Bone-fat linkage via interleukin-11 in response to mechanical loading.

Positive regulators of bone formation, such as mechanical loading and PTH, stimulate and negative regulators, such as aging and glucocorticoid excess, suppress IL-11 gene transcription in osteoblastic cells. Signal transduction from mechanical loading and PTH stimulation involves two pathways: one is Ca2+-ERK-CREB pathway which facilitates binding of ∆FosB/JunD to the AP-1 site to enhance IL-11 gene transcription, and the other is Smad1/5 phosphorylation that promotes IL-11 gene transcription via SBE binding and complex formation with ∆FosB/JunD. The increased IL-11 suppresses Sost expression via IL-11Rα-STAT1/3-HDAC4/5 pathway and enhances Wnt signaling in the bone to stimulate bone formation. Thus, IL-11 mediates stimulatory and inhibitory signals of bone formation by affecting Wnt signaling. Physiologically important stimulation of bone formation is exercise-induced mechanical loading, but exercise simultaneously requires energy source for muscle contraction. Exercise-induced stimulation of IL-11 expression in the bone increases the secretion of IL-11 from the bone. The increased circulating IL-11 acts like a hormone to enhance adipolysis as an energy source with a reduction in adipogenic differentiation via a suppression of Dkk1/2 expression in the adipose tissue. Such bone-fat linkage can be a mechanism whereby exercise increases bone mass and, at the same time, maintains energy supply from the adipose tissue.

Inflammatory Cytokine-Induced Muscle Atrophy and Weakness Can Be Ameliorated by an Inhibition of TGF-ß-Activated Kinase-1.

Chronic inflammation causes muscle wasting. Because most inflammatory cytokine signals are mediated via TGF-ß-activated kinase-1 (TAK1) activation, inflammatory cytokine-induced muscle wasting may be ameliorated by the inhibition of TAK1 activity. The present study was undertaken to clarify whether TAK1 inhibition can ameliorate inflammation-induced muscle wasting. SKG/Jcl mice as an autoimmune arthritis animal model were treated with a small amount of mannan as an adjuvant to enhance the production of TNF-α and IL-1ß. The increase in these inflammatory cytokines caused a reduction in muscle mass and strength along with an induction of arthritis in SKG/Jcl mice. Those changes in muscle fibers were mediated via the phosphorylation of TAK1, which activated the downstream signaling cascade via NF-κB, p38 MAPK, and ERK pathways, resulting in an increase in myostatin expression. Myostatin then reduced the expression of muscle proteins not only via a reduction in MyoD1 expression but also via an enhancement of Atrogin-1 and Murf1 expression. TAK1 inhibitor, LL-Z1640-2, prevented all the cytokine-induced changes in muscle wasting. Thus, TAK1 inhibition can be a new therapeutic target of not only joint destruction but also muscle wasting induced by inflammatory cytokines.

Cancer-nerve interplay in cancer progression and cancer-induced bone pain.

INTRODUCTION: Cancer-induced bone pain (CIBP) is one of the most common and debilitating complications associated with bone metastasis. Although our understanding of the precise mechanism is limited, it has been known that bone is densely innervated, and that CIBP is elicited as a consequence of increased neurogenesis, reprogramming, and axonogenesis in conjunction with sensitization and excitation of sensory nerves (SNs) in response to the noxious stimuli that are derived from the tumor microenvironment developed in bone. Recent studies have shown that the sensitized and excited nerves innervating the tumor establish intimate communications with cancer cells by releasing various tumor-stimulating factors for tumor progression. APPROACHES: In this review, the role of the interactions of cancer cells and SNs in bone in the pathophysiology of CIBP will be discussed with a special focus on the role of the noxious acidic tumor microenvironment, considering that bone is in nature hypoxic, which facilitates the generation of acidic conditions by cancer. Subsequently, the role of SNs in the regulation of cancer progression in the bone will be discussed together with our recent experimental findings. CONCLUSION: It is suggested that SNs may be a newly-recognized important component of the bone microenvironment that contribute to not only in the pathophysiology of CIBP but also cancer progression in bone and dissemination from bone. Suppression of the activity of bone-innervating SNs, thus, may provide unique opportunities in the treatment of cancer progression and dissemination, as well as CIBP.

Myeloma bone disease: pathogenesis and management in the era of new anti-myeloma agents.

