Reduced expression of semaphorin 3A in osteoclasts causes lymphatic expansion in a Gorham-Stout disease (GSD) mouse model. / ç ´éª¨ç»†èƒžä¸­ä¿¡å·ç´ 3Aè¡¨è¾¾çš„å‡å°‘å¯¼è‡´å°é¼ GSDæ¨¡åž‹ä¸­æ·‹å·´ç®¡æ‰©å¼ .

Gorham-Stout disease (GSD) is a sporadic chronic disease characterized by progressive bone dissolution, absorption, and disappearance along with lymphatic vessel infiltration in bone-marrow cavities. Although the osteolytic mechanism of GSD has been widely studied, the cause of lymphatic hyperplasia in GSD is rarely investigated. In this study, by comparing the RNA expression profile of osteoclasts (OCs) with that of OC precursors (OCPs) by RNA sequencing, we identified a new factor, semaphorin 3A (Sema3A), which is an osteoprotective factor involved in the lymphatic expansion of GSD. Compared to OCPs, OCs enhanced the growth, migration, and tube formation of lymphatic endothelial cells (LECs), in which the expression of Sema3A is low compared to that in OCPs. In the presence of recombinant Sema3A, the growth, migration, and tube formation of LECs were inhibited, further confirming the inhibitory effect of Sema3A on LECs in vitro. Using an LEC-induced GSD mouse model, the effect of Sema3A was examined by injecting lentivirus-expressing Sema3A into the tibiae in vivo. We found that the overexpression of Sema3A in tibiae suppressed the expansion of LECs and alleviated bone loss, whereas the injection of lentivirus expressing Sema3A short hairpin RNA (shRNA) into the tibiae caused GSD-like phenotypes. Histological staining further demonstrated that OCs decreased and osteocalcin increased after Sema3A lentiviral treatment, compared with the control. Based on the above results, we propose that reduced Sema3A in OCs is one of the mechanisms contributing to the pathogeneses of GSD and that expressing Sema3A represents a new approach for the treatment of GSD.

The impact of sirolimus therapy on lesion size, clinical symptoms, and quality of life of patients with lymphatic anomalies.

BACKGROUND: Lymphatic anomalies (LAs) include several disorders in which abnormal lymphatic tissue invades the neck, chest, and various organs. Progressive cases may result in lethal outcomes and have proven difficult to treat. Sirolimus is showing promising results in the management of vascular anomalies. We examined the efficacy and safety of sirolimus treatment in patients with progressive LAs. METHODS: All patients with LAs treated with sirolimus from May 2015 to September 2018 were included. They received oral sirolimus once a day and the dose was adjusted so that the trough concentration remained within 5-15 ng/mL. We prospectively reviewed the response to drugs (the response rate of radiological volumetric change of the target lesion), severity scores, reported quality of life (QOL), and adverse effects at 6 months after administration. RESULTS: Twenty patients (five with cystic lymphatic malformation (LM), three with kaposiform lymphangiomatosis, three with generalized lymphatic anomaly, six with Gorham-Stout disease, and three with central conducting lymphatic anomaly) were treated with sirolimus at our institution. Fifty percent of patients (10/20) demonstrated a partial response by a radiological examination and a significant improvement in disease severity and QOL scores (P = 0.0020 and P = 0.0117, respectively). Ten patients who had no reduction in lesion size (stable disease group) showed no significant improvement in disease severity and QOL scores. Eighty percent of patients (16/20) had side effects, such as stomatitis, infection, and hyperlipidemia. CONCLUSIONS: Sirolimus impacts the reduction of the lymphatic tissue volume of LMs and could lead to improvement in clinical symptoms and QOL. TRIAL REGISTRATION: UMIN Clinical Trials Registry, UMIN000016580 . Registered 19 February 2015.

[Lymphangiomatosis and Gorham-Stout disease].

Lymphangiomatosis (recently renamed "generalized lymphatic anomaly") is a rare disease of unknown etiology that features an increase in the number of lymphatic vessels in many different tissues. Gorham-Stout disease(GSD) is a related disease characterized by lymphatic vessels involving the bones and resulting in progressive bone destruction. Respective definitions remain unclear because these conditions largely overlap in the clinical setting and are both associated with pleural effusion and other visceral lesions. These two conditions have recently been differentiated based on imaging findings. GSD is characterized by progressive osteolysis with loss of cortical bone. These diseases present considerable diagnostic and therapeutic challenges. Implementation of basic and clinical research is mandatory to improve understanding of these conditions and optimize management.

Induction of retinol-binding protein 4 and placenta-specific 8 expression in human prostate cancer cells remaining in bone following osteolytic tumor growth inhibition by osteoprotegerin.

