Tubastatin alleviates epidural fibrosis via negatively targeting TGFß/PI3K/Akt pathway.

Epidural fibrosis (EF) is a chronic, progressive and severe disease. Histone deacetylase 6 (HDAC6) regulates biological signals and cell activities by deacetylating lysine residues and participates in TGF-ß-induced epithelial-mesenchymal transition (EMT). Nevertheless, the effect and mechanism of HDAC6 in EF remain unclear. To investigate the effect and mechanism of HDAC6 inhibition on repressing epidural fibrosis. HDAC6 expression and α-smooth muscle actin (α-SMA) in normal human tissue and human EF tissue were assessed by quantitative real-time PCR (qRT-PCR) and western blotting. Human fibroblasts were treated with TGF-ß ± HDAC6 inhibitors (Tubastatin) and fibrotic markers including collagen I, collagen III, α-SMA and fibronectin were assessed using western blotting. Then TGFß1 receptor (TGFß1-R), PI3K and Akt were analyzed using qRT-PCR and western blotting. Rats were undergone laminectomy± Tubastatin (intraperitoneally injection; daily for 7 days) and epidural scar extracellular matrix (ECM) expression was gauged using immunoblots. Increasing HDAC6 expression was associated with α-SMA enrichment. Tubastatin remarkably restrained TGF-ß-induced level of collagen and ECM deposition in human fibroblasts, and the discovery was accompanied by decreased PI3K and Akt phosphorylation. Moreover, Tubastatin also inhibited TGF-ß-mediated HIF-1α and VEGF expression. In the epidural fibrosis model, we found that Tubastatin weakened scar hyperplasia and collagen deposition, and effectively inhibited the process of epidural fibrosis. These results indicated that Tubastatin inhibited HDAC6 expression and decreased TGF-ß/ PI3K/ Akt pathway that promotes collagen and ECM deposition and VEGF release, leading reduction of myofibroblast activation. Hence, Tubastatin ameliorated epidural fibrosis development.

IFN-α-2b Inhibits the Proliferation and Migration of Fibroblasts via the TGFß/Smad Signaling Pathway to Reduce Postoperative Epidural Fibrosis.

Epidural fibrosis after lumbar laminectomy refers to a serious complication, and excessive proliferation of fibroblasts is considered the major factor. Interferon-alpha-2b (IFN-α-2b) can exert antiviral and antiproliferative effects, which has been suggested to effectively prevent several fibrotic diseases. However, the effect of IFN-α-2b on the prevention of epidural fibrosis (EF) and its possible mechanism remain unclear. In this study, in vitro and in vivo experiments were performed to examine the possible mechanism of IFN-α-2b for preventing EF. Cell counting kit-8 (CCK-8), cell cycle test, Edu incorporation, wound healing assay, transwell test, and Western blotting assay were performed to investigate the inhibitory effect of IFN-α-2b on the proliferation and migration of fibroblasts in vitro. As indicated from the results, IFN-α-2b was capable of inhibiting proliferation and migration of fibroblasts and inhibiting the activity of the transforming growth factor ß (TGFß)/Smad signaling pathway. In vivo, the effect of IFN-α-2b on the reduction of EF was determined by performing histological macroscopic evaluation and histological and immunohistochemical staining. As suggested from the results, IFN-α-2b significantly inhibited EF after laminectomy. As revealed from the mentioned results, IFN-α-2b may have a promising application for preventing EF in the future.

Pirfenidone inhibits fibroblast proliferation, migration or adhesion and reduces epidural fibrosis in rats via the PI3K/AKT signaling pathway.