INTRODUCTION: Multiple myeloma (MM) is a malignancy of plasma cells with characteristic bone disease. Despite recent great strides achieved in MM treatment owing to the implementation of new anti-MM agents, MM is still incurable and bone destruction remains a serious unmet issue in patients with MM. APPROACH: In this review, we will summarize and discuss the mechanisms of the formation of bone disease in MM and the available preclinical and clinical evidence on the treatment for MM bone disease. CONCLUSIONS: MM cells produce a variety of cytokines to stimulate receptor activator of nuclear factor-κB ligand-mediated osteoclastogenesis and suppress osteoblastic differentiation from bone marrow stromal cells, leading to extensive bone destruction with rapid loss of bone. MM cells alter the microenvironment through bone destruction where they colonize, which in turn favors tumor growth and survival, thereby forming a vicious cycle between tumor progression and bone destruction. Denosumab or zoledronic acid is currently recommended to be administered at the start of treatment in newly diagnosed patients with MM with bone disease. Proteasome inhibitors and the anti-CD38 monoclonal antibody daratumumab have been demonstrated to exert bone-modifying activity in responders. Besides their anti-tumor activity, the effects of new anti-MM agents on bone metabolism should be more precisely analyzed in patients with MM. Because prognosis in patients with MM has been significantly improved owing to the implementation of new agents, the therapeutic impact of bone-modifying agents should be re-estimated in the era of these new agents.

Nonsurgical orthodontic treatment for a patient with Sotos syndrome.

Sotos syndrome is a genetic disorder characterized by overgrowth in childhood, specific facial manifestations, advanced bone age, and mental retardation. The purpose of this article is to describe the nonsurgical orthodontic treatment of a 10-year-old boy with a skeletal mandibular protrusion, unilateral posterior crossbite, and Sotos syndrome. After maxillary lateral expansion, the skeletal Class III relationship with an anterior crossbite improved because of mandibular clockwise rotation, whereas the facemask had a marginal effect. After growth at 16 years, he had a skeletal Class I relationship, and thus, conventional orthodontic treatment with preadjusted edgewise appliances was initiated. After 41 months of multibracket treatment, acceptable occlusion with a functional Class I relationship was obtained. One year postretention, few changes in occlusion and facial features were observed. Our results demonstrate that considering the maxillofacial vertical growth during the peripubertal period associated with Sotos syndrome, more attention should be paid to the early orthopedic treatment with the facemask and/or chincap.

TAK1 is a pivotal therapeutic target for tumor progression and bone destruction in myeloma.

Along with the tumor progression, the bone marrow microenvironment is skewed in multiple myeloma (MM), which underlies the unique pathophysiology of MM and confers aggressiveness and drug resistance in MM cells. TGF-ß-activated kinase-1 (TAK1) mediates a wide range of intracellular signaling pathways. We demonstrate here that TAK1 is constitutively overexpressed and phosphorylated in MM cells, and that TAK1 inhibition suppresses the activation of NF-κB, p38MAPK, ERK and STAT3 to decrease the expression of critical mediators for MM growth and survival, including PIM2, MYC, Mcl-1, IRF4, and Sp1, along with a substantial reduction in the angiogenic factor VEGF in MM cells. Intriguingly, TAK1 phosphorylation was also induced along with upregulation of vascular cell adhesion molecule-1 (VCAM-1) in bone marrow stromal cells (BMSCs) in cocultures with MM cells, which facilitated MM cell-BMSC adhesion while inducing IL-6 production and receptor activator of nuclear factor κ-Β ligand (RANKL) expression by BMSCs. TAK1 inhibition effectively impaired MM cell adhesion to BMSCs to disrupt the support of MM cell growth and survival by BMSCs. Furthermore, TAK1 inhibition suppressed osteoclastogenesis enhanced by RANKL in cocultures of bone marrow cells with MM cells, and restored osteoblastic differentiation suppressed by MM cells or inhibitory factors for osteoblastogenesis overproduced in MM. Finally, treatment with the TAK1 inhibitor LLZ1640-2 markedly suppressed MM tumor growth and prevented bone destruction and loss in mouse MM models. Therefore, TAK1 inhibition may be a promising therapeutic option targeting not only MM cells but also the skewed bone marrow microenvironment in MM.

Long-term Management of a Patient with Apert Syndrome.

