CpG methylation changes in human mesenchymal and neural stem cells in response to in vitro niche modifications.

Stem cell therapies hold promise in addressing the burden of neurodegenerative diseases with human embryonic neural stem cells (hNSC-H9s) and bone marrow-derived human mesenchymal stem cells (hMSCs) as viable candidates. The induction of hMSC neurospheres (hMSC-IN) generate a more lineage-restricted common neural progenitor-like cell population, potentially tunable by heparan sulfate proteoglycans (HSPGs). We examined CpG (5 mC) site methylation patterns using Illumina Infinium 850 K EPIC arrays in hNSC-H9, hMSCs and hMSC-IN cultures with HSPG agonist heparin at early and late phases of growth. We identified key regulatory CpG sites in syndecans (SDC2; SDC4) that potentially regulate gene expression in monolayers. Unique hMSC-IN hypomethylation in glypicans (GPC3; GPC4) underscore their significance in neural lineages with Sulfatase 1 and 2 (SULF1 &2) CpG methylation changes potentially driving the neurogenic shift. hMSC-INs methylation levels at SULF1 CpG sites and SULF2:cg25401628 were more closely aligned with hNSC-H9 cells than with hMSCs. We further suggest SOX2 regulation governed by lncSOX2-Overall Transcript (lncSOX2-OT) methylation changes with preferential activation of ENO2 over other neuronal markers within hMSC-INs. Our findings illuminate epigenetic dynamics governing neural lineage commitment of hMSC-INs offering insights for targeted mechanisms for regenerative medicine and therapeutic strategies.

Unravelling the Genetic Landscape of Hemiplegic Migraine: Exploring Innovative Strategies and Emerging Approaches.

Migraine is a severe, debilitating neurovascular disorder. Hemiplegic migraine (HM) is a rare and debilitating neurological condition with a strong genetic basis. Sequencing technologies have improved the diagnosis and our understanding of the molecular pathophysiology of HM. Linkage analysis and sequencing studies in HM families have identified pathogenic variants in ion channels and related genes, including CACNA1A, ATP1A2, and SCN1A, that cause HM. However, approximately 75% of HM patients are negative for these mutations, indicating there are other genes involved in disease causation. In this review, we explored our current understanding of the genetics of HM. The evidence presented herein summarises the current knowledge of the genetics of HM, which can be expanded further to explain the remaining heritability of this debilitating condition. Innovative bioinformatics and computational strategies to cover the entire genetic spectrum of HM are also discussed in this review.

The effects of OPRM1 118A>G on methadone response in pain management in advanced cancer at end of life.

Cancer pain is the most feared symptom at end of life. Methadone has advantages over other opioids but is associated with significant variability in clinical response, making dosing challenging in practice. OPRM1 is the most studied pharmacogene associated with the pharmacodynamics of opioids, however reports on the association of the A118G polymorphism on opioid dose requirements are conflicting, with no reports including methadone as the primary intervention. This association study on OPRM1 A118G and response to methadone for pain management, includes a review of this genetic factor's role in inter-patient variability. Fifty-four adult patients with advanced cancer were recruited in a prospective, multi-centre, open label dose individualization study. Patient characteristics were not shown to influence methadone response, and no significant associations were observed for methadone dose or pain score. The findings of our review of association studies for OPRM1 A118G in advanced cancer pain demonstrate the importance of taking ancestry into account. While our sample size was small, our results were consistent with European populations, but in contrast to studies in Chinese patients, where carriers of the A118G polymorphism were associated with higher opioid dose requirements. Pharmacogenetic studies in palliative care are challenging, continued contribution will support future genotype-based drug dosing guidelines.

Exonic mutations in cell-cell adhesion may contribute to CADASIL-related CSVD pathology.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a condition caused by mutations in NOTCH3 and results in a phenotype characterised by recurrent strokes, vascular dementia and migraines. Whilst a genetic basis for the disease is known, the molecular mechanisms underpinning the pathology of CADASIL are still yet to be determined. Studies conducted at the Genomics Research Centre (GRC) have also identified that only 15-23% of individuals clinically suspected of CADASIL have mutations in NOTCH3. Based on this, whole exome sequencing was used to identify novel genetic variants for CADASIL-like cerebral small-vessel disease (CSVD). Analysis of functionally important variants in 50 individuals was investigated using overrepresentation tests in Gene ontology software to identify biological processes that are potentially affected in this group of patients. Further investigation of the genes in these processes was completed using the TRAPD software to identify if there is an increased number (burden) of mutations that are associated with CADASIL-like pathology. Results from this study identified that cell-cell adhesion genes were positively overrepresented in the PANTHER GO-slim database. TRAPD burden testing identified n = 15 genes that had a higher number of rare (MAF < 0.001) and predicted functionally relevant (SIFT < 0.05, PolyPhen > 0.8) mutations compared to the gnomAD v2.1.1 exome control dataset. Furthermore, these results identified ARVCF, GPR17, PTPRS, and CELSR1 as novel candidate genes in CADASIL-related pathology. This study identified a novel process that may be playing a role in the vascular damage related to CADASIL-related CSVD and implicated n = 15 genes in playing a role in the disease.

