Bone Tissue Of Rats Research Articles

Application of lactoferrin for the prevention and restoration of bone tissue in Wistar rats under conditions of hindlimb unloading

The influence of gravitational unloading (antiorthostatic suspension) and subsequent recovery on the mineral density and mechanical properties of the femoral and tibial bones of Wistar rats was studied with oral administration of a biotechnological analog of human lactoferrin (200 mg/kg) derived from the milk of producer goats. Bone mineral density was determined by dual-energy X-ray absorptiometry, and strength and stiffness were assessed through three-point bending tests. It was shown that gravitational unloading for 21 days led to a decrease in the mineral density of the tibial and femoral bones. The administration of lactoferrin did not significantly affect the mineral density or projected area of the studied bones. No statistically significant differences in mechanical stiffness were found between the experimental groups, but after readaptation, the ultimate strength was significantly higher in the groups that received lactoferrin. Thus, the obtained results may indicate the potential of lactoferrin preparations as prophylactic agents for maintaining bone strength. At the same time, maintaining bone mineral density under deficit-stimulating conditions requires consideration of alternative dosages and delivery methods of the drug.

8353 Impact of a plant-based protein diet on bone health and body composition in Sprague Dawley rats

Abstract Disclosure: M.M. Gomes: None. I.M. de Araújo: None. S.V. Rodriguez: None. F.R. Jorge: None. F.J. de Paula: None. Introduction:Vegetarian and vegan diets are associated with some health benefits; this has contributed to their growing popularity. Although studies remain limited, there is evidence that these patients may be at greater risk of reduced bone mineral density (BMD) and increased fracture risk. The general objective of this study was to analyze the impact of a high-protein, plant-based diet on bone tissue and body composition in male Sprague Dawley rats. Methodology: The study was approved by the Animal Ethics Committee. This study was done with 10 rats in the control group (CG), which received a standard AIN-93M diet; 11 in the normoprotein vegetarian group (NVG), with a normoprotein AIN-93 diet modified with pea protein and methionine; and 11 in the high-protein vegetarian group (HVG), with a modified AIN-93 diet with 40% pea protein and methionine. The dietary intervention lasted 8 weeks. The weight of the animals was measured weekly. Basal blood glucose levels were measured at baseline. At the end of the study, 6 rats from the CG, 6 rats from the NVG, and 5 rats from the HVG were subjected to a glucose tolerance test (GTT). The dual-energy X-ray absorptiometry (DXA) technique was applied in the baseline and final periods of the experiment to evaluate body composition, bone mineral content (BMC) and BMD. After sacrifice, bone strength was measured via a three-point flexion mechanical test on the tibia; brown adipose, epididymal, and retroperitoneal tissues, as well as the liver, were weighed on an analytical balance. Blood was used to measure circulatory levels of insulin, CTX, and P1NP (n=6/group). Results: Basal weight was similar between the groups, but the final weight was lower in the HVG as compared to the CG. In the DXA evaluation, the final lean mass was not different between the groups. On the other hand, total fat mass was lower in the HVG than in the CG and the NVG and the fat percentage was lower in the HVG than in the CG. The weight of epididymal adipose tissue was lower in the HVG than in the NVG, but retroperitoneal and brown adipose tissues were lower in HVG than CG. Liver weight was similar between groups. BMD was similar between groups; however, BMC was lower in the HVG than in the CG and the NVG. Bone strength was similar between groups. There was no difference in glycemia at baseline or during GTT at the eighth week. Serum levels of insulin, CTX, and P1NP were similar between groups. Discussion and Conclusion: A normoprotein vegetarian diet that includes all essential amino acids appears to have no negative impact on body composition or BMD in rats. On the other hand, a high-protein diet with plant protein appears to have a negative impact on bone mineral content, in addition to reducing the amount of body fat and weight. This finding expands on previous results by showing that high-protein diets have a negative impact on bone even when the protein is of plant origin. Presentation: 6/1/2024

SEC31a-ATG9a Interaction Mediates the Recruitment of COPII Vesicles for Autophagosome Formation.