AIM AND OBJECTIVE: To present an Apert syndrome patient with midfacial growth deficiency treated with Le Fort III distraction osteogenesis and subsequent two-jaw surgery. BACKGROUND: Apert syndrome is expressed as a severe and irregular craniosynostosis, midfacial hypoplasia, and symmetric syndactyly in the fingers and toes. For craniosynostosis syndromes, treatment planning is complex due to the disharmony between facial profile and occlusion. CASE DESCRIPTION: A 4-year-and-5-month-old boy, diagnosed with Apert syndrome, showed a concave profile accompanied with midfacial hypoplasia, moderate exorbitism, a reversed occlusion of -10.0 mm, an anterior open bite of -5.0 mm, and skeletal class III jaw-base relationship. The patient, aged 15 years and 4 months, underwent a Le Fort III osteotomy, and subsequent osteodistraction was performed via a rigid external distraction (RED) device. His midfacial bone was advanced by approximately 7.0 mm. One year after the distraction, preoperative treatment with 0.018-in preadjusted edgewise appliances was initiated. Two-jaw surgery with a Le Fort I osteotomy and bilateral sagittal split ramus osteotomy was performed after 42 months of preoperative orthodontic treatment. At the age of 20 years and 9 months, his facial profile dramatically changed to a straight profile, and an acceptable occlusion with an adequate interincisal relationship was obtained. A functional occlusion with an excellent facial profile was maintained throughout the 2-year retention period, although the upper dental arch width was slightly decreased, resulting in the recurrence of the left posterior crossbite. CONCLUSION: Our report indicates the necessity of long-term follow-up in patients with craniosynostosis because of syndrome-specific growth and methodologically induced relapse. CLINICAL SIGNIFICANCE: The two-stage operation combining early distraction osteogenesis and postgrowth orthognathic surgery proves to be an effective therapy for correcting midfacial hypoplasia and skeletal mandibular protrusion caused by Apert syndrome.

A Long-term Follow-up of Mandibular Deviation Caused by Congenital Cervical Lymphangioma Treated with an Orthodontic Approach.

AIM: To report a treatment case of mandibular deviation caused by congenital cervical lymphangioma with traditional orthodontic techniques, following-up by 10-year retention. BACKGROUND: Lymphangiomas, developmental anomalies, can induce various disturbances of swallowing, mastication, speech, breathing, and skeletal deformities as well as psychological stress and anxiety for the patient and their family. Lymphangiomas are benign with virtually no possibility of turning into a malignant lesion, so clinical management aims to treat the patient functionally. CASE DESCRIPTION: A girl, aged 6 years and 4 months, complained about facial asymmetry and anterior crossbite caused by congenital cervical lymphangioma. Her facial profile was the straight type with an adequate lip position. Anterior and right-side posterior crossbites were observed. On the frontal cephalogram, the menton shifted 3.0 mm to the right. A functional appliance with an expander was placed to correct her dental midline deviation and posterior crossbite. After 2-year treatment, the anterior and right-side posterior crossbites were improved. Multibracket treatment began after the growth spurt. After 44-month active treatment, a functional occlusion, including a Class I molar relationship with a proper interincisal relationship, was achieved. A functional occlusion was maintained during a 10-year retention period, while a mandibular downward growth was observed through the retention period. CONCLUSION: Conventional orthodontic techniques enable functional and stable occlusion even in patients with mandibular deviation caused by congenital cervical lymphangioma, although only using early orthodontic management by itself may have some limitations. CLINICAL SIGNIFICANCE: The hybrid technique combining functional appliance and intermaxillary elastics proves to be an effective therapy for correcting occlusal cant and mandibular deviation caused by cervical lymphangioma.

Hemifacial Microsomia Caused by First and Second Brachial Arch Syndrome Treated with Orthodontic Approach: A Case Report.

AIM AND OBJECTIVE: To present a growing patient with unilateral mandibular hypoplasia and microtia involved in the first and second branchial arch syndrome (FSBAS) treated with functional appliance. BACKGROUND: The FSBAS comprises several developmental facial hypoplasia in ear and maxillofacial bones, resulting in hemifacial microsomia. Treatment for hemifacial microsomia varies greatly depending on the grade of mandibular deformities. Functional appliance treatment during growth period is available for mild to moderate mandibular deformities. However, there are few reports of hemifacial microsomia treated with functional appliance. CASE DESCRIPTION: The patient, an 8-year-and-5-month-old girl, had a chief complaint of mandibular deviation. She had been diagnosed with the FSBAS at birth. Her facial profile was straight and panoramic radiograph indicated that the mandibular ramal height of the affected side was about 60.4% compared to the unaffected side. The occlusal cant was 6°, and the right maxilla and mandible showed severe growth deficiency. At the age of 10 years, functional appliance with expander was used; for 2 years 6 months, the maxillomandibular growth was controlled and from panoramic radiograph, the ramus height of the affected side was increased to 65.0% compared to the unaffected left mandibular ramus. At the age of 12 years and 8 months, multibracket treatment was initiated. After 32 months of active treatment, proper occlusion with functional Class I canine and molar relationships was obtained, although facial asymmetry associated with the difference of ramus heights still existed. The resulting occlusion was stable during 1.5-year retention period. CONCLUSION: Our results indicated the importance of orthopedic treatment during growth period in the patient with hemifacial microsomia involving the FSBAS. CLINICAL SIGNIFICANCE: This report proposes an efficacy of conventional orthodontic treatment for growing patients with hemifacial microsomia involved in the FSBAS.

