[Early effectiveness of local injection of multimodal drug cocktail during anterior cruciate ligament reconstruction and its influence on cartilage].

Objective: To explore the early effectiveness and influence on cartilage of local injection of multimodal drug cocktail (MDC) during anterior cruciate ligament reconstruction (ACLR). Methods: Between February 2022 and August 2023, patients undergone arthroscopic ACLR using autologous hamstring tendons were selected as the study subjects. Among them, 90 patients met the selection criteria and were randomly divided into 3 groups ( n=30) according to the different injection drugs after ligament reconstruction. There was no significant difference in baseline data such as gender, age, body mass index, surgical side, disease duration, preoperative thigh circumference, and preoperative levels of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), IL-1, matrix metalloproteinase 3 (MMP-3), MMP-13, and aggrecan (ACAN) in synovial fluid between groups ( P>0.05). After the ligament reconstruction during operation, corresponding MDC (consisting of ropivacaine, tranexamic acid, and betamethasone in group A, and ropivacaine, betamethasone, and saline in group B) or saline (group C) were injected into the joint and tendon site, respectively. The length of hospital stay, postoperative tramadol injection volume, incidence of complications, degree of knee joint swelling and range of motion, visual analogue scale (VAS) score, International Knee Documentation Committee (IKDC) score, Lyshlom score, and Hospital for Special Surgery (HSS) score were recorded and compared between groups. The T2 * values in different cartilage regions were detected by MRI examination and the levels of TNF-α, IL-6, IL-1, MMP-3, MMP-13, and ACAN in synovial fluid were detected by ELISA method. Results: The patients in group A, B, and C were followed up (12.53±3.24), (13.14±2.87), and (12.82±3.32) months, respectively. All incisions healed by first intention. Compared with group C, group A and group B had shorter length of hospital stay, less tramadol injection volume, and lower incidence of complications, showing significant differences ( P<0.05); there was no significant difference between group A and group B ( P>0.05). The degree of knee swelling in group A was significantly less than that in group B and group C ( P<0.05), but there was no significant difference between group B and group C ( P>0.05). At 3, 6, 12, 24, and 48 hours after operation, VAS scores of group A and group B were significantly lower than those of group C ( P<0.05); at 72 hours after operation, there was no significant difference among the three groups ( P>0.05). At 3 days, 14 days, and 1 month after operation, the range of motion of knee joint in group A were significantly better than those in group C ( P<0.05), and there was no significant difference between the other groups ( P>0.05). At 1 month after operation, the IKDC score of group A and group B was significantly higher than that of group C ( P<0.05); there was no significant difference among the three groups at other time points ( P>0.05). There was no significant difference in Lyshlom score and HSS score among the three groups at each time point ( P>0.05). At 14 days after operation, the levels of IL-1 and IL-6 in the synovial fluid in groups A and B were significantly lower than those in group C ( P<0.05). There was no significant difference in the levels of TNF-α, MMP-3, MMP-13, and ACAN between groups A and B ( P>0.05). At 1 month after operation, there was no significant difference in the above indicators among the three groups ( P>0.05). At 3, 6, and 12 months after operation, there was no significant difference in the T2 * values of different cartilage regions among the three groups ( P>0.05). Conclusion: Injecting MDC (ropivacaine, tranexamic acid, betamethasone) into the joint and tendon site during ACLR can achieve good early effectiveness without significant impact on cartilage.

[Research progress on early postoperative pain management strategies after arthroscopic anterior cruciate ligament reconstruction].

