[Short-term effectiveness of unilateral biportal endoscopic transforaminal lumbar interbody fusion for Meyerding degree Ⅰ or Ⅱ single-segment lumbar spondylolisthesis]

Objective

To investigate the short-term effectiveness of unilateral biportal endoscopic transforaminal lumbar interbody fusion (UBE-TLIF) in the treatment of Meyerding degree Ⅰ or Ⅱ single-segment lumbar spondylolisthesis.

Methods

The clinical data of 26 patients with Meyerding degree Ⅰ or Ⅱ single-segment lumbar spondylolisthesis treated with UBE-TLIF between January 2021 and August 2021 were retrospectively analyzed. Among them, there were 10 males and 16 females with a mean age of 61.5 years (range, 35-76 years). The lesion segment included L 3, 4 in 2 cases, L 4, 5 in 18 cases, and L 5, S 1 in 6 cases. There were 17 cases of degenerative spondylolisthesis and 9 cases of isthmic spondylolisthesis; according to the Meyerding classification of spondylolisthesis, 19 cases were grade Ⅰ and 7 cases were grade Ⅱ. Twenty-one cases were complicated with lumbar disc herniation and spinal stenosis and 5 cases with lumbar spinal stenosis. The operation time, hospitalization stay, complications, hemoglobin (Hb) and serum creatine kinase (CK) levels before operation and at 1 day after operation were recorded; lumbar lordosis angle changes and postoperative spondylolisthesis reduction were evaluated by lumbar anteroposterior and lateral X-ray films before operation and at last follow-up; visual analogue scale (VAS) score was used to evaluate the low back pain and leg pain before operation, at 2 days, 1 week, 2 weeks after operation, and at last follow-up; Oswestry disability index (ODI) was used to evaluate the functional recovery of the patients before operation and at last follow-up.

Results

The operation was successfully completed in all 26 patients, with an average operation time of 181.9 minutes (range, 130-224 minutes) and an average hospitalization stay of 6.3 days (range, 3-9 days). Hb levels were significantly lower and serum CK levels were significantly higher at 1 day after operation when compared with those before operation ( t=7.594, P<0.001; t=-15.647, P<0.001). No serious complication occurred during and after operation. CT examination at 3 days after operation showed that the percutaneous screw was not in good position in 1 case, and nerve paralysis (pain, numbness) occurred in 2 cases after operation, which were improved within 2 weeks after operation. All the 26 patients were followed up 6-11 months, with an average of 8.7 months. Complete reduction (the slippage reduction rate was 100%) was achieved in 24 patients (92.3%), and partial reduction (the slippage reduction rate was 87.5%) in 2 patients (7.7%). During the follow-up, there was no complication such as incision infection, fusion Cage subsidence or displacement, and internal fixator loosening. The VAS scores of low back pain and leg pain significantly improved at each time point after operation when compared with those before operation ( P<0.05); there was no significant difference in the VAS scores of low back pain and leg pain between at 2 days and 1 week after operation, the VAS scores of low back pain between at 1 week and 2 weeks after operation, and the VAS scores of leg pain between at 2 weeks after operation and last follow-up ( P>0.05); but there was significant difference between the other time points after operation ( P<0.05). ODI and lumbar lordosis angle significantly improved at last follow-up ( P<0.05).

Conclusion

UBE-TLIF provides favorable short-term effectiveness and obvious advantages of minimally invasive in the treatment of Meyerding degree Ⅰ or Ⅱ single-segment lumbar spondylolisthesis. However, the safety and long-term effectiveness need to be further studied.

[Research Updates: The Role of Interaction between Oral Microbiota, Immune Cells, and Epithelial Barrier in Oral Mucosal Homeostasis and Pathogenesis]

In a healthy state, the interaction between the oral microorganisms, mucosal immune cells and epithelial barrier can maintain the oral microecological stability. However, the oral microecology is disrupted under a diseased state and various pathogenic bacteria and their virulence factors and metabolites irritate the immune system, which causes direct or indirect damage to the epithelial barrier, promotes the pathogenesis and progression of oral mucosal diseases, and triggers immune inflammatory response or the irreversible transformation from inflammation into cancer. We herein reviewed the interaction between oral microorganisms, immune cells and epithelial barrier from two perspectives, the maintenance of the oral homeostasis and the pathogenesis of oral mucosal diseases. We intended to gain further understanding of the oral mucosal homeostasis and the mechanism of action of the pathogenesis and progression of oral mucosal diseases, and to provide thereby ideas and scientific and theoretical basis for developing new strategies for the diagnosis and treatment of oral mucosal diseases through re-establishing mucosal homeostasis.

