Selective Agonists of Nuclear Retinoic Acid Receptor Gamma Inhibit Growth of HCS-2/8 Chondrosarcoma Cells

Chondrosarcoma is the second most common primary bone sarcoma. Treatment of chondrosarcoma is limited to surgery due to radiation and chemotherapy resistance of this cancer. An ideal treatment for chondrosarcoma would be a well-tolerated, minimally invasive local or systemic treatment modality to halt or slow tumor growth prior to resection of local, unresectable local, or metastatic disease. Palovarotene, an agonist of nuclear retinoic acid receptor γ (RARγ) has shown therapeutic action for treatment of heterotopic ossification and osteochondroma without serious adverse effects in animal models. We hypothesized that selective agonists of RARγ would have an inhibitory effect on chondrosarcoma. All human chondrosarcoma specimens expressed RARγ as determined by immunohistochemical staining. The ΗCS-2/8 chondrosarcoma cell line, established from low-grade human chondrosarcoma, was used to examine the actions of RARγ agonists. In ΗCS2/8 pellet cultures, RARγ agonist treatment reduced the mass size and significantly decreased total glycosaminoglycan, protein amounts, and gene expression levels of cartilage matrix molecules when compared with control groups. Systemic treatment with RARγ agonists significantly inhibited the growth of ΗCS-2/8 cell transplants in vivo. Furthermore, local injection of RARγ agonist-loaded poly-lactic acid nanoparticles induced regression of the mass size of the transplants. Histologic analysis demonstrated that RARγ agonist treatment inhibited cell proliferation activity and stimulated encapsulation of the tumor. These findings indicate that RARγ agonists, including palovarotene, may have an anti-tumor effect on low-grade chondrosarcomas. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:1045-1051, 2020.

Intermittent parathyroid hormone 1-34 induces oxidation and deterioration of mineral and collagen quality in newly formed mandibular bone

Intermittent parathyroid hormone (PTH) administration is known to promote bone healing after surgical procedures. However, the mechanism and influence of PTH on the mineral and collagen quality of the jaw are not well understood. Most studies have focused on analyzing the bone density and microstructure of the mandible, and have insufficiently investigated its mineral and collagen quality. Oxidative stress activates osteoclasts, produces advanced glycation end products, and worsens mineral and collagen quality. We hypothesized that PTH induces oxidation and affects the mineral and collagen quality of newly formed mandibular bone. To test this, we examined the mineral and collagen quality of newly formed mandibular bone in rats administered PTH, and analyzed serum after intermittent PTH administration to examine the degree of oxidation. PTH administration reduced mineralization and worsened mineral and collagen quality in newly formed bone. In addition, total anti-oxidant capacity in serum was significantly decreased and the oxidative-INDEX was increased among PTH-treated compared to vehicle-treated rats, indicating serum oxidation. In conclusion, intermittent administration of PTH reduced mineral and collagen quality in newly formed mandibular bone. This effect may have been induced by oxidation.

Molecular alterations of newly formed mandibular bone caused by zoledronate

Bone quality is defined by structural and material characteristics. Most studies on the mandible have focused on the analysis of structural characteristics, with insufficient investigation of material characteristics. This study tested whether zoledronate affects the material characteristics of newly formed mandibular bone. Thirty-six female Wistar rats were assigned to three groups: sham-ovariectomized rats (SHAM, n=12), ovariectomized rats (OVX, n=12), and ovariectomized rats treated with zoledronate (ZOL, n=12). The left side of the mandibular ramus of all rats was drilled bicortically. Twenty-eight days after surgery, all surviving rats were euthanized and all mandibles were removed. Raman microspectroscopy was performed, and five spectra per specimen of newly formed mandibular bone were analysed. Compared with OVX rats, the mineral/matrix ratio in ZOL rats was significantly increased (5.43±1.88 vs. 7.86±2.05), while crystallinity (0.055±0.002 vs. 0.050±0.002), relative proteoglycan content (0.43±0.10 vs. 0.31±0.05), and collagen structural integrity (1.16±0.21 vs. 0.72±0.06) were significantly decreased. These changes in material characteristics may explain why rats that received zoledronate exhibited peculiar biological phenomena such as bisphosphonate-related osteonecrosis of the jaw.