OBJECTIVE: This present study aims to assess the effect of pirfenidone (PFD) on inhibiting fibroblast proliferation, migration or adhesion in vitro and reducing laminectomy-induced epidural fibrosis in vivo. METHODS: The effect of PFD on proliferation inhibition was evaluated with flow cytometry, CCK-8, EdU and western-blotting assays. Altered properties in migration and adhesion were confirmed by wound-scratch, transwell, immunofluorescence (IF), cell adhesion and western-blotting assays. Additionally, fifty male healthy Sprague-Dawley rats were subjected to laminectomy and then treated with various concentrations of PFD. After 4 weeks, the degree of epidural fibrosis was evaluated by histological analysis. RESULTS: In vitro, the results of flow cytometry, CCK-8, EdU and western-blotting assays showed that PFD reduced fibroblast proliferation by a dose-dependent manner. And the results of wound-scratch, transwell, IF, cell adhesion and western-blotting assays showed that the migration and adhesion of fibroblasts could be inhibited and the cytoskeleton could also be altered in a dose-dependent manner. And the inhibitory effect of PFD could be partially reversed in the PI3K overexpression experiment, which indicated that the capability of PFD to inhibit fibroblast proliferation, migration and adhesion might be through the PI3K/AKT signaling pathway. In vivo, an obvious reduction in epidural fibrosis was observed in groups topically treated with PFD. CONCLUSIONS: Topical PFD application obviously suppressed laminectomy-induced epidural fibrosis, possibly by inhibiting fibroblast proliferation, migration and adhesion via the PI3K/AKT signaling pathway. PFD may be a safe and effective pharmaceutical to reduce clinical epidural fibrosis.

Impact of radial extracorporeal shock wave therapy in post-laminectomy epidural fibrosis in a rat model.

OBJECTIVES: This study aims to investigate the effect of radial extracorporeal shock wave therapy (rESWT) treatment in the prevention of epidural fibrosis after laminectomy in rats. MATERIALS AND METHODS: Eighteen 16-month-old male Sprague-Dawley rats weighing 300 g were used in this experimental study between November 2019 and February 2020. The rats were randomly divided into two groups as the control group (L3-L4 total laminectomy without any treatment) and the study group (L3-L4 total laminectomy plus rESWT). The rats were sacrificed at the postoperative sixth week and the lumbar spine was excised en bloc, fixed, and decalcified. Sections were stained with hematoxylin-eosin to evaluate epidural fibrosis, acute inflammation, chronic inflammation, and vascular proliferation. RESULTS: The median value and standard deviations were obtained based on histological examinations. Accordingly, epidural fibrosis decreased significantly in the study group compared to the control group. There was no statistically significant difference between the groups in terms of acute and chronic inflammation response and vascular proliferation. CONCLUSION: The rESWT application immediately after surgery is effective in preventing epidural fibrosis after laminectomy in rats.

Contrast Medium Volume Needed to Reach Anterior Epidural Space via the Kambin Triangle or Subpedicular Approach for Transforaminal Epidural Injection.

BACKGROUND: Transforaminal (TF) lumbar injection is a commonly used minimally invasive intervention for management of chronic low back pain. TF injection can be performed using various approaches to inject the drug to the anterior epidural space (AES). OBJECTIVES: To identify the volumes of contrast medium needed to reach the AES and other landmarks in the Kambin triangle (KB) and subpedicular (SP) approach of TF injection in patients with lumbosacral radicular pain. STUDY DESIGN: Randomized controlled trial. SETTING: Pain clinic and operating room of a tertiary care hospital. METHODS: Seventy-five eligible patients were randomized to receive TF epidural injection either by SP (SP group; n = 38) or the KB (KB group; n = 37) approach under fluoroscopic guidance. After confirming the appropriate needle position, contrast medium was injected at 0.5 mL increments up to 2 mL under intermittent fluoroscopy. Contrast medium volumes needed to reach specific landmarks, that is, AES, medial to superior pedicle, medial to inferior pedicle, medial aspect of both the superior, and neural spread, were recorded. Following this, 4 mL of the drug (0.5% lidocaine 1 mL + methylprednisolone 80 mg + 1 mL normal saline solution) was injected. Patients were evaluated for Visual Analog Scale (VAS) and modified Oswestry Disability Questionnaire (MODQ) scores after epidural injections at 2 weeks, 1 month, and 2 months. RESULTS: Average volume of contrast medium needed to reach AES was 1.10 ± 0.46 mL in the KB approach and 1.10 ± 0.38 mL in the SP approach. Contrast medium volume needed to reach other landmarks showed comparable results in both groups. AES was seen in 27.02% (10/37) patients in the KB group and 23.6% (9/38) patients in the SP group with 0.5 mL of contrast medium. This increased to 56.76% (21/37) and 77.7% (28/38) with 1 mL of contrast medium (P = 0.03, chi-square test). No anterior spread was seen even after 2 mL of contrast medium in 4 patients in the KB group and 2 patients in the SP group. Neural spread was seen in 100% of patients in the KB group after 0.5 mL of contrast medium, but in 34 (89.4%) patients in the SP group (P = 0.03, chi-square test). We did not note any contralateral spread. Short-term effectiveness in pain relief in terms of VAS for back pain and functional improvement in terms of MODQ score over time showed similar results in both groups. Intravascular needle puncture and needle paresthesia was comparable in both groups. LIMITATIONS: Small follow-up duration is one the limitations of this study. Future studies will be needed to assess any long-term differences in outcome between approach methods. Also, use of intermittent fluoroscopy might have limited detection of intravascular injections of the contrast medium in comparison to the continuous fluoroscopy. CONCLUSIONS: To conclude, our study revealed that average volume of contrast medium needed to reach AES and other landmarks were comparable with both approaches of TF injection. KEY WORDS: Transforaminal injection, subpedicular approach, Kambin triangle approach, contrast medium spread, anterior epidural spread.