GSTM1 and GSTT1 polymorphisms associated with pain in a chemotherapy-induced peripheral neuropathy cohort.

PURPOSE: Chemotherapy induced peripheral neuropathy (CIPN) is a debilitating condition that is a direct consequence of receiving cancer treatment. The molecular aetiology of CIPN is not well understood, and it is theorised that there may be a genetic component. Genetic polymorphisms in Glutathione-S Transferase (GST) genes, including GSTT1, GSTM1 and GSTP1, encode for enzymes known to metabolise drugs used in chemotherapy, and have been theorised to be associated with CIPN. This study aimed to investigate four markers in these genes for an association in a mixed cancer cohort in relation to CIPN (n = 172). METHODS: CIPN was measured using the neuropathy item from the Patient Reported Outcome Common Terminology Criteria for Adverse Event (PRO-CTCAE) assessment. Genotyping for all samples was performed using PCR for the GSTM1 and GSTT1 null variants and restriction fragment length polymorphisms for the GSTP1 and GSTM1 polymorphisms. RESULTS: No associations were found for the GST gene markers in relation to CIPN within our study, or CIPN severity. Longitudinal stratification of the CIPN phenotypes to examine links for neuropathy, identified nominally significant protective associations with the GSTM* null allele (p-value = 0.038, OR = 0.55) and the presence of pain at month 2 of treatment, as well as a risk factor for pain related month 2 of treatment for individuals with the GSTT1*null allele (p-value = 0.030, OR = 1.64). Higher severity of pain in patients with CIPN persisted at each time-point compared to those without CIPN. CONCLUSION: No significant results for an association between CIPN with polymorphisms in GSTM1, GSTT1 and GSTP1 were identified. However, associations for the GSTM1¬-null and GSTT1-null polymorphisms with pain at month 2 following chemotherapy were identified.

Global reported impacts of COVID-19 on lymphoma patients and the emerging clinical management approaches in response to the ongoing pandemic.

The Coronavirus disease 2019 (COVID-19) pandemic has dramatically impacted the health risk and management of patients with lymphoma. Clinical evaluations on the impact of COVID-19 on lymphoma patients are currently limited however, reports have shown a correlation with specific variants and more severe COVID-19 complications and higher mortality rates relative to other disease states and age-matched populations. During peak pandemic periods this created a concerning management problem for clinicians and raised the question of how different immunocompromised states increase COVID-19-associated risk and provided insights into how immunity interacts with the circulating variant, including the effects of low virulent variants in vaccinated lymphoma populations. Treatment management approaches, polymerase chain reaction tests and rapid antigen screening guidelines have been offered in an attempt to reduce the risk of harm to lymphoma patients, particularly prior to and following bone marrow or stem cell transplant. Here we systematically review the current literature to provide a novel global perspective on incidence, mortality, management and rapid antigen test (RAT) screening for COVID-19, in patients with various subtypes of lymphoma. Furthermore, lessons learned from emerging variants that continue to inform evolving lymphoma management and public health policies are addressed across these associated matters.

Data on 2D culture characterisation of potential markers in human HER2-positive breast cancer cell lines.

To obtain this dataset, two human HER2-positive breast cancer cell lines (SKBR3 and MDA-MB-453 cell lines) were cultured in basal growth media to 80% confluence. Cells were passaged and total RNA extracted, RNA converted to cDNA and diluted to a working concentration of 40 ng/µL. Gene expression panels of cancer markers including Fibroblast growth factors (FGF), FGF receptors (FGFRs), cyclin-dependent kinases, cytokeratins, and WNT pathway components were then examined using Q-PCR. Gene expression was normalised against the expression of the endogenous gene 18S. This article describes the data used in the research article "Syndecan-4 regulates the HER2-positive breast cancer cell proliferation cells via CK19/AKT signaling" [1]. The data presented demonstrates the range of gene expression profiles of these cells and aims to provide more detail of all gene expression changes observed in these cell lines.