Autophagy plays an important role in determining stem-cell differentiation. During the osteogenic differentiation of mesenchymal stem cells (MSCs), autophagosome formation is upregulated but the reason is unknown. A long-standing quest in the autophagy field is to find the membrane origin of autophagosomes. In this study, cytoplasmic coat protein complex II (COPII) vesicles, endoplasmic reticulum-derived vesicles responsible for the transport of storage proteins to the Golgi, are demonstrated to be a critical source of osteoblastic autophagosomal membrane. A significant correlation between the number of COPII vesicle and the autophagy level is identified in the rat bone tissues. Disruption of COPII vesicles restrained osteogenesis and decreased the number and size of autophagosomes. SEC31a (an outer coat protein of COPII vesicle) is found to be vital to regulate COPII vesicle-dependent autophagosome formation via interacting with ATG9a of autophagosomal seed vesicles. The interference of Sec31a inhibited autophagosome formation and osteogenesis in vitro and in vivo. These results identified a novel mechanism of autophagosome formation in osteogenic differentiation of stem cells and identified SEC31a as a critical protein that mediates the interplay between COPII and ATG9a vesicles. These findings broaden the understanding of the regulatory mechanism in the osteogenic differentiation of MSCs.

Electroacupuncture ameliorates senile osteoporosis by promoting bone remodeling and regulating autophagy.

Osteoporosis is widely regarded as a typical aged-related disease caused by impaired bone remodeling. This research was designed to explore the protective effects of electroacupuncture (EA) on senile osteoporosis in a rat model and investigate the underlying mechanisms. Three-month-old rats were randomly selected as the youth group, and 24-month-old rats were randomly assigned to the elderly and EA groups. Rats in the EA group received 30 min of EA at bilateral SP10, ST36, K13 and GB34 daily, 5 days a week for 8 weeks. Bone mineral density (BMD), microstructure of the bone tissue, bone turnover biomarkers and expression level of autophagy-related proteins were detected. Compared with the elderly group, EA treatment significantly increased BMD of the femur and ameliorated the microstructure. EA treatment increased trabecular bone volume ratio (= bone volume / total volume [BV/TV]) and trabecular number (Tb.N) and decreased trabecular separation (Tb.Sp) in senile osteoporosis rats. Compared with the elderly group, the serum N-terminal telopeptide of type I collagen (NTX1) level in the EA group was lower, and the serum procollagen type I N-terminal propeptide (PINP) concentration was higher. In addition, the expression of Beclin 1, microtubule-associated protein I light chain 3 (LC3B) and P62 was inhibited in the senile osteoporosis rats after EA treatment. EA can effectively alleviate aging-related bone loss and improve the microstructure of bone tissue in senile osteoporosis rats, and the regulation of autophagy might be one of the important mechanisms.

Altered extracellular matrix and mechanotransduction gene expression in rat bone tissue following long-term estrogen deficiency.

Osteoporosis is primarily associated with bone loss, but changes in bone tissue matrix composition and osteocyte mechanotransduction have also been identified. However, the molecular mechanisms underlying these changes and their relation to bone loss are not fully understood. The objectives of this study were to (1) conduct comprehensive temporal gene expression analyses on cortical bone tissue from ovariectomized rats, with a specific focus on genes known to govern matrix degradation, matrix production, and mechanotransduction, and (2) correlate these findings with bone mass, trabecular and cortical microarchitecture, and mineral and matrix composition. Microarray data revealed 35 differentially expressed genes in the cortical bone tissue of the ovariectomized cohort. We report that catabolic gene expression abates after the initial accelerated bone loss period, which occurs within the first 4wk of estrogen deficiency. However, in long-term estrogen deficiency, we report increased expression of genes associated with extracellular matrix deposition (Spp1, COL1A1, COL1A2, OCN) and mechanotransduction (Cx43) compared with age-matched controls and short-term estrogen deficiency. These changes coincided with increased heterogeneity of mineral-to-matrix ratio and collagen maturity, to which extracellular matrix markers COL1A1 and COL1A2 were positively correlated. Interestingly, mineral heterogeneity and collagen maturity, exhibited a negative correlation with PHEX and IFT88, associated with mechanosensory cilia formation and Hedgehog (Hh) signaling. This study provides the first insight into the underlying mechanisms governing secondary mineralization and heterogeneity of matrix composition of bone tissue in long-term estrogen deficiency. We propose that altered mechanobiological responses in long-term estrogen deficiency may play a role in these changes.

