Montelukast inhibits RANKL‑induced osteoclast formation and bone loss via CysLTR1 and P2Y12

1,4-dihydroxy quininib modulates the secretome of uveal melanoma tumour explants and a marker of oxidative phosphorylation in a metastatic xenograft model

Uveal melanoma (UM) is an intraocular cancer with propensity for liver metastases. The median overall survival (OS) for metastatic UM (MUM) is 1.07 years, with a reported range of 0.84-1.34. In primary UM, high cysteinyl leukotriene receptor 1 (CysLT₁) expression associates with poor outcomes. CysLT₁ antagonists, quininib and 1,4-dihydroxy quininib, alter cancer hallmarks of primary and metastatic UM cell lines in vitro. Here, the clinical relevance of CysLT receptors and therapeutic potential of quininib analogs is elaborated in UM using preclinical in vivo orthotopic xenograft models and ex vivo patient samples. Immunohistochemical staining of an independent cohort (n = 64) of primary UM patients confirmed high CysLT₁ expression significantly associates with death from metastatic disease (p = 0.02; HR 2.28; 95% CI 1.08-4.78), solidifying the disease relevance of CysLT₁ in UM. In primary UM samples (n = 11) cultured as ex vivo explants, 1,4-dihydroxy quininib significantly alters the secretion of IL-13, IL-2, and TNF-α. In an orthotopic, cell line-derived xenograft model of MUM, 1,4-dihydroxy quininib administered intraperitoneally at 25 mg/kg significantly decreases ATP5B expression (p = 0.03), a marker of oxidative phosphorylation. In UM, high ATP5F1B is a poor prognostic indicator, whereas low ATP5F1B, in combination with disomy 3, correlates with an absence of metastatic disease in the TCGA-UM dataset. These preclinical data highlight the diagnostic potential of CysLT₁ and ATP5F1B in UM, and the therapeutic potential of 1,4-dihydroxy quininib with ATP5F1B as a companion diagnostic to treat MUM.

Emulate randomized clinical trials using heterogeneous treatment effect estimation for personalized treatments: Methodology review and benchmark

Big data and (deep) machine learning have been ambitious tools in digital medicine, but these tools focus mainly on association. Intervention in medicine is about the causal effects. The average treatment effect has long been studied as a measure of causal effect, assuming that all populations have the same effect size. However, no "one-size-fits-all" treatment seems to work in some complex diseases. Treatment effects may vary by patient. Estimating heterogeneous treatment effects (HTE) may have a high impact on developing personalized treatment. Lots of advanced machine learning models for estimating HTE have emerged in recent years, but there has been limited translational research into the real-world healthcare domain. To fill the gap, we reviewed and compared eleven recent HTE estimation methodologies, including meta-learner, representation learning models, and tree-based models. We performed a comprehensive benchmark experiment based on nationwide healthcare claim data with application to Alzheimer's disease drug repurposing. We provided some challenges and opportunities in HTE estimation analysis in the healthcare domain to close the gap between innovative HTE models and deployment to real-world healthcare problems.

Montelukast and Acute Coronary Syndrome: The Endowed Drug

Acute coronary syndrome (ACS) is a set of signs and symptoms caused by a reduction of coronary blood flow with subsequent myocardial ischemia. ACS is associated with activation of the leukotriene (LT) pathway with subsequent releases of various LTs, including LTB4, LTC4, and LTD4, which cause inflammatory changes and induction of immunothrombosis. LTs through cysteine leukotriene (CysLT) induce activation of platelets and clotting factors with succeeding coronary thrombosis. CysLT receptor (CysLTR) antagonists such as montelukast (MK) may reduce the risk of the development of ACS and associated complications through suppression of the activation of platelet and clotting factors. Thus, this critical review aimed to elucidate the possible protective role of MK in the management of ACS. The LT pathway is implicated in the pathogenesis of atherosclerosis, cardiac hypertrophy, and heart failure. Inhibition of the LT pathway and CysL1TR by MK might be effective in preventing cardiovascular complications. MK could be an effective novel therapy in the management of ACS through inhibition of pro-inflammatory CysLT1R and modulation of inflammatory signaling pathways. MK can attenuate thrombotic events by inhibiting platelet activation and clotting factors that are activated during the development of ACS. In conclusion, MK could be an effective agent in reducing the severity of ACS and associated complications. Experimental, preclinical, and clinical studies are recommended to confirm the potential therapeutic of MK in the management of ACS.

