Biomechanical Analysis of Hybrid Artificial Discs or Zero-Profile Devices for Treating 1-Level Adjacent Segment Degeneration in ACDF Revision Surgery.

OBJECTIVE: Cervical hybrid surgery optimizes the use of cervical disc arthroplasty (CDA) and zero-profile (ZOP) devices in anterior cervical discectomy and fusion (ACDF) but lacks uniform combination and biomechanical standards, especially in revision surgery (RS). This study aimed to investigate the biomechanical characteristics of adjacent segments of the different hybrid RS constructs in ACDF RS. METHODS: An intact 3-dimensional finite element model generated a normal cervical spine (C2-T1). This model was modified to the primary C5-6 ACDF model. Three RS models were created to treat C4-5 adjacent segment degeneration through implanting cages plus plates (Cage-Cage), ZOP devices (ZOP-Cage), or Bryan discs (CDA-Cage). A 1.0-Nm moment was applied to the primary C5-6 ACDF model to generate total C2-T1 range of motions (ROMs). Subsequently, a displacement load was applied to all RS models to match the total C2-T1 ROMs of the primary ACDF model. RESULTS: The ZOP-Cage model showed lower biomechanical responses including ROM, intradiscal pressure, maximum von Mises stress in discs, and facet joint force in adjacent segments compared to the Cage-Cage model. The CDA-Cage model exhibited the lowest biomechanical responses and ROM ratio at adjacent segments among all RS models, closely approached or lower than those in the primary ACDF model in most motion directions. Additionally, the maximum von Mises stress on the C3-4 and C6-7 discs increased in the Cage-Cage and ZOP-Cage models but decreased in the CDA-Cage model when compared to the primary ACDF model. CONCLUSION: The CDA-Cage construct had the lowest biomechanical responses with minimal kinematic change of adjacent segments. ZOP-Cage is the next best choice, especially if CDA is not suitable. This study provides a biomechanical reference for clinical hybrid RS decision-making to reduce the risk of ASD recurrence.

Is the interspinous process device safe and effective in elderly patients with lumbar degeneration? A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND CONTEXT: Lumbar spinal stenosis is one of the most common diseases affecting the elderly that is characterized by the narrowing of the spinal canal and peripheral neural pathways which may cause back pain and neurogenic intermittent claudication in affected patients. Recently, as an alternative treatment between conservative therapy and decompression surgery, interspinous process device (IPD) such as X-stop, Coflex, DIAM, Aperius, Wallis, etc., has gained enough popularity. PURPOSE: The purpose of this study was to evaluate the efficacy and safety of IPD in the treatment of degenerative lumbar spinal stenosis compared with decompression surgery. STUDY DESIGN: This study was a systematic review and meta-analysis of randomized controlled trials. PATIENT SAMPLE: 555 patients' samples were collected for this study. OUTCOME MEASURES: The Visual Analogue Scale and the Oswestry Disability Index were analyzed, as well as the Zurich Claudication Questionnaire For efficacy evaluation. Complication and reoperation rate was utilized for the assessment of safety. METHODS: A comprehensive literature search was performed through Pubmed, EMBASE, Web of Science, and Cochrane Library until October 2023. Among the studies meeting the eligible criteria, any study in which IPD was utilized in the treatment of degenerative lumbar spinal stenosis was included in the current review. For efficacy evaluation, the Visual Analogue Scale and the Oswestry Disability Index were analyzed, as well as the Zurich Claudication Questionnaire. Complication and reoperation rates were utilized for the assessment of safety. RESULTS: Five randomized controlled trials with 555 patients were included. There were no significant differences in VAS leg pain (SMD - 0.08, 95% CI - 0.32 to 0.15) and back pain (SMD 0.09, 95%CI-0.27 to 0.45), ODI scores (MD 1.08, 95% CI - 11.23 to 13.39) and ZCQ physical function (MD-0.09, 95% CI-0.22 to 0.05) for IPD compared with decompression surgery. In terms of ZCQ symptom severity (MD - 0.22, 95% CI - 0.27 to - 016), decompression surgery showed superior to the IPD. As for complications (RR 1.08, 95% CI 0.36 to 3.27), the IPD had no advantages compared to decompression surgery, whereas inferior to it in reoperation rate (RR 2.58, 95% CI 1.67 to 3.96). CONCLUSIONS: This systematic review and meta-analysis indicated no superiority in the clinical outcome for IPD compared with decompression surgery. However, more clinical studies are warranted to determine the efficacy and safety of IPD.

