CRLF1 Is a Key Regulator in the Ligamentum Flavum Hypertrophy

Abstract

Hypertrophy of the ligamentum flavum (HLF) is one of the common causes of lumbar spinal stenosis (LSS). The key molecules and mechanisms responsible for HLF remain unclear. Here, we used an integrated transcriptome and proteomics analysis of human ligamentum flavum (LF), and subsequent immunohistochemistry and real-time PCR assays, to show upregulation of CRLF1 to be the dominant response to HLF. TGF-β1 significantly increased mRNA expression of CRLF1 through SMAD3 pathway. CRLF1 enhanced LF fibrosis via ERK signaling pathway at the post-transcriptional level and was required for the pro-fibrotic effect of TGF-β1. Knockdown of CRLF1 was shown here to reduce fibrosis caused by inflammatory cytokines and mechanical stress. Furthermore, we found that bipedal standing posture can cause HLF and upregulation of CRLF1 expression in mice LF. Overexpression of CRLF1 was indicated to cause HLF in vivo, whereas CRLF1 knockdown impeded the formation of HLF in bipedal standing mice. These results revealed a crucial role of CRLF1 in LF hypertrophy. We propose that inhibition of CRLF1 is a potential therapeutic strategy to treat HLF.

Integrative analysis of genome-wide DNA methylation and single-nucleotide polymorphism identified ACSM5 as a suppressor of lumbar ligamentum flavum hypertrophy

“…For example, Cao et al reported that p38 MAPK signaling pathway promoted the homeostasis of the extracellular matrix and the hypertrophy of LF [ 31 ]. Zheng et al indicated that the inhibitor of MAPK/ERK signaling pathway restrained TGF-1β-induced LF fibrosis, suggesting a crucial role of MAPK/ERK signaling pathway in HLF [ 32 ]. The involvement of WNT signaling pathway in HLF has been reported by Taiki et al [ 33 ].…”

Identification of Dysregulated Complement Activation Pathways Driven by N-Glycosylation Alterations in T2D Patients

“…The routine clinical tests for the diagnosis and follow-up of diabetes have certain limitations; for example, they may not be sufficiently sensitive at early disease stages (the Association A.D., 2019). Recent advances in proteomics and glycoproteomics technologies hold great potential in providing additional insights into the disease biology and discovering new biomarkers (Vajaria and Patel, 2017;Zheng et al, 2020). Herein, we presented the global proteomic and glycoproteomic landscape in the fasting plasma of the 24 Chinese participants, and provided some clues for diagnosis and treatment of T2D.…”

“…Recent advances in proteome technologies have now enabled the large-scale studies of proteins in tissues and body fluids, and identified many candidate protein biomarkers to diagnose T2D (Zhao et al, 2017;Nowak et al, 2018;Sohail et al, 2018;Jiang et al, 2019;Zhang et al, 2019;Zheng et al, 2020). However, few of those potential biomarkers have been successfully translated into clinical use.…”

miR‐10396b‐3p inhibits mechanical stress‐induced ligamentum flavum hypertrophy by targeting IL‐11

“…Flexercell Tension System, FX‐5000 (Flexcell International Corp., USA) was used to apply cyclic stretch (elongation strength was 20%, at 10s stretch, and 10s relaxation) for 6 hours and 12 hours. These chosen strain parameters were based on our previous study 24 . Within Flexercell Tension System, the flexible membranes of the culture plates were stretched when negative pressure was applied.…”

“…Each obtained LF sample was cut into halves, the final LF samples (n = 120) were stored in PBS solution (n = 60) and liquid nitrogen (n = 60) temporarily. Among the 120 LF samples, 24 Subsequent experiments were conducted using LF cells from the third passage. To identify LF fibroblasts, the cells were processed to immunofluorescence assay, according to the manufacturer's instructions stained with antibodies against vimentin (1:100, Abcam, ab8978, UK) and collagen I (1:100, Abcam, ab260043, UK).…”