Long non-coding RNA DUXAP8 regulates proliferation and invasion of esophageal squamous cell cancer

OBJECTIVE

The purpose of this research was to detect the expression of long non-coding RNA DUXAP8 in esophageal cancer, and to explore its underlying mechanism in the development of esophageal squamous cell carcinoma (ESCC).

PATIENTS AND METHODS

We collected 78 pairs of esophageal cancer tissues and normal adjacent tissues. The mRNA level of DUXAP8 in these esophageal cancer tissues and corresponding adjacent tissues was detected by quantitative Real-time polymerase chain reaction (qRT-PCR). The relationship between DUXAP8 expression and the prognosis of esophageal cancer was analyzed. Small interfering RNA (siRNA) was applied to reduce the expression of DUXAP8 in ESCC cell lines (TE-1 and KYSE520). Meanwhile, the specific effect of DUXAP8 on the biological functions of ESCC cells was analyzed by CCK-8 assay (cell counting kit-8), colony formation assay and transwell assay, respectively. Furthermore, the regulatory effect of DUXAP8 on Wnt/β-catenin pathway was detected by Western blot.

RESULTS

DUXAP8 was overexpressed in ESCC tissues than that of normal adjacent tissues. DUXAP8 expression was positively correlated to tumor stage and lymph node metastasis, whereas negatively correlated to the survival rate of ESCC patients. Cell proliferation, colony formation and invasion abilities were significantly decreased after knockdown of DUXAP8 in ESCC cells. Western blot results showed that DUXAP8 could regulate the occurrence of ESCC via Wnt/β-catenin pathway.

CONCLUSIONS

DUXAP8 expression was significantly correlated with tumor stage, lymph node metastasis and poor prognosis of ESCC patients. DUXAP8 may promote the occurrence of ESCC via Wnt/β-catenin pathway.

MicroRNA-210 promotes spinal cord injury recovery by inhibiting inflammation via the JAK-STAT pathway

OBJECTIVE

To investigate the effect of microRNA-210 on the spinal cord injury (SCI) and its underlying mechanism.

MATERIALS AND METHODS

The mouse SCI model was established. Mice were randomly assigned into 4 groups, namely the sham operation group (sham group), surgery group (SCI group), surgery+NC group (SCI+NC group) and surgery+microRNA-210 overexpression group (SCI+microRNA-210 mimics group). The mRNA levels of microRNA-210 and the key genes in the JAK-STAT pathway of the four groups were detected by Real-Time Polymerase Chain Reaction (RT-PCR) at different time points. Protein levels of JAK2 and STAT3 in mice of the four groups were detected by Western blot. To investigate the role of microRNA-210 in SCI recovery, changes in the motor function of mice were detected.

RESULTS

Grip strengths of right and left forelimbs in mice from the sham group were temporarily decreased at the early stage after surgery, which were gradually recovered to the preoperative levels on the 3rd postoperative day. However, mice in SCI group were unable to complete the grip strength determination at the early stage after surgery. Mice in SCI group were capable of grasping on the 7th postoperative day. Besides, grip strengths of mice in SCI group were remarkably lower than those of sham group until the end-point (on the 50th day). Furthermore, mRNA levels of microRNA-210 in mice of SCI group were decreased in a time-dependent manner (p<0.05). Higher grip strengths were observed in mice of SCI+microRNA-210 mimics group in comparison with those of SCI group and SCI+NC group (p<0.05). In addition, Western blot showed that protein levels of JAK2 and STAT3 in mice of SCI group were increased in a time-dependent manner (p<0.05). Moreover, protein levels of JAK2, STAT3, and MCP-1 in mice of SCI+NC group were remarkably higher than those in the sham group and SCI+microRNA-210 mimics group (p<0.05).

CONCLUSIONS

MicroRNA-210 is down-regulated in SCI mice. Grip strengths of SCI mice can be recovered after microRNA-210 overexpression via inhibiting inflammatory response by the JAK-STAT pathway.