PLCG2 and IFNAR1: The Potential Biomarkers Mediated by Immune Infiltration and Osteoclast Differentiation of Ankylosing Spondylitis in the Peripheral Blood.

Objectives: Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease characterized by chronic spinal inflammation, arthritis, gut inflammation, and enthesitis. We aimed to identify the key biomarkers related to immune infiltration and osteoclast differentiation in the pathological process of AS by bioinformatic methods. Methods: GSE25101 from the Gene Expression Omnibus was used to obtain AS-associated microarray datasets. We performed bioinformatics analysis using R software to validate different expression levels. The purpose of the GO and KEGG enrichment analyses of DEGs was to exclude key genes. Using weighted correlation network analysis (WGCNA), we examined all expression profile data and identified differentially expressed genes. The objective was to investigate the interaction between genetic and clinical features and to identify the essential relationships underlying coexpression modules. The CIBERSORT method was used to make a comparison of the immune infiltration in whole blood between the AS group and the control group. The WGCNA R program from Bioconductor was used to identify hub genes. RNA extraction reverse transcription and quantitative polymerase chain reaction were conducted in the peripheral blood collected from six AS patients and six health volunteers matched by age and sex. Results: 125 DEGs were identified, consisting of 36 upregulated and 89 downregulated genes that are involved in the cell cycle and replication processes. In the WGCNA, modules of MCODE with different algorithms were used to find 33 key genes that were related to each other in a strong way. Immune infiltration analysis found that naive CD4+ T cells and monocytes may be involved in the process of AS. PLCG2 and IFNAR1 genes were obtained by screening genes meeting the conditions of immune cell infiltration and osteoclast differentiation in AS patients among IGF2R, GRN, SH2D1A, LILRB3, IFNAR1, PLCG2, and TNFRSF1B. The results demonstrated that the levels of PLCG2 mRNA expression in AS were considerably higher than those in healthy individuals (P=0.003). IFNAR1 mRNA expression levels were considerably lower in AS than in healthy individuals (P < 0.0001). Conclusions: Dysregulation of PLCG2 and IFNAR1 are key factors in disease occurrence and development of AS through regulating immune infiltration and osteoclast differentiation. Explaining the differences in immune infiltration and osteoclast differentiation between AS and normal samples will contribute to understanding the development of spondyloarthritis.

Hydrogel and Nanomedicine-Based Multimodal Therapeutic Strategies for Spinal Cord Injury.

Spinal cord injury (SCI) is a severe neurodegenerative disease caused by mechanical and biological factors, manifesting as a loss of motor and sensory functions. Inhibition of injury expansion and even reversal of injury in the acute damage stage of SCI are important strategies for treating this disease. Hydrogels and nanoparticle (NP)-based drugs are the most effective, widely studied, and clinically valuable therapeutic strategies in the field of repair and regeneration. Hydrogels are 3D flow structures that fill the pathological gaps in SCI and provide a microenvironment similar to that of the spinal cord extracellular matrix for nerve cell regeneration. NP-based drugs can easily penetrate the blood-spinal cord barrier, target SCI lesions, and are noninvasive. Hydrogels and NPs as drug carriers can be loaded with various drugs and biological therapeutic factors for slow release in SCI lesions. They help drugs function more efficiently by exerting anti-inflammatory, antioxidant, and nerve regeneration effects to promote the recovery of neurological function. In this review, the use of hydrogels and NPs as drug carriers and the role of both in the repair of SCI are discussed to provide a multimodal strategic reference for nerve repair and regeneration after SCI.

Comparison of the Radiographic and Clinical Outcome Changes in Patients With Spinal Deformity Before and After Stretching DanceExercise: A Systematic Review and Meta-Analysis.