Syndecan-4 regulates the HER2-positive breast cancer cell proliferation cells via CK19/AKT signalling.

Despite the use of the highly specific anti-HER2 receptor (trastuzumab) therapy, HER2-positive breast cancers account for 20-30% of all breast cancer carcinomas, with HER2 status a challenge to treatment interventions. The heparan sulfate proteoglycans (HSPGs) are prominently expressed in the extracellular matrix (ECM), mediate breast cancer proliferation, development, and metastasis with most studies to date conducted in animal models. This study examined HSPGs in HER2-positive human breast cancer cell lines and their contribution to cancer cell proliferation. The study examined the cells following enhancement (via the addition of heparin) and knockdown (KD; using short interfering RNA, siRNA) of HSPG core proteins. The interaction of HSPG core proteins and AKT signalling molecules was examined to identify any influence of this signalling pathway on cancer cell proliferation. Our findings illustrated the HSPG syndecan-4 (SDC4) core protein significantly regulates cell proliferation with increased BC cell proliferation following heparin addition to cultures and decreased cell number following SDC4 KD. In addition, along with SDC4, significant changes in CK19/AKT signalling were identified as mediators of BC HER2-positive BC cell proliferation. This study provides evidence for a cell growth regulatory axis involving HSPGs/CK19 and AKT that represents a potential molecular target to prevent proliferation of HER2-positive breast cancer cells.

SDC4-rs1981429 and ATM-rs228590 may provide early biomarkers of breast cancer risk.

In Australia, 13% of women are diagnosed with breast cancer (BC) in their lifetime with approximately 20,000 women diagnosed with the disease in 2021. BC is characterised by complex histological and genomic influences with recent advances in cancer biology improving early diagnosis and personalised treatment interventions. The Phosphatidyl-inositol-3-kinase/Protein kinase B (PI3K/AKT) pathway is essential in apoptosis resistance, cell survival, activation of cellular responses to DNA damage and DNA repair. Heparan sulfate proteoglycans (HSPGs) are ubiquitous molecules found on the cell surface and in the extracellular matrix with essential functions in regulating cell survival, growth, adhesion and as mediators of cell differentiation and migration. HSPGs, particularly the syndecans (SDCs), have been linked to cancers, making them an exciting target for anticancer treatments. In the PI3K/AKT pathway, syndecan-4 (SDC4) has been shown to downregulate AKT Serine/Threonine Kinase (AKT1) gene expression, while the ATM Serine/Threonine Kinase (ATM) gene has been found to inhibit this pathway upstream of AKT. We investigated single-nucleotide polymorphisms (SNPs) in HSPG and related genes SDC4, AKT1 and ATM and their influence on the prevalence of BC. SNPs were genotyped in the Australian Caucasian Genomics Research Centre Breast Cancer (GRC-BC) population and in the Griffith University-Cancer Council Queensland Breast Cancer Biobank (GU-CCQ BB) population. We identified that SDC4-rs1981429 and ATM-rs228590 may influence the development and progression of BC, having the potential to become biomarkers in early BC diagnosis and personalised treatment.

Association of KCNJ6 rs2070995 and methadone response for pain management in advanced cancer at end-of-life.

Opioids are the therapeutic agents of choice to manage moderate to severe pain in patients with advanced cancer, however the unpredictable inter-individual response to opioid therapy remains a challenge for clinicians. While studies are few, the KCNJ6 gene is a promising target for investigating genetic factors that contribute to pain and analgesia response. This is the first association study on polymorphisms in KCNJ6 and response to methadone for pain management in advanced cancer. Fifty-four adult patients with advanced cancer were recruited across two study sites in a prospective, open label, dose individualisation study. Significant associations have been previously shown for rs2070995 and opioid response in opioid substitution therapy for heroin addiction and studies in chronic pain, with mixed results seen in postoperative pain. In this study, no associations were shown for rs2070995 and methadone dose or pain score, consistent with other studies conducted in patients receiving opioids for pain in advanced cancer. There are many challenges in conducting studies in advanced cancer with significant attrition and small sample sizes, however it is hoped that the results of our study will contribute to the evidence base and allow for continued development of gene-drug dosing guidelines for clinicians.

Syndecan-1 and -4 influence Wnt signaling and cell migration in human breast cancers.