The influence of zoledronate and teriparatide on gamma delta T cells in mice

Background/purpose

Few studies have investigated the possibility that bisphosphonate-related osteonecrosis of the jaw (BRONJ) might reflect an immune response; however, gamma delta T cells have been shown to significantly decline in the blood of BRONJ patients. Additionally, there have been some reports of teriparatide usage for the treatment of BRONJ. In this study, we compared the effects of zoledronate and teriparatide on lymphocyte populations and inflammatory cytokine production in mice.

Materials and methods

Thirty female ICR mice were divided into three groups (n = 10 each): a vehicle, a zoledronate, and a teriparatide group. Drugs were administered for 8 weeks in each group. Lymphocytes in the blood and thymus were analyzed and femurs were used for histological observation and lymphocytes analysis of bone marrow. Cytokines were measured in separated serum using Milliplex^® multiplex immunoassay analysis.

Results

Zoledronate decreased the T cell number in the bone marrow. Additionally, serum levels of interleukin (IL)-2, IL-7, IL-12, IL-15 and RANTES, which are cytokines that affect T cell activation, differentiation and/or proliferation, were significantly lower in zoledronate treated mice. Conversely, teriparatide treatment induced an increase in gamma delta T cells in peripheral blood.

Conclusion

Gamma delta T cells in the bone marrow are expected to decrease with zoledronate treatment and increase with teriparatide treatment. If BRONJ involves a loss of gamma delta T cells in the circulation or bone marrow, then the increase in gamma delta T cells that is induced by teriparatide may account for its ability to resolve BRONJ.

Maxillary Advancement for Unilateral Crossbite in a Patient with Sleep Apnea Syndrome

This article reports the case of a 44-year-old male with skeletal Class III, Angle Class III malocclusion and unilateral crossbite with concerns about obstructive sleep apnea syndrome (OSAS), esthetics and functional problems. To correct the skeletal deformities, the maxilla was anteriorly repositioned by employing LeFort I osteotomy following pre-surgical orthodontic treatment, because a mandibular setback might induce disordered breathing and cause OSAS. After active treatment for 13 months, satisfactory occlusion was achieved and an acceptable facial and oral profile was obtained. In addition, the apnea hypopnea index (AHI) decreased from 18.8 preoperatively to 10.6 postoperatively. Furthermore, after a follow-up period of 7 months, the AHI again significantly decreased from 10.6 to 6.2. In conclusion, surgical advancement of the maxilla using LeFort I osteotomy has proven to be useful in patients with this kind of skeletal malocclusion, while preventing a worsening of the OSAS.

CCN2 as a novel molecule supporting energy metabolism of chondrocytes

CCN2/connective tissue growth factor (CTGF) is a unique molecule that promotes both chondrocytic differentiation and proliferation through its matricellular interaction with a number of extracellular biomolecules. This apparently contradictory functional property of CCN2 suggests its certain role in basic cellular activities such as energy metabolism, which is required for both proliferation and differentiation. Comparative metabolomic analysis of costal chondrocytes isolated from wild-type and Ccn2-null mice revealed overall impaired metabolism in the latter. Among the numerous metabolites analyzed, stable reduction in the intracellular level of ATP, GTP, CTP, or UTP was observed, indicating a profound role of CCN2 in energy metabolism. Particularly, the cellular level of ATP was decreased by more than 50% in the Ccn2-null chondrocytes. The addition of recombinant CCN2 (rCCN2) to cultured Ccn2-null chondrocytes partly redeemed the cellular ATP level attenuated by Ccn2 deletion. Next, in order to investigate the mechanistic background that mediates the reduction in ATP level in these Ccn2-null chondrocytes, we performed transcriptome analysis. As a result, several metabolism-associated genes were found to have been up-regulated or down-regulated in the mutant mice. Up-regulation of a number of ribosomal protein genes was observed upon Ccn2 deletion, whereas a few genes required for aerobic and anaerobic ATP production were down-regulated in the Ccn2-null chondrocytes. Among such genes, reduction in the expression of the enolase 1 gene was of particular note. These findings uncover a novel functional role of CCN2 as a metabolic supporter in the growth-plate chondrocytes, which is required for skeletogenesis in mammals.