Objective: To summarize the early postoperative pain management strategies for anterior cruciate ligament reconstruction (ACLR), and to select a reasonable and effective pain management plan to promote functional rehabilitation after ACLR. Methods: The literature about the early postoperative pain management strategies of ACLR both domestically and internationally in recent years was extensiverly reviewed, and the effects of improving postoperative pain were reviewed. Results: Currently, physical therapy and oral medication have advantages such as economy and simplicity, but the effect of improving postoperative pain is not satisfactory, often requires a combination of intravenous injection or intravenous pump, which is also a common way to relieve pain. However, in order to meet the analgesic needs of patients, the amount of analgesic drugs used is often large, which increases the incidence of various adverse reactions. Local infiltration analgesia (LIA), including periarticular or intra-articular injection of drugs, can significantly improve the early postoperative pain of ACLR, and achieve similar postoperative effectiveness as nerve block. LIA can be used as an analgesic technique instead of nerve block, and avoid the corresponding weakness of innervated muscles caused by nerve block, which increases the risk of postoperative falls. Many studies have confirmed that LIA can alleviate postoperative early pain in ACLR, especially the analgesic effects of periarticular injection are more satisfactory. It can also avoid the risk of cartilage damage caused by intra-articular injection. However, the postoperative analgesic effect and timeliness still need to be improved. It is possible to consider combining multimodal mixed drug LIA (combined with intra-articular and periarticular) with other pain intervention methods to exert a synergistic effect, in order to avoid the side effects and risks brought by single drugs or single administration route. LIA is expected to become one of the most common methods for relieving postoperative early pain in ACLR. Conclusion: Early pain after arthroscopic ACLR still affects the further functional activities of patients, and all kinds of analgesic methods can achieve certain effectiveness, but there is no unified standard at present, and the advantages and disadvantages of various analgesic methods need further research.

[Return to sports WeChat applet for evaluating the rehabilitation effects after anterior cruciate ligament reconstruction].

Objective: To clarify the intervention guidance of return to sports WeChat applet and evaluate the rehabilitation effectiveness after anterior cruciate ligament (ACL) reconstruction. Methods: Between September 2020 and September 2022, 80 patients who met the selection criteria and underwent ACL anatomical single bundle reconstruction were selected as the research objects. According to the double-blind random method, they were divided into the applet group and the regular group, with 40 cases in each group. Patients in the applet group were rehabilitated under the guidance of the return to sports WeChat applet, and the patients were asked to perform the test once a month after operation, including patients' subjective scores [Tegner score, knee injury and osteoarthritis outcome score (KOOS), International Knee Documentation Committee (IKDC) score, American Hospital for Special Surgery (HSS) score], psychological assessment [ACL recovery sports injury scale (ACL-RSI) score], jumping test, balance test, bending angle test. Patients in the regular group were followed up by doctors and nurses regularly by telephone every month. All the patients were reexamined at 3, 6, 9, and 12 months after operation, and the range of motion of the knee joint with 6 degrees of freedom (flexion and extension angle, varus and valgus angle, internal and external rotation angle, anteroposterior displacement, superior and inferior displacement, and internal and external displacement) recorded by Opti_Knee three-dimensional knee joint motion measurement gait analysis system was observed. The anterior tibial translation difference (ATTD) was measured by Ligs knee measuring instrument when a forward thrust of 120 N was applied to the posterior part of the proximal tibia. Tegner score, IKDC score, KOOS score (including KOOS-Pain score, KOOS-Symptoms score, KOOS-Activities of daily living score, KOOS-Sport score, and KOOS-Quality of life score), HSS score, ACL-RSI score, jumping ability, balance ability, patients' satisfaction with the rehabilitation process, and ACL healing grading according to ACL continuity and signal intensity shown by MRI. Results: There were significant differences in various indicators between different time points after operation in the two groups ( P<0.05). At 3 months after operation, except that the ACL-RSI score of the applet group was significantly higher than that of the regular group ( P<0.05), there was no significant difference in the other indicators between the two groups ( P>0.05). At 6 months after operation, the ACL-RSI score, IKDC score, Tegner score, KOOS scores of different items, HSS score, balance and jumping ability of the applet group were significantly higher than those of the regular group ( P<0.05), and there was no significant difference in the other indicators between the two groups ( P>0.05). At 9 months after operation, there was no significant difference in all indicators between the two groups ( P>0.05). At 12 months after operation, 27 cases (67.5%) in the applet group and 21 cases (52.5%) in the regular group returned to sport, with a significant difference of the return to sports incidence between the two groups [ RR(95% CI)=1.50 (1.00, 2.25), P=0.049]. In the applet group, 27 cases were very satisfied with the rehabilitation process, 10 cases were satisfied, 2 cases were basically satisfied, and 1 case was not satisfied, while 19, 13, 5, and 3 cases in the regular group, respectively. The satisfaction degree of the applet group was significantly better than that of the regular group ( P=0.049). MRI examination of the two groups showed that the ACL was continuous without secondary rupture or necrosis. The ACL healing grade of the applet group was 31 cases of grade 1 and 9 cases of grade 2, and that of the regular group was 28 cases of grade 1 and 12 cases of grade 2, there was no significant difference in ACL healing grade between the two groups ( P=0.449). Conclusion: The application of return to sports WeChat applet in the rehabilitation of patients after ACL reconstruction can significantly reduce the fear of return to sports and improve the rate of return to sports. The return to sports WeChat applet is convenient to operate, with high utilization rate and high patient compliance, which significantly improves the satisfaction.