Heparan sulfate proteoglycans (HSPGs) participate in numerous normal and pathophysiological cellular functions. HSPGs are crucial components of the extracellular matrix (ECM) binding signalling molecules such as fibroblast growth factors (FGF) and Wnts to mediate various cellular processes including cell proliferation, migration, and cancer invasion. The syndecans (SDCs1-4) are a major family of four HSPGs, implicated in the development of breast carcinomas. This study examined syndecan-1 (SDC1) and syndecan-4 (SDC4; SDC1/4) in breast cancer (BC) in vitro cell models and their role in tumorigenesis. Gene expression of HSPG core proteins, biosynthesis and modification enzymes along with Wnt/FGF morphogen pathway components were examined following inhibition of SDC1 and SDC4 via small interfering RNA (siRNA), and enhancement of HSPGs via addition of heparin and FGF. siRNAs knockdowns (KDs) were performed in the MCF-7 (lowly invasive and poorly metastatic) and the MDA-MB-231 (highly invasive and metastatic) human BC cell lines. Significantly decreased gene expression of SDC1 and SDC4 was observed in both cell lines following KD. Additionally, via gene expression analysis, downregulation of SDC1/4 decreased the biosynthesis of heparan sulfate modification enzymes and reduced expression of Wnt signalling molecules. Following the enhancement/inhibition of HSPGs via heparin/siRNA treatment, heparin increased the migratory characteristics of MCF-7 cells while KD of SDC1 increased cell migration in both MCF-7 and MDA-MB-231 cells when compared to scramble negative control conditions. Our findings suggest that a niche-specific function exists for SDC1/4 in the BC microenvironment, mediating Wnt signalling cascades and potentially regulating migration of BC cells.

Association of polymorphisms in ARRB2 and clinical response to methadone for pain in advanced cancer.

Background: The prescription of methadone in advanced cancer poses multiple challenges due to the considerable interpatient variation seen in effective dose and toxicity. Previous reports have suggested that ARRB2 influences the response to methadone in opioid substitution therapy. Associations with opioid response for pain management in advanced cancer are conflicting, with no studies including methadone as the primary intervention. Methods: In a prospective, multicenter, open-label dose-individualization study, we investigated whether polymorphisms in ARRB2 were associated with methadone dose requirements and pain severity. Results: Significant associations were found for rs3786047, rs1045280, rs2036657 and pain score. Conclusion: While studies are few and the sample size small, ARRB2 genotyping may assist in individualized management of the most feared symptom in advanced cancer.

Epigenetic Regulation of miR-92a and TET2 and Their Association in Non-Hodgkin Lymphoma.

MicroRNAs (miRNAs) are well known for their ability to regulate the expression of specific target genes through degradation or inhibition of translation of the target mRNA. In various cancers, miRNAs regulate gene expression by altering the epigenetic status of candidate genes that are implicated in various difficult to treat haematological malignancies such as non-Hodgkin lymphoma by acting as either oncogenes or tumour suppressor genes. Cellular and circulating miRNA biomarkers could also be directly utilised as disease markers for diagnosis and monitoring of non-Hodgkin lymphoma (NHL); however, the role of DNA methylation in miRNA expression regulation in NHL requires further scientific inquiry. In this study, we investigated the methylation levels of CpGs in CpG islands spanning the promoter regions of the miR-17-92 cluster host gene and the TET2 gene and correlated them with the expression levels of TET2 mRNA and miR-92a-3p and miR-92a-5p mature miRNAs in NHL cell lines, tumour samples, and the whole blood gDNA of an NHL case control cohort. Increased expression of both miR-92a-3p and miR-92a-5p and aberrant expression of TET2 was observed in NHL cell lines and tumour tissues, as well as disparate levels of dysfunctional promoter CGI methylation. Both miR-92a and TET2 may play a concerted role in NHL malignancy and disease pathogenesis.

Skeletal muscle methylome and transcriptome integration reveals profound sex differences related to muscle function and substrate metabolism.

