Circ-Slain2 Alleviates Cartilage Degradation and Inflammation of TMJOA

Temporomandibular joint osteoarthritis (TMJOA) is a degenerative disease with the cessation of matrix anabolism and aggravation of inflammation, which results in severe pain and impaired joint function. However, the mechanisms are not well understood. Circular RNAs (circRNAs) are reported to have various biological functions and participate in the development, diagnosis, prognosis, and treatment of different diseases. This study aimed to investigate the roles and mechanisms of circ-slain2 in TMJOA. We first established TMJOA mouse models and found circ-slain2 was lowly expressed in the cartilage of TMJOA through sequencing data. We observed that circ-slain2 is predominantly localized in the cytoplasm and downregulated in mouse condylar chondrocytes (mCCs) treated with tumor necrosis factor α (TNFα) and interferon γ (IFNγ). Micro-computed tomography and histological examination showed that intra-articular injection of circ-slain2 overexpressing adeno-associated virus could alleviate cartilage catabolism and synovial inflammation to relieve TMJOA in vivo. In addition, elevated circ-slain2 also showed anticatabolic and anti-inflammatory effects on IFNγ- and TNFα-stimulated mouse condylar chondrocytes (mCCs). Functional enrichment analysis indicated that protein processing in endoplasmic reticulum (ER) was associated with TMJOA, and further functional experiments confirmed that circ-slain2 could suppress ER stress in OA mCCs. RNA binding protein immunoprecipitation assay revealed an overt interaction between activating transcription factor 6 (ATF6) and circ-slain2. Inhibition of the expression of both ATF6 and circ-slain2 resulted in dilation of the ER and enhanced the expression of ER stress markers, whose ER stress level was higher than inhibition of ATF6 but lower than knockdown of circ-slain2 expression. Collectively, our research demonstrated that circ-slain2 could regulate ATF6 to relieve ER stress, reducing temporomandibular joint cartilage degradation and synovial inflammation. These findings provide prospects for developing novel osteoarthritis therapies based on circ-slain2 by focusing on reducing the inflammation of synovium and the imbalance between matrix synthesis and degradation.

Ubiquitination in the regulation of autophagy

Autophagy, an efficient and effective approach to clear rapidly damaged organelles, macromolecules, and other harmful cellular components, enables the recycling of nutrient materials and supply of nutrients to maintain cellular homeostasis. Ubiquitination plays an important regulatory role in autophagy. This paper summarizes the most recent progress in ubiquitin modification in various stages of autophagy, including initiation, elongation, and termination. Moreover, this paper shows that ubiquitination is an important way through which selective autophagy achieves substrate specificity. Furthermore, we note the distinction between monoubiquitination and polyubiquitination in the regulation of autophagy. Compared with monoubiquitination, polyubiquitination is a more common strategy to regulate the activity of the autophagy molecular machinery. In addition, the role of ubiquitination in the closure and fusion of autophagosomes warrants further study. This article not only clarifies the regulatory mechanism of autophagy but also contributes to a deeper understanding of the importance of ubiquitination modification.

The ontogenesis of catabolic abilities and energy metabolism during endogenous nutritional periods of tongue sole, Cynoglossus semilaevis

The ontogenesis of catabolic abilities and energy metabolism during endogenous nutritional periods of tongue sole was investigated. In this work, trypsin-like proteases (TRY) and triglyceride lipase (LIP) activities were measured to assess the capacities to catabolize proteins and lipids, respectively. Meanwhile, specific enzymes including pyruvate kinase (PK), glutamic oxalo acetic transaminase (GOT) and glutamate dehydrogenase (GDH), and hydroxyacyl CoA dehydrogenase (HOAD) as well as their ratios were assayed to evaluate the abilities to use energy substrates of carbohydrates, amino acids and fatty acids, respectively, for energy production. In addition, activities of citrate synthase (CS) and lactate dehydrogenase (LDH) and LDH/CS ratio were calculated to analyse the evolution of aerobic and anaerobic pathways. The study found that hatching occurred at 38.8 h after fertilization (HAF), mouth-opening day of eleuteroembryo appeared at 3 days after hatching (DAH), and the most rapid embryonic growth was observed in blastula stage before hatching. Enzymatic assay revealed that except for PK which appeared in cleavage stage onwards, all the other enzymes functioned after fertilization, preparing well for the coming embryogenesis of tongue sole. By comparing the average specific activity of enzyme in each period, it can be found that the highest value occurred at 3 DAH (for TRY, LIP, PK and LDH), 2 DAH (for GDH), fertilized egg (for GOT) and segmentation stage (for HOAD and CS), and the lowest value occurred at fertilized egg (for HOAD, CS and GDH), cleavage stage (for TRY, PK and LDH), gastrula stage (for GOT) and hatching day (for LIP). Based on the changeable patterns of metabolic enzymatic activities and ratios, it is concluded that metabolic capacities on three energy substrates displayed stage-specific traits, and the dominant energy substrate was fatty acids before segmentation stage, amino acids until hatching day and carbohydrate during eleuteroembryo period. As for energy production mode, aerobic pathway appeared to increase greater in fertilized egg and gastrula stage, whereas anaerobic pathway played a predominant role during cleavage stage, blastula stage, segmentation stage and eleuteroembryo stage. These results are valuable to elucidate the nutritional requirements of embryonic stages in tongue sole and to further understand their energy metabolic mechanisms.