Increased expression of long noncoding RNA HMMR-AS1 in epithelial ovarian cancer: an independent prognostic factor

OBJECTIVE

Evidence has indicated that long noncoding RNA (lncRNAs) may have significant roles in cancer. In this study, we aimed to investigate the expression pattern and prognostic value of a noncoding RNA named as HMMR antisense RNA 1 (HMMR-AS1) in epithelial ovarian cancer (EOC).

PATIENTS AND METHODS

Differences in the expression of HMMR-AS1 between EOC and matched normal tissues were analyzed using RT-PCR. The correlation between HMMR-AS1 levels and the clinicopathological factors of the EOC patients was analyzed by x2-test. Kaplan-Meier analysis and Cox proportional hazards regression models were explored to reveal the correlations of HMMR-AS1 expression with survival of patients.

RESULTS

HMMR-AS1 was significantly upregulated in human EOC tissues compared with adjacent normal tissues (p < 0.01). Clinicopathologic analysis revealed that high expression of HMMR-AS1 was associated with advanced FIGO stage (p = 0.013) and positive lymphatic metastasis (p = 0.010). Moreover, patients with higher HMMR-AS1 expression displayed shorter overall survival time (p = 0.0075) and progression-free survival time (p = 0.0013) than those with lower HMMR-AS1 expression. More importantly, multivariate analysis suggested that high expression of HMMR-AS1 was an independent prognostic indicator for EOC patients.

CONCLUSIONS

Our data suggested that HMMR-AS1 may be considered a novel prognostic factor in EOC and a specific diagnostic indicator for patients with EOC.

Application of Mismatch Negative in Evaluation of Severity of Mental Disorders due to Traumatic Brain Injury

Objective To explore the applied value of mismatch negative （MMN） in evaluation of severity of mental disorders due to traumatic brain injury. Methods Thirty-five patients（case group） that conform to the diagnostic criteria of organic （traumatic brain injury） mental disorder in ICD-10 Classification of Mental and Behavioural Disorders criteria were selected. Twenty-four healthy subjects （normal control group） that matched the case group in terms of gender, age composition ratio and educational level were selected. All subjects were evaluated by Activity of Daily Living Scale （ADL） and Social Disability Screening Schedule （SDSS） and then examined by Event-Related Potential （ERP）. A statistical analysis of the data was made by SPSS 22.0 software. Results The 32 patients and 24 normal control subjects completed the study. The scores of ADL and SDSS were significantly higher in the case group than in the normal control group （P<0.05）. The latency of Fz, FCz, Cz and Pz in the case group was significantly longer than that in the normal control group （P<0.05）. In the case group, the latency of Fz, FCz, Cz and Pz was positively correlated with the scores of ADL and SDSS （P<0.05）. The equation can be well fitted with the scores of ADL and SDSS. The latency and amplitude of Fz, FCz, Cz and Pz were used as concomitant variables and whether or not the subjects had mental disorders due to traumatic brain injury as dependent variables. Conclusion The latency of MMN can be used as an indicator in potential evaluation of the severity of mental disorders due to traumatic brain injury, which means that the longer the latency of MMN is, the more severe mental disorders due to traumatic brain injury may be. The combined application of ADL, SDSS and MMN can be an objective indicator in preliminary judgment of mental disorders due to traumatic brain injury.

High levels of long non-coding RNA DICER1-AS1 are associated with poor clinical prognosis in patients with osteosarcoma

OBJECTIVE

Long noncoding RNA DICER1-AS1 (DICER1-AS1) has been reported to be upregulated in osteosarcoma cells and to serve as a tumor promoter. However, the clinical significance of DICER1-AS1 in osteosarcoma remains unclear. The aim of this study was to investigate the association of DICER1-AS1 expression with prognosis of osteosarcoma.

PATIENTS AND METHODS

The expression of DICER1-AS1 was measured in 214 osteosarcoma samples and normal bone samples by using Real-time PCR. The correlations between DICER1-AS1 expression and clinical features were statistically analyzed. Overall survival (OS) and disease-free survival (DFS) were examined using Kaplan-Meier curves. Multivariate analyses were performed to analyze the prognostic significance of DICER1-AS1 expression.

