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Background: Effectively reducing the expression of certain aversive memories (fear or trauma memories) with extinction training is generally viewed to be therapeutically important. A deeper understanding of the biological basis for a more effective extinction process is also of high scientific importance. Methods: Our study involved intraventricular injection or local injection into the dorsal dentate gyrus of anti-neuregulin 1 antibodies (anti-NRG1) before fear extinction training, followed by testing the expression of fear memory 24 hours afterward or 9 days later. We used local injection of chemogenetic or optogenetic viruses into the dorsal dentate gyrus to manipulate the activity of the dorsal dentate gyrus and test the expression of fear memory. We also examined the effect of deep brain stimulation in the dorsal dentate gyrus on the expression of fear memory. Results: Mice that received intraventricular injection with anti-NRG1 antibodies exhibited lower expression of fear memory and increased density of activated excitatory neurons in the dorsal dentate gyrus. Injection of anti-NRG1 antibodies directly into the dorsal dentate gyrus also led to lower expression of fear memory and more activated neurons in the dorsal dentate gyrus. Inhibiting the activity of dorsal dentate gyrus excitatory neurons using an inhibitory designer receptor exclusively activated by designer drugs (DREADD) eliminated the effects of the anti-NRG1 antibodies. Enhancing the activity of the dorsal dentate gyrus with an excitatory DREADD or optogenetic stimulation resulted in lower expression of fear memory in mice that did not receive infusion of anti-NRG1 antibodies. Deep brain stimulation in the dorsal dentate gyrus effectively suppressed expression of fear memory, both during and after fear extinction training. Limitations: The mechanism for the contribution of the dorsal dentate gyrus to the expression of fear memory needs further exploration. Conclusion: Activation of the dorsal dentate gyrus may play an important role in modulating the expression of fear memory; its potential use in fear memory extinction is worthy of further exploration. [ABSTRACT FROM AUTHOR]

Background: Hepatocellular carcinoma (HCC) is one of the most lethal cancers worldwide owing to its high rates of metastasis and recurrence. The oncogene IQ motif-containing GTPase activating protein 3 (IQGAP3) is ubiquitously overexpressed in several human cancers, including liver, ovary, lung, large intestine, gastric, bone marrow, and breast malignancies and is involved in the invasion and metastasis of cancer cells. Therefore, we aimed to determine the biological role and molecular mechanism of IQGAP3 in HCC.Methods: We used 120 archived clinical HCC samples, 9 snap-frozen HCC tumor tissues, and 4 normal liver tissues. Expression of IQGAP3 mRNA and protein in HCC cell lines (Hep3B, SMMC-7721, HCCC-9810, HepG2, BEL-7404, HCCLM3, QGY-7701, Huh7, and MHCC97H) and normal liver epithelial cells LO2 was examined by western blot, quantitative polymerase chain reaction, and immunohistochemistry. In addition, wound-healing and transwell matrix penetration assays were used to assess the migratory and invasive abilities of HCC cells, respectively.Results: Expression of the IQGAP3 was robustly upregulated in HCC cells and tissues. High expression of IQGAP3 in HCC correlated with aggressive clinicopathological features and was an independent poor prognostic factor for overall survival. Furthermore, ectopic expression of IQGAP3 markedly enhanced HCC cell migration, invasion, and epithelial-to-mesenchymal transition (EMT) in vitro and promoted metastasis of orthotopic hepatic tumors in nude mice. Conversely, silencing endogenous IQGAP3 showed an opposite effect. Mechanistically, IQGAP3 promoted EMT and metastasis by activating TGF-β signaling.Conclusions: IQGAP3 functions as an important regulator of metastasis and EMT by constitutively activating the TGF-β signaling pathway in HCC. Our findings present new evidence of the role of IQGAP3 in EMT and metastasis, indicating its potential as a prognostic biomarker candidate and a therapeutic target against HCC. [ABSTRACT FROM AUTHOR]

Background: The maintenance of nucleus pulposus (NP) viability in vitro is difficult. The annulus fibrosus (AF) pathway reflects one nutrient transport channel and may have an important effect on NP viability in disc organ cultures. The present study describes a feasible disc pre-treatment involving the AF and investigates its efficacy in improving NP bioactivity in an in vitro disc bioreactor culture.Methods: Rabbit discs that were randomly assigned to the experimental group (EG) were pretreated via the surgical removal and controlled trypsinization of the outer AF. The discs in the control group (CG) did not receive any special treatment. All discs were organ-cultured in a self-developed bioreactor. Solute transport into the central NP was measured using a methylene blue solution. On days 7 and 14, histological properties, cell viability, cell membrane damage, gene expression and matrix composition within the NP in these two groups were compared with each other and with the corresponding parameters of fresh NP samples. Additionally, the structures of the outer AF and the cartilage endplate (CEP) following pre-treatment were also assessed.Results: The outer AF in the EG became disorganized, but no specific changes occurred in the CEP or the inner AF following pre-treatment. The discs in the EG exhibited increased penetration of methylene blue into the central NP. On days 7 and 14, the NP bioactivity in the EG was improved compared with that of the CG in terms of cell viability, cell membrane damage, gene expression profile and matrix synthesis. Moreover, cell viability and matrix synthesis parameters in the EG were more similar to those of fresh samples than they were to the same parameters in the CG on day 14.Conclusions: Using this disc pre-treatment, i.e., the surgical removal and controlled trypsinization of the outer AF, NP bioactivity was better maintained for up to 14 days in an in vitro disc bioreactor culture. [ABSTRACT FROM AUTHOR]