Evaluation of gamma ray-induced gastrointestinal tract morphological and proliferative activity changes in rhesus monkeys

To provide support for future pharmacology and preclinical studies, we have established a stable nonhuman primate animal model to demonstrate the histopathological changes in the gastrointestinal tract following gamma ray irradiation. In this study, 12 healthy rhesus monkeys were divided into 2 groups (control and radiation groups). Animals in the radiation group were exposed to gamma rays (cobalt 60 source) at a dose level of 6.5 Gy total body irradiation bilaterally (i.e. 3.25 Gy on each side). Control animals were sham exposed using identical procedures. After a 5-day in-life observation period, gastrointestinal tract tissues (esophagus, stomach, duodenum, jejunum, ileum, colon, and rectum) were collected and fixed in 10% neutral-buffered formalin for subsequent hematoxylin and eosin and 5-bromo-2-deoxyuridine (BrdU) immunohistochemistry processing. The results showed that the esophagus was undergoing degeneration without obvious inflammatory changes, while the stomach and duodenum exhibited both degeneration and inflammation. From the jejunum to the rectum, late-stage inflammation with glandular regeneration, as well as a high-level BrdU labeling index, was present.

A 12-week subchronic intramuscular toxicity study of risperidone-loaded microspheres in rats

Long-acting injectable formulations of antipsychotics have been an important treatment option to increase the compliance of the patient with schizophrenia by monitoring drug administration and identifying medication noncompliance and to improve the long-term management of schizophrenia. Risperidone, a serotoninergic 5-HT2 and dopaminergic D2 receptor antagonist, was developed to be a long-acting sustained-release formulation for the treatment of schizophrenia. In this study, 12-week subchronic toxicity study of risperidone-loaded microspheres (RMs) in rats by intramuscular injection with an 8-week recovery phase was carried out to investigate the potential subchronic toxicity of a novel long-acting sustained-release formulation. The results indicated that the dosage of 10-90 mg/kg of RM for 2 weeks did not cause treatment-related mortality. The main drug-related findings were contributed to the dopamine D2 receptor and α1-adrenoceptor antagonism of risperidone such as elevation of serum and pituitary prolactin levels and ptosis and changes in reproductive system (uterus, ovary, vagina, mammary gland, testis, seminal vesicle, epididymis, and prostate). In addition, foreign body granuloma in muscle at injection sites caused by poly-lactide-co-glycolide was observed. At the end of the recovery phase, these changes mostly returned to normal. The results indicated that RM had a good safety profile in rats.

A 12-week intramuscular toxicity study of risperidone-loaded microspheres in Beagle dogs

Long-acting formulations of antipsychotics are important treatment options to increase the compliance of schizophrenic patients. Risperidone, a 5-HT2 and dopaminergic D2 receptor antagonist, was developed as long-acting sustained-release microspheres with poly(lactide-co-glycolide) (PLGA) as a drug carrier for the treatment of schizophrenia. In the present study, the main objective is to determine the nonclinical safety profile of risperidone-loaded microspheres (RM) in Beagle dogs after intramuscular administration for 3 months, once in 2 weeks, followed by 8-week recovery phase. No animal death was found and no special toxicological findings were observed. The findings, such as hypoactivity, ptosis, increased heart rate, and elevated serum and pituitary prolactin levels, were observed and related to the pharmacological effects of risperidone. The changes in the reproductive system (uterus, ovary, vagina, cervix, and mammary gland) were considered secondary to the prolactin elevation, and the congestion of spleen was related to risperidone. The foreign body granulomas at injection sites might be caused by PLGA. At the end of recovery phase, the above changes mostly recovered to normal, and on administering 3 mg/kg dose level once in 2 weeks on Beagle dogs showed no observed adverse effect. Taken together, RM had exhibited the acceptable safety.