Nearly all human complex traits and diseases exhibit some degree of sex differences, with epigenetics being one of the main contributing factors. Various tissues display sex differences in DNA methylation; however, this has not yet been explored in skeletal muscle, despite skeletal muscle being among the tissues with the most transcriptomic sex differences. For the first time, we investigated the effect of sex on autosomal DNA methylation in human skeletal muscle across three independent cohorts (Gene SMART, FUSION, and GSE38291) using a meta-analysis approach, totalling 369 human muscle samples (222 males and 147 females), and integrated this with known sex-biased transcriptomics. We found 10,240 differentially methylated regions (DMRs) at FDR < 0.005, 94% of which were hypomethylated in males, and gene set enrichment analysis revealed that differentially methylated genes were involved in muscle contraction and substrate metabolism. We then investigated biological factors underlying DNA methylation sex differences and found that circulating hormones were not associated with differential methylation at sex-biased DNA methylation loci; however, these sex-specific loci were enriched for binding sites of hormone-related transcription factors (with top TFs including androgen (AR), estrogen (ESR1), and glucocorticoid (NR3C1) receptors). Fibre type proportions were associated with differential methylation across the genome, as well as across 16% of sex-biased DNA methylation loci (FDR < 0.005). Integration of DNA methylomic results with transcriptomic data from the GTEx database and the FUSION cohort revealed 326 autosomal genes that display sex differences at both the epigenome and transcriptome levels. Importantly, transcriptional sex-biased genes were overrepresented among epigenetic sex-biased genes (p value = 4.6e-13), suggesting differential DNA methylation and gene expression between male and female muscle are functionally linked. Finally, we validated expression of three genes with large effect sizes (FOXO3A, ALDH1A1, and GGT7) in the Gene SMART cohort with qPCR. GGT7, involved in antioxidant metabolism, displays male-biased expression as well as lower methylation in males across the three cohorts. In conclusion, we uncovered 8420 genes that exhibit DNA methylation differences between males and females in human skeletal muscle that may modulate mechanisms controlling muscle metabolism and health.

Meta-analysis of genome-wide DNA methylation and integrative omics of age in human skeletal muscle.

BACKGROUND: Knowledge of age-related DNA methylation changes in skeletal muscle is limited, yet this tissue is severely affected by ageing in humans. METHODS: We conducted a large-scale epigenome-wide association study meta-analysis of age in human skeletal muscle from 10 studies (total n = 908 muscle methylomes from men and women aged 18-89 years old). We explored the genomic context of age-related DNA methylation changes in chromatin states, CpG islands, and transcription factor binding sites and performed gene set enrichment analysis. We then integrated the DNA methylation data with known transcriptomic and proteomic age-related changes in skeletal muscle. Finally, we updated our recently developed muscle epigenetic clock (https://bioconductor.org/packages/release/bioc/html/MEAT.html). RESULTS: We identified 6710 differentially methylated regions at a stringent false discovery rate <0.005, spanning 6367 unique genes, many of which related to skeletal muscle structure and development. We found a strong increase in DNA methylation at Polycomb target genes and bivalent chromatin domains and a concomitant decrease in DNA methylation at enhancers. Most differentially methylated genes were not altered at the mRNA or protein level, but they were nonetheless strongly enriched for genes showing age-related differential mRNA and protein expression. After adding a substantial number of samples from five datasets (+371), the updated version of the muscle clock (MEAT 2.0, total n = 1053 samples) performed similarly to the original version of the muscle clock (median of 4.4 vs. 4.6 years in age prediction error), suggesting that the original version of the muscle clock was very accurate. CONCLUSIONS: We provide here the most comprehensive picture of DNA methylation ageing in human skeletal muscle and reveal widespread alterations of genes involved in skeletal muscle structure, development, and differentiation. We have made our results available as an open-access, user-friendly, web-based tool called MetaMeth (https://sarah-voisin.shinyapps.io/MetaMeth/).

Genetic Association Analysis Implicates Six MicroRNA-Related SNPs With Increased Risk of Breast Cancer in Australian Caucasian Women.