The effect of Mongolian Medicine Chagan Gaoyou-4 Powder on bone mineral density induced by retinoic acid in rats

Objective: To investigate the effects of Chagan-Gaoyou-4 powder on spine bone mineral density and serum estrogen and estrogen receptor alpha (ERa) and estrogen receptor beta (ERβ) protein expression in bone tissue induced by retinoic acid in rats. Methods: Sixty 3-month-old SPF female SD rats were randomly divided into model group (retinoin group), normal group (SHAM group), Mongolian medicine group (Chagan-Gaoyou 4 group), and control group (Gushukang granule group). After 14 days of administration, spinal Bone Mineral Density (BMD) was measured, and external manifestations were observed. Results: Compared with the SHAM group, the BMD values of all medication groups decreased (P < 0.05, P < 0.001). Compared with the model group, the spinal BMD value of the Chagan Gaoyou-4 group was increased after 21 days of treatment, and the difference was statistically significant (P < 0.01, P < 0.05). After 21 days, the spinal BMD value of all treatment groups was increased (P < 0.05), the spinal BMD value was also increased, especially Chagan Gaoyou-4 group was more obviously increased (P < 0.05). Compared with the normal group, ERa and ERβ levels in the model group were significantly decreased (P < 0.001), and ERa and ERβ levels in all drug groups were significantly increased (P < 0.001) compared with the model group. After 21 days of treatment, there was no significant difference among the three treatment groups (P > 0.05). ERa and ERβ levels in the Chagan Gaoyou-4 group were higher than those in the model group (P < 0.05), but there was no significant difference between the group and the Gushukang granule group (P > 0.05). The E2 content of the Chagan Gaoyou-4 group was higher than that of the model group (P < 0.05). The mRNA expression of estrogen receptor ERa and ERβ in bone tissue of the left proximal femur was detected by RT-PCR. Compared with the model group, the expression of ERa and ERβ mRNA in the Chagan Gaoyou-4 group and Gushukang granule group was increased. Compared with the model group, ERp mRNA expression was increased in the Chagan Gaoyou-4 powder medium-dose group. Compared with the Gushukang granule group, there was no significant difference in ERm RNA expression in the Chagan Gaoyou-4 dose groups. Chagan Gaoyou-4 can up-regulate the expression of ERa and ERβ induced by retinoic acid in rats, indicating that the Chagan Gaoyou-4 powder group may promote bone formation, regulate bone resorption, improve bone mineral density, and achieve the purpose of preventing and treating OP by increasing estrogen level, stimulating estrogen receptor, and increasing the expression of ERa and ERβ in bone tissue. Conclusion: Chagan-Gaoyu-4 powder may have estrogen-like effects on the bone tissue of rats induced by retinoic acid and may increase the level of serum estrogen, ERa, and ERβ protein expression, thereby improving the spinal BMD of experimental rats. The Chagan-Gaoyou-4 powder group could improve the general condition of osteoporosis induced by retinoic acid in rats.

Sirtuin 3-activated superoxide dismutase 2 mediates fluoride-induced osteoblastic differentiation in vitro and in vivo by down-regulating reactive oxygen species.

Skeletal fluorosis is a chronic metabolic bone disease caused by long-term excessive fluoride intake. Abnormal differentiation of osteoblasts plays an important role in disease progression. Research on the mechanism of fluoride-mediated bone differentiation is necessary for the prevention and treatment of skeletal fluorosis. In the present study, a rat model of fluorosis was established by exposing it to drinking water containing 50mg/L F-. We found that fluoride promoted Runt-related transcription factor 2 (RUNX2) as well as superoxide dismutase 2 (SOD2) and sirtuin 3 (SIRT3) expression in osteoblasts of rat bone tissue. In vitro, we also found that 4mg/L sodium fluoride promoted osteogenesis-related indicators as well as SOD2 and SIRT3 expression in MG-63 and Saos-2 cells. In addition, we unexpectedly discovered that fluoride suppressed the levels of reactive oxygen species (ROS) and mitochondrial reactive oxygen species (mtROS) in osteoblasts. When SOD2 or SIRT3 was inhibited in MG-63 cells, fluoride-decreased ROS and mtROS were alleviated, which in turn inhibited fluoride-promoted osteogenic differentiation. In conclusion, our results suggest that SIRT3/SOD2 mediates fluoride-promoted osteoblastic differentiation by down-regulating reactive oxygen species.