TRBV kinetics and its association with HLA disparity and aGVHD following allogeneic hematopoietic stem cell transplantation

INTRODUCTION

The relative expression of T cell receptor (TCR) beta variable (TRBV) and TCR diversity was compared between recipients receiving human leukocyte antigen (HLA)-mismatched transplants and those receiving HLA-matched transplants, using granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem cells and bone marrow as grafts.

METHODS

The kinetics of the relative expression of TRBV family members were analyzed using real-time quantitative PCR. Additionally, the association of TRBV clonotype with acute graft-versus-host disease (aGVHD) was determined by cloning and sequence analysis of the CDR3 region.

RESULTS

The TCR diversity in recipients receiving HLA-mismatched transplants was significantly lower than in those receiving HLA-matched transplants at 1 month and 2 months after hematopoietic stem cell transplantation (HSCT) (both P < 0.05). However, these differences disappeared 3 months after transplantation. The relative expression of TRBV27 (n = 7 recipients) at the onset of aGVHD was higher than in corresponding donors (P = 0.025), but no significant differences were observed between recipients lacking aGVHD and their donors at serial time points after HSCT.

CONCLUSION

Our results suggest that HLA disparity may affect the relative expression of TRBV in the early phase after transplantation, and TRBV27 may be associated with the onset of aGVHD.

Identification of Piccolo as a regulator of behavioral plasticity and dopamine transporter internalization

Dopamine transporter (DAT) internalization is a mechanism underlying the decreased dopamine reuptake caused by addictive drugs like methamphetamine (METH). We found that Piccolo, a presynaptic scaffolding protein, was overexpressed in the nucleus accumbens (NAc) of the mice repeatedly administrated with METH. Piccolo downexpression by antisense technique augmented METH-induced behavioral sensitization, conditioned reward and synaptic dopamine accumulation in NAc. Expression of Piccolo C2A domain attenuated METH-induced inhibition of dopamine uptake in PC12 cells expressing human DAT. Consistent with this, it slowed down the accelerated DAT internalization induced by METH, thus maintaining the presentation of plasmalemmal DAT. In immunostaining and structural modeling Piccolo C2A domain displays an unusual feature of sequestering membrane phosphatidylinositol 4,5-bisphosphate, which may underlie its role in modulating DAT internalization. Together, our results indicate that Piccolo upregulation induced by METH represents a homeostatic response in the NAc to excessive dopaminergic transmission. Piccolo C2A domain may act as a cytoskeletal regulator for plasmalemmal DAT internalization, which may underlie its contributions in behavioral plasticity.

Noradrenaline in the bed nucleus of the stria terminalis is critical for stress-induced reactivation of morphine-conditioned place preference in rats

The effect of noradrenaline in the bed nucleus of the stria terminalis and locus coeruleus on maintenance and reactivation of morphine-conditioned place preference induced by footshock stress was investigated in rats. After receiving alternate injection of morphine (10 mg/kg) and saline for 6 consecutive days, the rats spent more time in the drug-paired compartment (morphine-conditioned place preference) on day 7. These animals did not show morphine-conditioned place preference on day 37 following sham-footshock once every 3 days from days 8 to 36 (28 days drug-free). However, 15 min of intermittent footshock once every 3 days could induce the maintenance of morphine-conditioned place preference on day 37 with significantly more time spent in the drug-paired compartment than on day 0. Microinjection of the alpha(2)-adrenoceptor agonist, clonidine (0.1 or 1 microg), into the locus coeruleus 30 min before footshock did not affect stress-induced maintenance of conditioned place preference. However, infusions of clonidine (1 microg) into the bed nucleus of the stria terminalis significantly attenuated the maintenance of conditioned place preference induced by footshock stress. In another experiment, after a 21-day extinction of morphine-conditioned place preference, a single footshock could reactivate the morphine place preference that was significantly blocked by pretreatment with infusion of clonidine (0.1 or 1 microg) into the bed nucleus of the stria terminalis but not the locus coeruleus. Reactivation of morphine-conditioned place preference elicited by footshock stress was significantly inhibited by 6-hydroxydopamine-induced lesions in the ventral noradrenergic bundle, most of the norepinephrine input to the bed nucleus of the stria terminalis arising from caudal brain stem noradrenergic cell groups. In contrast, chemical lesions of the dorsal noradrenergic bundle that arises from the locus coeruleus had no such effects. These findings suggest that noradrenergic neurons in locus coeruleus are not involved in stress-induced reinstatement of drug-seeking and further clearly demonstrate that noradrenaline in the bed nucleus of the stria terminalis plays a critical role in mediating this effect. Comprehension of the neurochemical events underlying the stress-induced and the bed nucleus of the stria terminalis-mediated reinstatement of drug-seeking may, therefore, throw more light on the biological bases of drug dependence and addictive behavior