OBJECTIVE: This study aimed to compare radiographic and clinical outcomes of scoliosis and thoracic hyperkyphosis before and after stretching-based exercises. METHODS: Embase, PubMed, Cochrane Library, Web of Science, and Scopus databases were comprehensively searched for relevant studies from their inception to June 2022. Radiographic outcomes, including the Cobb angle of the main curve and thoracic kyphosis, and clinical outcomes, including the angle of trunk rotation (ATR), chest expansion, Numeric Rating Scale (NRS), and Scoliosis Research Society-22 Patient Questionnaire (SRS-22), were extracted. Pooled and subgroup analyses were performed using random or fixed-effects models based on I2 heterogeneity. RESULTS: In total, 334 patients from ten studies, including 255 patients with scoliosis and 79 patients with thoracic hyperkyphosis, were included in the meta-analysis. After stretching, the pooled results showed that the Cobb angle of the main curve and thoracic kyphosis significantly decreased (P < 0.001) in patients with scoliosis, and thoracic kyphosis, respectively. Angle of trunk rotation (ATR) decreased significantly (P = 0.003), and chest expansion improved significantly (P = 0.04) after stretching-based exercise. In addition, our pooled results showed that the NRS score was significantly reduced (P < 0.001) and that the SRS-22 scores of mental health (P = 0.003) and self-perceived image (P < 0.001) were significantly increased after stretching. CONCLUSIONS: Partial correction can be achieved using stretching-based exercises. Moreover, stretching-based exercises can reduce pain in patients and improve their quality of life. However, the optimal duration required further elucidation.

The Incidence, Changes and Treatments of Cervical Deformity After Infection and Inflammation.

A healthy cervical spine with normal movement is the basis of many daily activities and is essential for maintaining a good quality of life. However, the alignment, fusion, and structure of the cervical spine can change for various reasons, leading to cervical deformity, mainly kyphosis. Approximately 5%‒20% of spinal infections in the cervical spine cause cervical deformity. The deformity can recover early; however, the disease's long-term existence or the continuous action of abnormal stress may lead to intervertebral fusion and abnormal osteophytes. Many gaps and controversies exist regarding infectious cervical deformities, including a lack of clear definitions and an acceptable classification system thereby requiring further research. Moreover, there is no consensus on the indications for postinfectious cervical deformity associated with Mycobacterium tuberculosis, Staphylococcus aureus, and Brucellosis. Therefore, we reviewed and discussed the incidence, clinical manifestations, changes, and treatment of infectious and inflammatory secondary cervical deformities from common to rare to provide a theoretical basis for clinical decision-making.

Surgical Treatment of Scoliosis Lenke Type 5, Anterior Versus Posterior, Which Approach is Better?: A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: This study aimed to compare the radiographical and clinical outcomes between anterior spinal fusion (ASF) and posterior spinal fusion (PSF) in Lenke type 5 adolescence idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: PSF has been the standard operation for adolescence idiopathic scoliosis. ASF can also achieve a good curve correction effect with fewer fusion segments and minor invasion of paraspinal structures. MATERIALS AND METHODS: A systematic literature research was conducted in PubMed, Embase, Cochrane Library, and Web of Science. Use meta-analysis to compare the changes of thoracolumbar/lumbar and thoracic curves and other important outcomes between ASF and PSF. RESULTS: A total of 427 ASF and 392 PSF patients from 12 studies were included. There was no significant difference in the correction degree of thoracolumbar/lumbar and thoracic curve between ASF and PSF ( P >0.05), except for PSF had more compensatory correction degree of thoracic curve at postoperation ( P <0.05). Besides, the loss of correction in thoracic curve in PSF at the last follow-up was significantly less than that in ASF ( P <0.05). PSF presented larger change values of thoracic kyphosis and lumbar lordosis at the last follow-up ( P <0.05). PSF showed a better effect in correcting trunk shift distance at the postoperation ( P <0.05) but less trunk shift distance correction from postoperation to last follow-up ( P <0.05). There was no significant difference in the incidence of proximal junctional kyphosis and estimated blood loss between the two approaches ( P >0.05). Moreover, ASF showed fewer fusion segments, but longer operation and hospital stay time ( P <0.05). CONCLUSION: ASF is capable of achieving similar correction in coronal curve and balance as PSF with fewer fusion segments. Spine surgeons should select an appropriate approach tailored to individual patients needs while considering procedural risks and benefits. LEVEL OF EVIDENCE: Level II.