Nasolabial morphologic changes after a Le Fort I osteotomy: a three-dimensional anthropometric study

After a Le Fort I osteotomy, nasal and labial changes are sometimes undesirable. The aim of this study was to perform a three-dimensional evaluation of the morphologic changes of the nose and lips after a Le Fort I osteotomy with a three-dimensional laser scanner.Twelve female patients who underwent a Le Fort I osteotomy with bilateral sagittal split ramus osteotomy (mean age, 24.2 y) were selected. Three-dimensional facial morphology was measured immediately after surgery and 6 months after surgery with a three-dimensional laser scanner. Analysis of the three-dimensional data was performed with three-dimensional image analyzing software. The evaluation was performed by (1) linear and angular analyses of landmarks, (2) three-dimensional curvature, and (3) visual qualitative analysis using superimposing mapping images. The results were compared control with data taken from volunteers (mean age, 24.5 y).Lateral expansion of nasal alae was commonly observed after surgery. The labial changes were mainly due to movements of the jawbone, and obvious flattening was not detected in this study. There was no relationship between the nasal changes and maxillary advancement.The nasal morphologic changes after a Le Fort I osteotomy consist mainly of a widening of the nasal alae caused by the release of the muscle insertion and their retraction. This change was not influenced by the direction of maxillary movements.

Lyapunov exponents for Japanese vowels in normal adult and cleft palate speakers

OBJECTIVE

The purpose of this study was to explore the possibility of using Lyapunov exponents (LE) to evaluate the voice and speech in cleft palate (CP) patients.

SUBJECTS AND METHODS

Fifty healthy adults (25 males and 25 females) and 17 adult patients (10 males and 7 females) with repaired CP, who had no hypernasality, were enrolled. Five Japanese vowels were recorded at 44.1 kHz. Nasalance scores were measured simultaneously. The first LE was computed for each 1-second interval, and the mean for the first LE from all intervals (mLE(1)) was then calculated. The delay time and embedding dimension were estimated at 13, 40, 34, 27 and 22 points for the vowels /a/, /i/, /u/, /e/ and /o/, respectively, and at 8 points for all vowels.

RESULTS

The mLE(1)s for all vowels did not differ between normal males and females. The mLE(1)s for /a/ were significantly higher both in males and females with CP than in normal individuals. The correlation coefficient between the mLE(1)s and nasalance scores for all vowels was not significant for both normal and CP subjects.

CONCLUSION

The LE seemed to be related to pathological disorders of the vocal cords in CP patients, but was independent of resonance parameters.

Atypical lipomatous tumor of the tongue: report of a case

The term atypical lipomatous tumor (ALT) is synonymous with well-differentiated liposarcoma (WDL). This tumor occurs very rarely in the tongue. Thus, it is difficult to predict its prognosis. Although recurrence of ALT/WDL is thought to be unlikely after complete excision, long-term follow-up is necessary when considering the pathologic conditions of this tumor at other sites. Here, we report a case of an ALT of the tongue, with a review of the literature. A 68-year-old man was referred to our hospital because of a tumor on the left side of his tongue. Upon palpation, the tumor was 12mm in diameter, circumscribed, elastic and hard, well demarcated, movable, and painless. We diagnosed the lesion as a lipoma and extirpated the tumor under local anesthesia. Because the specimen was histopathologically diagnosed as an ALT, as a precaution, we excised an additional 5mm from the area surrounding the original tumor under general anesthesia. Three years after the operation, the tongue demonstrated good healing without paresthesia or dysfunction, and to date there has been no evidence of recurrence.

Postoperative course after SSRO in mandibular asymmetries with or without MMF

OBJECTIVE

The aim of this study was to assess the necessity of maxillo-mandibular fixation (MMF) from a viewpoint of postoperative stability to treat mandibular asymmetries.

MATERIALS AND METHODS

Twenty-four patients who underwent surgical correction of mandibular asymmetry were analyzed. The surgical procedure in all patients consisted of bilateral sagittal splitting ramus osteotomy (SSRO). The segments were then fixed rigidly with titanium screws. A postoperative MMF was performed in 12 patients within 1 day of the SSRO. The MMF lasted for 1 week. The other 12 patients were free to move their jaw on the day of the surgery and received occlusal guidance with elastics starting from the third postoperative day. Posterior-anterior cephalograms were taken preoperatively, 1 day postoperatively, and at 1, 3, 6, 12, and 24 months after surgery. Skeletal and occlusal stabilities along with postoperative complications were then assessed.

RESULTS

Nausea and pharyngeal discomforts were observed very often in both groups. Even without MMF, occlusions were guided to the objective positions by an average of 3.5 days after surgery. Occlusal and skeletal stability was satisfactory in both groups, and there was no correlation between the surgical results and the use of postoperative MMF.