[Prospects on the application of toxicogenomics in assessing the safety of chemical compounds]

Toxicogenomics has been developing with the rapid advances in Human Genome Project in recent two years. The categories and specialty of tox-gene; the application of tox-gene microarray in safety assessment, analysis of gene mutation and gene polymorphism, extrapolation of animal tests results, clarification of mechanism and safety assessment of mixtures; some problems of toxicogenomics need to be solved in spite of its great prospective application.

[Large-capacity expanded cytoline-induced killer cells and its cytotoxic activity]

This study was conducted to establish the large-capacity culture methd of cytokine-induced killer (CIK) cells for clinical therapy and assess its effect on the fuction of cell-mediated immunity following autologous CIK cells reinfusion. Autologus CIK cells were expanded in 1000 ml culture-bag and reinfused back. The MTT method was used to test the cytotoxic activity of CIK cells before and after reinfusion. The results showed that the total amount of autologous CIK cells reinfusion exceeded 1.6 x 10(10) with the use of the culture method of large-capacity. The PBMNC from patients treated by CIK cells showed significant increase in cytotoxic activity, no side effects were observed, and therefore the large-capacity culture method of CIK cells is a simle and safe therapy for treating the minimum residue of diseases.

[Role of metallothionein in the resistance of rat osteoblasts to zinc excess and deficiency]

This study is expected to investigate the role of metallothionein(MT) in the resistance of osteoblasts to high or low zinc conditions. Antisense MT oligonucleotide was used to reduce the content of MT in osteoblast. Cellular MT content was determined by silver/hemolysate saturation method, and the cytotoxicity was measured by the activity of LDH releasing from damaged cells. The results showed that antisense MT oligonucleotide markedly decreased the resistance of osteoblast to zinc excess and zinc deficiency. It suggested that MT played an important role in the modulation and maintenance of intracellular zinc homeostasis of osteoblasts.

[Zinc modulates the Ca(2+)-ATPase activity of rat osteoblast membrane]

The effect and mechanism of zinc on Ca(2+)-ATPase and Na+, K(+)-ATPase activity of rat osteoblast membrane were studied. The activities were measured by colorimetric method. The effect of special inhibitors of protein kinase C or calmodulin on membrane Ca(2+)-ATPase and Na+, K(+)-ATPase activity which induced by zinc were also examined. The results showed that zinc could increase membrane Ca(2+)-ATPase activity, but no influence was observed on Na+, K(+)-ATPase activity. R24571, a special inhibitor of calmodulin, had no effect on membrane Ca(2+)-ATPase activity. Calmodulin also could not promote the basic Ca(2+)-ATPase activity of membrane. But trifluoperazine, a special inhibitor of protein kinase C, obviously reduced its activity. It was concluded that the modulation of zinc on membrane Ca(2+)-ATPase activity of rat osteoblast could be mediated by protein kinase C.

[Zinc promotes proliferation and differentiation of osteoblast in rats in vitro]

OBJECTIVE

Effect of zinc on proliferation and differentiation of osteoblast in rats was studied in vitro.

METHODS

Osteoblasts were isolated from the rat calvaria and subcultured in DMEM media. Rats were divided into four groups in the study, with administration of 0 micromol/L (as control), 10 micromol/L, 25 micromol/L and 50 micromol/L of Zn(2+), respectively. DNA synthesis at varied time points was determined with incorporation of (3)H-thymidine, and cell cycle was analyzed by flow cytometry. Synthesis of collagen was measured with incorporation of (3)H-proline. Activity of alkaline phosphatase (AKP) and osteocalcin content were measured by enzyme dynamics method and radioimmunoassay, respectively.