OLIF versus ALIF: Which is the better surgical approach for degenerative lumbar disease? A systematic review.

PURPOSE: The aim of this study was to compare the clinical and radiographical outcomes between OLIF and ALIF in treating lumbar degenerative diseases. METHODS: We searched PubMed, Embase, Web of Science, and Cochrane Library for relevant studies. Changes in disc height (DH), segmental lordosis angle (SLA), lumbar lordosis (LL), visual analogue scale (VAS) score, and Oswestry disability index (ODI) between baseline and final follow-up, along with other important surgical outcomes, were assessed and analysed. Data on the global fusion rate and main complications were collected and compared. RESULTS: Approximately, 2041 patients from 36 studies were included, consisting of 1057 patients who underwent OLIF and 984 patients who underwent ALIF. The results reveal no significant difference in DH, SLA, VAS score, and ODI between the two groups (all P > 0.05). The operation time, estimated blood loss, and length of hospital stay were also comparable between the two groups. Over 90% of the fusion rate was achieved in both groups. The OLIF group showed a higher complication rate than the ALIF group (OLIF 18.83% vs ALIF 7.32%). CONCLUSIONS: OLIF leads to a higher complication rate, with the most notable complication being cage subsidence. Both OLIF and ALIF are effective treatments for degenerative lumbar diseases and have similar therapeutic effects. ALIF was expected to be more expensive for patients because of the necessity of involving vascular surgeons.

Biomechanical Analysis of the Reasonable Cervical Range of Motion to Prevent Non-Fusion Segmental Degeneration After Single-Level ACDF.

The compensatory increase in intervertebral range of motion (ROM) after cervical fusion can increase facet joint force (FJF) and intradiscal pressure (IDP) in non-fusion segments. Guiding the post-ACDF patient cervical exercise within a specific ROM (defined as reasonable ROM) to offset the increase in FJF and IDP may help prevent segmental degeneration. This study aimed to determine the reasonable total C0-C7 ROM without an increase in FJF and IDP in non-fusion segments after anterior cervical discectomy and fusion (ACDF). A three-dimensional intact finite element model of C0-C7 generated healthy cervical conditions. This was modified to the ACDF model by simulating the actual surgery at C5-C6. A 1.0 Nm moment and 73.6 N follower load were applied to the intact model to determine the ROMs. A displacement load was applied to the ACDF model under the same follower load, resulting in a total C0-C7 ROM similar to that of the intact model. The reasonable ROMs in the ACDF model were calculated using the fitting function. The results indicated that the intervertebral ROM of all non-fusion levels was increased in the ACDF model in all motion directions. The compensatory increase in ROM in adjacent segments (C4/5 and C6/7) was more significant than that in non-adjacent segments, except for C3/4 during lateral bending. The intervertebral FJF and IDP of C0-C7 increased with increasing ROM. The reasonable ROMs in the ACDF model were 42.4°, 52.6°, 28.4°, and 42.25° in flexion, extension, lateral bending, and axial rotation, respectively, with a decreased ROM of 4.4-7.2%. The postoperative increase in FJF and IDP in non-fusion segments can be canceled out by reducing the intervertebral ROM within reasonable ROMs. This study provided a new method to estimate the reasonable ROMs after ACDF from a biomechanical perspective, and further in vitro and clinical studies are needed to confirm this.

The Role of Microglia/Macrophages Activation and TLR4/NF-κB/MAPK Pathway in Distraction Spinal Cord Injury-Induced Inflammation.