Correlation between paravertebral spread of injectate and clinical efficacy in lumbar transforaminal block.

The potential paravertebral space includes spinal nerves, dorsal rami, rami communicants, and sympathetic chains. This study evaluated correlations between paravertebral spread of injectate and clinical efficacy in lumbar transforaminal block. We retrospectively analysed the data of 88 patients who received transforaminal blocks for lumbar radicular pain. We categorized patients into two groups: patients with ≥ 50% pain reduction on a numeric rating scale at 30 min following a block (responder group), and patients with < 50% pain reduction (non-responder group). Paravertebral spread of injectate was graded as limited to the anterior, middle, and posterior 1/3 of the anterolateral aspect of vertebral bodies; spread between the posterolateral margins of bodies and the posterior epidural space was considered no spread. Clinical and fluoroscopic data, perfusion index, temperature, and cold sensation were compared between the groups. Among 54 patients analysed, 26 (48.1%) experienced ≥ 50% and 28 (51.9%) < 50% pain reduction. Paravertebral spread occurred in 33 (61.1%) patients; 19 (57.6%) responders and 14 (42.4%) non-responders. On analysis, paravertebral spread, epidural spread patterns, perfusion index change ratios, temperature changes, and cold sensation changes showed no differences between responder and non-responder groups. Paravertebral spread occurred in 61.1%, with no correlation with the clinical efficacy of lumbar transforaminal block.

Suberoylanilide hydroxamic acid attenuates epidural fibrosis via inhibiting myofibroblast differentiation and increasing fibroblast apoptosis.

OBJECTIVE: Epidural fibrosis represents a fatal stage of failed back surgery syndrome (FBSS) of known and idiopathic etiology, but no valid therapy is presently available. Previous evidence demonstrated that suberoylanilide hydroxamic acid (SAHA), a histone deacetylases inhibitor, has antifibrotic and anti-inflammatory potential. Current studies have proved that SAHA inhibits myofibroblast differentiation and increases fibroblast apoptosis to attenuate epidural fibrosis. The purpose of this study was to investigate the effect and mechanism of SAHA on repressing epidural fibrosis. PATIENTS AND METHODS: First, the levels of acetylation of histone and α-tubulin in adult human fibroblasts (AHF) and human epidural fibroblasts (HEF) were analyzed following SAHA and transforming growth factor-ß(TGF-ß) treatment. Then, mRNA and protein obtained from human fibroblasts following TGF-ß activation and SAHA treatment in vitro culture were used to test the influence of SAHA on the activation and apoptosis of fibroblasts, so as to further explore the related mechanism of SAHA. Then, a laminectomy model was established in rats to observe the therapeutic effect of SAHA on epidural scar tissue. RESULTS: The present research proved that the increases of HDAC 3 and α-tubulin were observed in AHF and HEF after TGF-ß administration, but SAHA decreased HDAC 3 and α-tubulin expressions. In addition, cell study demonstrated that SAHA inhibited fibroblast activation via decreasing TGF-ß function and accelerated apoptosis by promoting cleaved-caspase-3. In the epidural fibrosis model, it was found that SAHA weakened scar hyperplasia and collagen deposition, and effectively inhibited the process of epidural fibrosis. CONCLUSIONS: These results indicated that SAHA inhibited HDAC 3 expression, decreased TGF-ß effect, and enhanced caspase-3 in fibroblasts, leading reduction of myofibroblast activation and apoptosis elevation. Hence, SAHA ameliorated epidural fibrosis development.