Background: Many researches have investigated the changes associated with immobilization-induced osteoarthritis (OA). However, there are only few studies focusing on the effect of unilateral knee immobilization on cartilage matrix changes in the contralateral mobile knee. The aim of the present study was to investigate the influence of immobilization on the cartilage matrix in the contralateral mobile knees in a rabbit model of OA induced by immobilization.Methods: Right knees (experimental knees) of eighteen mature female rabbits were immobilized at an extension of 180° with orthopedic casting tape for 2, 4, or 8 weeks. Left knees (contralateral knees) of the immobilized rabbits were not subjected to immobilization. The knees of six non-immobilized rabbits were designated as control knees. Following immobilization, cartilage specimens from the medial femoral condyle underwent macroscopic, histological, immunohistochemical, and biochemical evaluations.Results: Roughness of cartilage surface was detected in the experimental knees at 2 weeks, and cartilage degeneration was further developed. In the contralateral knee, cartilage showed degenerative changes after 4 weeks. Safranin-O staining and glycosaminoglycan (GAG) contents were reduced in the experimental knees following immobilization and in the contralateral intact knees after 4 and 8 weeks. Type II collagen staining was gradually reduced, type I collagen accumulation was obviously detected in the upper and middle layers of cartilage in experimental knees after 8 weeks, and the collagen orientation was gradually disorganized in both knees at 4 and 8 weeks. For both experimental and contralateral knees, collagen contents were significantly decreased at 8 weeks, and Mankin and Osteoarthritis Research Society International (OARSI) scores increased over time.Conclusion: OA developed in the contralateral intact knee with the progress of OA in the immobilized knee in a rabbit model of immobilization-induced OA. [ABSTRACT FROM AUTHOR]

Background: Various anterior lumbar surgical approaches, including the minimally invasive approach, have greatly improved in recent years. Vascular complications resulting from ALIF are frequently reported. Little information is available about the safety of large blood vessel stretch. We evaluated the right side stretch limit (RSSL) of the abdominal aorta (AAA) and the inferior vena cava (IVC) without blood flow occlusion and investigated stretch‑induced histological injury and thrombosis in the iliac and femoral arteries and veins and the stretched vessels. Materials and Methods: The RSSL of blood vessels in five adult goats was measured by counting the number of 0.5‑cm‑thick wood slabs that were inserted between the right lumbar edge and the stretch hook. Twenty seven adult goats were divided into three groups to investigate histological injury and thrombosis under a stretch to 0.5 cm (group I) 1.5 cm (group II) for 2 h, or no stretch (group III). Blood vessel samples from groups I and II were analyzed on postsurgical days 1, 3, and 7. Thrombogenesis was examined in the iliac and femoral arteries and veins. Results: The RSSL of large blood vessels in front of L4/5 was 1.5 cm from the right lumbar edge. All goats survived surgery without complications. No injury or thrombosis in the large blood vessels in front of the lumbar vertebrae and in the iliac or femoral arteries and veins was observed. Under light microscopy, group I showed slight swelling of endothelial cells in the AAA and no histological injury of the IVC. The AAA of group II showed endothelial cell damage, unclear organelles, and incomplete cell connections by electron microscopy. Conclusions: The AAA and IVC in a goat model can be stretched by ≤0.5 cm, with no thrombosis in the AAA, IVC, iliac or femoral arteries and veins. [ABSTRACT FROM AUTHOR]

Qiangli Tianma Duzhong capsule (TMDZ), a Chinese herbal drug, is clinically used to improve functional outcome in patients with ischemic stroke in China. This study was conducted to establish whether postischemic long-term treatment with TMDZ could reduce the loss of injured hemisphere and confer the improvements of neurological outcome in chronic survival of rats with 2 h middle cerebral artery occlusion (MCAO)/reperfusion brain injury and its primary mechanisms. We found that TMDZ (44.5, 89, or 178mg/kg), administered per os 6 h after the onset of ischemia and for 28 consecutive days, significantly improved the behavior deficits, beginning on day 7, and further improved later. TMDZ treatment also markedly reduced the tissue loss of the injured hemisphere and improved histopathology. In the meantime, TMDZ treatment could improve hemorrheology and inhibit platelet aggregation. These results provide the first evidence that post-ischemic long-term treatment with TMDZ confers the improvements of neurological outcome and the loss of injured hemisphere in an animal ischemic stroke model, and its mechanisms might be associated with the improvements of hemorrheology and the inhibition of platelet aggregation. [ABSTRACT FROM AUTHOR]

Several lines of evidence have demonstrated that acute administration of ketamine elicits fast-acting antidepressant effects. Moreover, tramadol also has potential antidepressant effects. The aim of this study was to investigate the effects of pretreatment with tramadol on ketamine-induced antidepressant activity and was to determine the expression of mammalian target of rapamycin (mTOR) in rat hippocampus and prefrontal cortex. Rats were intraperitoneally administrated with ketamine at the dose of 10 mg/kg or saline 1 h before the second episode of the forced swimming test (FST). Tramadol or saline was intraperitoneally pretreated 30 min before the former administration of ketamine or saline. The locomotor activity and the immobility time of FST were both measured. After that, rats were sacrificed to determine the expression of mTOR in hippocampus and prefrontal cortex. Tramadol at the dose of 5 mg/kg administrated alone did not elicit the antidepressant effects.More importantly, pretreatment with tramadol enhanced the ketamine-induced antidepressant effects and upregulated the expression of mTOR in rat hippocampus and prefrontal cortex. Pretreatment with tramadol enhances the ketamine-induced antidepressant effects, which is associated with the increased expression of mTOR in rat hippocampus and prefrontal cortex. [ABSTRACT FROM AUTHOR]