Distraction spinal cord injuries (DSCIs) often occur as the neurological complication of distraction forces following the implantation of internal fixation devices during scoliosis correction surgery. However, the underlying mechanism behind these injuries remains unclear. The present study aimed to explore the activation of microglia and macrophages, as well as changes in TLR4-mediated NF-κB and MAPK pathway activity after DSCIs in Bama miniature pigs. Prior to surgical intervention, the pigs were randomly divided into three groups: the sham group, the complete distraction spinal cord injury (CDSCI) group, and the incomplete distraction spinal cord injury (IDSCI) group. After surgery, the Tarlov scale and individual limb motor scale (ILMS) were used to evaluate changes in the pigs' behavior. All pigs were euthanized 7 days after surgery, and histopathological examinations of the spinal cord tissues were performed. Immunohistochemistry was used to detect Caspase-3 expression in the anterior horn of spinal gray matter tissues. Immunofluorescence staining was utilized to assess the M1/M2 phenotype changes in microglia/macrophages and NF-κB P65 expression in central DSCI lesions, while western blotting was performed to determine the expression of TLR4/NF-κB/MAPK pathway-related proteins. The results of the present study showed that the Tarlov and ILMS scores decreased significantly in the two DSCI groups compared with the sham group. Hematoxylin and eosin (HE) and Nissl staining revealed that the tissue structure and nerve fiber tracts in the distracted spinal cord tissues were destroyed. Both DSCI groups showed the number of survived neurons decreased and the Caspase-3 expression increased. The results of the immunofluorescence staining indicated that the CD16 and CD206 expression in the microglia/macrophages increased. Between the two DSCI groups, the CDSCI group showed increased CD16 and decreased CD206 expression levels. The intensity of the fluorescence of NF-κB P65 was found to be significantly enhanced in pigs with DSCIs. Moreover, western blot results revealed that the expression of TLR4, p-IκBα, NF-κB P65, p-JNK, p-ERK, and p-P38 proteins increased in spinal cord tissues following DSCI. The present study was based on a porcine DSCI model that closely mimicked clinical DSCIs while clarifying DSCI-associated neuroinflammation mechanisms, in turn providing evidence for identifying potential anti-inflammatory targets.

Elucidating the Potential Mechanisms Underlying Distraction Spinal Cord Injury-Associated Neuroinflammation and Apoptosis.

The incidence of distraction spinal cord injury (DSCI), which results from spinal cord ischemia due to vascular compromise and spinal cord tract disturbances, remains high. Furthermore, because no ideal animal model that mimics DSCI in clinical settings is available thus far, the related molecular mechanisms underlying DSCI remain unclear. Thus, this study aimed to establish a porcine model of DSCI and investigate the neuroinflammation and apoptosis mechanisms in these pigs. Before surgery, all pigs were randomly divided into three groups: sham group, osteotomy surgery only; the incomplete distraction spinal cord injury (IDSCI) and complete distraction spinal cord injury (CDSCI) group, osteotomy plus DSCI surgery with a motor-evoked potential (MEP) amplitude decreased by approximately 75% and 100%, respectively. After surgery, modified Tarlov scoring and MRC muscle strength scoring were used to evaluate neurologic function in each group. We observed the distracted spinal cord using MRI, and then all pigs were sacrificed. Inflammatory cytokine levels in the spinal cord and cerebrospinal fluid (CSF) were also analyzed. We used immunofluorescence staining to assess the neuronal and microglial structure and function and astrocyte hyperplasia in the central DSCI lesions (T15). Western blotting was used to determine the expression of apoptosis-related proteins. Results showed that the modified Tarlov scoring and muscle strength decreased significantly in the two DSCI groups. T2-MRI showed a relative enhancement at the center of the DSCI lesions. H&E and Lxol fast blue staining revealed that spinal cord distraction destroyed the normal structure of spinal cord tissues and nerve fiber tracts, exacerbating inflammatory cell infiltration, hyperemia, and edema. The IL-1ß, IL-6, and TNF-α levels increased in the spinal cord and CSF following DSCI. Immunofluorescence staining results indicated the GFAP, Iba-1 expression increased following DSCI, whereas the NeuN expression reduced. Moreover, DSCI promoted the protein expression of P53, Bcl-2-associated X protein (Bax), and Caspase-3 in the spinal cord tissues, whereas it reduced the Bcl-2 expression. This study successfully established a porcine DSCI model that closely mimics DSCI in clinical settings, and clarified the mechanisms underlying DSCI-associated neuroinflammation and apoptosis; thus, our findings highlight potential DSCI-treatment strategies for further establishing suitable drug therapies.