Mast Cells and Vitamin D Status: A Clinical and Biological Link in the Onset of Allergy and Bone Diseases

The immune system is made up by an extremely composite group of cells, whose regulated and harmonious activity is fundamental to maintain health. The mast cells are an essential effector of inflammatory response which is characterized by a massive release of mediators accumulated in cytoplasmic secretory granules. However, beyond the effects on immune response, mast cells can modify bone metabolism and are capable of intervening in the genesis of pathologies such as osteoporosis and osteopenia. Vitamin D is recognized to induce changes in bone metabolism, but it is also able to influence immune response, suppressing mast cell activation and IgE synthesis from B cells and increasing the number of dendritic cells and IL-10-generating regulatory T cells. Vitamin D deficit has been reported to worsen sensitization and allergic manifestations in several different experimental models. However, in clinical situations, contradictory findings have been described concerning the correlation between allergy and vitamin D deficit. The aim of this review was to analyze the close relationships between mast cells and vitamin D, which contribute, through the activation of different molecular or cellular activation pathways, to the determination of bone pathologies and the onset of allergic diseases.

Upregulation of P2Y12 inhibits chondrocyte apoptosis in lumbar osteoarthritis through the PI3K/AKT signaling pathway

Lumbar facet osteoarthritis (FJOA) is a major cause of severe lower back pain and disability worldwide. However, the mechanism underlying cartilage degeneration in FJOA remains unclear. The purpose of this study was to investigate the regulation and mechanism of P2Y12 on chondrocyte apoptosis in FJOA. The experimental rats were randomly divided into non-operation (n = 20) and operation groups (n = 20). In the operation group, Sodium iodoacetate (MIA, Sigma, 200 mg/mL) was injected into the right L4/5 facet process using a blunt nanoneedle 26 (WPI, Sarasota, FL, USA) under the control of an injection pump. The final injection volume was 5µL and the injection rate was 2µL/min. The facet joint was removed four weeks after surgery. After the operation, samples were stored at -80 °C until further use, whereby the right facet joints in each group were tested. Hematoxylin and eosin (HE) and iron-red solid green staining were used to observe the degeneration of articular chondrocytes in rats. Immunohistochemistry and western blotting were used to observe the expressions of P2Y12, Matrix metalloproteinase 13 (MMP13), Collagen II (COL2), and other cartilage degeneration and apoptosis-related genes. Co-localization of P2Y12-cleaved caspase-3 in the apoptosis model was detected by dual-standard immunofluorescence staining. Apoptosis was also detected by flow cytometry and TUNEL assay.P2Y12 is highly expressed in OA cartilage tissue, and inhibits IL-1β -induced chondrocyte apoptosis through PI3K/AKT signaling pathway, thus playing a certain protective role on cartilage.

Vitamin D Deficiency, Osteoporosis and Effect on Autoimmune Diseases and Hematopoiesis: A Review

Vitamin D (VD) is essential for bone homeostasis, but it is also involved in pleiotropic effects on various organs and tissues. In adults, VD deficiency can cause or exacerbate osteoporosis and induce osteomalacia. However, every tissue and cell in the body has a VD receptor, including the brain, heart, stomach, pancreas, skin, gonads, and immune cells, and a deficiency may modify the function of these organs. Thus, the wide-ranging actions of VD help to explain why a reduction in VD amount has been correlated with numerous chronic diseases. In fact, VD deficiency increases the risk of osteoporosis and several other diseases and complications characterized by impaired bone metabolisms, such as autoimmune diseases, inflammatory bowel diseases, allergy, endocrinological diseases, hematological malignancies, and bone marrow transplantation. This review aims to investigate the link between VD deficiency, osteoporosis, and its concomitant diseases. Further epidemiological and mechanistic studies are necessary in order to ascertain the real role of hypovitaminosis in causing the reported diseases; however, adequate vitamin supplementation and restoration of metabolic normality could be useful for better management of these pathologies.