Neferine alleviates ovariectomy-induced osteoporosis by enhancing osteogenic differentiation of bone marrow mesenchymal stem cells via regulation of the p38MAPK pathway

ABSTRACT Objective Osteoporosis, a skeletal ailment marked by bone metabolism imbalance and disruption of bone microarchitecture, Neferine, a bisbenzylisoquinoline alkaloid with diverse pharmacological activities, has received limited attention in the context of osteoporosis treatment. Methods We employed a bilateral ovariectomy (OVX) rat model to induce osteoporosis and subsequently administered Neferine treatment for four weeks following successful model establishment. Throughout the modeling and treatment phases, we closely monitored rat body weights. We assessed alterations in bone tissue microstructure through micro-CT, HE staining, and safranin O-fast green staining. Levels of bone formation and resorption markers in serum were evaluated using ELISA assay. Western blot analysis was employed to determine the expression levels of p38MAPK, p-p38MAPK, and bone formation-related genes in bone tissue. We isolated and cultured OVX rat BMSCs (OVX-BMSCs) and induced osteogenic differentiation while simultaneously introducing Neferine and the p38MAPK inhibitor SB203580 for intervention. Results Neferine treatment effectively curbed the rapid weight gain in OVX rats, ameliorated bone loss, and decreased serum levels of TRAP, CTX-I, PINP, and BALP. Most notably, Neferine promoted the expression of bone formation-related factors in bone tissue of OVX rats, while concurrently activating the p38MAPK signaling pathway. In in vitro experiments, Neferine facilitated the expression of bone formation-related factors in OVX-BMSCs, increased the osteogenic differentiation potential of OVX-BMSCs, and activated the p38MAPK signaling pathway. Nevertheless, SB203580 partially reversed Neferine’s promotive effect. Conclusion Neferine can boost the osteoblastic differentiation of BMSCs and alleviate OVX-induced osteoporosis in rats by activating the p38MAPK signaling pathway.

Treadmill exercise promotes bone tissue recovery in rats subjected to high + Gz loads.

High + Gz loads, the gravitational forces experienced by the body in hypergravity environments, can lead to bone loss in pilots and astronauts, posing significant health risks. To explore the effect of treadmill exercise on bone tissue recovery, a study was conducted on 72 male Wistar rats. These rats were subjected to four weeks of varying levels of periodic high + Gz loads (1G, 8G, 20G) experiments, and were subsequently divided into the treadmill group and the control group. The treadmill group underwent a continuous two-week treadmill experiment, while the control group rested during this period. The mechanical properties, microstructure, and molecular markers of their tibial bone tissue were measured using three-point bending, micro-CT, and PCR. The results showed that treadmill exercise improved the elastic modulus, ultimate deflection, and ultimate load of rat bone tissue. It also increased the number, density, and volume fraction of bone trabeculae, and decreased their separation. Moreover, treadmill exercise enhanced osteogenesis and inhibited osteoclastogenesis. This study demonstrates that treadmill exercise can promote the recovery of bone tissue in rats subjected to high + Gz loads, providing a potential countermeasure for bone loss in pilots and astronauts.

Caffeine induces alveolar bone loss in rats submitted to orthodontic movement via activation of receptor activator of nuclear factor ҡB, receptor activator of nuclear factor ҡB ligand, and osteoprotegerin pathway

Caffeine is a widely consumed substance with several effects on bone metabolism. This study aimed to investigate the effect of caffeine on the bone tissue of rats submitted to orthodontic movement. Twenty-five male Wistar rats underwent orthodontic movement (21 days) of the first permanent maxillary molars on the left side. The experimental group (caffeine; n= 13) and control group (n= 12) received caffeine and water, respectively, by gavage. Microcomputed tomography was performed to analyze orthodontic movement. Histologic analysis of the inflammatory infiltrate and osteoclast count by tartrate-resistant acid phosphatase were conducted. Maxilla tissue was evaluated for receptor activator of nuclear factor ҡB (RANK), RANK ligand (RANKL), and osteoprotegerin by immunohistochemistry. Caffeine exhibited a lower bone volume/tissue volume ratio (78.09% ± 5.83%) than the control (86.84% ± 4.89%; P<0.05). Inflammatory infiltrate was increased in the caffeine group compared with the control group (P<0.05). A higher number of tartrate-resistant acid phosphatase-positive cells was observed in the caffeine (9.67 ± 1.73) than in the control group (2.66 ± 0.76; P<0.01). Immunoexpression of RANK and RANKL in the caffeine group was greater than the control (P<0.05). The use of caffeine thermogenic induces alveolar bone loss in rats submitted to orthodontic movement via activation of RANK, RANKL, and osteoprotegerin signaling pathways.