Unique anti-myeloma activity by thiazolidine-2,4-dione compounds with Pim inhibiting activity.

Proviral Integrations of Moloney virus 2 (PIM2) is overexpressed in multiple myeloma (MM) cells, and regarded as an important therapeutic target. Here, we aimed to validate the therapeutic efficacy of different types of PIM inhibitors against MM cells for their possible clinical application. Intriguingly, the thiazolidine-2,4-dione-family compounds SMI-16a and SMI-4a reduced PIM2 protein levels and impaired MM cell survival preferentially in acidic conditions, in contrast to other types of PIM inhibitors, including AZD1208, CX-6258 and PIM447. SMI-16a also suppressed the drug efflux function of breast cancer resistance protein, minimized the sizes of side populations and reduced in vitro colony-forming capacity and in vivo tumourigenic activity in MM cells, suggesting impairment of their clonogenic capacity. PIM2 is known to be subject to ubiquitination-independent proteasomal degradation. Consistent with this, the proteasome inhibitors bortezomib and carfilzomib increased PIM2 protein levels in MM cells without affecting its mRNA levels. However, SMI-16a mitigated the PIM2 protein increase and cooperatively enhanced anti-MM effects in combination with carfilzomib. Collectively, the thiazolidine-2,4-dione-family compounds SMI-16a and SMI-4a uniquely reduce PIM2 protein in MM cells, which may contribute to their profound efficacy in addition to their immediate kinase inhibition. Their combination with proteasome inhibitors is envisioned.

Crosstalk Between Sensory Nerves and Cancer in Bone.

PURPOSE OF REVIEW: Sensory nerves (SNs) richly innervate bone and are a component of bone microenvironment. Cancer metastasis in bone, which is under the control of the crosstalk with bone microenvironment, induces bone pain via excitation of SNs innervating bone. However, little is known whether excited SNs in turn affect bone metastasis. RECENT FINDINGS: Cancer cells colonizing bone promote neo-neurogenesis of SNs and excite SNs via activation of the acid-sensing nociceptors by creating pathological acidosis in bone, evoking bone pain. Denervation of SNs or inhibition of SN excitation decreases bone pain and cancer progression and increases survival in preclinical models. Importantly, patients with cancers with increased SN innervation complain of cancer pain and show poor outcome. SNs establish the crosstalk with cancer cells to contribute to bone pain and cancer progression in bone. Blockade of SN excitation may have not only analgesic effects on bone pain but also anti-cancer actions on bone metastases.

Effect of pulsed ultrasound toothbrush on Streptococcus mutans biofilm removal.

PURPOSE: To evaluate the effect of pulsed ultrasound toothbrush on the removal of biofilm formed by Streptococcus mutans (S. mutans). METHODS: S. mutans biofilm grown on apatite pellet was destructed with four different sonic action toothbrushes: 1) pulsed ultrasound with sonic vibration (PUV); 2) continuous ultrasound with sonic vibration (CUV); 3) sonic vibration only (SV); and 4) no ultrasound nor sonic vibration (control). After 3 minutes of noncontact brushing, the amount of water-insoluble glucan was measured, and the residual biofilm was observed by scanning electron microscopy. RESULTS: PUV group revealed the smallest amount of the residual water-insoluble glucans (32 ± 19%), followed by the CUV group (54 ± 12%) and the SV group (64 ± 13%). The PUV group showed a significantly lower amount of the residual water-insoluble glucan than the SV group, while no significant difference was found between SV and CUV. The bacterial adherence and aggregation notably decreased in the PUV group, compared to the remaining three groups. CLINICAL SIGNIFICANCE: The sonic vibration with pulsed ultrasound showed more reduction of the biofilm compared to the control and the sonic vibration with and without continuous ultrasound. Thus, pulsed ultrasound action may be beneficial for biofilm removal of interproximal regions.

[Bone and calcium metabolism associated with malignancy. Mechanism of cancer-induced bone pain.]

Patients with bone colonized cancer frequently suffer from severe uncontrollable cancer-associated bone pain(CABP)during the course of illness. However, since current treatments do not satisfactorily control CABP and can elicit serious side effects, new therapeutic strategyies are needed to manage CABP. According to the recent study including ours, the cancer cell and osteoclast created-acidic extracellular microenvironment is expected to be therapeutic target for CABP.