RESULTS

It was found that the expression levels of DICER1-AS1 in osteosarcoma tissues were significantly higher than those in corresponding noncancerous bone tissues (p < 0.01). Higher DICER1-AS1 had significant association with clinical stage (p = 0.005) and distant metastasis (p = 0.000). Kaplan-Meier survival analysis showed that patients with high DICER1-AS1 expression had a shorter OS and DFS compared with the low DICER1-AS1 expression group (p = 0.007 and p < 0.0001). In a multivariate Cox model, our results showed that DICER1-AS1 expression was an independent poor prognostic factor for both 5-year OS (HR = 3.236, 95% CI: 1.148-5.347; p = 0.004) and 5-year DFS (HR = 3.935, 95% CI: 1.556-6.349; p = 0.001).

CONCLUSIONS

DICER1-AS1 is up-regulated in osteosarcoma and may serve as a potential prognostic biomarker for osteosarcoma.

MiR-137 attenuates spinal cord injury by modulating NEUROD4 through reducing inflammation and oxidative stress

OBJECTIVE

To explore the role of microRNA (miR) 137 in spinal cord injury and its mechanism.

MATERIALS AND METHODS

The model of spinal cord injury in mice was established to detect the recovery differences of grip strength in upper and lower limbs of mice. The expressions of miR-137 and neuronal differentiation 4 (NEUROD4) were detected at the same time. The inflammation level and the oxidative stress response after spinal cord injury were subsequently detected after overexpression of miR-137. Target genes of miR-137 were identified by bioinformatics. Finally, dual-luciferase reporter gene assay was used to identify the target genes of miR-137.

RESULTS

By establishing the model of spinal cord injury in mice, the strength of upper and lower limbs recovered after 7 days of injury in mice. The expression of miR-137 in spinal cord injury was found to decrease in a time-dependent manner by quantitative Real-time polymerase chain reaction (qRT-PCR), while the expression of NEUROD4 gradually increased. Inflammation indicators and oxidative stress level were found to be significantly higher after spinal cord injury. However, the inflammation level and oxidative stress were significantly reduced after transfection of miR-137. Finally, we predicted the target gene of miR-137 through bioinformatics website and found that NEUROD4 was a potential target gene of miR-137. Using dual luciferase reporter assays, we found that NEUROD4 bound to miR-137. After overexpression of miR-137, the expression of NEUROD4 was significantly reduced. Overexpression of NEUROD4 could promote spinal cord injury inflammation and oxidative stress. After intracellular transfection of NEUROD4 and miR-137 at the same time, the inflammation level and oxidative stress of spinal cord injury decreased significantly.

CONCLUSIONS

These results suggested that miR-137 promoted the recovery of spinal cord injury by degrading NEUROD4 to relieve the spinal cord inflammation and the progression of oxidative stress, thus promoting the recovery of spinal cord injury.

MicroRNA-125b promotes the regeneration and repair of spinal cord injury through regulation of JAK/STAT pathway

OBJECTIVE

Spinal cord injury (SCI) is a severe trauma to the central nervous system. Long non-coding RNAs have been reported to play essential roles in spinal cord injury. This study mainly explored the role of micro-125 in the regulation of spinal cord injury by regulating STAT3.

MATERIALS AND METHODS

The stable mouse model of cervical spinal cord contusion was established by Infinite Horizon spinal cord striker, and the model mice' motor function was analyzed. Bioinformatics databases were used to screen the target mRNAs of micro-125b. qRT-PCR was performed to detect the expression of micro-125b and its target genes in injury area of mice' spinal cord. Western Blot and ELISA were introduced to detect the expression of inflammation and apoptosis-related proteins in each group. The recovery status of spinal cord after SCI was assessed by motor function scores and axon counts of mice in each group.