Does Allergy Break Bones? Osteoporosis and Its Connection to Allergy

: Osteoporosis and allergic diseases are important causes of morbidity, and traditionally their coexistence has been attributed to causality, to independent processes, and they were considered unrelated. However, the increasing knowledge in the field of osteoimmunology and an increasing number of epidemiological and biological studies have provided support to a correlation between bone and allergy that share pathways, cells, cytokines and mediators. If the link between allergic pathology and bone alterations appears more subtle, there are conditions such as mastocytosis and hypereosinophilic or hyper-IgE syndromes characterized by the proliferation of cells or hyper-production of molecules that play a key role in allergies, in which this link is at least clinically more evident, and the diseases are accompanied by frank skeletal involvement, offering multiple speculation cues. The pathophysiological connection of allergy and osteoporosis is currently an intriguing area of research. The aim of this review is to summarize and bring together the current knowledge and pursue an opportunity to stimulate further investigation.

Cysteinyl leukotriene receptor antagonism: a promising pharmacological strategy for lowering the severity of arthritis

BACKGROUND AND AIMS

Though cyclooxygenase inhibitors are employed in rheumatoid arthritis treatment, modulators of leukotrienes are underexplored. We investigated the therapeutic potential of montelukast, a known cysteinyl leukotriene receptor-1 (CysLT1) inhibitor in an experimental rat model of arthritis.

METHODS

Arthritis was induced in rats, and montelukast (5 mg/kg body wt.) was administered prophylactically (PAM) and therapeutically (TAM) through oral route.

RESULTS AND DISCUSSION

Blood and joint tissue markers of oxidative stress (lipid peroxidation, protein carbonyls, and nitric oxides) were significantly (p < 0.05) reduced in montelukast administered rats. Paw inflammation, RA markers (RF and CRP), eicosanoids (PGE₂, LTB₄, and LTC₄), cytokines (IL-1β and MCP-1), activity of hydrolytic enzymes (collagenase, elastase, and hyaluronidase), expression of matrix metalloproteinases (MMP), and EP-4 receptor were significantly (p < 0.05) reduced in montelukast administered rats. This study established that leukotriene inhibition through montelukast lowered the severity of arthritis and thus a potential strategy for reducing the severity of arthritis.

Small Molecules Enhance Scaffold-Based Bone Grafts via Purinergic Receptor Signaling in Stem Cells

The need for bone grafts is high, due to age-related diseases, such as tumor resections, but also accidents, risky sports, and military conflicts. The gold standard for bone grafting is the use of autografts from the iliac crest, but the limited amount of accessible material demands new sources of bone replacement. The use of mesenchymal stem cells or their descendant cells, namely osteoblast, the bone-building cells and endothelial cells for angiogenesis, combined with artificial scaffolds, is a new approach. Mesenchymal stem cells (MSCs) can be obtained from the patient themselves, or from donors, as they barely cause an immune response in the recipient. However, MSCs never fully differentiate in vitro which might lead to unwanted effects in vivo. Interestingly, purinergic receptors can positively influence the differentiation of both osteoblasts and endothelial cells, using specific artificial ligands. An overview is given on purinergic receptor signaling in the most-needed cell types involved in bone metabolism-namely osteoblasts, osteoclasts, and endothelial cells. Furthermore, different types of scaffolds and their production methods will be elucidated. Finally, recent patents on scaffold materials, as wells as purinergic receptor-influencing molecules which might impact bone grafting, are discussed.