Contribution of acidic extracellular microenvironment of cancer-colonized bone to bone pain.

Solid and hematologic cancer colonized bone produces a number of pathologies. One of the most common complications is bone pain. Cancer-associated bone pain (CABP) is a major cause of increased morbidity and diminishes the quality of life and affects survival. Current treatments do not satisfactorily control CABP and can elicit adverse effects. Thus, new therapeutic interventions are needed to manage CABP. However, the mechanisms responsible for CABP are poorly understood. The observation that specific osteoclast inhibitors can reduce CABP in patients indicates a critical role of osteoclasts in the pathophysiology of CABP. Osteoclasts create an acidic extracellular microenvironment by secretion of protons via vacuolar proton pumps during bone resorption. In addition, bone-colonized cancer cells also release protons and lactate via plasma membrane pH regulators to avoid intracellular acidification resulting from increased aerobic glycolysis known as the Warburg effect. Since acidosis is algogenic for sensory neurons and bone is densely innervated by sensory neurons that express acid-sensing nociceptors, the acidic bone microenvironments can evoke CABP. Understanding of the mechanism by which the acidic extracellular microenvironment is created in cancer-colonized bone and the expression and function of the acid-sensing nociceptors are regulated should facilitate the development of novel approaches for management of CABP. Here, the contribution of the acidic microenvironment created in cancer-colonized bone to elicitation of CABP and potential therapeutic implications of blocking the development and recognition of acidic microenvironment will be described. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.

Ex vivo expansion and activation of Vγ9Vδ2 T cells by CELMoDs in combination with zoledronic acid.

As multiple myeloma (MM) progresses, immune effector cells decrease in number and function and become exhausted. This remains an insurmountable clinical issue that must be addressed by development of novel modalities to revitalize anti-MM immunity. Human Vγ9Vδ2 T (Vδ2+ γδ T) cells serve as the first line of defense against pathogens as well as tumors and can be expanded ex vivo from peripheral blood mononuclear cells (PBMCs) upon treatment with amino-bisphosphonates in combination with IL-2. Here, we demonstrated that next-generation immunomodulators called cereblon E3 ligase modulators (CELMoDs), as well as lenalidomide and pomalidomide, expanded Th1-like Vδ2+ γδ T cells from PBMCs in the presence of zoledronic acid (ZA). However, the expansion of Th1-like Vδ2+ γδ T cells by these immunomodulatory drugs was abolished under IL-2 blockade, although IL-2 production was induced in PBMCs. BTN3A1 triggers phosphoantigen presentation to γδ T-cell receptors and is required for γδ T-cell expansion and activation. ZA but not these immunomodulatory drugs upregulated BTN3A1 in monocytes. These results suggest that immunomodulatory drugs and ZA have cooperative roles in expansion of Th1-like Vδ2+ γδ T cells, and provide the important knowledge for clinical application of human Vδ2+ γδ T cells as effector cells.

Acute accumulation of PIM2 and NRF2 and recovery of ß5 subunit activity mitigate multiple myeloma cell susceptibility to proteasome inhibitors.

Resistance to proteasome inhibitors (PIs) has emerged as an important clinical issue. We investigated the mechanisms underlying multiple myeloma (MM) cell resistance to PIs. To mimic their pharmacokinetic/pharmacodynamic (PK/PD) profiles, MM cells were treated with bortezomib and carfilzomib for 1 h at concentrations up to 400 and 1,000 nM, respectively. Susceptibility to these PIs markedly varied among MM cell lines. Pulsatile treatments with PIs suppressed translation, as demonstrated by incorporation of puromycin at 24 h in PI-susceptible MM.1S cells, but not PI-resistant KMS-11 cells. Inhibition of ß5 subunit activity decreased at 24 h in KMS-11 cells, even with the irreversible PI carfilzomib, but not under suppression of protein synthesis with cycloheximide. Furthermore, the proteasome-degradable pro-survival factors PIM2 and NRF2 acutely accumulated in MM cells subjected to pulsatile PI treatments. Accumulated NRF2 was trans-localized into the nucleus to induce the expression of its target gene, HMOX1, in MM cells. PIM and Akt inhibition restored the anti-MM effects of PIs, even against PI-resistant KMS-11 cells. Collectively, these results suggest that increased synthesis of ß5 proteasome subunit and acute accumulation of PIM2 and NRF2 reduce the anti-MM effects of PIs.