3D-printed drill guide template, a promising tool to improve pedicle screw placement accuracy in spinal deformity surgery: A systematic review and meta-analysis.

PURPOSE: This study aimed to compare the pedicle screw placement accuracy and surgical outcomes between 3D-printed (3DP) drill guide template technique and freehand technique in spinal deformity surgery. METHODS: A comprehensive systematic literature search of databases (PubMed, Embase, Cochrane Library, and Web of Science) was conducted. The meta-analysis compared the pedicle screw placement accuracy and other important surgical outcomes between the two techniques. RESULTS: A total of seven studies were included in the meta-analysis, comprising 87 patients with 1384 pedicle screws placed by 3DP drill guide templates and 88 patients with 1392 pedicle screws placed by freehand technique. The meta-analysis results revealed that the 3DP template technique was significantly more accurate than the freehand technique to place pedicle screws and had a higher rate of excellently placed screws (OR 2.22, P < 0.001) and qualifiedly placed screws (OR 3.66, P < 0.001), and a lower rate of poorly placed screws (OR 0.23, P < 0.001). The mean placement time per screw (WMD-1.99, P < 0.05), total screw placement time (WMD-27.86, P < 0.001), and blood loss (WMD-104.58, P < 0.05) were significantly reduced in the 3DP template group compared with the freehand group. Moreover, there was no significant statistical difference between the two techniques in terms of the operation time and correction rate of main bend curve. CONCLUSIONS: This study demonstrated that the 3DP drill guide template was a promising tool for assisting the pedicle screw placement in spinal deformity surgery and deserved further promotion.

Mechanism of Action of Mesenchymal Stem Cell-Derived Exosomes in the Intervertebral Disc Degeneration Treatment and Bone Repair and Regeneration.

Exosomes are extracellular vesicles formed by various donor cells that regulate gene expression and cellular function in recipient cells. Exosomes derived from mesenchymal stem cells (MSC-Exos) perform the regulatory function of stem cells by transporting proteins, nucleic acids, and lipids. Intervertebral disc degeneration (IDD) is one of the main causes of low back pain, and it is characterized by a decreased number of nucleus pulposus cells, extracellular matrix decomposition, aging of the annulus fibrosus, and cartilage endplate calcification. Besides, nutrient transport and structural repair of intervertebral discs depend on bone and cartilage and are closely related to the state of the bone. Trauma, disease and aging can all cause bone injury. However, there is a lack of effective drugs against IDD and bone injury. Recent MSC-Exos fine tuning has led to significant progress in the IDD treatment and bone repair and regeneration. In this review, we looked at the uniqueness of MSC-Exos, and the potential treatment mechanisms of MSC-Exos with respect to IDD, bone defects and injuries.

Diffusion tensor imaging with fiber tracking provides a valuable quantitative and clinical evaluation for compressed lumbosacral nerve roots: a systematic review and meta-analysis.

PURPOSE: This study aimed to investigate the diagnostic value of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the diffusion tensor imaging (DTI) with fiber tracking in patients with compressed lumbosacral nerve roots. METHODS: A systematic literature search of databases (PubMed, Embase, Cochrane Library, and Web of Science) was carried out. FA values and ADC values were compared between compressed nerve roots and healthy controls. Pooled and subgroup analyses were performed using fixed or random-effect models based on I2 heterogeneity. RESULTS: A total of 262 patients from ten studies with 285 compressed lumbosacral nerve roots and 285 contralateral normal nerve roots were included in the meta-analysis. It was showed in pooled results that FA value was significantly reduced (SMD - 3.03, 95% CI [ - 3.75 to - 2.31], P < 0.001) and ADC value was significantly increased (SMD 2.07, 95% CI [0.92 to 3.22], P < 0.001) in the compressed nerve roots, compared with contralateral normal nerve roots. Subgroup analysis comparing the FA values and ADC values in different nerve root ranges (L2-S1, L4-S1, L5-S1, L5, S1) revealed the different ranges of nerve roots were possible sources of heterogeneity. CONCLUSIONS: This study showed that FA value reduction and ADC value increase were valuable indicators of compressed lumbosacral nerve roots. These changes may be related to the neurological symptoms of patients. DTI with fiber tracking can directly visualize and accurately locate the compression zone of nerve roots to help make surgical treatment plans, is more advanced than conventional MRI.