Investigating the Effect of Resistance-Aerobic Training on the Absorption and Resorption Biomarkers of Bone Tissue in Young, Adult and Elderly Male Rats

Introduction: Exercise training is likely to be a non-pharmacological intervention to improve bone health in children and the elderly. The aim of this study was to investigate the effect of resistance-aerobic training on RUX2, CTX, RANKL and ALP biomarkers in rats of different ages. Methods: In the present experimental study, 30 male Wistar rats were obtained from Instituto Pasteur of Iran and were divided into three groups according to their age: immature (2 weeks old), mature (6 weeks old) and elderly (96 weeks old). In each age group, the mice were randomly divided into two training (n=5) and control (n=5) groups. Six weeks of combined training included three sessions of aerobic training and three sessions of resistance training per week. Extracting genes by PCR method was used. One-way analysis of variance and Tukey's post hoc test and SPSS16 software were used. The significance level P≥0.05 was considered. Results: One-way analysis of variance showed that resistance-aerobic training has had a significant effect on RUNX2, RANKL and ALP variables of rats in different age groups (P &lt; 0.05). This significance was not observed in CTX variable (P &gt; 0.05). On the other hand, the results of Tukey's RUNX2 test were significantly different between the adult training and elderly training groups (p=‌0.019) as well as between the elderly control groups (p = 0.01) and adult training (p = 0.002). Regarding the RANKL variable, it showed that there was a significant difference only between the adult exercise group and the elderly control group (p = 0.01). Conclusion: Resistance-endurance training probably increases absorption and reabsorption biomarkers such as RUX2, RANKL and ALP in immature, mature and elderly male rats.

Polysacharide of Agaricusblazei gel mitigates bone necrosis in model of the jaws related to bisphosphonate via Wnt signaling

To investigate de effect of PAb gel on the bone tissue of rats submitted to Bisphosphonate-related osteonecrosis of the jaws (BRONJ). Initially, 54 animals were submitted to BRONJ model by Zoledronic Acid (ZA) (0.1 mg/kg 3x/wk for 9 wk, ip), followed by the 1st upper left molar extraction at the 8th wk. After tooth removal, the animals were divided into 3 groups, ZA that received placebo gel or PAb gel that received 1% PAb gel, inside the dental alveolus. The control Group (CONTROL) received 0.1 mg/kg of 0.9% saline and then placebo gel. Three weeks after tooth extraction, the animals were euthanized, and maxillae were colleted for macroscopic, radiographic, histological and Raman spectomery assays. Additionally, GSK3b, beta-catenin, and Runx2 mRNA expressions were determined. Blood samples were collected for the analysis of Bone-specific alkaline phosphatase (BALP) levels. PAb gel improved mucosal healing, increased the number of viable osteocytes, while it reduced the number of empty lacunae, as well as the amount of bone sequestration. Furthermore, PAb gel positively influenced the number and functionality of osteoblasts by stimulating Wnt signaling, thereby inducing bone remodeling. Additionally, PAb gel contributed to improved bone quality, as evidenced by an increase in bone mineral content, a decrease in bone solubility, and an enhancement in the quality of collagen, particularly type I collagen. PAb gel mitigated bone necrosis by stimulating of bone remodeling through Wnt signaling and concurrently improved bone quality. PAb gel emerges as a promising pharmacological tool for aiding in BRONJ therapy or potentially preventing the development of BRONJ.

Genistein Supplementation and Bone Health in Breast Cancer in Rats.

The aim of our study was to analyse the effect of supplementation with various forms of genistein (nano-, micro-, and macro-) on the mineral status of rat femurs in conditions of DMBA-induced mammary gland neoplasia. Thirty-two 30-day-old Sprague Dawley rats were used in the study. The rats were divided into four experimental groups: a control group (without supplementation) and groups supplemented with nanosized (92 ± 41 nm), microsized (587 ± 83 nm), and macrosized genistein. Micromorphometric and histological examination of the rat femurs were performed, as well as analysis of the weight and mineral composition (17 elements). Quadrupole ICP-MS was used for analysis of all trace elements. Supplementation with genistein (nano-, micro-, and macro-) was shown to cause changes in the mineral composition of the bones. In the rats receiving nanogenistein, disintegration of the bone tissue was observed. The femurs of these animals had higher content of calcium (by nearly 300%) and potassium (by 25%) than the other groups, while the level of magnesium was about 22% lower. In the case of microelements, there were increases in copper (by 67%), boron (48%), manganese (13%), and nickel (100%), and a 16% decrease in strontium compared to the bones of rats without genistein supplementation. Changes in micromorphometric parameters, resulting in increased bone fragility, were observed. Administration of genistein was found to have an effect on the amount of trace elements in the bone tissue of rats with breast cancer.