RESULTS

Micro-125b appeared to be significantly down-regulated over-time after SCI. JAK1 and STAT1, two important neuregulin proteins, were predicted to be the target genes of micro-125b, and overexpression of micro-125b induced the decrease of phosphorylated JAK1 and STAT1. Enhanced micro-125b expression also allowed axons from the injury area of spinal cord to extend into the outer periphery of the damaged area, thus improving the motor function of the injured rats. Besides, overexpression of micro-125b demonstrated significant neuronal protective effects by reducing apoptosis and inflammatory responses in neurons.

CONCLUSIONS

Our data revealed that micro-125b was down-regulated in injured spinal cord, and overexpression of micro-125b promoted the repair and regeneration following spinal cord injury through the regulation of the JAK/STAT pathway.

[Establishment of a nomogram model for predicting lymph node metastasis in patients with cN0 gastric cancer based on combination of preoperative C-reactive protein/albumin ratio]

Objective: To investigate the relationship between systemic inflammatory markers such as neutrophil/lymphocyte ratio (NLR) and C-reactive protein/albumin ratio (CAR), and lymph node metastasis in patients with cN0 gastric cancer. To establish a nomogram model to predict the risk of lymph node metastasis in patients with cN0 gastric cancer. Methods: The preoperative systemic inflammatory markers and clinical data of 134 patients with cN0 gastric cancer were retrospectively analyzed, and these markers of patients with negative (pN0) or positive (pN+ ) lymph node metastasis in postoperative pathological diagnosis were compared. The receiver operating characteristic (ROC) curve was used to evaluate the predictive effect of preoperative systemic inflammatory markers on lymph node metastasis. The influencing factors for lymph node metastasis were assessed by univariate analysis and multivariate logistic regression analysis. A nomogram subsequently established by R software was validated by Bootstrap resampling as internal validation. Results: Compared with pN0 group, NE (P=0.022), CRP (P<0.001), NLR (P<0.001), PLR (P=0.003) and CAR (P<0.001) were higher, LY (P=0.003) and Alb (P=0.042) were lower in pN+ group. ROC curve analysis showed that the area under the curve (AUC) of postoperative pathological lymph node metastasis in patients with cN0 gastric cancer diagnosed by NLR, PLR and CAR were 0.687, 0.651 and 0.694, respectively, and the best cutoff values were 2.12, 113.59 and 0.02, respectively. The corresponding sensitivity and specificity were 62.9% and 72.2%, 77.4% and 48.6%, 74.2% and 58.3%, respectively. Univariate analysis showed that tumor size, depth of invasion, NLR, PLR and CAR were associated with lymph node metastasis in cN0 gastric cancer patients (all P<0.05). Multivariate analysis showed that depth of invasion, NLR and CAR were independent influencing factors of lymph node metastasis in patients with cN0 gastric cancer. OR were 8.084, 3.540 and 3.092, respectively (all P<0.05). The C-index of the nomogram model was 0.847 (95% CI: 0.782-0.915). The predicting calibration curve was properly fit with the ideal curve in calibration chart. Conclusion: Combination of NLR and CAR to establish a nomogram model has a good consistency and can accurately predict the risk of lymph node metastasis in patients with cN0 gastric cancer.

Three-dimensional damage morphologies of thermomechanically deformed sintered nanosilver die attachments for power electronics modules