Effects of D-Chiro-Inositol on Glucose Metabolism in db/db Mice and the Associated Underlying Mechanisms.

In this study, we observed the effect of D-chiro-inositol (DCI) on glucose consumption in type 2 diabetic db/db mice, and investigated the relevant mechanism. We discovered that the stability of 24-h blood glucose under the nonfasting condition and decreased glucose tolerance were both alleviated after treatment with DCI. Moreover, the content of glycosylated protein and advanced glycation end products in the serum was reduced, the damage in the liver tissue was alleviated, and the synthesis of liver glycogen was significantly promoted. In addition, DCI increased the expression of insulin receptor substrate 2 (IRS2), phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), glucose transporters 4 (GLUT4), and phospho-AKT (S473) protein. In contrast, DCI decreased the expression level of glycogen synthase kinase 3ß (GSK3ß) protein in liver tissue to various degrees, as shown by immunohistochemistry and western blotting. Furthermore, DCI increased the mRNA expression of IRS2, PI3K, AKT, and GLUT4, and reduced that of GSK3ß in liver tissue, as demonstrated by polymerase chain reaction. Finally, DCI promoted glucose consumption in high glucose-stimulating HepG2 cells and increased the expression of IRS2 protein in HepG2 cells, as revealed by fluorescence staining and flow cytometry. Our results indicate that DCI can significantly improve glucose metabolism in diabetic mice and HepG2 cells. This effect may be associated with the upregulation of IRS2, PI3K, AKT, and GLUT4 and downregulation of GSK3ß.

Protective effects of rutin on liver injury in type 2 diabetic db/db mice.

The aim of this study was to evaluate the protective effect of rutin on the liver of type 2 diabetic mice and explore the correlation mechanism. The db/db mice, selected as the type 2 diabetes mellitus (T2DM) models, have random blood glucose (RBG) and glucose level after 2 h of oral glucose loading of more than 16.7 mmol/L. After administration of 120 mg/kg or 60 mg/kg rutin, to T2DM mice, RBG, oral glucose tolerance, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum, and advanced glycation end products (AGEs) in vivo and vitro of different groups were detected. The liver pathological changes were observed under light and electron microscopy. Western blotting was used to detect the protein expression of insulin receptor substrate 2 (IRS-2) and phosphorylation of phosphatidylinositol 3 kinase (PI3K) on p85, Akt on Ser473, glycogen synthase kinase 3ß (GSK-3ß) on Ser9, real-time quantitative PCR was used to detect IRS-2 mRNA expression. Moreover, dynamically observing the effect of rutin on the generation of AGEs in non-enzymatic protein glycosylated system, Cell Counting Kit-8 (CCK-8) method was used to detect the effect of rutin on proliferation activity of HepG2 liver cells. The results showed that RBG and glucose levels of oral glucose tolerance test (OGTT) of mice in model group were significantly higher than that of normal group, which were significantly reduced after the rutin treatment. Rutin could reduce the ALT, AST activities and AGEs level in serum and potentiate the expression of IRS-2, P-PI3K (p85), P-Akt (Ser473), P-GSK-3ß (Ser9) protein and IRS-2 mRNA in the liver tissue of db/db mice. Moreover, rutin could significantly alleviate the structure disorder of liver, reduce the degeneration and necrosis of liver cells and formation of collagen fibers of db/db mice. The results in vitro also showed that rutin could obviously inhibit the generation of AGEs, and promoted the proliferation activity of high glucose-stimulating HepG2 cells. In general, the protective effect of rutin on the liver of T2DM may be mediated by facilitating signal transduction and activated state of insulin IRS-2/PI3K/Akt/GSK-3ß signal pathway, promoting hepatocyte proliferation, reducing blood glucose level and generation of AGEs.