The bone-protective benefits of kaempferol combined with metformin by regulation of osteogenesis-angiogenesis coupling in OVX rats

This study was to investigate the potential mechanisms of treatment with metformin (Met) combined with kaempferol (Kae) against postmenopausal osteoporosis. Experiments were conducted in both ovariectomy (OVX)-induced osteoporosis rats and in vitro using RAW264.7 cells, MC3T3-E1 cells, and HUVECs. Results demonstrated the therapeutic effect of Met combined with Kae on osteoporosis. In vivo, Kae alone and in combination with Met treatments enhanced tibial trabecular microstructure, bone mineral density (BMD), and mechanical properties in OVX rats without causing hepatotoxicity and nephrotoxicity. It also reduced bone resorption markers (CTX-1 and TRAP) and increased the bone formation marker (PINP) level in the serum of OVX rats. The expression of bone resorption marker TRAP was reduced, while bone formation markers Runx2 and ALP were enhanced in the bone tissue of OVX rats. Furthermore, Met combined with Kae also promoted the expression of angiogenesis-related markers CD31 and VEGF in OVX rats. In vitro, MC3T3-E1s cells treated with Met combined with Kae showed higher expression of ALP, Runx2, and VEGF. Interestingly, the treatment did not directly promote HUVECs migration and angiogenesis, but enhanced osteoblast-mediated angiogenesis by upregulating VEGF levels. Additionally, Met combined with Kae treatment promoted VEGF secretion in MC3T3-E1, and activated the Notch intracelluar pathway by upregulating HES1 and HEY1 in HUVECs. Meantime, their stimulation on CD31 expression were inhibited by DAPT, a Notch signaling inhibitor. Overall, this study demonstrates the positive effects of Met combined with Kae on osteoporotic rats by promoting osteogenesis-angiogenesis coupling, suggesting their potential application in postmenopausal osteoporosis.

MiR-345-3p Modulates M1/M2 Macrophage Polarization to Inhibit Inflammation in Bone Infection via Targeting MAP3K1 and NF-κB Pathway.

Infection after fracture fixation (IAFF), a complex infectious disease, causes inflammatory destruction of bone tissue and poses a significant clinical challenge. miR-345-3p is a biomarker for tibial infected nonunion; however, the comprehensive mechanistic role of miR-345-3p in IAFF is elusive. In this study, we investigated the role of miR-345-3p in IAFF pathogenesis through invivo and invitro experiments. In vivo, in a rat model of IAFF, miR-345-3p expression was downregulated, accompanied by increased M1 macrophage infiltration and secretion of proinflammatory factors. In vitro, LPS induced differentiation of primary rat bone marrow-derived macrophages into M1 macrophages, which was attenuated by miR-345-3p mimics. miR-345-3p promoted M1 to M2 macrophage transition-it reduced the expression of cluster of differentiation (CD) 86, inducible NO synthase, IL-1β, and TNF-α but elevated those of CD163, arginase-1, IL-4, and IL-10. MAPK kinase kinase 1 (MAP3K1), a target mRNA of miR-345-3p, was overexpressed in the bone tissue of IAFF rats compared with that in those of the control rats. The M1 to M2 polarization inhibited MAP3K1 signaling pathways invitro. Conversely, MAP3K1 overexpression promoted the transition from M2 to M1. miR-345-3p significantly inhibited NF-κB translocation from the cytosol to the nucleus in a MAP3K1-dependent manner. In conclusion, miR-345-3p promotes the polarization of M1 macrophages to the M2 phenotype by inhibiting the MAP3K1 and NF-κB pathways. These findings provide insight into the pathogenesis and immunotherapeutic strategies for IAFF and offer potential new targets for subsequent research.

UPLC-Q-TOF-MS-based metabolomics reveals mechanism of Morinda officinalis iridoid glycosides in treating rheumatoid arthritis and bone loss