[Effectiveness of anterior cruciate ligament reconstruction with personalized femoral locator based on apex of deep cartilage].

Objective: To investigate the effectiveness of anterior cruciate ligament (ACL) reconstruction assisted by personalized femoral locator based on the apex of deep cartilage (ADC) combined with patient imaging data. Methods: Between January 2021 and January 2022, a total of 40 patients with primary ACL rupture were selected and randomly divided into study group (ACL reconstruction assisted by personalized femoral locator based on ADC) and control group (ACL reconstruction assisted by intraoperative fluoroscopy and traditional femoral locator), with 20 cases in each group. There was no significant difference in gender, age, body mass index, affected side, cause of injury, and preoperative International Knee Documentation Committee (IKDC) score, Lyshlom score, and Tegner score between the two groups ( P>0.05). IKDC score, Lyshlom score, and Tegner score were used to evaluate the functional recovery of the affected knee before operation and at 3, 6, and 12 months after operation. CT scan and three-dimensional reconstruction were performed before and after operation to measure the horizontal distance from ADC to the anterior cartilage margin (L) and the horizontal distance from ADC to the center of the femoral canal (I), and the anteroposterior position of the bone canal (R) was calculated by I/L; the distance from the center to the distal cartilage margin (D) was measured on the two-dimensional cross section; the R value and D value were compared between the two groups. Results: The operation time of the study group was significantly less than that of the control group [ MD=-6.90 (-8.78, -5.03), P<0.001]. The incisions of the two groups healed by first intention, and no complication such as intra-articular infection, nerve injury, and deep vein thrombosis of lower limbs occurred. There was no significant difference in the R value and D value between the preoperative simulated positioning and the actual intraoperative positioning in the study group [ MD=0.52 (-2.85, 3.88), P=0.758; MD=0.36 (-0.39, 1.11), P=0.351]. There was no significant difference in the actual intraoperative positioning R value and D value between the study group and the control group [ MD=1.01 (-2.57, 4.58), P=0.573; MD=0.24 (-0.34, 0.82), P=0.411]. The patients in both groups were followed up 12-13 months (mean, 12.4 months). The IKDC score, Lysholm score, and Tegner score of the two groups increased gradually with time, and there were significant differences between pre- and post-operation ( P<0.05). There was no significant difference in the scores between the two groups at each time point after operation ( P>0.05). Conclusion: The personalized femoral locator based on ADC can accurately assist the femoral tunnel positioning in ACL reconstruction, which can shorten the operation time when compared with traditional surgical methods, and achieve satisfactory early effectiveness.

[Three-dimensional kinematic analysis of knee joint after anterior cruciate ligament reconstruction with personalized femoral positioner based on apex of deep cartilage].

