p38 Mitogen-Activated Protein Kinase Is Involved in Interleukin-6 Secretion from Human Ligamentum Flavum–Derived Cells Stimulated by Tumor Necrosis Factor-α

Yagi Kiyoshi,Goto Yuta,Kato Kenji,Suzuki Nobuyuki,Kondo Akira,Waseda Yuya,Mizutani Jun,Kawaguchi Yohei,Joyo Yuji,Waguri-Nagaya Yuko,Murakami Hideki 대한척추외과학회 2021 Asian Spine Journal Vol.15 No.6

Study Design Human ligamentum flavum–derived cells (HFCs) were obtained from surgical samples for a basic experimental study. Purpose We sought to evaluate the inflammatory response of human ligamentum flavum cells to investigate hypertrophic changes occurring in the ligamentum flavum. Overview of Literature Lumbar spinal stenosis (LSS) is a disease commonly observed in the elderly. The number of patients with LSS has increased over time, yet the pathomechanisms of LSS still have not been fully elucidated. One of the clinical features of LSS is hypertrophy of the ligamentum flavum, which results in narrowing of the lumbar spinal canal. Some reports have suggested that ligamentum flavum hypertrophy is associated with inflammation and fibrosis; meanwhile, the p38 mitogen-activated protein (MAP) kinase is involved in the hypertrophy of human ligamentum flavum cells. Methods HFCs were obtained from patients with LSS who underwent surgery. HFCs were stimulated by tumor necrosis factor-α (TNF-α) and a p38 MAP kinase inhibitor, SB203580. Phosphorylation of the p38 MAP kinase was analyzed by western blotting. The concentration of interleukin-6 (IL-6) in the conditioned medium was measured by enzyme-linked immunoassay and IL-6 messenger RNA expression levels were determined by real-time polymerase chain reaction. Results TNF-α induced the phosphorylation of p38 MAP kinase in a time-dependent manner, which was suppressed by the p38 MAP kinase inhibitor, SB203580. TNF-α also stimulated IL-6 release in both a time- and dose-dependent manner. On its own, SB203580 did not stimulate IL-6 secretion from HFCs; however, it dramatically suppressed the degree of IL-6 release stimulated by TNF-α from HFCs. Conclusions This is the first report suggesting that TNF-α stimulates the gene expression and protein secretion of IL-6 via p38 MAP kinase in HFCs. A noted association between tissue hypertrophy and inflammation suggests that the p38 MAP kinase inflammatory pathway may be a therapeutic molecular target for LSS.

Segmental Arteries and Veins at Higher Lumbar Levels Can Intersect the Adjacent Caudal Intervertebral Disc in the Anterior Part of the Spinal Column: A Cadaveric Analysis

Yagi Kiyoshi,Suzuki Nobuyuki,Mizutani Jun,Kato Kenji,Kondo Akira,Waseda Yuya,Goto Yuta,Murakami Hideki 대한척추외과학회 2022 Asian Spine Journal Vol.16 No.1

Study Design: A cadaveric study.Purpose: To investigate the anatomical features of segmental arteries and veins in the anterior part of the spinal column to prevent segmental vessel injury.Overview of Literature: The lateral transpsoas approach to the lumbar intervertebral discs (IVD) is associated with the risk of segmental vessel injury. Previous studies have described the vascular anatomy on the lateral part of the vertebral body. However, there are no studies that describe the segmental vessels on its anterior aspect. Here, we report the important anatomical features of the segmental arteries and veins that can intersect the anterior part of the IVD. These vessels are considered at risk of vascular injury when placing the anterior retractors during lateral lumbar interbody fusion or cutting the anterior longitudinal ligament during anterior column realignment.Methods: Five formalin-embalmed human cadavers were used. We assessed the proportion of segmental arteries and veins that intersected the IVD in the L2–L5 range and their course on the anterior part of the spinal column.Results: The segmental arteries and veins commonly intersect the anterior part of the IVD (artery, 28.1%; vein, 42.1%). Seven of 10 (70%) segmental arteries at L2 intersected the IVD, but only one artery intersected the IVD at L3 and L4. The proportions of segmental veins that intersected the IVD were 60%, 50%, and 16.7% at L2, L3, and L4, respectively.Conclusions: The segmental arteries and veins frequently intersect the IVD in the anterior part of the spinal column. Therefore, it is necessary to consider these individual anatomical features to prevent vascular damage during lateral lumbar interbody fusion surgery.

