Euphemie Bassonga

University of Western Australia | UWA · Medical School / Faculty of Health and Medical Sciences

Osteoclasts are giant bone-digesting cells that harbor specialized lysosome-related organelles termed secretory lysosomes (SLs). SLs store cathepsin K and serve as a membrane precursor to the ruffled border, the osteoclast’s ‘resorptive apparatus’. Yet, the molecular composition and spatiotemporal organization of SLs remains incompletely understood...

Osteoclasts are giant bone-digesting cells that harbour specialized lysosome-related organelles termed secretory lysosomes (SLs). SLs store cathepsin K and serve as a membrane precursor to the ruffled border, the osteoclast’s ‘resorptive apparatus’. Yet, the molecular composition and spatiotemporal organization of SLs remains incompletely understoo...

Background Rotator Cuff (RC) tendon tearing is a common clinical problem and there is a high incidence of revision surgery due to re-tearing. In an effort to improve patient outcome and reduce surgical revision, scaffolds have been widely used for augmentation of RC repairs. However, little is known about how scaffolds support tendon stem cell grow...

Background Botulinum toxin (Botox) injection is in widespread clinical use for the treatment of muscle spasms and tendinopathy but the mechanism of action is poorly understood. Hypothesis We hypothesised that the reduction of patellar-tendon mechanical-loading following intra-muscular injection of Botox results in tendon atrophy that is at least i...

Background Botulinum toxin (Botox) injection is in widespread clinical use for the treatment of muscle spasms and tendinopathy but the mechanism of action is poorly understood. Hypothesis We hypothesised that the reduction of patellar-tendon mechanical-loading following intra-muscular injection of Botox results in tendon atrophy that is at least i...

Background: Botulinum toxin (Botox) injection is in widespread clinical use for the treatment of muscle spasms and tendinopathy but the mechanism of action is poorly understood. Hypothesis: We hypothesised that the reduction of patellar-tendon mechanical-loading following intra-muscular injection of Botox results in tendon atrophy that is at least...

Treatment of cortical bone defects is a clinical challenge. Guided bone regeneration (GBR), commonly used in oral in maxillofacial dental surgery, may show promise for orthopedic application in repair of cortical defects. However, a limitation in the use of GBR for cortical bone defects is the lack of an ideal scaffold that provides sufficient mech...

Background: Treatment of cortical bone defects is a clinical challenge. Guided bone regeneration (GBR), commonly used in oral in maxillofacial dental surgery, may show promise for orthopedic application in repair of cortical defects. However, a limitation in the use of GBR for cortical bone defects is the lack of an ideal scaffold that provides suf...

Objectives Obesity is a well-recognised risk factor for osteoarthritis (OA). Our aim is to characterise body mass index (BMI)-associated pathological changes in the osteochondral unit and determine if obesity is the major causal antecedent of early joint replacement in patients with OA. Methods We analysed the correlation between BMI and the age a...

Alveolar bone loss is a common problem that affects dental implant placement. A barrier between the bone substitute and gingiva that can prevent fibro-tissue ingrowth, bacterial infection and induce bone formation is a key factor in improving the success of alveolar ridge reconstruction. This study aims to develop a bioactive collagen barrier mater...

Micro-CT analysis has become the standard method for assessing bone volume and architecture in small animals. However, micro-CT does not allow the assessment of bone turnover parameters such as bone formation rate and osteoclast (OC) number and surface. For these crucial variables histomorphometric analysis is still an essential technique. Histomor...

The parathyroid hormone 1 receptor (PTHR) is central to the process of bone formation and remodelling. PTHR signaling requires receptor internalisation into endosomes, which is then terminated by recycling or degradation. Here we show that sorting nexin 27 (SNX27) functions as an adaptor that couples PTHR to the retromer trafficking complex. SNX27...

Osteoclasts (OCs) play a pivotal role in a variety of lytic bone diseases including osteoporosis, arthritis, bone tumors, Paget's disease and the aseptic loosening of orthopedic implants. The primary focus for the development of bone-protective therapies in these diseases has centered on the suppression of OC formation and function. In this study w...

Objectives To analyze the differences in microarchitecture and bone remodeling of subchondral bone in femoral heads from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Designs Peri-articualr bone samples, including subchondral trabecular bone (STB) and deeper trabecular bone (DTB) were extracted from the load-bearing region of fe...

Identification of functional programmable mechanical stimulation (PMS) on tendon not only provides the insight of the tendon homeostasis under physical/pathological condition, but also guides a better engineering strategy for tendon regeneration. The aims of the study are to design a bioreactor system with PMS to mimic the in vivo loading condition...