Objective: To investigate the changes of knee joint kinematics after anterior cruciate ligament (ACL) reconstruction assisted by personalized femoral positioner based on the apex of deep cartilage (ADC). Methods: Between January 2021 and January 2022, a total of 40 patients with initial ACL rupture who met the selection criteria were randomly divided into the study group (using the personalized femoral positioner based on ADC design to assist ACL reconstruction) and the control group (not using the personalized femoral positioner to assist ACL reconstruction), with 20 patients in each group. Another 20 volunteers with normal knee were collected as a healthy group. There was no significant difference in gender, age, body mass index, and affected side between groups ( P>0.05). Gait analysis was performed at 3, 6, and 12 months after operation using Opti _ Knee three-dimensional knee joint motion measurement and analysis system, and the 6 degrees of freedom (flexion and extension angle, varus and valgus angle, internal and external rotation angle, anteroposterior displacement, superior and inferior displacement, internal and external displacement) and motion cycle (maximum step length, minimum step length, and step frequency) of the knee joint were recorded. The patients' data was compared to the data of healthy group. Results: In the healthy group, the flexion and extension angle was (57.80±3.45)°, the varus and valgus angle was (10.54±1.05)°, the internal and external rotation angle was (13.02±1.66)°, and the anteroposterior displacement was (1.44±0.39) cm, the superior and inferior displacement was (0.86±0.20) cm, and the internal and external displacement was (1.38±0.39) cm. The maximum step length was (51.24±1.29) cm, the minimum step length was (45.69±2.28) cm, and the step frequency was (12.45±0.47) step/minute. Compared with the healthy group, the flexion and extension angles and internal and external rotation angles of the patients in the study group and the control group decreased at 3 months after operation, and the flexion and extension angles of the patients in the control group decreased at 6 months after operation, and the differences were significant ( P<0.05); there was no significant difference in the other time points and other indicators when compared with healthy group ( P>0.05). In the study group, the flexion and extension angles and internal and external rotation angles at 6 and 12 months after operation were significantly greater than those at 3 months after operation ( P<0.05), while there was no significant difference in the other indicators at other time points ( P>0.05). There was a significant difference in flexion and extension angle between the study group and the control group at 6 months after operation ( P<0.05), but there was no significant difference of the indicators between the two groups at other time points ( P>0.05). Conclusion: Compared with conventional surgery, ACL reconstruction assisted by personalized femoral positioner based on ADC design can help patients achieve more satisfactory early postoperative kinematic results, and three-dimensional kinematic analysis can more objectively and dynamically evaluate the postoperative recovery of knee joint.

[Progress in evaluation of return to sports after anterior cruciate ligament reconstruction].

Objective: To summarize the evaluation methods of return to sports (RTS) after anterior cruciate ligament reconstruction (ACLR) in recent years, in order to provide reference for clinical practice. Methods: The literature related to the RTS after ACLR was searched from CNKI, Wanfang, PubMed, and Foreign Medical Information Resources Retrieval Platform (FMRS) databases. The retrieval range was from 2010 to 2023, and 66 papers were finally included for review. The relevant literature was summarized and analyzed from the aspects of RTS time, objective evaluation indicators, and psychological evaluation. Results: RTS is the common desire of patients with ACL injury and doctors, as well as the initial intention of selecting surgery. A reasonable and perfect evaluation method of RTS can not only help patients recover to preoperative exercise level, but also protect patients from re-injury. At present, the main criterion for clinical judgement of RTS is time. It is basically agreed that RTS after 9 months can reduce the re-injury. In addition to time, it is also necessary to test the lower limb muscle strength, jumping, balance, and other aspects of the patient, comprehensively assess the degree of functional recovery and determine the different time of RTS according to the type of exercise. Psychological assessment plays an important role in RTS and has a good clinical predictive effect. Conclusion: RTS is one of the research hotspots after ACLR. At present, there are many related evaluation methods, which need to be further optimized by more research to build a comprehensive and standardized evaluation system.

[Effectiveness analysis of arthroscopic single/double-row suture techniques in repairing of moderate rotator cuff tears].