New drugs that inhibit the osteoprotegerin (OPG)/receptor activator of NF-κB ligand (RANKL)/RANK pathway have demonstrated efficacy for the treatment of bone metastasis. Toxicities induced by these drugs, however, including osteonecrosis of the jaw and hypocalcemia, may adversely affect therapy. The aim of this study was to identify additional therapeutic targets that can be combined with OPG/RANKL/RANK pathway inhibition in the treatment of prostate cancer bone metastasis. We established a stable transfectant that produces high levels of OPG mRNA and protein from PC-3 human prostate cancer cells (PC3-OPG). The culture medium of PC3-OPG cells significantly inhibited the differentiation of mouse monocytes into mature osteoclasts. Furthermore, when PC3-OPG cells were injected into the bones of nude mice, bone destruction and tumor-induced osteoclast formation were reduced. Injection into bone of the mixtures containing equal amounts of green fluorescent protein (GFP)-expressing PC-3 cells (PC3-GFP) and PC3-OPG cells also reduced bone destruction, compared to the control mixture. PC3-GFP cells were subsequently isolated from bone tumors and used for microarray analysis to assess changes in gene expression following osteolytic tumor growth inhibition by OPG. We selected the top 10 upregulated genes based on results from microarrays and confirmed mRNA expression of each gene by RT-PCR. The expression patterns of retinol-binding protein 4 (RBP4) and placenta-specific 8 (PLAC8) were consistent with microarray results. Expression of these genes was also increased in the bone tumors of PC3-GFP/PC3-OPG-injected mice. Knockdown of both RBP4 and PLAC8 by siRNA inhibited the growth of PC-3 cells in vitro. Thus, RBP4 and PLAC8 may become new therapeutic targets for prostate cancer bone metastasis, in combination with OPG/RANKL/RANK pathway inhibition.

CD105/endoglin expression in Gorham disease of bone.

BACKGROUND: Gorham disease is a rare pathological condition characterised by a proliferation of vascular channels of haematic and lymphatic origin in bone and adjacent soft tissues, which results in a progressive destruction of the involved bone segment. AIM: To evaluate expression of the vascular endothelial cell marker CD105/endoglin in Gorham disease of bone. METHODS: An immunohistochemical analysis was conducted on four cases of Gorham disease of bone, and for comparison on eight cases of conventional haemangioma of bone and on normal fetal and adult bone tissue specimens. RESULTS: Diffuse and intense immunostaining of endothelial cells for CD105 was observed in the specimens of fetal bone in areas undergoing ossification and in the growth plate of young adults. In medullary bone, CD105 positivity was limited to sinusoids of haemopoietic marrow, while endothelial cells of capillaries and small arterioles and venules within fatty marrow were either negative or showed weak immunostaining. The mean percentage of positive vessels in Gorham disease was significantly higher than in osseous haemangioma (58.9 (SEM 14.9) vs 17.2 (SEM 12.0); p = 0.03, Mann-Whitney U test). A significant direct correlation was observed between the proliferative activity assessed by MIB-1 immunostaining, and the percentage of CD105 positive vessels in the entire series (r = 0.681; p = 0.01). CONCLUSIONS: Data indicate that the phenotype of proliferating endothelial cells of Gorham disease is similar to that of the endothelial lining of vessels of metabolically active bone characterised by high expression of CD105, while that of conventional haemangioma is more similar to that of metabolically quiescent bone tissue, such as fatty marrow, with low levels of expression of CD105. This may have potential therapeutic and diagnostic applications.

Is angiomatosis an intrinsic pathohistological feature of massive osteolysis? Report of an autopsy case and a review of the literature.

We report here an autopsied patient who had died during the clinical course of massive osteolysis (MO), which is a rare chronic disease that begins insidiously and is characterized by progressive regional loss of bone. Since the original description by Gorham and Stout in 1955, vascular proliferation, e.g., hemangiomatosis, has been considered to be the characteristic feature related to the pathogenesis. However, no such vascular changes were observed in the present patient. It was also important to note that a significant number of cases of MO that showed no vascular proliferation have been described previously. Therefore, we consider that vascular proliferation is not always associated with the osteolysis in MO and that the increased vascularity, if any, may be one of the results of the disease rather than the cause.

High turnover osteoporosis in acro-osteolysis (Hajdu-Cheney syndrome).

Acro-osteolysis with diffuse osteoporosis in the absence of other associated diseases is named Hajdu-Cheney syndrome. Reduced bone formation rather than enhanced bone resorption has been indicated as the mechanism of osteoporosis. On the assumption that in this syndrome the active bone resorption which produces distal osteolysis must also predominate in generalized osteoporosis, we investigated bone histology, calcium kinetics, calciotropic hormones and bone markers in a patient suffering from sporadic Hajdu-Cheney syndrome. A radius bone biopsy taken far from the osteolytic lesions showed severe osteoporosis with a marked increase in osteoclastic bone resorption and reduced bone formation. Total body calcium clearance, performed through an analysis of the kinetics of calcium infusion, was 2.8 times higher than in normal controls, indicating the presence of active osteoclastic bone resorption. Serum parathormone, 1,25-dihydroxycholecalciferol, alkaline phosphatase and urinary hydroxiproline were in the normal range. These data indicate that in Hajdu-Cheney syndrome trabecular osteoporosis is produced by the same mechanism that induces distal osteolysis, which suggests that it may be sustained by local acting factors stimulating osteoclastic resorption.