Mocetinostat suppresses epidural fibrosis following laminectomy by inhibiting myofibroblast activation and increasing apoptosis.

OBJECTIVE: To investigate the effect and mechanism of mocetinostat on diminishing epidural fibrosis. Dysregulated wound repair usually occurs after injury or surgery and is featured by excessive scar tissue contributed by fibrosis. Increasing researches demonstrated that histone acetylation, an epigenetic alteration, plays a crucial role in fibrosis. However, the mechanism of the complicated process remains unclear. In the current study, the effect of histone deacetylase (HDAC) inhibitor mocetinostat in a rat model of epidural fibrosis was detected, and it was discovered that mocetinostat suppressed myofibroblast activation and increased apoptosis by reducing Akt/GSK3b signaling. PATIENTS AND METHODS: First, the levels of histone acetylation in the patients' epidural fibroblasts were analyzed. Then, mRNAs and proteins obtained from human fibroblasts following TGF-ß activation and mocetinostat treatment in vitro were used to examine the influence of mocetinostat on the activation and survival of fibroblasts, so as to explore the related mechanism of mocetinostat. The laminectomy model was established in rats to observe the therapeutic effect of mocetinostat on epidural scar tissues. RESULTS: In this research, it was found that the increase of HDAC1 in human dura scar was accompanied by the aggravation of fibrosis. In addition, cell assay demonstrated that mocetinostat inhibited fibroblast activation and accelerated apoptosis by inhibiting Akt/GSK3b pathway. In the rat model, mocetinostat weakened scar hyperplasia and collagen deposition and effectively inhibited the process of epidural fibrosis. CONCLUSIONS: The above results indicate that mocetinostat inhibits HDAC1 expression and decreases the conduction of the AKT/GSK3b pathway in fibroblasts, leading to myofibroblast activation and apoptosis elevation. Hence, mocetinostat ameliorates epidural fibrosis.

Using cross-linked hyaluronic acid gel to prevent postoperative lumbar epidural space adhesion: in vitro and in vivo studies.

PURPOSE: Hyaluronic acid prevents tissue adhesion after different surgeries. Physical barriers and inflammatory regulation have been suggested to be involved in the mechanism of these clinical effects. However, the molecular mechanism by which hyaluronic acid prevents epidural adhesion has not yet been reported. METHODS: In the current in vivo studies, we investigated cross-linked hyaluronic acid gel in the regulation of scar gene expression, the accumulation of fibroblasts in scar tissue, and the prevention of epidural adhesion. The effect of cross-linked hyaluronic acid gel on the secretion of inflammatory factors was observed in vitro. In addition, to ensure the accuracy and reliability of the in vivo gene expression results, we used a cell model to detect the target genes in vitro. RESULTS: The expression levels of TGFß1 and COL1A1 mRNA were decreased in the cross-linked hyaluronic acid gel-treated group, and the protein expression of levels TGFß1 and COL1A1 were also reduced, as detected by Western blotting in vitro and in vivo (P < 0.05). Histomorphometry results demonstrated that the number of fibroblasts in the experimental group was significantly lower than that in the control group 2 weeks postoperatively. Micro-CT scans showed that the cross-linked hyaluronic acid gel could reduce adhesion in the epidural space after laminectomy. Additionally, the cross-linked hyaluronic acid gel could inhibit IL-6 secretion. CONCLUSIONS: These results indicate that cross-linked hyaluronic acid gel can prevent epidural adhesion by inhibiting inflammatory factors, such as IL-6, and downregulating TGFß1 and COL1A1 mRNA expression. These slides can be retrieved under Electronic Supplementary Material.

Effectiveness of Percutaneous Adhesiolysis in Managing Chronic Central Lumbar Spinal Stenosis: A Systematic Review and Meta-Analysis.

