Notochordal cell-secreted factors stimulate matrix production by canine nucleus pulposus cells and bone marrow derived stromal cells

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Soluble and pelletable factors in porcine, canine and human notochordal cell-conditioned medium: implications for IVD regeneration

During intervertebral disc (IVD) maturation, notochordal cells (NCs) are replaced by chondrocyte-like cells (CLCs) in the nucleus pulposus, suggesting that NCs play a role in maintaining tissue health. Affirmatively, NC-conditioned medium (NCCM) exerts regenerative effects on CLC proliferation and extracellular matrix (ECM) production. The aim of this study was to identify NC-secreted substances that stimulate IVD regeneration. By mass spectrometry of porcine, canine and human NCCM, 149, 170 and 217 proteins were identified, respectively, with 66 proteins in common. Mainly ECM-related proteins were identified, but also organelle-derived and membrane-bound vesicle proteins. To determine whether the effect of NCCM was mediated by soluble and/or pelletable factors, porcine and canine NCCM were separated into a soluble (NCCM-S; peptides and proteins) and pelletable (NCCM-P; protein aggregates and extracellular vesicles) fraction by ultracentrifugation, and tested on bovine and canine CLCs in vitro, respectively. In each model, NCCM-S exerted a more pronounced anabolic effect than NCCM-P. However, glycosaminoglycan (GAG) uptake from the medium into the carrier gel prevented more definite conclusions. While the effect of porcine NCCM-P on bovine CLCs was negligible, canine NCCM-P appeared to enhance GAG and collagen type II deposition by canine CLCs. In conclusion, porcine and canine NCCM exerted their anabolic effects mainly through soluble factors, but also the pelletable NCCM factors showed moderate regenerative potential. Although the regenerative potential of NCCM-P should not be overlooked, future studies should focus on unraveling the protein-based regenerative mechanism from NCCM produced from isolated NCs, e.g. by NCCM fractionation and pathway blocking studies

Semi-synthetic degradable notochordal cell-derived matrix hydrogel for use in degenerated intervertebral discs: Initial in vitro characterization

Low back pain is the leading cause of disability worldwide, but current therapeutic interventions are palliative or surgical in nature. Loss of notochordal cells (NCs) and degradation of the healthy matrix in the nucleus pulposus (NP), the central tissue of intervertebral discs (IVDs), has been associated with onset of degenerative disc changes. Recently, we established a protocol for decellularization of notochordal cell derived matrix (NCM) and found that it can provide regenerative cues to nucleus pulposus cells of the IVD. Here, we combined the biologically regenerative properties of decellularized NCM with the mechanical tunability of a poly(ethylene glycol) hydrogel to additionally address biomechanics in the degenerate IVD. We further introduced a hydrolysable PEG-diurethane crosslinker for slow degradation of the gels in vivo. The resulting hydrogels were tunable over a broad range of stiffness's (0.2 to 4.5 kPa), matching that of NC-rich and -poor NP tissues, respectively. Gels formed within 30 min, giving ample time for handling, and remained shear-thinning post-polymerization. Gels also slowly released dNCM over 28 days as measured by GAG effusion. Viability of encapsulated bone marrow stromal cells after extrusion through a needle remained high. Although encapsulated NCs stayed viable over two weeks, their metabolic activity decreased, and their phenotype was lost in physiological medium conditions in vitro. Overall, the obtained gels hold promise for application in degenerated IVDs but require further tuning for combined use with NCs

Metabolic effects of early life stress and pre-pregnancy obesity are long lasting and sex specific in mice

Early life stress (ELS) is associated with metabolic, cognitive, and psychiatric diseases and has a very high prevalence, highlighting the urgent need for a better understanding of the versatile physiological changes and identification of predictive biomarkers. In addition to programming the hypothalamic-pituitary-adrenal (HPA) axis, ELS may also affect the gut microbiota and metabolome, opening up a promising research direction for identifying early biomarkers of ELS-induced (mal)adaptation. Other factors affecting these parameters include maternal metabolic status and diet, with maternal obesity shown to predispose offspring to later metabolic disease. The aim of the present study was to investigate the long-term effects of ELS and maternal obesity on the metabolic and stress phenotype of rodent offspring. To this end, offspring of both sexes were subjected to an adverse early-life experience, and their metabolic and stress phenotypes were examined. In addition, we assessed whether a prenatal maternal and an adult high-fat diet (HFD) stressor further shape observed ELS-induced phenotypes. We show that ELS has long-term effects on male body weight (BW) across the lifespan, whereas females more successfully counteract ELS-induced weight loss, possibly by adapting their microbiota, thereby stabilizing a balanced metabolome. Furthermore, the metabolic effects of a maternal HFD on BW are exclusively triggered by a dietary challenge in adult offspring and are more pronounced in males than in females. Overall, our study suggests that the female microbiota protects against an ELS challenge, rendering them more resilient to additional maternal- and adult nutritional stressors than males.This work was supported by the “GUTMOM” grant of the ERA-Net Cofund HDHL-INTIMIC (INtesTInal MIcrobiomics) under the JPI HDHL (Joint Programming Initiative – A healthy diet for a healthy life) umbrella (01EA1805; MVS), the SCHM2360-5-1 grant (MVS) from the German Research Foundation (DFG), the ZonMw grant from the Netherlands Organisation for Health Research and Development (project number 529051019), the DIM-ELI-2 grant of La Fundación La Marató-TV3 (ref. 2018-27/30-31), the PID2019-108973RB-C22 and PCIN2017-117 grants from the Ministerio de Ciencia e Innovación of Spain and the grants GV/2020/048 and IDIFEDER/2021/072 from the Generalitat Valenciana of Spain. Open Access funding enabled and organized by Projekt DEAL.Peer reviewe