Mechanism of bone destruction due to middle ear cholesteatoma as revealed by laser-Raman spectrometry.

In an investigation of the mechanism of bone destruction caused by chronic otitis media complicated with cholesteatoma, both the processes of demineralization and remineralization were studied in an animal model and clinically at the molecular level, using a laser-Raman spectrometer. From this investigation, it is proposed that the mechanism of bone destruction associated with cholesteatoma is a form of demineralization.

Bone loss and reduced osteoblast function in primary biliary cirrhosis.

The association of bone loss with primary biliary cirrhosis is poorly understood. In 15 premenopausal female patients, only 2 of whom had fractures, mean bone mineral density was reduced at the lumbar spine but not at the midradius or distal radius. Bone loss was not statistically related to the duration or severity of liver disease. Urinary hydroxyproline excretion, an index for bone resorption, was not different from that of 15 age-matched normal women, but the serum concentration of bone Gla-protein (osteocalcin), a specific marker for bone turnover, was decreased (p less than 0.001). Bone histomorphometric examination in 13 patients showed no osteomalacia but a reduced bone formation rate despite normal values for fractional osteoblast-osteoid interface. The substantial early loss of trabecular bone is mediated by a severe reduction in osteoblast function, which may be caused by retained toxic substances associated with cholestasis.

Effect of hyperthyroidism and its treatment on bone mineral content.

Patients with hyperthyroidism may develop osteopenia associated with fractures; however, there has been no general agreement on the incidence of osteopenia in hyperthyroidism or the recovery of the mineral loss after treatment of hyperthyroidism. We conducted a longitudinal prospective study on the effect of hyperthyroidism and its treatment on bone mineral content (BMC) using photon absorptiometry. We observed that both young and older hyperthyroid patients showed a significantly decreased baseline BMC compared with age- and sex-matched controls. We also observed a slight recovery of BMC in hyperthyroid patients at the two-year interval after a euthyroid state had been achieved. However, the BMC was still much lower than that of controls, and we did not find any significant restoration of BMC following "cure" of hyperthyroidism.

Tetracycline double-labelling in post-traumatic osteopenia in man.

Biopsy specimens were taken from parts of earlier fractured bones in seven patients with post-traumatic osteopenia and one healthy volunteer, who were all administered a double dose of tetracycline for the purpose of prelabelling. In the volunteer, specimens were taken from both the proximal tibia epiphysis and the iliac crest. The fraction of labelled surfaces and the rate of apposition were calculated. The results were also compared with normative data from the iliac crest. At least in the first year after fracture, post-traumatic osteopenia appears to be a condition with an increased appositional activity.

[Essential deformans osteolysis. Report of a case with progressive and generalized evolution (author's transl)]. / Ostéolyse progressive généralisée déformante. A propos d'une observation.

The authors report a clinical and radiographic course of a 16 years old caucasian girl with a progressive deformation of her skeleton. The primary lesions occur in knees and wrists. This disease was at first considered as a rheumatoid arthritis, then as a dysplasia epiphysialis multiplex, and now as essential deformans osteolysis (with carpal lysis, shortening of the forearm bones, dislocation of the elbows, disparition of the humeral and femoral heads, contracture of hips and knees, posterior tarsal lysis, and kypho-scoliosis). The clinical (particularly ophtalmologic), biological (including inflammatory, phospho-calcic and nephrologic evaluation with mucopolysaccharidosis urinary excretion) and histological (skin, muscle and bone) check-up were normal. They review the different classification established on lesion topography, on association or not with a nephropathy, finally on an dominant or recessive autosomal inheritance. Then the authors think that their case is similar to the ones of Winchester and Hollister. They discuss the etiopathogenic factors, and do not consider their case as a new mucopolysaccharidosis, but rather as a generalized disease of the collagen of bones.

Myopathy in bone loss of ageing: improvement by treatment with 1 alpha-hydroxycholecalciferol and calcium.

1. Eleven patients with the bone loss of ageing were treated with the vitamin D analogue 1 alpha-hydroxycholecalciferol and calcium for 3--6 months. 2. Muscle biopsies were taken from the vastus lateralis before and after the treatment and the activity of several enzymes was measured. Succinate dehydrogenase and total phosphorylase activities, which are a measure of the oxidative capacity, were low and increased significantly with the treatment. The lactate dehydrogenase activity, which can be taken as a measure of the anaerobic metabolism, was normal and did not change with treatment. The phosphagen stores, ATP and creatine phosphate were low and increased to normal with treatment. 3. Histochemical classification of the fibre composition revealed that the treatment induced an increase in the relative number of fast-twitch a (FTa or type II A) fibres accompanied by a reduction of the fast-twitch b (FTb or type II B) fibres. The cross-sectional area of the FTa fibres also increased with the treatment. 4. The present findings indicate that treatment with the active vitamin D analogue, 1 alpha-hydroxycholecalciferol, and calcium improves the myopathy associated with the bone loss of ageing.