BACKGROUND: Symptomatic lumbar spinal stenosis is a condition affecting a growing number of individuals resulting in significant disability and pain, leading to a multitude of interventions ranging from simple over the counter medication to opioids, and, finally, to complex surgical fusions. After failure of conservative treatment with drug therapy, physical therapy, and other conservative modalities including epidural injections, percutaneous adhesiolysis with targeted delivery of drugs into the epidural space can be offered in lumbar central spinal stenosis prior to minimally invasive surgical options or complex surgical fusions. To date there has been only one systematic review which has assessed the role of percutaneous adhesiolysis in treating central spinal stenosis, compared to post lumbar surgery syndrome which has multiple systematic reviews and randomized controlled trials (RCTs). STUDY DESIGN: A systematic review of RCTs and observational studies assessing the role of percutaneous adhesiolysis in managing lumbar central spinal stenosis. OBJECTIVE: To evaluate the effectiveness of percutaneous adhesiolysis in managing central lumbar spinal stenosis, utilizing currently available literature. METHODS: This systematic review was performed utilizing Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) for literature search, Cochrane review criteria, Interventional Pain Management techniques - Quality Appraisal of Reliability and Risk of Bias Assessment (IPM-QRB), and Interventional Pain Management Techniques - Quality Appraisal of Reliability and Risk of Bias Assessment for Nonrandomized Studies (IPM-QRBNR) to assess methodologic quality assessment and qualitative analysis utilizing best evidence synthesis principles, and meta-analysis.PubMed, Cochrane library, US National Guideline Clearinghouse, Google Scholar, and prior systematic reviews and reference lists were utilized in the literature search from 1966 through June 2019. The evidence was summarized utilizing principles of the best evidence synthesis on a scale of 1 to 5. OUTCOME MEASURES: The primary outcome or hard endpoint was defined as the proportion of patients with 50% pain relief and improvement in functionality, whereas the secondary outcome measures or soft endpoints were pain relief and/or improvement in functionality. Short-term effectiveness was defined as improvement of 6 months or less, whereas long-term effectiveness was defined as more than 6 months. RESULTS: Based on search criteria, 9 manuscripts were identified and considered for inclusion with final inclusion of 2 RCTs and 4 observational studies in this systematic review and 5 studies for single arm meta-analysis. The results showed Level II evidence for short-term and long-term improvement in pain and function with application of percutaneous adhesiolysis in managing central lumbar spinal stenosis. LIMITATIONS: There was a significant paucity of evidence assessing the role of percutaneous adhesiolysis in managing lumbar central spinal stenosis, leading to Level II or strong evidence. CONCLUSION: Overall, the present analysis shows Level II (moderate) evidence for percutaneous adhesiolysis in managing lumbar central spinal stenosis based on relevant high quality RCTs and observational studies. KEY WORDS: Lumbar central spinal stenosis, percutaneous adhesiolysis, randomized controlled trials, systematic reviews, neuroplasty.

Emodin promotes fibroblast apoptosis and prevents epidural fibrosis through PERK pathway in rats.

BACKGROUND: Laminectomy is usually classed as a common orthopedic surgery, but postoperative epidural fibrosis often leads to less-than-desirable clinical outcomes. As demonstrated by prior studies, emodin (EMO) exerts an anti-fibrotic effect. Here, we carried out investigation into the inhibitory effect created by EMO application on epidural fibrosis after laminectomy in rats. METHODS: The paper conducts a series of experiment. In vitro, we observed the effect of EMO on fibroblasts by Cell Counting Kit-8 (CCK-8) assay. Apoptosis of fibroblasts induced by EMO was detected by western blot, TUNEL assay, and flow cytometry. The results revealed that EMO was capable of inducing fibroblast apoptosis, and the proteins of PERK pathway also changed accordingly. In vivo, the effect of EMO on epidural fibrosis in 12 male Sprague-Dawley rats was observed by histological staining. RESULTS: CCK-8 assay indicated that EMO was effective in reducing fibroblast viability in a time- and a dose-dependent manner. TUNEL assay and flow cytometry analysis have demonstrated that the apoptotic rate of fibroblasts increased as the EMO concentration rose. Western blot analysis proved that EMO promoted the relative expression of p-perk and p-eIF2α and that the expression of its downstream proteins CHOP and GRP78 was also enhanced. The expression of apoptotic protein Bax and cleaved PARP was upregulated, whereas the expression of anti-apoptotic protein Bcl-2 was downregulated. In addition, histological and immunohistochemical analysis demonstrated that EMO functioned to inhibit epidural fibrosis and increase GRP78 expression in fibrous tissue by promoting apoptosis of fibroblasts. CONCLUSIONS: EMO could have inhibitory effect on epidural fibrosis in a concentration-dependent manner. The potential mechanism might be through PERK signaling pathway to promote fibroblast apoptosis. It has a possibility to be taken as a novel method for the treatment of epidural fibrosis.