The LRRK2 Arg1628Pro variant is a risk factor for Parkinson's disease in the Chinese population

The c.G4883C variant in the leucine-rich repeat kinase 2 (LRRK2) gene (protein effect: Arg1628Pro) has been recently proposed as a second risk factor for sporadic Parkinson's disease in the Han Chinese population (after the Gly2385Arg variant). In this paper, we analyze the Arg1628Pro variant and the associated haplotype in a large sample of 1,337 Han subjects (834 patients and 543 controls) ascertained from a single referral center in Taiwan. In our sample, the Arg1628Pro allele was more frequent among patients (3.8%) than among controls (1.8%; p = 0.004, OR 2.13, 95% CI 1.29-3.52). Sixty heterozygous and two homozygous carriers of the Arg1628Pro variant were identified among the patients, of which only one was also a carrier of the LRRK2 Gly2385Arg variant. We also show that carriers of the Arg1628Pro variant share a common, extended haplotype, suggesting a founder effect. Parkinson's disease onset age was similar in patients who carried the Arg1628Pro variant and in those who did not carry it. Our data support the contention that the Arg1628Pro variant is a second risk factor for Parkinson's disease in the Han Chinese population. Adding the estimated effects of Arg1628Pro (population attributable risk [PAR] ∼4%) and Gly2385Arg variants (PAR ∼6%) yields a total PAR of ∼10%

Professionals’ Attitudes Toward Reducing Restraint: The Case of Seclusion in The Netherlands

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The Role of Best Friends in Educational Identity Formation in Adolescence

This 4-year longitudinal study examined over-time associations between adolescents’ educational identity, perceived best friends’ balanced relatedness, and best friends’ educational identity. Adolescents (N = 464, Mage = 14.0 years at baseline, 56.0% males, living in the Netherlands) and their self-nominated best friends reported on their educational commitment, in-depth exploration, and reconsideration. Target adolescents also reported on the level of balanced relatedness provided by their best friend. Cross-lagged panel models showed that balanced relatedness significantly predicted adolescents’ reconsideration, and was predicted by in-depth exploration and, in an inconsistent pattern, by commitment. Best friends’ educational identity did not positively predict adolescents’ educational identity. Perceiving a best friend as high on balanced relatedness seems to reduce adolescents’ problematic educational reconsideration, while, in turn, adaptive educational identity processes might foster balanced relatedness

The role of best friends in educational identity formation in adolescence

This 4-year longitudinal study examined over-time associations between adolescents' educational identity, perceived best friends' balanced relatedness, and best friends' educational identity. Adolescents (N = 464, Mage = 14.0 years at baseline, 56.0% males, living in the Netherlands) and their self-nominated best friends reported on their educational commitment, in-depth exploration, and reconsideration. Target adolescents also reported on the level of balanced relatedness provided by their best friend. Cross-lagged panel models showed that balanced relatedness significantly predicted adolescents' reconsideration, and was predicted by in-depth exploration and, in an inconsistent pattern, by commitment. Best friends' educational identity did not positively predict adolescents' educational identity. Perceiving a best friend as high on balanced relatedness seems to reduce adolescents' problematic educational reconsideration, while, in turn, adaptive educational identity processes might foster balanced relatedness

Potential application of notochordal cells for intervertebral disc regeneration: an in vitro assessment

Recent studies suggest that notochordal cells (NCs) might be involved in intervertebral disc homeostasis, a role exploitable to counteract matrix degradation as observed during degeneration. This study aimed to evaluate the potential of NCs to promote matrix production by nucleus pulposus cells (NPCs) and to compare it to the currently proposed addition of bone marrow stromal cells (BMSCs). Using alginate beads, bovine NPCs were exposed for 28 d to porcine NC conditioned medium (NCCM); direct co-culture with porcine NCs or bovine BMSCs; or the combination of BMSCs and NCCM. Effects on cell proliferation, disc matrix production (proteoglycans, collagens) and disc matrix protein expression (aggrecan, collagen 1 and 2, SOX9) were determined and compared to TGFβ stimulation. NCCM strongly promoted NPC proliferation (x 2.2) and matrix production (x 3.9) to levels similar to that with TGFβ, whereas the direct addition of NCs had no effect. Co-culture of NPCs and BMSCs led to proteoglycan synthesis similar to NPCs alone, which was slightly improved by NCCM (x 1.5). Histological analysis confirmed biochemical data. Gene expression of analysed proteins remained stable for all groups and unaffected by medium conditions. NCs could substantially stimulate NPCs through factors secreted into conditioned medium and in levels similar to the addition of BMSCs. This study showed that molecular agents secreted by NCs constitute a promising alternative to the proposed “standard” injection of BMSCs for disc repair: their effects are similar, do not require the injection of a large number of cells and can be further amplified when the factors are identified