A time-lapse study of thermomechanical fatigue damage has been undertaken using three-dimensional X-ray computer tomography. Morphologies were extracted from tomography data and integrated with data from microscopy modalities at different resolution levels. This enables contextualization of some of the fine-scale properties which underpin the large-scale damage observed via tomography. Lateral views of crack development are presented, which show networks analogous to mud-cracks. Crack fronts which develop in the most porous regions within the sintered attachment layer travel across the boundary into the copper substrate. The propagation characteristics of these cracks within the substrate are analysed. Evidence is provided of heterogeneous densification within the sintered joint under power cycling, and this is shown to play a major role in driving the initiation and propagation of the cracks. Examination of the texture (differing levels of X-ray absorption) of virtual cross-sectional images reveals the origins of the nonuniformity of densification. Finally, cracks within the sintered joint are shown to have a negligible impact on the conduction pathway of the joint due to their aspect ratio and orientation with respect to the assembly. LAY DESCRIPTION: This paper concerns the use of three-dimensional (3D) X-ray tomography, a nondestructive technique, to perform cradle-to-grave studies of sintered nanosilver die-attachments under operation. Sintered nanosilver die-attachments have been proposed as a more reliable and environmentally friendly alternative to solder alloy joints for emerging power electronics module designs. However, their degradation mechanisms are not as well understood. This same sample-study is about observing how the fine-scale structure of a sintered attachment evolves and degrades over time. Using 3D tomography affords otherwise infeasible perspectives, such as virtual cross-sections in the lateral plane of the attachment. These perspectives provide qualitative information which elucidates the degradation mechanisms. They demonstrate, for example, that the structure of the sintered attachment densifies under operation, and a consequence of this is the formation of shrinkage cracks in the most porous regions, much like mud-cracks. Other imaging techniques (metallographic etching and scanning electron microscopy) have been used in correlation with 3D renderings of these cracks to analyse their propagation and reveal their relationship both with the internal structure of the sintered attachment itself, and the structure of the substrate to which it is joined. It is shown that the cracks develop within the sintered attachment layer and eventually cross over into the substrate. A comparison of two sintered attachments with contrasting bulk porosities allows the effect of initial bond quality on crack development to be examined.

BRAF inhibitors: efficacious and tolerable in BRAF-mutant acral and mucosal melanoma

BRAF inhibitors substantially have impressive clinical efficacy in cutaneous melanoma. However, their role in acral and mucosal melanoma remains unclear. Records were reviewed of patients with metastatic or unresectable BRAF-mutant acral and mucosal melanoma hospitalized and administrated BRAF inhibitors during January 2011 and March 2016. Clinical data were collected to determine PFS, ORR, DCR, OS, and safety. Among 28 acral and 12 mucosal melanoma patients treated with BRAF inhibitors, median PFS were 3.6 (95%CI 3.0-6.4) and 4.4 (95%CI 0.8-12.7) months, median OS were 6.2 (95%CI 6.1-12.1) and 8.2 (95%CI 6.6-19.9) months; ORRs were 38.1% and 20.0%, DCRs were 81.0% and 70.0% in acral and mucosal melanoma, respectively. BRAF inhibitors were well tolerated. The most common adverse effects (AEs) were cutaneous and hematological. Grade 3/4 AEs were relatively rare. In conclusion, BRAF inhibitors have acceptable efficacy and good tolerance in BRAF mutant acral and mucosal melanoma.

MiR-34a regulates cell apoptosis after myocardial infarction in rats through the Wnt/β-catenin signaling pathway

OBJECTIVE

To explore the molecular mechanism of micro ribonucleic acid-34a (miR-34a) in promoting the apoptosis of myocardial cells in the rat model of myocardial infarction (MI).

MATERIALS AND METHODS

Sprague-Dawley (SD) rats were ligated with a left anterior descending branch to construct the MI model. The rats were randomly divided into four groups: sham operation group (Sham group), MI group, MI + miR-34a inhibitor group (MI + miR-34a antagomir group) and MI + miR-34a inhibitor negative control group (MI + antagomir NC group). Echocardiography (ECG) and magnetic resonance imaging (MRI) were adopted to detect the ejection fraction [EF (%)] and fraction shortening [FS (%)] of SD rats. Polymerase chain reaction (PCR) and Western blotting were used to detect expression levels of the apoptotic marker Caspase-3 and genes in Wnt/β-catenin signaling pathway. Hematoxylin and eosin (H&E) staining was applied to detect cardiac injury. In in vitro experiments, the rat-derived myocardial cell line H9C2 was selected to simulate myocardial ischemia and hypoxia at the time of MI with an anoxic and serum-free injury model. C59, the Wnt/β-catenin signaling pathway inhibitor was applied in MI + miR-34a antagomir + C59 group, and the effect of miR-34a on the apoptosis of myocardial cells through regulating the Wnt/β-catenin pathway was measured with Real-Time quantitative PCR (qPCR) and 3-(4,5)-dimethylthiazol(-z-y1)-3,5-diphenyltetrazolium bromide (MTT) cell activity detection kits, respectively.

