ABSTRACT
Objective:To investigate the therapeutic effect and possible mechanism of low intensity pulsed ultrasound（LIPUS）on painful gait in mice with Achilles tendon injury.Methods:Male C57BL/6 mice were selected to establish the Achilles tendon injury model by surgically full-thinkness tear of the right Achilles tendon. The mice were divided into Achilles tendon injury group and Achilles tendon injury+LIPUS group according to the random number table method，with 7 mice per group. The Catwalk gait analysis system was used to evaluate the gait function of the mice by measuring the following five parameters 14 days after operation，including print area，standing time，step cycle，max intensity and stride length. Morphological changes of the Achilles tendon were observed by HE staining. Immunofluorescence staining was used to detect the expression level of nitric oxide synthase（iNOS）in the Achilles tendon tissues. At the same time，Achilles tendon cells were isolated and cultured in vitro. The cells were induced by 100 ng/ml lipopolysaccharide（LPS）for 12 hours to establish in vitro model（LPS group），and treated with LIPUS（LPS+LIPUS group）. The control group was set as well（without any treatment）. The nuclear translocation of nuclear transcription factor-κB（NF-κB）P65 was detected by immunofluorescence staining，and the expression of iNOS and phosphorylation（p）-NF-κB p65 protein was detected by Western blotting. Results:Compared with Achilles tendon injury group［（0.14±0.10）cm 2］，the print area of the affected limb in Achilles tendon injury+LIPUS group［（0.28±0.13）cm 2］was increased（ P<0.05）. Compared with Achilles tendon injury group［（0.11±0.04）seconds］，the standing time of the affected limb in Achilles tendon injury+LIPUS group［（0.21±0.03）seconds］was increased（ P<0.05）. Compared with Achilles tendon injury group［（0.25±0.05）seconds］，the step cycle of the affected limb in Achilles tendon injury+LIPUS group［（0.40±0.05）seconds］was increased（ P<0.05）. There was no significant difference in the max intensity and stride length between Achilles tendon injury group and Achilles tendon injury+LIPUS group（ P>0.05）. HE staining showed obvious hyperplasia of Achilles tendon tissues in Achilles tendon injury group，with loosely and randomly arranged fibers，accompanied by neovascularization and inflammatory cell infiltration. Achilles tendon injury+LIPUS group showed more orderly arranged fibers in Achilles tendon tissues，and the degree of neovascularization and inflammatory cell infiltration were reduced. Compared with Achilles tendon injury group［（5.70±0.81）%］，the expression level of iNOS in Achilles tendon injury+LIPUS group［（2.84±0.94）%］was decreased 14 days after operation（ P<0.05）. Immunofluorescence results of Achilles tendon cells showed that NF-κB p65 protein entered the nucleus in LPS group compared with control group，and that LIPUS treatment inhibited nuclear translocation. In control group，Western blotting showed that iNOS was not expressed，and that the expression of phosphorylated NF-κB p65 was 0.63±0.16. Compared with control group，the expression levels of iNOS（0.99±0.22）and p-NF-κB P65（1.02±0.19）in LPS group were significantly increased（ P<0.05）. Compared with LPS group，the expression levels of iNOS（0.62±0.10）and p-NF-κB P65（0.65±0.21）in LPS+LIPUS group were decreased（ P<0.05）. Conclusion:LIPUS treatment can alleviate pain gait in mice with Achilles tendon injury and inhibit iNOS expression in vivo and in vitro，which may be related to inhibition of NF-κB signaling pathway.
ABSTRACT
Growth plate,the developmental center of endochondral osteogenesis,can be divided morphologically and functionally into a resting zone,a proliferative zone,a prehypertrophic zone and a hypertrophic zone.Injuries to growth plate often lead to bone growth defects including limb length discrepancy and angulation deformity in children.Currently,their orthopedic corrective surgeries are invasive and limitedly effective and no effective biotherapy has been available.Previous studies on animal models of growth plate damage have investigated the related cellular and molecular events in the repair of damaged growth plates in the 4 distinct inflammatory,fibrogenic,osteogenic and remodeling phases.Related molecules involved in the regulation of the above processes,such as inflammatory cytokines tumor necrosis factor alpha,mitogenic platelet-derived growth factor and bone morphogenetic protein,are found to participate in the regulation of growth plate injury.Exploration of the mechanisms may provide new targets for biotherapy.In addition,development of cartilage tissue engineering,especially application of mesenchymal stem cells,also provides potential interventions for growth plate injury.