Objective: To compare the early effectiveness of arthroscopic repair of moderate rotator cuff tears with single-row modified Mason-Allen technique and double-row suture bridge technique. Methods: The clinical data of 40 patients with moderate rotator cuff tears who met the selection criteria between January 2021 and May 2022 were retrospectively analyzed. Among them, 20 cases were repaired with single-row modified Mason-Allen suture technique (single-row group) and 20 cases with double-row suture bridge technique (double-row group). There was no significant difference in gender, age, disease duration, rotator cuff tear size, and preoperative visual analogue scale (VAS) score, Constant-Murley score, and T2* value between the two groups ( P>0.05). The VAS score, Constant-Murley score (including subjective influence, pain, flexion, internal rotation, external rotation, abduction, and muscle strength score) were compared between the two groups before operation and at 6 weeks, 3, 6, and 12 months after operation. Functional MRI and ultrashort-echo-time (UTE)-T2* technique were performed to calculate T2* value and quantitatively evaluate the healing of rotator cuff tissue; and the healing of rotator cuff was evaluated by Sugaya classification at 12 months after operation. Results: Patients in both groups were followed up 1 year. There was no complication such as muscle atrophy, joint stiffness, or postoperative rotator cuff tear. The intra-group comparison showed that the scores of pain, subjective influence, flexion, abduction, and muscle strength in Constant-Murley scores at each time point after operation in the two groups were significantly higher than those before operation, while VAS scores were significantly lower than those before operation ( P<0.05). Internal rotation, external rotation, and total score of Constant-Murley score in the two groups were lower at 6 weeks due to abduction immobilization within 6 weeks after operation, and gradually increased at 6 months after operation, with significant differences at 3, 6, and 12 months after operation when compared with those before operation and at 6 weeks after operation ( P<0.05). The T2* values of the two groups showed a downward trend over time, and there were significant differences between the two groups at other time points ( P<0.05), except that there was no significant difference between at 6 and 12 months after operation in the single-row group and between at 3, 6, and 12 months after operation in the double-row group ( P>0.05). The comparison between groups showed that the VAS score and T2* values of the double-row group were significantly lower than those of the single-row group at 6 weeks, 3 months, 6 months, and 12 months after operation ( P<0.05). The scores of subjective influence, flexion, abduction, and internal rotation in the double-row group were significantly better than those in the single-row group at 6 weeks and 3 months after operation ( P<0.05), and the external rotation score and total score in the double-row group were significantly better than those in the single-row group at 3 months after operation ( P<0.05), but there was no significant difference at 6 and 12 months after operation ( P>0.05). There was no significant difference in muscle strength and pain scores between the two groups at 6 weeks, 3 months, 6 months, and 12 months after operation ( P>0.05). There was no significant difference in the results of Sugaya classification between the two groups at 12 months after operation ( Z=1.060, P=0.289). Conclusion: The effectiveness of arthroscopic repair of moderate rotator cuff tears with modified Mason-Allen technique and double-row suture bridge technique is satisfactory, but suture bridge technique is helpful to the early rehabilitation training of shoulder joint and the recovery of motor function of patients.

[Evaluation methods of postoperative healing of supraspinatus tendon tear].

Objective: To summarize the evaluation methods of postoperative healing of supraspinatus tendon tear in recent years, in order to provide reference for clinic. Methods: CNKI, Wanfang, PubMed, and Foreign Medical Literature Retrieval Service (FMRS) databases were used to search the literatures between 2005 and 2022. The literature related to the diagnosis and postoperative healing of supraspinatus tendon tear was included. Finally, 50 articles were reviewed. Results: Supraspinatus tendon tear is a common shoulder disease. Physical examination, clinical score, and imaging examination are used to predict and evaluate the postoperative healing. Among them, physical examination and clinical score are non-invasive and the most economical methods, but their accuracy and sensitivity are lower than imaging examination, so they can only be used as auxiliary methods. The acromio-humeral distance (AHD) and upward migration index (UMI) measured by X-ray films can directly reflect the change of supraspinatus tendon thickness, but they are impossible to distinguish whether there is tear or not. Ultrasound and MRI are the main methods for the clinical diagnosis of supraspinatus tendon tear, but the commonly used MRI sequence can not accurately judge the internal healing of the tendon. Shear wave elastrography (SWE) and ultrashort-echo-time (UTE) techniques are the latest research directions in recent years, but different studies have shown opposite conclusions on the application of SWE technique. This conclusion shows that the principle of SWE technique and its relationship with tendons need to be further studied. UTE technique has good clinical effect, and the T2* value obtained by UTE technique is more accurate than that of traditional Sugaya typing, but there are still few research samples. Conclusion: AHD and UMI measured by X-ray film and T2* value measured by UTE technique can be used as effective methods for evaluating the healing of supraspinatus tendon tear after repairing, and can be used as a follow-up evaluation method combined with physical examination and clinical score for patients with supraspinatus tendon tear.

Localized delivery of brain-derived neurotrophic factor from PLGA microspheres promotes peripheral nerve regeneration in rats.

