mice, while glycogen levels remained consistent.
  • The research indicates that Fsp27 is crucial for fat storage in muscles and directly affects muscle performance, highlighting a metabolic paradox where Fsp27-knockout mice have healthy glucose metabolism but poor exercise capacity.
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  • The GH/IGF axis is crucial for development and aging, involving various proteins and receptors that are tightly regulated, although this regulation isn't fully understood.
  • Recent findings have identified mutations in the gene for the PAPP-A2 protease, which plays a key role in releasing IGFs from binding proteins to enable their action on IGF receptor 1.
  • This review discusses the effects of PAPP-A2 on growth physiology, drawing insights from studies on genetically modified animals and patients lacking PAPP-A2.
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Somatopause refers to the gradual declines in growth hormone (GH) and insulin-like growth factor-1 throughout aging. To define how induced somatopause affects skeletal integrity, we used an inducible GH receptor knockout (iGHRKO) mouse model. Somatopause, induced globally at 6 months of age, resulted in significantly more slender bones in both male and female iGHRKO mice.

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Studies in multiple species indicate that reducing growth hormone (GH) action enhances healthy lifespan. In fact, GH receptor knockout (GHRKO) mice hold the Methuselah prize for the world's longest-lived laboratory mouse. We previously demonstrated that GHR ablation starting at puberty (1.

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There is no cure for osteogenesis imperfecta (OI), and current treatments can only partially correct the bone phenotype. Stem cell therapy holds potential to improve bone quality and quantity in OI. Here, we conduct a systematic review and meta-analysis of published studies to investigate the efficacy of stem cell therapy to rescue bone brittleness in mouse models of OI.

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Osteoarthritis (OA), the most prevalent joint disease, is a major cause of disability worldwide. Growth hormone (GH) has been suggested to play significant roles in maintaining articular chondrocyte function and ultimately articular cartilage (AC) homeostasis. In humans, the age-associated decline in GH levels was hypothesized to play a role in the etiology of OA.

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The insulin-like growth factors (IGF) are important players in the development of gynecological malignancies, including epithelial ovarian cancer (EOC). The identification of biomarkers that can help in the diagnosis and scoring of EOC patients is of fundamental importance in clinical oncology. We have recently identified the gene as a new candidate target of IGF1 action.

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Endometrial cancer is the most common gynecologic malignancy in Western countries. The insulin-like growth factor-1 (IGF1) axis has an important role in endometrial cancer biology and emerged as a promising therapeutic target in oncology. However, there is an urgent need to identify biomarkers that may help in patient stratification and prognosis.

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Patients with type 1 diabetes mellitus (T1DM) exhibit reduced BMD and significant increases in fracture risk. Changes in BMD are attributed to blunted osteoblast activity and inhibited bone remodeling, but these cannot fully explain the impaired bone integrity in T1DM. The goal of this study was to determine the cellular mechanisms that contribute to impaired bone morphology and composition in T1DM.

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Objectives: Sternal fractures (SFs) are rare pathologies that mainly occur as a result of traffic accidents, which can cause mortality due to concomitant complications. In this study, we aimed to evaluate clinical processes and termination status of patients diagnosed with a SF in the emergency department.

Methodology: Patients diagnosed with a SF in the emergency department during 8 years were retrospectively reviewed.

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Membrane-type 1 matrix metalloproteinase (MT1-MMP, MMP-14), a transmembrane proteinase with a short cytoplasmic tail, is a major effector of extracellular matrix remodeling. Genetic silencing of MT1-MMP in mouse ( ) and man causes dwarfism, osteopenia, arthritis, and lipodystrophy, abnormalities ascribed to defective collagen turnover. We have previously shown non-proteolytic functions of MT1-MMP mediated by its cytoplasmic tail, where the unique tyrosine (Y573) controls intracellular signaling.

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A reduction in hepatocyte growth hormone (GH)-signaling promotes non-alcoholic fatty liver disease (NAFLD). However, debate remains as to the relative contribution of the direct effects of GH on hepatocyte function vs indirect effects, via alterations in insulin-like growth factor 1 (IGF1). To isolate the role of hepatocyte GH receptor (GHR) signaling, independent of changes in IGF1, mice with adult-onset, hepatocyte-specific GHR knockdown (aHepGHRkd) were treated with a vector expressing rat IGF1 targeted specifically to hepatocytes.

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Growth hormone (GH) and its mediator, the insulin-like growth factor-1 (IGF-1) regulate somatic growth, metabolism and many aspects of aging. As such, actions of GH/IGF have been studied in many tissues and organs over decades. GH and IGF-1 are part of the hypothalamic/pituitary somatotrophic axis that consists of many other regulatory hormones, receptors, binding proteins, and proteases.

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