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Objective To explore the immune mechanism in the systemic lupus erythematosus MRL/lpr mice at different months of age, and to provide the basis for research of its pathogenesis. Methods 3-,4-,5- and 6-month old female MRL/lpr mice, and wild type C57 female mice were used in this study, 10 mice per each group. Their organ coefficients were determined. ELISA was performed to detect the serum levels of double stranded DNA(ds-DNA) antibody. The interleukins IL-2,IL-4,IL-17 and tumor necrosis factor-α(TNF-α)in spleen tissue were detected. Flow cytometry was used to assess the content of spleen lymphocyte CD3 cells and CD4/CD8 cell ratio. Results Compared with the 3-month old wild-type C57 mice,the spleen coefficient,the blood concentration of ds-DNA antibody,IL-2 and TNF-α in the 3- to 6-month old MRL/lpr mice were significantly increased(P < 0.05). There was no significant difference between the concentrations of interleukin IL-4(P> 0.05). The blood concentration of IL-17 in the 5- and 6-month old MRL/lpr mice was significantly lower(P < 0.05 or P < 0.01)than that in the 3-month old MRL/lpr mice. The rest indexes of MRL/lpr mice showed no obvious changes or significant difference in the mice at different ages. Compared with the 3-month old C57 mice,the spleen CD3 lymphocyte concentration in the MRL/lpr mice was significantly decreased(P< 0.01). With the increasing age, the CD3 lymphocyte concentration and D4 +/CD8 +cell ratio in the MRL/lpr mice were decreased, however, showing a non-significant difference(P ﹥0.05). Conclusions The data obtained in this study indicate that 3-month old lupus MRL/lpr mice have already immune injury,increasing with the increase of age of the mice.
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Objective To determine the main reproductive performance of six SPF mice and rats preserved in our laboratory, including C57BL/6, BALB/c, NIH, KM, ICR mice and SD rats.Methods Inbred mice mated with full sib and random mating.Meanwhile, closed colony animals were bred by cross circular mating.These indexes of reproductive performance were measured in the six kinds of animals during the first birth to the fourth birth, i.e.the average litter size (ALZ), average baby number reared ( ABN) and average weaning number ( AWN), and weaning rate ( WA) were calculated.Meanwhile, the initial mating age in days, initial bearing age in days, first gestation and intervals were measured.Results The ALZ of inbred mice were 6 to 7.The reproductive indexes were basically stable in the first 3 births, however, the various data were dramatically declined in the fourth birth ( P<0.05 ) .The WA of BALB/c mice were 98%to 99%, and that of C57BL/6 mice were 96%to 98%.The ALZ of closed colony animals were 12 to 15, and significantly increased in the second and third births compared with that of the first birth (P<0.05), then was significantly reduced ( P<0.05) .The WA maintained at 98%to 99%in the NIH, KM and ICR mice.In contrast, The WA of SD rats was slightly lower, reaching 95%to 97%.The initial mating age in days of mice was between 70 d to 80 d.The initial bearing age in days and first gestation of rats were less than that of inbred mice, the initial bearing age in days and first gestation of closed colony rats were 136.3 d and 27.7 d, respectively.The pregnancy interval of inbred mice was between 34 d to 40 d,the pregnancy interval of closed colony mice was between 25.5 d to 28.7 d, the pregnancy interval of rats was between 32.8 d to33.8 d.Conclusions The 6 mouse and rat strains have a higher reproductive performance, and the data obtained in this study provide a basis for commercialized production of mice and rats in southern areas of China, and for establishment of rodent experimental animal resource.
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Tumor cells exhibit two main different migration strategies when invading in 3D environment, i. e. mesenchymal migration and amoeboid migration. This review summarizes the internal reasons and characteristics on various modes of migration adaptation to the microenvironment, and the molecular mechanisms in particular environment where they are mutually interchangeable. A study of the mechanisms that may possibly trigger mesenchymal-amoeboid transition/amoeboid-mesenchymal transition help us to understand the change and the plasticity in the migration strategies of tumor cells. These are important for the development of a cancer treatment, which would efficiently suppress tumor cell invasiveness.