RESULTS

Incorporation of (3)H-thymidine in the three groups with different zinc-supplement was significantly higher than that in the control group at each time point, and supplement with 25 micromol/L and 50 micromol/L of Zn(2+) could promote the transition of cell cycle from phases G(0)/G(1) to S phase. Syntheses of collagen and osteocalcin and activity of AKP in the groups with zinc-supplement were greater, as compared with those in the control group.

CONCLUSION

Zinc could promote proliferation and differentiation of the rat osteoblast in vitro.

[Zinc deficiency inhibited the proliferation and differentiation of rat osteoblast in vitro]

The effect of zinc deficiency on proliferation and differentiation of rat osteoblast was studied in vitro. The osteoblasts were isolated from the rat calvaria, and were subcultured in DMEM medium. Zinc deficiency model in cell culture was made by chelating zinc from the medium with a special chelator TPEN. Incorporation of 3H-thymidine was measured to show the DNA synthesis at different time point, and cell cycle was analyzed by flow cytometry. A histochemistry method was used to detect changes of osteoblast cytoskeleton. Incorporation of 3H-proline was measured to show the synthesis of collagen. Alkaline phosphatase activity (AKP) and osteocalcin content were measured by enzyme dynamics method and radioimmunoassay respectively. The results showed that the incorporation of 3H-thymidine in the zinc deficient group was significantly less than that in the control group at different time points. The cells were blocked at G2/M phase of cell cycle, which is related to the impairment of cytoskeleton. Collagen synthesis, osteocalcin content and AKP activity in the zinc deficient group were reduced significantly as compared with those in the control group. But no differences in all the measurements were observed between the control group and the group of zinc deficiency supplemented with zinc. Therefore, it was concluded that zinc deficiency inhibited the proliferation and differentiation of rat osteoblast in vitro.

[Simultaneous assay of Ca(2+)-ATPase and Na+, K(+)-ATPase activities of osteoblast rat by malachite green colorimetic method]

The aim of this study was to find a method to measure simultaneously the activities of Ca(2+)-ATPase and Na+, K(+)-ATPase of rat osteoblast membrane. In this test, Ca(2+)-ATPase and Na+, K(+)-ATPase released inorganic phosphate (Pi) from ATP, and Pi was determined by colorimetric method using malachite green dye to show ATPase activities. Ca2+ concentration and osteoblast culture generation were important factors affecting ATPase activities. Ca2+ could elevate membrane ATPase activity. When Ca2+ concentration reached 40 mumol/L, ATPase activities were improved. Ca(2+)-ATPase activity decreased with the increase of osteoblast culture generation. Ca(2+)-ATPase activity was lower than Na+, K(+)-ATPase activity in osteoblast membrane. This method is simple, sensitive and reliable.

[Study on the dose-effect relationship of hypolipidemic effect of deepsea fish oil]

The dose-effect relationship of hypolipidemic effect of fish oil was studied. The rats were divided into four groups: 2.5, 5, 10 g/kg and high dietary fat control group. The experimental rat model of high serum lipids was developed. The results showed that there was a linear correlation between the levels of TG, HDL-c and the dosage of fish oil. Fish oil reduced TC level and elevated HDL-c level steadily. But no linear correlation was observed between TC, LDL-c and the dosage of fish oil. The level of TC and LDL-c decreased markedly at the dosage of 2.5 g/kg of fish oil.

[A study on relationship between chemotherapy of acute leukemia and apoptosis in vivo]

In order to investigate whether apoptosis occurs in vivo in patients with leukemia in different stage (before, during and after chemotherapy). We detect apoptosis of peripheral blood leukemia cells in 10 patients before, during and after chemotherapy with in situ TdT fluorescence measurement and DNA electrophoresis. The results showed that apoptotic cells were few (0-2.9%) before chemotherapy, increased obviously (11.4%-72.0%) during chemotherapy in patients with complete remission (CR) or partial remission (PR), but decreased (0-2.9%) after chemotherapy (10-14 days). Apoptotic cells were few (0-5.7%) during chemotherapy in four patients without remission. Therefore, only effective drug therapy could induce apoptosis. DNA ladder cannot be detected by agarose gel electrophoresis either before, during and after chemotherapy. So we considered that in situ TdT assay is possible to apoptosis in vivo in the early course of chemotherapy for immediate modification of chemotherapy, while electrophoretic analysis is not sensitive enough to detect apoptotic cells in vivo.