This study aimed to investigate the therapeutic effects of Morinda officinalis iridoid glycosides(MOIG) on paw edema and bone loss of rheumatoid arthritis(RA) rats, and analyze its potential mechanism based on ultra-high performance liguid chromatography-guadrupole time-of-flight tandem mass spectrometry(UPLC-Q-TOF-MS) serum metabolomics. RA rats were established by injecting bovin type Ⅱ collagen. The collagen-induced arthritis(CIA) rats were administered drug by gavage for 8 weeks, the arthritic score were used to evaluate the severity of paw edem, serum bone metabolism biochemical parameters were measured by ELISA kits, Masson staining was used to observe the bone microstructure of the femur in CIA rats. UPLC-Q-TOF-MS was used to analyze the alteration of serum metabolite of CIA rats, principal component analysis(PCA) and partial least squares-discriminant analysis(PLS-DA) were used to screen the potential biomarkers, KEGG database analysis were used to construct related metabolic pathways. The results demonstrated that the arthritic score, serum levels of IL-6 and parameters related with bone metabolism including OCN, CTX-Ⅰ, DPD and TRAP were significantly increased, and the ratio of OPG and RANKL was significantly decreased, the microstructure of bone tissue and cartilage were destructed in CIA rats, while MOIG treatments could significantly reduce arthritis score, mitigate the paw edema, reverse the changes of serum biochemical indicators related with bone metabolism, and improve the microstructure of bone tissue and cartilage of CIA rats. The non-targeted metabolomics results showed that 24 altered metabolites were identified in serum of CIA rats; compared with normal group, 13 significantly altered metabolites related to RA were identified in serum of CIA rats, mainly involving alanine, aspartate and glutamate metabolism; compared with CIA model group, MOIG treatment reversed the alteration of 15 differential metabolites, mainly involving into alanine, aspartate and glutamate metabolism, D-glutamine and D-glutamate metabolism, taurine and hypotaurine metabolism, valine, leucine and isoleucine biosynthesis. Therefore, MOIG significantly alleviated paw edema, improved the destruction of microstructure of bone and cartilage in CIA rats maybe through involving into the regulation of amino acid metabolism.

Ozone Improved Bone Dynamic of Female Rats Using Zoledronate.

The aim of this study was to analyze the effect of ozone (OZN) therapy on the dynamics of bone tissue in ovariectomized rats treated with zoledronic acid (ZOL). Female Wistar rats aged 6 months (n = 110) were subjected to bilateral ovariectomy (OVX). At month 3 post-OVX, 10 animals were euthanized to characterize the bone tissue architecture using microtomography (micro-CT). The remaining animals were divided into two groups: ZOL group, administered with ZOL (100 μg/kg body weight); saline (SAL) group (0.45 mL of SAL solution), both for 28 days. At month 3 post-treatment, 10 animals from each group were euthanized to characterize the bone architecture using micro-CT. The remaining animals were divided into the following groups: ZOL (n = 20), ZOL + OZN (n = 20); SAL (n = 20), and SAL + OZN (n = 20). The animals in ZOL + OZN and SAL + OZN groups were intraperitoneally administered with OZN (0.7 mg/kg body weight) once every 2 days. On days 30 and 60, six animals from each group were euthanized for analysis and structural characterization of bones in the femoral head and spine. Some samples of the femoral neck were subjected to biomechanical tests, while some samples were analyzed under a laser confocal microscope. The other samples collected from the femoral neck and spine were analyzed for area of neoformed bone and used for performing inflammatory cell and osteocyte counts. Data were submitted to statistical analysis considering a significance level of p < 0.05. Bone volume percentage and osteocyte and inflammatory cell counts were upregulated in the femoral head region of the ZOL + OZN group. Biomechanical analysis of the femoral neck revealed that the modulus of elasticity was similar between the ZOL and ZOL + OZN groups but differed significantly between the SAL and SAL + OZN groups. The positive areas for calcein and alizarin in the ZOL and ZOL + OZN groups were higher than those in the SAL and SAL + OZN groups. This suggested a positive synergistic effect of OZN and ZOL on the maintenance of bone mass and restoration of bone tissue vitality in ovariectomized rats.

Deleterious effect of chronic high-dose ethanol intake on biomechanical bone properties and periodontal status.

To evaluate the effect of high-graduation chronic ethanol (EtOH) intake on bone and periodontal tissues of rats. Male Wistar rats (250g) were divided into two groups of n = 12 each one. EtOH (5ml of 3g/kg) was administered to the experimental group by gastric gavage twice a day for 20days and the control group received water under the same conditions. The rats were euthanized and used to perform biochemical determination in plasma and gingival tissue, and histological and biomechanical studies in the femur and mandibular tissues. Alcohol increased both TNFα (p < 0.01) and PGE2 (p < 0.05) in plasma and gingiva (p < 0.05) as compared to controls. In addition, EtOH increased the alveolar bone loss as evidenced by the increased distance between the cement enamel junction and the alveolar crest (p < 0.01), the lower % of interradicular bone expressed as bone area/total area (B.Ar/T.Ar, p < 0.05) and the larger periodontal space (p < 0.05), as compared to controls. Likewise, the mandibular microtomographic analysis in alcoholized rats revealed a lower % of interradicular bone volume/total volume (BV/TV, p < 0.05), greater trabecular separation (p < 0.05) and greater % trabecular porosity (p < 0.05) than controls. No biomechanical alteration was observed in lower jaws, while the femur of alcoholized rats presented a decrease in the structural bone properties (p < 0.001), as a systemic consequence of deterioration of the diaphyseal architecture (p < 0.01) without changes in material properties. The consumption of high doses of alcohol produces deleterious effects on periodontal tissues that could be due not only to local but also systemic effects.

