Is intervertebral disc degeneration associated with reduction in serum ferritin?

Serum periostin levels correlate with severity of intervertebral disc degeneration

PURPOSE

Periostin, an extracellular matrix protein closely related to mechanical stress, inflammation, and ageing, has been implicated in intervertebral disc degeneration (IVDD) in basic research. However, it has not been examined in clinical cases. This study aimed to evaluate the association between IVDD severity and serum periostin concentration as well as to analyse potential associations between IVDD and clinical and demographic factors.

METHODS

This retrospective cohort study included 198 patients who underwent lumbar disc herniation and lumbar canal stenosis between January 2020 and December 2022. The severity of IVDD was evaluated using the Pfirrmann grading, whereas serum periostin levels were measured using ELISA kits. Clinical demographics, including age, sex, body mass index, comorbidities, psoas muscle index, and spinal disease, were also recorded.

RESULTS

This study demonstrated a significant correlation between high serum periostin levels and IVDD severity, as indicated by a high cumulative Pfirrmann score. Serum periostin levels were identified as an independent risk factor for IVDD in a multivariate regression model. Correlation analysis showed a correlation between periostin levels and Pfirrmann grade at each lumbar level (ρ = 0.458-0.550, p < 0.001) and a strong correlation with cumulative Pfirrmann score (ρ = 0.690, p < 0.001).

CONCLUSION

The higher the serum periostin level, the higher the cumulative Pfirrmann score. Multivariate analysis showed that serum periostin was an independent risk factor for IVDD. Periostin levels may be a clinically suitable and useful biomarker for diagnosing IVDD, estimating disease progression and activity, providing prognostic information, and evaluating treatment options.

Achilles' Heel-The Significance of Maintaining Microenvironmental Homeostasis in the Nucleus Pulposus for Intervertebral Discs

The dysregulation of intracellular and extracellular environments as well as the aberrant expression of ion channels on the cell membrane are intricately linked to a diverse array of degenerative disorders, including intervertebral disc degeneration. This condition is a significant contributor to low back pain, which poses a substantial burden on both personal quality of life and societal economics. Changes in the number and function of ion channels can disrupt the water and ion balance both inside and outside cells, thereby impacting the physiological functions of tissues and organs. Therefore, maintaining ion homeostasis and stable expression of ion channels within the cellular microenvironment may prove beneficial in the treatment of disc degeneration. Aquaporin (AQP), calcium ion channels, and acid-sensitive ion channels (ASIC) play crucial roles in regulating water, calcium ions, and hydrogen ions levels. These channels have significant effects on physiological and pathological processes such as cellular aging, inflammatory response, stromal decomposition, endoplasmic reticulum stress, and accumulation of cell metabolites. Additionally, Piezo 1, transient receptor potential vanilloid type 4 (TRPV4), tension response enhancer binding protein (TonEBP), potassium ions, zinc ions, and tungsten all play a role in the process of intervertebral disc degeneration. This review endeavors to elucidate alterations in the microenvironment of the nucleus pulposus during intervertebral disc degeneration (IVDD), with a view to offer novel insights and approaches for exploring therapeutic interventions against disc degeneration.

Association between anemia and lumbar disc degeneration in patients with low back pain: an observational retrospective study

OBJECTIVE

The goal of this study was to evaluate the possible associations between anemia and morphologic features of lumbar disc degeneration (LDD) in subjects with low back pain.

MATERIALS AND METHODS

A total of 131 patients with normocytic or microcytic anemia (mean age 41.0 ± 6.4 yrs, BMI: 24.8 ± 3.3 kg/m², 12.2% men) and a matched control group of 131 patients without anemia (mean age 41.0 ± 6.4 yrs, BMI: 24.9 ± 3.1 kg/m², 12.2% men) were evaluated for LDD according to the Pfirrmann scoring system. The primary outcome was the difference of radiological features of LDD between two groups. The second outcome was the correlation between the hemoglobin (Hb) value and disc degeneration (DD). Statistical associations were assessed by Student's t-test, Chi-square test, and Spearman correlation.

RESULTS

Anemic patients had a significantly higher number of degenerated discs than non-anemic patients in the level of L2/3 and L3/4 (p < 0.05). We also found that the severe DD occurred more frequently in the level of L2/3, L3/4 and L5/S1 among anemic patients (p < 0.05). In addition, we noticed that the incidence of multilevel LDD happened much more frequently in patients with anemia (p < 0.05). The Hb value showed a borderline negative correlation with the total score of DD (p = 0.056).

CONCLUSION

The results suggested that patients with anemia, and those without are radiologically different with varying patterns of DD. Patients with back pain and anemia were more likely to have extensive and severe DD. Although relevant mechanisms are not yet well understood, this study improved our understandings of the pathophysiology for LDD.

Targeting Ferroptosis Holds Potential for Intervertebral Disc Degeneration Therapy

Intervertebral disc degeneration (IVDD) is a common pathological condition responsible for lower back pain, which can significantly increase economic and social burdens. Although considerable efforts have been made to identify potential mechanisms of disc degeneration, the treatment of IVDD is not satisfactory. Ferroptosis, a recently reported form of regulated cell death (RCD), is characterized by iron-dependent lipid peroxidation and has been demonstrated to be responsible for a variety of degenerative diseases. Accumulating evidence suggests that ferroptosis is implicated in IVDD by decreasing viability and increasing extracellular matrix degradation of nucleus pulposus cells, annulus fibrosus cells, or endplate chondrocytes. In this review, we summarize the literature regarding ferroptosis of intervertebral disc cells and discuss its molecular pathways and biomarkers for treating IVDD. Importantly, ferroptosis is verified as a promising therapeutic target for IVDD.

Ferroptosis: A potential target for the intervention of intervertebral disc degeneration

Ferroptosis, an iron-dependent form of programmed cell death marked by phospholipid peroxidation, is regulated by complex cellular metabolic pathways including lipid metabolism, iron balance, redox homeostasis, and mitochondrial activity. Initial research regarding the mechanism of ferroptosis mainly focused on the solute carrier family 7 member 11/glutathione/glutathione peroxidase 4 (GPX4) signal pathway. Recently, novel mechanisms of ferroptosis, independent of GPX4, have been discovered. Numerous pathologies associated with extensive lipid peroxidation, such as drug-resistant cancers, ischemic organ injuries, and neurodegenerative diseases, are driven by ferroptosis. Ferroptosis is a new therapeutic target for the intervention of IVDD. The role of ferroptosis in the modulation of intervertebral disc degeneration (IVDD) is a significant topic of interest. This is a novel research topic, and research on the mechanisms of IVDD and ferroptosis is ongoing. Herein, we aim to review and discuss the literature to explore the mechanisms of ferroptosis, the relationship between IVDD and ferroptosis, and the regulatory networks in the cells of the nucleus pulposus, annulus fibrosus, and cartilage endplate to provide references for future basic research and clinical translation for IVDD treatment.