Negative regulation of PI3K/AKT/mTOR axis regulates fibroblast proliferation, apoptosis and autophagy play a vital role in triptolide-induced epidural fibrosis reduction.

Fibroblasts excessive proliferation was considered as a decisive reason for epidural fibrosis, which was known as a serious complication of lumbar laminectomy. As a traditional Chinese medicine, triptolide (TP) was used to be proved effective in preventing several fibrosis scar formation diseases. However, little is known about the effect of TP on preventing epidural fibrosis and its possible mechanism. Here, we performed in vitro and in vivo experiments to detect the possible mechanism of TP in preventing epidural fibrosis. In vitro, the effect of TP on impacting fibroblasts proliferation activities was detected by CCK-8, cell cycle assay and EdU incorporation assay. Also, the expressions of cell proliferation protein markers and the expressions of p-PI3K, p-AKT, p-mTOR were detect by Western blot. Besides, the effect of TP on inducing fibroblast apoptosis and autophagy was tested by Western blots, flow cytometry, TUNEL staining, Transmission electron microscope (TEM) analysis and LC3 immunofluorescent staining. The results suggested that TP could suppress the activation of PI3K/AKT/mTOR signaling pathway. Meanwhile, TP could inhibit fibroblast proliferation and induce fibroblast apoptosis as well as autophagy, which was known as two cellular self-destructions. Furthermore, we speculated the possible molecular pathway, through which that TP could inhibit fibroblast proliferation, induce fibroblast apoptosis and autophagy. We used PI3-kinase activator (740Y-P) to activate the PI3K/AKT/mTOR signaling. Activation of PI3K/AKT/mTOR signaling pathway increase the proliferation of fibroblasts and suppressed the autophagy and apoptosis induced by TP. In vivo, we built epidural fibrosis models in rats and locally applied TP of various concentrations. Hematoxylin-eosin (HE) and Masson's trichrome were used to detect the effect of TP on reducing epidural fibrosis. And the results showed that TP could significantly reduce the surgery-induced epidural fibrosis. In conclusion, the results above shown that TP could reduce epidural fibrosis formation, and the potential mechanism might through inhibiting fibroblast proliferation and stimulating apoptosis and autophagy via suppressing PI3K/AKT/mTOR signaling pathway. It might provide a novel thought for reducing surgery-induced epidural fibrosis.

Exogenous IL-19 mediates downregulation of TGF-ß through Erk and p38 pathway to inhibit epidural fibrosis.

OBJECTIVE: To evaluate the effect of interleukin-19 (IL-19) treatment on epidural fibrosis and its mechanism of action with transforming growth factor ß (TGF-ß). MATERIALS AND METHODS: Initially, IL-19 (10, 20, 50 and 100 ng/L) was used to pretreat rat fibroblasts. TGF-ß (10 µg/L) was then applied to activate fibroblasts. The protein expression levels of TGF-ß receptor, extracellular-signal-regulated kinase (Erk) and p-38 were measured by Western blotting. In addition, we performed laminectomy at T10 vertebral plate in rats, followed by injection of IL-19 in caudal vein one week after injury. Furthermore, IL-19, TGF-ß and fibrosis indexes were measured by quantitative Real-time polymerase chain reaction (qRT-PCR) and Western blotting at 7 and 28 days after injury, respectively. RESULTS: Concentration-dependent IL-19 significantly down-regulated TGF-ß receptor expression and inhibited phosphorylated Erk (p-Erk) and phosphorylated p38 (p-p38). In vivo, IL-19 reduced the expressions of TGF-ß and connective tissue growth factor (CTGF) at 7 days. Furthermore, IL-19 significantly suppressed extracellular matrix productions formation, including α smooth muscle actin (α-SMA) and collagen-1 (COL-1), and fibronectin at 28 days. CONCLUSIONS: IL-19 inhibited TGF-ß expression via Erk and p38 pathway. Moreover, it decreased CTGF expression to suppress α-SMA, COL-1 and fibronectin in scar tissues, thereby preventing spinal cord from compression of scar tissues.

Apigenin inhibits fibroblast proliferation and reduces epidural fibrosis by regulating Wnt3a/ß-catenin signaling pathway.

BACKGROUND: Failed back surgery syndrome (FBSS) is a common complication after the laminectomy. Epidural fibrosis is the major cause of lower back pain and other complications. Numerous studies have shown that apigenin (API) could treat various fibrotic diseases by regulating various signaling pathways, whereas no study has discussed whether API can inhibit fibroblast proliferation and reduce epidural fibrosis after the laminectomy by regulating Wnt3a/ß-catenin signaling pathway. METHODS: Human fibroblasts were cultured and treated with API in different concentrations for 24 h. CCK-8 detection and EdU incorporation assay were performed to detect cell viability and cell proliferation. Western blotting analysis was applied to detect expressions of proliferative proteins, Wnt3a, and its downstream proteins. Moreover, the Wnt3a gene was overexpressed in fibroblasts to define the relationship between Wnt3a/ß-catenin signaling pathway and fibroblast proliferation. Wnt3a overexpressed fibroblasts were treated with API to verify if it could reverse the effects of API treatment. Twenty-four Sprague-Dawley rats were randomly divided into four groups. Laminectomy was performed and the rats were gavaged with different doses of API or 5% sodium carboxyl methyl cellulose (CMC-Na) solution for 1 month. The abilities of API to inhibit fibroblast proliferation and to reduce epidural fibrosis were evaluated using histological and immunohistochemical analysis. RESULTS: CCK-8 detection and EdU incorporation assay demonstrated that API could inhibit the viability and proliferation rate of fibroblasts in a concentration-dependent manner. The Western blotting analysis revealed that API could inhibit the expressions of PCNA, cyclinD1, Wnt3a, and its downstream proteins. The overexpression of Wnt3a in fibroblasts could upregulate the expressions of proliferative proteins such as PCNA and cyclinD1. The inhibitory effect of API on PCNA, Wnt3a, and its downstream proteins was partially reversed by overexpression of Wnt3a. Moreover, the results of the histological and immunohistochemical analysis revealed that API could reduce the epidural fibrosis in rats by inhibiting fibroblast proliferation in a dose-dependent manner. CONCLUSIONS: API can inhibit fibroblast proliferation and reduce epidural fibrosis by suppressing Wnt3a/ß-catenin signaling pathway, which can be adopted as a new option to prevent epidural fibrosis after the laminectomy.

Effect of Curcumin on the Formation of Epidural Fibrosis in an Experimental Laminectomy Model in Rats.

AIM: To clarify the effects of topical application of curcumin on the prevention of epidural fibrosis. MATERIAL AND METHODS: Twenty-one rats were randomly divided into three equal groups (control, spongostan, local curcumin) and a laminectomy procedure was performed between T11 and L1 in all rats. Subsequently, spongostan soaked with curcumin (100 mg/kg) was applied topically. After four weeks, the vertebral column from T9 to L3, which included the paraspinal muscles and epidural scar tissue, was removed as a single piece and the epidural fibrosis and arachnoidal scarring were graded and histopathological analysis carried out accordingly. Kruskal-Wallis and Pearson Chi-Square tests were used for statistical analysis. A p-value of less than 0.05 was considered to be significant. RESULTS: The grading of epidural fibrosis was far lower in the experimental group with curcumin compared to the control and spongostan groups, but the difference was not statistically significant. CONCLUSION: The findings of this study show that local curcumin decreases the formation of epidural fibrosis and this effect of curcumin is thought to be mediated by reducing the functions of inflammatory cells such as macrophages, neutrophils and fibroblasts, and the anti-inflammatory and antioxidant effects.

Fluoroscopic evaluation of the influence of needle gauge on epidural spread in caudal block.