BACKGROUND: Repair of peripheral nerve defect presents a considerable challenge for reconstructive surgeons. The aim of this study is to develop a brain-derived neurotrophic factor (BDNF) from poly(D,L-lactide-co-glycolide) (PLGA) microspheres for the treatment of the peripheral nerve defect. METHOD: BDNF microspheres were prepared by using an oil-in-water emulsification-solvent evaporation method. The morphology, particle size, encapsulation efficiency, drug loading and sustained release performance of microspheres was observed and calculated. Adipose mesenchymal stem cells (ADSCs) were isolated and expanded. ADSCs were divided into four groups: control, BDNF, blank microsphere and BDNF microsphere groups. Cell count kit-8 (CCK-8) assays were used to assess cell proliferation. Cell migration was determined by Transwell assays. Twenty-eight male Sprague-Dawley rats underwent transection damage model on the right sciatic nerve. The wet weight ratio of the gastrocnemius muscle was calculated by comparing the weight of the gastrocnemius muscle from the operated side to that of the normal side. Neuroelectrophysiological testing was performed to assess nerve function recovery. Nerve regeneration was evaluated by histological analysis and immunohistochemical staining. RESULTS: The microspheres were spherical and had uniform size (46.38 ± 1.00 µm), high encapsulation efficiency and high loading capacity. In vitro release studies showed that BDNF-loaded microspheres had good sustained release characteristics. The duration of BDNF release was extended to more than 50 days. BDNF or BDNF microsphere promote the proliferation and migration of ADSCs than control group (P < 0.05). Compared with control group, BDNF significantly decreased the nerve conduction velocity (NCV) and compound amplitude (AMP) (P < 0.05). The nerve fibers in the BDNF microsphere group were closely arranged and uniformly distributed than control group. CONCLUSION: BDNF/PLGA sustained-release microsphere could promote the migration of ADSCs and promoted neural differentiation of ADSCs. Moreover, BDNF/PLGA sustained-release microsphere ameliorated nerve conduction velocity and prevented neuralgic amyotrophy.

Three-Dimensional Reconstruction Algorithm-Based Magnetic Resonance Imaging Evaluation of Biomechanical Changes in Articular Cartilage in Patients after Anterior Cruciate Ligament Reconstruction.

This study aimed to investigate the evaluation of biomechanical changes in articular cartilage in patients after anterior cruciate ligament (ACL) reconstruction by magnetic resonance imaging (MRI) based on a three-dimensional (3D) finite element model. The data of 90 patients undergoing arthroscopic ACL reconstruction in the hospital were collected and divided into the stable group (54 cases) and the unstable group (36 cases). A load of up to 134N was applied to the 3D finite element model, and the kinematics of knee flexion at 0°, 30°, 60°, and 90° were examined. The tibial anteversion, tibial rotation, and ACL/graft tension were recorded in the 3D finite element model, which was randomly divided into the normal group (intact group, n = 30), the ACL rupture group (deficient group, n = 30), and the anatomical reconstruction group (anatomical group, n = 30). When the graft was fixed at 0°, the anterior tibial translation at 30°, 60°, and 90° in the anatomic group was 8-19% higher than the normal value under 134 N anterior load. The tibial internal rotation in the anatomic group was 18% and 28% higher than the normal value at 30° and 90°. When the graft was fixed at 30°, the anterior tibial translation at 60° and 90° of the anatomic group was 15% higher than the normal value. The tibial internal rotation at 90° of the anatomic group was 16% higher than the normal value, and the above differences had statistical significance (P < 0.05). MRI images were used to assess the bone tunnel angle, and the statistical analysis by the independent-samples t-test showed that there were significant differences in the bone tunnel angle between the stable group and the unstable group (P < 0.05). Currently, based on the 3D finite element model, MRI can accurately evaluate the postoperative effect of anatomical ACL reconstruction in the position, diameter, and angle of tibial and femoral bone tunnels, which can be applied to clinical promotion.

MiR-155 promotes interleukin-1ß-induced chondrocyte apoptosis and catabolic activity by targeting PIK3R1-mediated PI3K/Akt pathway.

Osteoarthritis (OA) is a common joint disease characterized by progressive cartilage degradation, in which elevated chondrocyte apoptosis and catabolic activity play an important role. MicroRNA-155 (miR-155) has recently been shown to regulate apoptosis and catabolic activity in some pathological circumstances, yet, whether and how miR-155 is associated with OA pathology remain unexplored. We report here that miR-155 level is significantly up-regulated in human OA cartilage biopsies and also in primary chondrocytes stimulated by interleukin-1ß (IL-1ß), a pivotal pro-catabolic factor promoting cartilage degradation. Moreover, miR-155 inhibition attenuates and its overexpression promotes IL-1ß-induced apoptosis and catabolic activity in chondrocytes in vitro. We also demonstrate that the PIK3R1 (p85α regulatory subunit of phosphoinositide 3-kinase (PI3K)) is a target of miR-155 in chondrocytes, and more importantly, PIK3R1 restoration abrogates miR-155 effects on chondrocyte apoptosis and catabolic activity. Mechanistically, PIK3R1 positively regulates the transduction of PI3K/Akt pathway, and a specific Akt inhibitor reverses miR-155 effects on promoting chondrocyte apoptosis and catabolic activity, phenocopying the results obtained via PIK3R1 knockdown, hence establishing that miR-155 promotes chondrocyte apoptosis and catabolic activity through targeting PIK3R1-mediated PI3K/Akt pathway activation. Altogether, our study discovers novel roles and mechanisms of miR-155 in regulating chondrocyte apoptosis and catabolic activity, providing an implication for therapeutically intervening cartilage degradation and OA progression.

