Dataset Information

Intervertebral disc spheroids as an in vitro multicellular platform for recapitulating the microenvironment of intervertebral disc degeneration

ABSTRACT: Intervertebral disc (IVD) degeneration (IVDD) is a major contributor to chronic low back pain (LBP), representing a significant burden on the spinal healthcare system and a leading cause of long-term disability worldwide. Reliable in vitro models are lacking and thus monocultures of cell lines and 2D-based culture models are still used to study the patho-mechanisms of IVDD. We established functional multicellular IVD spheroid cultures using primary human annulus fibrosus (AF), nucleus pulposus and microglial cells. The IVD spheroid culture was observed to facilitate the IVD-specific phenotype and function. The spheroid culture markedly increased the expression of inflammatory mediators and chemokines in the presence of pro-inflammatory cytokines IL-1b, a master regulator of IVDD. Furthermore, we implemented our microfluidic chemotaxis platform to investigate microglial neuroinflammation in response to our reconstituted IVD spheroid models. Transcriptome sequencing revealed that microglia stimulated by potential contributing factors derived from IVDD spheroids exhibited a significant upregulation of chemotactic factors and cytokines including CCL2, 3, 4, 5, CXCL8, IL6, and IL1b (p < 0.05). Moreover, we observed considerable activation and infiltration of microglia induced by soluble factors derived from IVDD spheroids, which is expected to occur during IVDD. The chemotactic effects on microglia were reduced upon neutralization of CCL-2, IL-8 or inhibition of NF-kB signaling. These robust in vitro IVD spheroids can be used to model IVDD and provide a valuable platform for the assessment and development of IVDD therapeutics.

ORGANISM(S): Homo sapiens

PROVIDER: GSE278813 | GEO | 2025/12/25

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Very little is known about how intervertebral disc (IVD) is formed or maintained. Members of the TGF-ß superfamily are secreted signaling proteins that regulate many aspects of development including cellular differentiation. We recently showed that deletion of Tgfbr2 in Col2a expressing tissue results in alterations in development of IVD annulus fibrosus. The results suggested TGF-ß has an important role in regulating development of the axial skeleton, however, the mechanistic basis of TGF-ß action in these specialized joints is not known. One of the hurdles to understanding development of IVD is a lack of known markers. To identify genes that are enriched in the developing IVD and to begin to understand the mechanism of TGF-ß action in IVD development, we undertook a global analysis of gene expression comparing gene expression profiles in developing vertebrae and IVD. We also compared expression profiles in tissues from wild type and Tgfbr2 mutant mice. Lists of IVD and vertebrae enriched genes were generated. Expression patterns for several genes were verified either through in situ hybridization or literature/ database searches resulting in a list of genes that can be used as markers of IVD. Cluster analysis using genes listed under the Gene Ontology terms multicellular organism development and pattern specification indicated that mutant IVD more closely resembled vertebrae than wild type IVD. We propose TGF-ß has two functions in IVD development: 1) to prevent chondrocyte differentiation in the presumptive IVD and 2) to promote differentiation of annulus fibrosus from sclerotome. We have identified genes that are enriched in the IVD and regulated by TGF-ß that warrant further investigation as regulators of IVD development. Thirteen samples were analyzed. This includes three biological replicates of laser captured IVD from E13.5 day control mice, three biological replicates of laser captured vertebrae from the same E13.5 day control mice, three biological relicates of laser captured vertebrae from E13.5 day Col2aCre;Tgfbr2lox/lox mice, and four biological replicates of laser captured IVD from E13.5 day Col2aCre;Tgfbr2lox/lox mice.

Project description:Human intervertebral disc tissue was obtained from patients (average age 51 yrs) undergoing surgery for lumbar interbody fusion (n=3) or lumbar disc herniation (n=1). Cells were isolated by sequential pronase-collagenase digestion [3]. Cells were passaged twice in monolayer and suspended at a density of 2 x 106 cells/ml in 1.2% alginate (low viscosity, Sigma Chemical, St Louis, MO) dissolved in 150 mM NaCl. Alginate beads were formed by dropwise addition of the alginate from a 22 gauge needle into 102 mM CaCl2, followed by 10 minutes of curing, as described previously [13, 27]. Cell-gel beads were incubated in cell culture media consisting of Ham’s F-12 medium (Gibco BRL, Grand Island, NY), supplemented with 10% FBS (HyClone, Logan, UT), 25 μg/ml ascorbic acid (Sigma, St. Louis, MO), 100 U/ml penicillin, 100 μg/ml streptomycin, and 1 μg/ml Fungizone at 5% CO2 and 37° C. After 24 h, the cell culture medium was removed via pipette and exchanged for one of three osmotically active solutions, representing iso-osmotic, hyper-osmotic and hypo-osmotic media [12, 23, 34]. The iso-osmotic solution consisted of a defined cell culture medium (Ham’s F-12 with supplements as described above; 293 mOsm/kg H2O). The hypo-osmotic solution consisted of the same cell culture media diluted with de-ionized water to a final osmolarity of 250 mOsm/kg H2O. The hyper-osmotic solution consisted of the same cell culture media supplemented with sucrose to a final osmolarity of 450 mOsm/kg H20. The osmolarity of all solution formulations was determined using a freezing-point osmometer (Advanced Laboratory Wide Range 3W2, Advanced Instrument, Needham Heights, MA) as described previously [12]. Cell-alginate beads were cultured for a 4 hour period under one of these conditions, after which the cells were released from alginate in a dissolving buffer (55 mM Na-citrate and 150 mM NaCl), lysed and stored at –80°C. Intervertebral disc (IVD) cells experience a broad range of physical stimuli under physiologic conditions, including alterations in their osmotic environment. In this study, the gene expression profile of human IVD cells was quantified with gene array technology following exposure to varying osmolarity in order to capture the biological responses for a broad set of targets. A total of 42 genes were identified in IVD cells as significantly changed following culture under hyper-osmotic conditions, while a total of 18 genes were identified as significantly changed under hypo-osmotic conditions. Gene expression patterns were verified using RT-PCR. Genes identified in this study include those related to cytoskeleton remodeling and stabilization (ephrin-B2, sarcoglycan beta, IQGAP1), as well as membrane transport (ion transporter SLC21A12, osmolyte tranporter SLC5A3, monocarboxylic acid SLC16A6, and amino acid transporter SLC7A8). An unexpected finding was the differential regulation of the gene for the neurotrophin brain-derived neurotrophic factor by hyper-osmotic stimuli that may be indicative of a physiological response of IVD cells to physical stimuli important in regulating discogenic pain. Keywords = intervertebral disc Keywords = osmotic stimuli Keywords: other

Dataset Information

Intervertebral disc spheroids as an in vitro multicellular platform for recapitulating the microenvironment of intervertebral disc degeneration

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets