Effects of Expression of Matrix Metalloproteinases and Discoidin Domain Receptors in Ligamentum Flavum Fibrosis in Patients with Degenerative Lumbar Canal Stenosis

STUDY DESIGN

This is a retrospective cohort study.

PURPOSE

This study aimed to clarify the role of crosstalk between discoidin domain receptors (DDRs) and matrix metalloproteinases (MMPs) in the ligamentum flavum (LF) fibrosis obtained from patients with degenerative lumbar canal stenosis (DLCS).

OVERVIEW OF LITERATURE

The DDRs, DDR1 and DDR2, are cell surface receptors and have an essential role in collagen fiber accumulation in several fibrotic diseases. MMPs are one of the critical factors in extracellular matrix remodeling and elastic fiber degradation in LF tissues. However, the crosstalk between DDRs and MMPs and the role of this molecular signal in LF fibrosis remain unclear.

METHODS

A total of 35 patients were divided into two groups in this study. Spinal surgery was performed in 23 of these patients with the diagnosis of DLCS. Twelve patients with lumbar disk herniation (LDH) were included in the control group. On axial T2-weighted magnetic resonance imaging, LF thickness was measured bilaterally at the level of the facet joint. Histology, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blot analyses were performed on LF tissue samples. LF tissues were stained with hematoxylin and eosin. In addition, the grade of fibrosis was histologically assessed using Masson trichrome triple staining. DDR1 and DDR2 Western blot analyses were performed. DDR1, DDR2, MMP2, MMP3, MMP9, and MMP13 expression levels were measured using qRT-PCR analysis.

RESULTS

The grade of fibrosis and LF thickness were significantly higher in the DLCS patients than in the LDH patients. DDR1 and DDR2 gene expression and protein levels in LF tissues are significantly greater in DLCS samples than in control samples, according to both qRT-PCR and Western blot analyses. In addition, we detected a significant expression of the MMP3, MMP9, and MMP13, which are known to have important roles in extracellular matrix remodeling in DLCS. Furthermore, we discovered a link between DDR protein levels and LF thickness, fibrosis, and MMP3/MMP9.

CONCLUSIONS

Our results indicate that DDR1, DDR2, and MMP3 and MMP9 signals can be correlated with each other in LF tissues and be promoted LF fibrosis leading to spinal canal narrowing in patients with DLCS.

Antineoplastic multi-drug chemotherapy to sensitize tumors triggers multi-drug resistance and inhibits efficiency of maintenance treatment inglioblastoma cells

Combinations of the well-known antineoplastic agents 5-fluorouracil (5-Fu), cisplatin, and paclitaxel are employed to increase radiotherapy/immunotherapy efficacy against persistent and resistant tumors. However, data remains needed on the hormetic, chronic, and long-term side effects of these aggressive combination chemotherapies. Here we investigated cellular and molecular responses associated with these combined agents, and their potential to induce multi-drug resistance against the temozolomide (TMZ) and etoposide (EP) used in glioblastoma maintenance treatment. We analyzed resistance and survival signals in U87 MG cells using molecular probes, fluorescent staining, qRT-PCR, and immunoblot. Repeated treatment with combined 5-Fu, cisplatin, and paclitaxel induced cross-resistance against TMZ and EP. Resistant cells exhibited elevated gene/protein expression of MRP1/ABCC1, ABCC2, BRCP/ABCG2, and GST. Moreover, they managed oxidative stress, cell cycle, apoptosis, and autophagy signaling to ensure survival. In these groups TMZ and etoposide efficiency dramatically reduced. Our result suggests that combined high-dose treatments of classical antineoplastic agents to sensitize tumors may trigger multi-drug resistance and inhibit maintenance treatment. When deciding on antineoplastic combination therapy for persistent/resistant glioblastoma, we recommend analyzing the long-term hormetic and chronic effects on cross-resistance and multi-drug resistance in primary cell cultures from patients. See also the Graphical Abstract(Fig. 1).

The Effect of Cerebral Oxygen Saturation Changes on Early Postoperative Neuropsychological Function in Patients Undergoing Cranial Surgery

AIM

Early postoperative neuropsychological dysfunction is common after intracranial surgery. Although it is primarily caused due to the surgical procedure, it should be considered in intraoperative processes. Therefore, we aimed to compare the incidence of postoperative neuropsychological dysfunction in patients managed with cerebral saturation monitoring versus traditional approaches.

MATERIAL AND METHODS

A hundred patients undergoing elective intracranial surgery were divided into two groups to receive intraoperative management via cerebral saturation monitoring (Group O) or the conventional approach (Group C). The postoperative neuropsychological function was evaluated by the antisaccadic eye movement test (ASEM) and the Mini-Mental State Examination (MMSE). These tests were performed preoperatively and postoperatively on the first, second, and fifth days. The time for the modified Aldrete score to reach 9 (MAS 9), adverse effects, and pain using a Visual Analog Scale (VAS) scores were recorded.

RESULTS

Patient characteristics and surgery data were not statistically different. The MAS 9 of group O was significantly lower than that of group C (p 0.001). The MMSE at the postoperative 1, 2, and 5 days were significantly higher in Group O compared to Group C (p 0.001). ASEM was similar between groups. Group O was subdivided according to the type of surgery applied with diagnosis, and there were no statistically significant between-group differences in terms of areas under the curve for the cerebral regional oxygen saturation. There was no between-group difference regarding the mean arterial pressure at any time perioperatively. The heart rate at 80, 90, 100, and 110 min intraoperatively was significantly higher in group C than in Group O.

CONCLUSION

Intraoperative cerebral oxygenation monitoring can reduce patient mortality and morbidity by allowing early postoperative neurological evaluation to detect potential neurocognitive deficits.

The Dose Dependent Effects of Ruxolitinib on the Invasion and Tumorigenesis in Gliomas Cells via Inhibition of Interferon Gamma-Depended JAK/STAT Signaling Pathway

Objective

Glioblastoma multiforme (GBM) is the most aggressive for of brain tumor and treatment often fails due to the invasion of tumor cells into neighboring healthy brain tissues. Activation of the Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling pathway is essential for normal cellular function including angiogenesis, and has been proposed to have a pivotal role in glioma invasion. This study aimed to determine the dose-dependent effects of ruxolitinib, an inhibitor of JAK, on the interferon (IFN)-I/IFN-α/IFN-β receptor/STAT and IFN-γ/IFN-γ receptor/STAT1 axes of the IFN-receptor-dependent JAK/STAT signaling pathway in glioblastoma invasion and tumorigenesis in U87 glioblastoma tumor spheroids.

Methods

We administered three different doses of ruxolitinib (50, 100, and 200 nM) to human U87 glioblastoma spheroids and analyzed the gene expression profiles of IFNs receptors from the JAK/STAT pathway. To evaluate activation of this pathway, we quantified the phosphorylation of JAK and STAT proteins using Western blotting.

Results

Quantitative real-time polymerase chain reaction analysis demonstrated that ruxolitinib led to upregulated of the IFN-α and IFN-γ while no change on the hypoxia-inducible factor-1α and vascular endothelial growth factor expression levels. Additionally, we showed that ruxolitinib inhibited phosphorylation of JAK/STAT proteins. The inhibition of IFNs dependent JAK/STAT signaling by ruxolitinib leads to decreases of the U87 cells invasiveness and tumorigenesis. We demonstrate that ruxolitinib may inhibit glioma invasion and tumorigenesis through inhibition of the IFN-induced JAK/STAT signaling pathway.

Conclusion

Collectively, our results revealed that ruxolitinib may have therapeutic potential in glioblastomas, possibly by JAK/STAT signaling triggered by IFN-α and IFN-γ.

The Role of JAK-STAT Signaling Activation in Hypertrophied Ligamentum Flavum

BACKGROUND

Although previous studies have reported the expression of JAK1, STAT3, and phosphorylated STAT3 in hypertrophied ligamentum flavum (LF), the role of the Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling pathway in hypertrophied LF has not been fully elucidated. The aim of this study was to identify the important JAK/STAT gene expression patterns of the 3 main receptors involved in this pathway: interferon (IFN)-γ receptor (IFN-γR), IFN-α receptor (IFNAR), and interleukin (IL)-6 receptor (IL-6R).

METHODS

The human LF specimens were obtained from 28 patients who underwent lumbar spine surgery for either degenerative lumbar canal stenosis (DLCS) (n = 28) or lumbar disc herniation (LDH) (n = 20). In this design, patients with LDH served as the control group. The degree of fibrosis was demonstrated by Masson's trichrome staining. The location and expression profiling of the JAK/STAT pathway were analyzed by quantitative real-time polymerase chain reaction and Western blotting. The thickness of the LF was measured with axial T1-weighted magnetic resonance imaging.

RESULTS

The most severe fibrotic changes were on the dorsal side of the LF. IL-6 and IFN-I expression levels were significantly increased on the dorsal side of the LF. While expression levels of IL-6R and IFNAR on the dural and dorsal side were significantly higher in the DLCS samples, IFN-γR and endothelial epidermal growth factor receptor in LF samples showed a significant increase only on the dorsal side. JAK/STAT genes were significantly expressed, especially on the dorsal side.

CONCLUSIONS

Our data suggest that IFNAR- and IL-6R-dependent JAK/STAT signaling pathways may be significant targets in drug development strategies for the treatment of LF hypertrophy.

Efficiacy of resveratrol and quercetin after experimental spinal cord injury

BACKGROUND

The aim of this study was to investigate the effect of natural antioxidants resveratrol and quercetin on oxidative stress and secondary cell damage in rats with acute spinal cord injury.

METHODS

In this experimental study, 42 male Sprague-Dawley rats were used. Spinal cord injury was performed with clip compression method at level of T4-5. The study was conducted using 6 groups: control, trauma, trauma and solvent, trauma and resveratrol, trauma and quercetin, and trauma with combined resveratrol and quercetin. All rats were euthanized 48 hours after the procedure. Effects of resveratrol and quercetin on serum and tissue total antioxidant capacity and paraoxanase activity level were examined.

RESULTS

Compared to trauma group, there was a significant increase in total antioxidant capacity and paraoxanase activity level in resveratrol, quercetin, and combined treatment groups. There was no significant difference between resveratrol and quercetin groups with regard to total antioxidant capacity and paraoxanase activity level. Total antioxidant capacity and paraoxanase activity level were significantly higher in solvent group than trauma group. In histopathological evaluation, there was a decrease in polymorphonuclear leukocyte infiltration in solvent, resveratrol, quercetin, and combined treatment groups.

CONCLUSION

Biochemical and histological staining results of present study showed that resveratrol and quercetin may be effective in preventing secondary damage in spinal cord injury.

Incomplete Isolated C7 Root Injury Caused by Gunshot Wound: A Case Report

Gunshot wounds to the spine cause severe neurological and/or internal organs damages. Although most of publications in the literature are realized on military injuries, increased civilian arming which raises civilian gunshot injuries is a new social danger causing serious health problems. In gunshot injuries to the spine; vertebral column, spinal cord and nerve roots are damaged with direct, indirect and transient cavitation related mechanisms. In this case report, we present 24 years old male patient who had severe pain and monoparesis in left upper extremity followed by gunshot injury to the spine with clinical, radiological and postoperative follow-up findings.

True aneurysm of superficial temporal artery accompanying multiple intracranial aneurysm

Superficial temporal artery (STA) aneurysms are very infrequent. Moreover, true aneurysms, which are not pseudoaneurysms associated with trauma or previous surgery are even rarer. With this manuscript, authors present a case of a 79-year-old woman suffering from subarachnoid hemorrhage whose radiological examinations revealed multiple intracranial aneurysms along with an STA aneurysm. This very rare case, to the best of our knowledge, the second case reported so far, might contribute to the literature and lead further investigations toward the rare association between intracranial aneurysms and STA aneurysms.

Perimesencephalic subarachnoid hemorrhage: Etiologies, risk factors, and necessity of the second angiogram

Aim:

In this paper, we aim to present our experience with a series of patients with PMSAH. In addition, the clinical course of perimesencephalic subarachnoid hemorrgade (PMSAH) is discussed with an evaluation of etiologies, risk factors, and the necessity for a second angiogram on follow-up.

Materials and Methods:

The data for this study were obtained retrospectively from patients who were treated at the Uludag University, School of Medicine, Department of Neurosurgery, Division of Neurovascular Surgery's clinic with a diagnosis of PMSAH between January 1980 and March 2002.

Results:

We identified a total of 24 patients, 12 male. The mean age at the time of hemorrhage was 53 ± 12 years. In all patients, the onset was typical with a sudden severe headache. Five of the patients were Hunt-Hess Grade I, 15 were Grade II, and 4 were Grade III. The initial 4-vessel angiography was normal in 23 cases. Twenty-two had a second 4-vessel angiography, and all were normal. We observed acute hydrocephalus in 5 patients (20.8%). We did not observe re-bleeding during the follow-up of our patients.

Conclusion:

Patients with PMSAH have a particularly excellent outcome, and there is no need to evaluate these patients with repeat angiography.

Symptomatic foraminal extradural meningeal cyst

The authors described the case of a 39-year-old man with Klippel-Trénaunay syndrome, who had an extradural meningeal cyst expanding into intervertebral foramen of lumbar 2 and 3 vertebrae. The patient suffered from low back pain radiating to the left lower extremity. Magnetic resonance imaging revealed a huge extradural meningeal cyst growing through intervertebral foramen far laterally. A widened neural foramen of L2 and L3 vertebrae was observed on his plain radiography. The cyst was totally excised after tying the ostium connecting the subarachnoid space of the dural sac. This case supports the congenital theory in the pathogenesis of spinal cysts because the Klippel-Trénaunay syndrome is a congenital disorder including a mesodermal abnormality which may be the causative factor for a congenital defect in dura.