RESULTS

It was found that after miR-34a antagomir reversed FS (%) and EF (%) in MI rats, the messenger RNA (mRNA) and protein levels of Caspase-3 in Sham group and MI + miR-34a antagomir group were significantly lower than those in the MI group (p < 0.05), indicating that the addition of miR-34a antagomir inhibited myocardial cell apoptosis after infarction, while the mRNA and protein levels of Wnt/β-catenin were both higher than those in the MI group. Besides, H&E staining proved that miR-34a reversed the myocardial injury after MI. Similarly, in vitro experiments showed that, compared with those in Hypoxia group, the level of Caspase-3 decreased in Hypoxia + miR-34a inhibitor group and Sham group, while the apoptosis level in Hypoxia + miR-34a inhibitor + C59 group increased (p < 0.05). The results of the MTT assay were consistent with those of PCR. MiR-34a affects myocardial cell apoptosis by regulating the activation and inactivation of the Wnt/β-catenin signaling pathway.

The clinical significance of perineural invasion in patients with de novo metastatic prostate cancer

BACKGROUND

The clinical value of perineural invasion (PNI) in patients with localized prostate cancer (PCa) is widely explored. However, its role in metastatic PCa (mPCa) remains unknown.

OBJECTIVES

We aim to investigate the clinical significance of PNI in patients with mPCa.

MATERIALS AND METHODS

Data of 515 mPCa patients between 2012 and 2018 were retrospectively studied. PNI and its intensity were identified by prostate biopsy. The prognostic value of PNI was evaluated by Kaplan-Meier curves and Cox proportional-hazards model.

RESULTS

Perineural invasion was detected in 170/515 (33.0%) cases. Among them 73/170 (42.9%) and 97/170 (57.1%) harbored unifocal PNI (uni-PNI) and multifocal PNI (multi-PNI), respectively. Compared to patients without PNI, those with PNI had statistically shorter castration-resistant PCa-free survival (CFS) and numerically shorter overall survival (OS) (mCFS: 15.4- vs. 18.5-Mo, p = 0.015; mOS: 63.8- vs. 71.4-Mo, p = 0.108). Patients harboring multi-PNI were associated with poorer clinical outcomes than those with uni-PNI (mCFS: 12.4- vs. 18.0-Mo, p = 0.040; mOS: 39.7-Mo vs. NR, p = 0.018) or those without PNI (mCFS: 12.4- vs. 18.5-Mo, p = 0.002; mOS: 39.7- vs. 71.4-Mo, p = 0.002). Totally, neither uni-PNI nor multi-PNI was an independent risk factor impacting survival outcomes in multivariate analyses. While remarkably, for patients with favorable/intermediate-risk mPCa, multi-PNI was an independent adverse prognosticator for both CFS and OS (CFS: HR: 1.705, 95% CI: 1.029-2.825, p = 0.038; OS: HR: 3.294, 95% CI: 1.464-7.413, p = 0.004).

DISCUSSION AND CONCLUSION

This study filled the blank of the clinical significance of PNI in mPCa. We found that multi-PNI could distinguish men with relatively poor prognosis from patients initially regarded as with favorable survival outcomes by other prognosticators, and thus, avoid disease underestimation in this group of patients. Our finding would help physicians have a deeper understanding of the heterogeneity of mPCa and make better individualized therapeutic strategy.

Association of Fruit and Vegetable Intake and Frailty among Chinese Elders: A Cross-Sectional Study in Three Cities

OBJECTIVES

To examine the association of FVI and frailty in Chinese elders.

DESIGN

A sectional study was conducted in three cities (Shanghai, Zhengzhou, and Baoji) in China from June 2017 to June 2018.

PARTICIPANTS

A total of 5699 participants from 49 districts were included in the current study by two-stage sampling methods.

MEASUREMENTS

Frailty was measured by a validated Chinese version of the FRAIL scale. FVI per day was measured by two single questions.