Long noncoding RNA LINC00314 facilitates osteogenic differentiation of adipose-derived stem cells through the hsa-miR-129-5p/GRM5 axis via the Wnt signaling pathway.

BACKGROUND: Many studies have shown that long noncoding RNAs (lncRNAs) are closely related to the stimulation of osteogenic differentiation of adipose-derived stem cells (ADSCs) and the prevention of osteoporosis. Current research aimed to investigate the novel lncRNA and explored the function and molecular mechanism of the LINC00314/miR-129-5p/GRM5 axis in regulating osteogenic differentiation of ADSCs. METHODS: LncRNA and miRNA sequencing was performed in normal and osteogenic differentiation-induced ADSCs (osteogenic group). Abnormally expressed lncRNAs and miRNAs were obtained by the R software and the relative expression of LINC00314, miR-129-5p, and GRM5 during osteogenic induction was measured by RT-PCR. ADSCs were then transfected with pcDNA3.1-sh-LINC00314 and agomiR-129-5p. Alizarin red staining (ARS) and alkaline phosphatase (ALP) staining were performed to identify the mechanism of the LINC00314/miR-129-5p/GRM5 axis in regulating osteogenic differentiation of ADSCs. RESULTS: LINC00314 was significantly upregulated in the group of osteogenic-induced ADSCs. LINC00314 and GRM5 mimics increased the early and late markers of osteogenic differentiation, which manifest in not only the markedly increased ALP activity but also higher calcium deposition, while miR-129-5p mimic had the opposite effects. LINC00314 directly targeted miR-129-5p through luciferase reporter assay, and miR-129-5p suppressed GRM5 expression. Moreover, the LINC00314/miR-129-5p/GRM5 regulatory axis activated the Wnt/ß-catenin signaling pathway. CONCLUSIONS: LINC00314 confers contributory function in the osteogenic differentiation of ADSCs and thus the LINC00314/miR-129-5p/GRM5 axis may be a novel mechanism for osteogenic-related disease.

Development of a multi-mimotope peptide as a vaccine immunogen for infectious bursal disease virus.

To explore the mimotope vaccine approach against infectious bursal disease virus (IBDV), five IBDV-specific monoclonal antibodies (mAbs) were prepared and their binding peptides were screened against a phage-displayed 12-mer peptide library. After three rounds of biopanning, 12 phages were selected for each mAbs and their specificity to IBDV was verified by sandwich and competitive inhibition ELISAs. Seven phages per mAb were sequenced and their amino acid sequences were deduced. The five representative sequences of mimotopes corresponding mAbs were determined. An artificial gene, designated 5epis (5 epitopes) and consisting of the five mimotopes arranged in tandem (F1-F7-B34-2B1-2G8) with four GGGS spacers, was chemically synthesized and cloned into a prokaryotic expression plasmid pET28b. The protein, designated r5EPIS, was efficiently expressed in Escherichia coli and showed a size of 10kDa in SDS-PAGE. The r5EPIS protein reacted with anti-IBDV mAbs and polyclonal antibodies in Western blot immunoassays. Immunization of SPF chickens with r5EPIS protein (with Freund adjuvant, 50mug per injection on day 0 and 14) evoked high levels of antibody (12,800 by ELISA/1600 by virus neutralizing assay at day 21) and protected 100% of the chickens against a challenge of 200 ELD(50) of IBDV GX8/99 strain, which sharply contrasted with the, respectively, 13.3% and 6.6% survival rate in the adjuvant group and the untreated group. The multi-mimotope protein r5EPIS promises to be a novel subunit vaccine candidate for IBDV.