Остеодистрофія в умовах експериментальної інтоксикації алюмінієм як наслідок порушень у травному тракті щурів

Relevance. The growing level of aluminum content in the environment: in the atmosphere, soil, water causes concern due to its toxic properties. The central nervous system, bones, kidneys and other are the target-organs for excessive intake of aluminum in the body. The mechanism by which aluminum induces changes in bone tissue has not been fully deciphered and, according to the authors, can be carried out not only due to its antagonistic action in relation to calcium, but also indirectly – due to pathological changes in the digestive tract and inhibition of the absorption of essential substances, which are necessary for bone tissue remodeling. The aim of the work is an experimental study of the effect of long-term intoxication with aluminum chloride on the condition of the mucous membranes of the digestive tract and bone tissue of rats. Materials and methods. The experiment was conducted on 16 male white rats weighing 239–268 g, which were divided into groups: group 1 – intact animals (n=8); group 2 – injection of 0.5 ml of 12 % AlCl3×6H2O solution (80 mg Al/kg) (n=8). On the 60th day of the study, the rats were removed from the experiment, blood serum was collected, the mandible and mucous membranes of the oral cavity, stomach, small and large intestine were isolated. In the mucous membranes of the digestive tract of rats, the activity of acid phosphatase, elastase, urease, catalase and the content of malonic dialdehyde were determined, in the mandibles – atrophy of the alveolar process, the content of aluminum, calcium and biochemical indexes of bone tissue remodeling (activity of elastase, acid and alkaline phosphatase), in blood serum – «liver» markers and calcium content. Results and conclusions. Long-term intoxication with aluminum chloride caused increase the activity of elastase, acid phosphatase, urease and decrease the activity of catalase in the mucous membranes of the digestive tract of rats against the background of increase the level of malonic dialdehyde. The most significant pathological changes were registered in the mucous membranes of the small and large intestines. Enter of aluminum chloride to rats for two months caused a hepatotoxic effect: increased the activity of aminotransaminases, the content of bilirubin and cholesterol in the blood serum of animals. Increased atrophy of the alveolar process of the mandibles of rats simulated aluminum intoxication, accumulation of aluminum in bone tissue and simultaneous decreased calcium level, and increased activity of acid phosphatase against the background of decreased activity of elastase and alkaline phosphatase were established. The extremely wide range of toxic effects of aluminum on the body requires the development of effective approaches to the prevention of intoxication.

Histological evaluation of tissue reaction and new bone formation of different calcium silicate-based cements in rats.

The purpose of this study was to evaluate the local reactions and new bone formation of rat subcutaneous and bone tissue to different calcium silicate cements. In this study, 80 rats were divided into five groups as control, BIOfactor MTA (BIO), NeoMTA Plus (NEO), MTA Repair Hp (REP), Biodentine (DENT) and then into two subgroups according to sacrification times (7, 30 days; n = 8). Polyethylene tubes filled with appropriate materials (test groups); empty tubes (control group) were implanted into the dorsum of each rat subcutaneously. For intraosseous implantation, materials were placed in the cavities created in tibia of rats. Subcutaneous tissue and tibia samples were stained with haematoxylin-eosin and subjected to histopathological analysis. A score (0-3) was used to grade inflammatory reaction and new bone formation. Data were analysed by Kruskal-Wallis and Mann-Whitney U tests (P < 0.05). Inflammatory reaction observed in subcutaneous and intraosseous tissues for 7 days decreased significantly in all groups over time (P < 0.05). It was determined that there was significant increase in new bone formation in REP, BIO, DENT groups over time (P < 0.05). Four contemporary bioceramic materials induced local inflammation and tissues changes shortly after subcutaneous implantation, which were reduced over time. In ıntraosseous implantation, all materials induced new bone formation over time. ADJ-03-23-0134. © 2023 Australian Dental Association.