Mutations of SQSTM1 occur in about10% of patients with Paget's disease of bone (PDB), but it is unclear whether they play a causal role or regulate susceptibility to an environmental trigger. Here we show that mice with a proline to leucine mutation at codon 394 of mouse sqstm1 (P394L), equivalent to the P392L SQSTM1 mutation in humans, develop a b...

The type 2 cannabinoid receptor (CB2) has been reported to regulate bone mass and bone turnover but the mechanisms responsible are incompletely understood. In this study we investigated the role that the CB2 pathway plays in bone metabolism using a combination of genetic and pharmacological approaches. Bone mass and turnover were normal in young mi...

The NFκB pathway plays a critical role in the regulation of osteoclast activity, and activation of the pathway is dependent on IκB kinase (IKK), which phosphorylates IκB, targeting it for proteasomal degradation. Pharmacological inhibitors of IKK exhibit anti-inflammatory properties and prevent bone erosions in models of inflammatory arthritis. How...

The vanilloid type 1 ion channel (TRPV1) is known to play an important role in the regulation of pain and inflammation. Pharmacological ligands of TRPV1 regulate human osteoclast formation in vitro, but the effects of these agents on osteoblast function have not been studied and their effects on bone loss in vivo are unknown. Here we examined the e...

Age-related osteoporosis is characterized by reduced bone formation and accumulation of fat in the bone marrow compartment. Here, we report that the type 1 cannabinoid receptor (CB1) regulates this process. Mice with CB1 deficiency (CB1(-/-)) had increased peak bone mass due to reduced bone resorption, but developed age-related osteoporosis with re...

The NF-kappaB signaling pathway is known to play an important role in the regulation of osteoclastic bone resorption and cancer cell growth. Previous studies have shown that genetic inactivation of IkappaB kinase (IKK), a key component of NF-kappaB signaling, inhibits osteoclastogenesis, but the effects of pharmacologic IKK inhibitors on osteolytic...

Osteoporosis is characterised by reduced bone formation with replacement of the bone marrow compartment by fat, due to an age-dependent reduction in osteoblast differentiation and a reciprocal increase in adipocyte differentiation. Here we report that the type 1 cannabinoid receptor (CB1) regulates this process to protect against age related bone l...

The NF-κB signaling pathway is known to play an impor-tant role in the regulation of osteoclastic bone resorptionand cancer cell growth. Previous studies have shown thatgenetic inactivation of IκB kinase (IKK), a key componentof NF-κB signaling, inhibits osteoclastogenesis, but the ef-fects of pharmacologic IKK inhibitors on osteolytic bonemetastas...

Pharmacological modulators of beta-adrenoceptors can influence bone mineral density and fracture risk in humans. Studies reported that beta-adrenoceptor ligands stimulate bone resorption by enhancing the expression of RANK-L, whereas the mechanisms by which beta-adrenoreceptors regulate bone formation are poorly understood. Here we show that beta2-...

The endocannabinoid system has recently been shown to play a role in the regulation of bone metabolism. The type 2 cannabinoid receptor (CB2) has been reported to regulate bone mass, but conflicting results have been reported with regard to its effects on bone resorption and osteoclast function. Here we investigated the role that CB2 plays in regul...

Bisphosphonates are widely used in the treatment of osteoporosis, but they inhibit bone formation and blunt the anabolic effect of PTH. Here we describe a novel series of compounds that have potent antiresorptive effects in vitro and in vivo that do not adversely affect osteoblast function. The effects of the compounds on osteoclast formation and s...

We have shown recently that some indigestible carbohydrate (short-chain fructo-oligosaccharides [sc-FOS]) reduced colon tumor incidence in Apc+/Min mice, and that this effect depended on a functional local immune system. In addition, IL-15 mRNA was concomitantly modulated in the mucosa. Since intraepithelial lymphocytes (IELs) are in close contact...

Adenomatous polyposis coli (APC) functions are involved in the heterotypic interactions occurring between intestinal epithelial cells (IECs) and intra-epithelial lymphocytes (IELs). These interactions may be of interest in cancer prevention, since recent data provide evidence for lymphocyte mediated immunosurveillance of epithelial cancers. The pre...

On the basis of studies using the Min mouse model of colon carcinogenesis, we have recently proposed that a fibre-like food (short-chain fructo-oligosaccharides, sc-FOS) fermented in the colon may stimulate a mechanism of cancer immunosurveillance. In the present paper, we have investigated the expression of cytokines as potential effector molecule...

We have previously shown that addition of short chain fructo-oligosaccharides (indigestible carbohydrates) to food prevented colon tumors in C57BL/6-ApcMin/+ mice, a model for human colon cancer. As gut-associated lymphoid tissue was concomitantly developed, we suggested that the immune response generated by this food may interfere with carcinogene...