Autocorrelation Coefficient for Detecting the Frequency of Bio-Telemetry

Yoshiya Muraki,Yukako Yagi,Kiyoshi Kurokawa,Isao Nakajima 한국멀티미디어학회 2022 The journal of multimedia information system Vol.9 No.3

A MATLAB program was developed to calculate the half-wavelength of a sine-curve baseband signal with white noise by using an autocorrelation function, a SG filter, and zero-crossing detection. The frequency of the input signal can be estimated from 1) the first zero-crossing (corresponding to ¼λ) and 2) the R value (the Y axis of the correlogram) at the center of the segment. Thereby, the frequency information of the preceding segment can be obtained. If the segment size were optimized, and a portion with a large zero-crossing dynamic range were obtained, the frequency discrimination ability would improve. Furthermore, if the values of the correlogram for each frequency prepared on the CPU side were prepared in a table, the volume of calculations can be reduced by 98%. As background, period detection by autocorrelation coefficients requires an integer multiple of 1/2λ (when using a sine wave as the object of the autocorrelation function), otherwise the correlogram drawn by R value will not exhibit orthogonality. Therefore, it has not been used in bio-telemetry where the frequencies move around.

Transforming Growth Factor-β Induces Interleukin-6 Secretion from Human Ligamentum Flavum–Derived Cells through Partial Activation of p38 and p44/42 Mitogen-Activated Protein Kinases

Goto Yuta,Kato Kenji,Yagi Kiyoshi,Kawaguchi Yohei,Yonezu Hiroki,Koshimae Tomoko,Waguri-Nagaya Yuko,Murakami Hideki,Suzuki Nobuyuki 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.6

Study Design: This experimental study was performed using human ligamentum flavum–derived cells (HFCs).Purpose: To investigate the intracellular signaling mechanism of interleukin-6 (IL-6) secretion in transforming growth factor-β (TGF- β)-stimulated HFCs.Overview of Literature: Lumbar spinal stenosis (LSS) is a prevalent disease among the elderly, characterized by debilitating pain in the lower extremities. Although the number of patients with LSS has increased in recent years, the underlying pathomechanism remains unclear. Clinical examinations typically rely on magnetic resonance imaging to diagnose patients, revealing ligamentum flavum hypertrophy. Some studies have suggested an association between ligamentum flavum hypertrophy and inflammation/fibrosis, and expression of TGF-β and IL-6 has been observed in surgically obtained ligamentum flavum samples. However, direct evidence linking TGF-β and IL-6 expression in HFCs is lacking.Methods: HFCs were obtained from patients with LSS who had undergone decompression surgery. The cells were stimulated with TGF-β and pretreated with either the p38 mitogen-activated protein (MAP) kinase inhibitor SB203580 or the p44/42 MAP kinase inhibitor FR180204. IL-6 secretion in the cell culture medium and IL-6 messenger RNA (mRNA) expression levels were analyzed using an enzyme-linked immunoassay and real-time polymerase chain reaction, respectively.Results: TGF-β administration resulted in a dose- and time-dependent stimulation of IL-6 release. Treatment with SB203580 and FR180204 markedly suppressed TGF-β–induced IL-6 secretion from HFCs. Moreover, these inhibitors suppressed IL-6 mRNA expression in response to TGF-β stimulation.Conclusions: Our findings indicate that TGF-β induces IL-6 protein secretion and gene expression in HFCs through the activation of p38 or p44/42 MAP kinases. These results suggest a potential association between IL-6–mediated inflammatory response and tissue hypertrophy in LSS, and we provide insights into molecular targets for therapeutic interventions targeting LSS-related inflammation through our analysis of the MAP kinase pathway using HFCs.