[Role of M2 Macrophage Exosomes in Osteogenic Differentiation of Mouse Bone Marrow Mesenchymal Stem Cells under High-Glucose and High-Insulin]

OBJECTIVE

To study the role of M2 macrophage-derived exosomes (M2-exo) in osteogenic differentiation and Hedgehog signaling pathway of mouse bone marrow mesenchymal stem cells (BMSCs) under in vitro high-glucose and high-insulin conditions.

METHODS

RAW 264.7 cells were induced toward M2 macrophage polarization and then M2-exo were extracted and identified. Immunofluorescence assay was performed to detect the internalization of M2-exo by BMSCs. BMSCs were divided into the normal control group (Control group), the high-glucose and high-insulin group (HGI group), and the HGI with M2-exo intervention group (HGI+M2e group). BMSCs in the Control group were cultured in osteogenic inductive medium with 5.5 mmol/L glucose, but no insulin or M2-exo. BMSCs in the HGI group were cultured in osteogenic inductive medium with 25 mmol/L glucose and 174 nmol/L insulin. BMSCs in the HGI+M2e group were cultured in the same medium as that of the HGI group, with the additional treatment of 6, 30, 60 μg/mL M2-exo, respectively. After osteogenic induction for 7 days and 14 days, alkaline phosphatase (ALP) staining and alizarin red staining were performed respectively to assess the osteogenic differentiation potential of BMSCs from different groups. In addition, BMSCs in the Control group, HGI group, and HGI+M2e group treated with 30 μg/mL M2-exo were examined with qPCR after osteogenic induction for 14 days and Western blot after osteogenic induction for 21 days to assess the osteogenesis and the expression of Hedgehog pathway-related genes and proteins.

RESULTS

M2 macrophage polarization was induced successfully, with highly positive expression of CD206, the M2 polarization surface marker. The M2-exo had the typical structure of round or oval-shaped bilayered-membrane vesicles. The diameter distribution of M2-exo ranged from 50 to 125 nm (accounting for 99.14% of all M2-exo). M2-exo samples showed positive expression of exosomal markers CD9, CD63 and CD81 proteins. Immunofluorescence staining showed that M2-exo were taken up and internalized by BMSCs. After osteogenic induction for 7 days, the ALP activity of BMSCs in the HGI group was lower than that of the Control group. After interventions of 6 μg/mL, 30 μg/mL, and 60 μg/mL M2-exo, the ALP activity of the HGI+M2-exo group was significantly increased compared with that of the HGI group ( P<0.05). After osteogenic induction for 14 days, the number of mineralized nodules in the HGI group was lower than that in the Control group, and after intervention, only the HGI+M2e group treated with 30 μg/mL M2-exo showed higher level of mineralization than that in the HGI group ( P<0.05). qPCR analysis revealed that the expression levels of the osteogenesis-related genes, including Runx2, Alp and Ocn, and Hedgehog pathway-related genes, including Gli1, Smo and Ptch1, were downregulated in the HGI group, all being lower than those of the Control group to varying degrees, while 30 μg/mL M2-exo treatment could promote the up-regulation of these genes, showing significant difference in comparison with their expression levels in the HGI group ( P<0.05). In addition, Western blot analysis showed that the expression of the osteogenesis-related proteins, including RUNX2 and COL1A1, and GLI1, the Hedgehog signaling pathway protein, was down-regulated in the HGI group, while the expression of COL1A1 and GLI1 was up-regulated after 30 μg/mL M2-exo treatment, showing significant difference when compared with that of the HGI group ( P<0.05).

CONCLUSION

High glucose and high insulin had inhibitory effect on the osteogenic differentiation potential of BMSCs. After intervention with M2-exo, the Hedgehog signaling pathway in BMSCs was activated and the osteogenic differentiation potential was enhanced, suggesting that M2-exo might have therapeutic potentials for the treatment of diabetic bone disease.