RESULTS

The sample proportion with sufficient fruit intake was 36.7%, and 44.7% reported sufficient vegetable intake. The sample proportions that were robust, pre-frail, and frail were 43.6%, 38.3%, and 18.1%, respectively. Compared with low FVI, after including covariates, the odds ratio (OR) of frailty was 0.84 (95% CI: 0.73-0.97) for moderate fruit intake and 0.81 (95% CI: 0.70-0.94) for enough fruit intake; the OR of frailty was 0.83 (95% CI: 0.68-0.91) for moderate vegetable intake and 0.77 (95% CI: 0.64-0.93) for enough vegetable intake.

CONCLUSION

High FVI was negatively associated with the OR of frailty in Chinese elders. This finding implies it is important to promote FVI among adults to prevent frailty.

Immune Tolerance Induced by Decitabine Combined With Multiple Allogeneic Bone Marrow Mononuclear Cell Infusion

OBJECTIVE

The aim of our study was to investigate the strategy of immune tolerance induced by the demethylating drug decitabine (DAC) combined with multiple allogeneic bone marrow mononuclear cell (BMMNC) infusions.

METHODS

An animal model with C57BL/6 mice as recipients and a BALB/c mouse as the donor was established. C57BL/6 mice were randomly divided into the following groups: DAC, BMMNC, DAC+BMMNC, and the control groups. Mice in the DAC and DAC+BMMNC groups were given DAC (5 μg/kg) on days 1, 2, 7, 8, 13, and 14. On experimental days 3, 9, and 15, BMMNCs (5 × 10⁶/mouse/time) from BALB/c mice were infused into mice of the BMMNC and DAC+BMMNC groups. One-way mixed lymphocyte reaction (MLR), interleukin-2 reverse test, and in vitro adoptive transfer experiments were performed. The ratio of regulatory T cells in splenocytes, chimera detection, and median survival time of skin grafts were recorded.

RESULTS

MLR showed that the stimulation index of the DAC+BMMNC group was significantly lower compared with the other 3 groups (P < .01), but still showed a strong proliferative response to the third-party unrelated donor KM mice, with no significant difference compared with the other 3 groups. The MLR low reactivity of the DAC+BMMNC group could be reversed by exogenous interleukin-2. After adding an equal amount of splenocytes from a C57BL/6 mouse in the DAC+BMMNC group, MLR of control group significantly decreased (P < .05). Flow cytometry showed the ratio of regulatory T cells in splenocytes from DAC and DAC+BMMNC groups was significantly higher than that from the BMMNC and control groups (P < .05). Chimeric rate of the DAC+BMMNC (60%) group was significantly higher than that of the BMMNC group (30%). Moreover, survival time of skin grafts in the DAC+BMMNC group was significantly longer than that in the other 3 groups (P < .001). No death or graft-vs-host disease was observed.

CONCLUSION

DAC combined with multiple allogeneic BMMNC infusion could successfully induce specific immune tolerance in mice, which may provide some new strategies to improve immune tolerance after organ transplant.

Evolutionary divergence of mitochondrial genomes in two Tetranychus species distributed across different climates

There is increasing evidence that mitochondrial genomes (mitogenomes) can be under selection, whereas the selective regimes shaping mitogenome evolution remain largely unclear. To test for mitogenome evolution in relation to the climate adaptation, we explored mtDNA variation in two spider mite (Tetranychus) species that distribute across different climates. We sequenced 26 complete mitogenomes of Tetranychus truncates, which occurs in both warm and cold regions, and nine complete mitogenomes of Tetranychus pueraricola, which is restricted to warm regions. Patterns of evolution in the two species' mitogenomes were compared through a series of d_N /d_S methods and physicochemical profiles of amino acid replacements. We found that: (1) the mitogenomes of both species were under widespread purifying selection; (2) elevated directional adaptive selection was observed in the T. truncatus mitogenome, perhaps linked to the cold climates adaptation of T. truncatus; and (3) the strength of selection varied across genes, and diversifying positive selection detected on ND4 and ATP6 pointed to their crucial roles during adaptation to different climatic conditions. This study gained insight into the mitogenome evolution in relation to the climate adaptation.