CONCLUSION

MMF is not necessary after rigid fixation SSRO for mandibular asymmetry, considering the risks of airway distress.

Mandibular stability after SSRO with or without postoperative maxillo-mandibular fixation for Class III malocclusion

OBJECTIVE

The objective of this study was to assess the usefulness of maxillo-mandibular fixation (MMF) from a viewpoint of skeletal and occlusal stability and to investigate the complications after surgery with and without MMF.

MATERIALS AND METHODS

Twenty-seven patients who underwent surgical correction of class III malocclusion were analyzed. The surgical procedure in all cases consisted of a bilateral sagittal splitting ramus osteotomy (SSRO). The segments were then fixed rigidly with titanium screws. A postoperative MMF was performed in 13 patients within 1 day of the SSRO. The MMF lasted for 1 week. The other 14 patients were free to move their jaw on the day of the surgery and received occlusal guidance with elastics starting from the third postoperative day. Cephalograms were taken preoperatively, at 1 day postoperatively and at 1, 3, 6, 12, and 24 months after surgery. Skeletal and occlusal stabilities along with postoperative complications were then assessed.

RESULTS

Discomfort of the pharynx and postoperative pain was more severe in the MMF group. Even without MMF, occlusion was guided to the ideal position by an average of 5.3 days after surgery. Occlusal and skeletal stability was satisfactory in both groups, and there was no correlation between the surgical results and postoperative MMF.

CONCLUSION

MMF may not be necessary after a rigid fixation SSRO, considering the risks of airway problems.

Hypoxic regulation of stability of connective tissue growth factor/CCN2 mRNA by 3′-untranslated region interacting with a cellular protein in human chondrosarcoma cells

Connective tissue growth factor (CTGF/CCN2) can be induced by various forms of stress such as exposure to high glucose, mechanical load, or hypoxia. Here, we investigated the molecular mechanism involved in the induction of ctgf/ccn2 by hypoxia in a human chondrosarcoma cell line, HCS-2/8. Hypoxia increased the ctgf/ccn2 mRNA level by altering the 3'-untranslated region (UTR)-mediated mRNA stability without requiring de novo protein synthesis. After a series of extensive analyses, we eventually found that the cis-repressive element of 84 bases within the 3'-UTR specifically bound to a cytoplasmic/nuclear protein. By conducting a UV crosslinking assay, we found the cytoplasmic/nuclear protein to be a 35 kDa molecule that bound to the cis-element in a hypoxia-inducible manner. These results suggest that a cis-element in the 3'-UTR of ctgf/ccn2 mRNA and trans-factor counterpart(s) play an important role in the post-transcriptional regulation by determining the stability of ctgf/ccn2 mRNA.

Comparative study on isolation calls emitted from hamster pups

Waveforms of isolation calls emitted from hamster pups, which were Syrian hamsters, Djungarian hamsters, and Chinese hamsters, were compared in a basic study on improving reproduction by decrease of cannibalism, because it was reported that maternal behavior was induced by isolation calls in rodents. Isolation calls of hamster pups, isolated from their mother and receiving cold stress, were collected by Real-Time Spectrogram (RTS), and calculated to spectrograms and power spectra by SIGNAL. Isolation calls consisted of ultrasonic vocalizations (USVs) and audible vocalizations (ADVs) in each species. Waveforms of isolation calls emitted by the hamster pups, were shown to have several characteristic features. In this study, the species specificity of isolation calls was shown in hamster pups. It would seem that the species specificity originates in the differences of sensitivity to cold stress via the autonomic nerve in hamsters.

Simultaneous observation of ingestive and copulatory behavior of the male rat

In a preliminary test male rats were allowed to ingest a 1 M solution of sucrose from a drinking spout. After daily intake of sucrose became stabilized, the males were given a sexually receptive or non-receptive female and the bottle filled with sucrose solution simultaneously. The ingestive and copulatory behavior was observed for 60 min under illumination by a red lamp. The data obtained from this study showed that the ingestive behavior of males was suppressed by the presence of sexually receptive females and, conversely, the sexual behavior of males was not affected by the presence of a bottle of sucrose. These results suggest that the presence of a sexual partner inhibits appetitive ingestive behavior, i.e., the responses used by male rats to obtain food.