Caudal block has limited injectate distribution to the desired lumbar level due to the relatively long distance from the injection site and reduction in the volume of injectate due to leakage into the sacral foramen. The objective of this study was to investigate the influence of needle gauge on fluoroscopic epidural spread and to assess the correlation between the spread level and analgesic efficacy in patients undergoing caudal block. We retrospectively analyzed data from 80 patients who received caudal block for lower back and radicular pain. We categorized patients based on the epidural needle gauge used into group A (23 gauge), group B (20 gauge), and group C (17 gauge). Fluoroscopic image of the final level of contrast injected through the caudal needle and pain scores before the block and 30 minutes after the block recorded using a numerical rating scale, were evaluated. Of the 80 patients assessed for eligibility, 7 were excluded. Thus, a total of 73 patients were finally analyzed. Age, sex, body mass index, diagnosis, lesion level, lesion severity, and duration of pain did not differ among the 3 groups. All patients showed cephalic spread of contrast. Contrast spread beyond L5 was seen in 26.9% of patients in group A, 41.7% in group B, 39.1% in group C, and 35.6% overall; there was no significant difference among the groups (P = .517). Analgesic efficacy was not significantly different among the groups (P = .336). The needle gauge did not influence the level of epidural spread or analgesic efficacy in caudal block.

Combining Spinal-Epidural Anesthesia versus Single-Shot Spinal Anesthesia for Cesarean Delivery: A Meta-Analysis of 5 Randomized Controlled Trials.

BACKGROUND This study compared combined spinal-epidural anesthesia (CSEA) and single-shot spinal anesthesia (SSSA) by performing a meta-analysis. MATERIAL AND METHODS An electronic search of relevant studies was done through 2017. Primary endpoints included duration of surgery, and time for (1) sensory recovery to thoracic vertebra (T10), (2) maximal sensory, (3) motor blockade, and (4) motor recovery. Secondary endpoints were the adverse effects. RevMan 5.3 analytical software was used with odds ratios (OR) and 95% confidence intervals (CIs) as the analytic parameters. Standard deviation and mean were used to evaluate data by weighted mean differences (WMDs) with 95% CI. RESULTS A total of 370 patients were analyzed. A similar duration of surgery was observed with CSEA and SSSA (WMD: 0.24, 95%CI: -3.41-3.89; P=0.90). Time to maximal sensory blockade (WMD: 0.96, 95%CI: -2.91-4.83), time to maximal motor blockade (WMD: 0.25, 95%CI: -2.46-2.96), time for complete motor recovery (WMD: -6.28, 95%CI: -29.42-16.86), and time for sensory recovery to T10 vertebra (WMD: 0.42, 95%CI: -11.07-11.91) were not significantly different. Adverse effects such as hypotension (OR: 1.49, 95%CI: 0.27-8.31), pruritus (OR: 0.23, 95%CI: 0.03-2.18), nausea/vomiting (OR: 0.84, 95%CI: 0.12-5.99). and shivering (OR: 0.53, 95%CI: 0.11-2.56) were also similar with CSEA and SSSA. CONCLUSIONS CSEA was not associated with significantly different maximal duration of sensory/motor blockade, complete motor recovery, sensory regression to T10, or adverse drug events compared to SSSA. Hence, both should be considered effective in cesarean delivery.

Hyaluronic acid in tobacco-exposed rats. Inflammatory reaction, and duration of effect1.

PURPOSE: To evaluate the hyaluronic acid (HA) inflammatory reaction, fibroblasts, fibrosis and duration of effect in the dorsal region of tobacco-exposed rats. METHODS: Ten Wistar rats were divided into two groups: tobacco-exposed-group (TEG;n=5) and air-control-group (CG;n=5). The TEG animals were tobacco-exposed twice a day, 30-minutes/session, during 60 days. After this period, all animals received 0.1 mL HA subcutaneous injection in the dorsal area. The volume of HA was measured immediately after HA injection and weekly using a hand-caliper in nine weeks. After this period, all the animals were euthanized, and a specimen of was collected to evaluate inflammatory cells, fibroblasts, and fibrosis by HE. RESULTS: This study showed a higher inflammatory reaction in TEG than CG: inflammatory cell-count (CG: 1.07±0.9; TEG: 8.61±0.36, p<0.001); fibroblast count (CG: 2.92±0.17; TEG: 19.14±0.62, p<0.001), and fibrosis quantification (CG: 2.0; TEG: 3.75, p<0.001). The analysis of the HA volume in nine weeks in the dorsal region did not show a difference between groups (p=0.39). CONCLUSIONS: This study suggested that the HA injection in the TEG caused an increase in inflammatory cell count, fibroblast, and fibrosis quantification when compared to the CG. There was no difference in the duration of effect of HA between the groups.