INTRODUCTION: Breast cancer (BC), a heterogeneous disease, features microRNA-related single nucleotide polymorphisms (miRSNPs) as underlying factors of BC development, thus providing targets for novel diagnostic and therapeutic strategies. This study investigated miRSNPs in BC susceptibility in Australian Caucasian women. PATIENTS AND METHODS: The study population included patients 33 to 80 years of age stratified by molecular subtypes of breast tumors (luminal A, 47.59%), stage (stage I, 36.96%), tumor-type (ductal, 44.95%), grading (intermediate, 35.52%), size (10.1-25 mm, 31.14%), and lymph node (sentinel negative, 38.93%). Sixty-five miRSNPs underwent allelic analysis in two independent case-control cohorts (GU-CCQ-BB, 377 cases and 521 controls; GRC-BC, 267 cases and 201 controls) using a MassARRAY platform. GU-CCQ-BB, GRC-BC, and the combined populations (BC-CA) (644 cases and 722 controls) underwent independent statistical analysis. RESULTS: In the GU-CCQ-BB population, miRSNPs TET2-rs7670522, ESR1-rs2046210, FGFR2-rs1219648, MIR210-rs1062099, HIF1A-rs2057482, and CASC16-rs4784227 were found to be associated with increased BC risk (P ≤ .05). Only ESR1-rs2046210 was also significantly associated (P ≤ .05) when replicated in the GRC-BC and BC-CA populations. No significant association was correlated with BC-clinical features (pathological types and ER/PR/HER2 status); however, MIR210-rs1062099 was found to be significantly associated (P ≤ .05) with age (>50 years) in the GU-CCQ-BB cohort. CONCLUSION: This is the first study to demonstrate the association of MIR210-rs1062099 and TET2-rs7670522 with increased BC risk. Additionally, four previously reported SNPs (ESR1-rs2046210, FGFR2-rs1219648, HIF1A-rs2057482, and CASC16-rs4784227) were confirmed as BC risk variants. Replication and functional studies in larger Caucasian cohorts are necessary to elucidate the role of these miRSNPS in the development of BC.

Mini review: genome and transcriptome editing using CRISPR-cas systems for haematological malignancy gene therapy.

The recent introduction of clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR associated protein (Cas) systems, offer an array of genome and transcriptome editing tools for clinical repair strategies. These include Cas9, Cas12a, dCas9 and more recently Cas13 effectors. RNA targeting CRISPR-Cas13 complexes show unique characteristics with the capability to engineer transcriptomes and modify gene expression, providing a potential clinical cancer therapy tool across various tissue types. Cas13 effectors such as RNA base editing for A to I replacement allows for precise transcript modification. Further applications of Cas13a highlights its capability of producing rapid diagnostic results in a mobile platform. This review will focus on the adaptions of existing CRISPR-Cas systems, along with new Cas effectors for transcriptome or RNA modifications used in disease modelling and gene therapy for haematological malignancy. We also address the current diagnostic and therapeutic potential of CRISPR-Cas systems for personalised haematological malignancy.

Regulatory Mechanisms of Epigenetic miRNA Relationships in Human Cancer and Potential as Therapeutic Targets.

Initiation and progression of cancer are under both genetic and epigenetic regulation. Epigenetic modifications including alterations in DNA methylation, RNA and histone modifications can lead to microRNA (miRNA) gene dysregulation and malignant cellular transformation and are hereditary and reversible. miRNAs are small non-coding RNAs which regulate the expression of specific target genes through degradation or inhibition of translation of the target mRNA. miRNAs can target epigenetic modifier enzymes involved in epigenetic modulation, establishing a trilateral regulatory "epi-miR-epi" feedback circuit. The intricate association between miRNAs and the epigenetic architecture is an important feature through which to monitor gene expression profiles in cancer. This review summarises the involvement of epigenetically regulated miRNAs and miRNA-mediated epigenetic modulations in various cancers. In addition, the application of bioinformatics tools to study these networks and the use of therapeutic miRNAs for the treatment of cancer are also reviewed. A comprehensive interpretation of these mechanisms and the interwoven bond between miRNAs and epigenetics is crucial for understanding how the human epigenome is maintained, how aberrant miRNA expression can contribute to tumorigenesis and how knowledge of these factors can be translated into diagnostic and therapeutic tool development.

Syndecan-1 Facilitates the Human Mesenchymal Stem Cell Osteo-Adipogenic Balance.

Bone marrow-derived human mesenchymal stems cells (hMSCs) are precursors to adipocyte and osteoblast lineage cells. Dysregulation of the osteo-adipogenic balance has been implicated in pathological conditions involving bone loss. Heparan sulfate proteoglycans (HSPGs) such as cell membrane-bound syndecans (SDCs) and glypicans (GPCs) mediate hMSC lineage differentiation and with syndecan-1 (SDC-1) reported in both adipogenesis and osteogenesis, these macromolecules are potential regulators of the osteo-adipogenic balance. Here, we disrupted the HSPG profile in primary hMSC cultures via temporal knockdown (KD) of SDC-1 using RNA interference (RNAi) in undifferentiated, osteogenic and adipogenic differentiated hMSCs. SDC-1 KD cultures were examined for osteogenic and adipogenic lineage markers along with changes in HSPG profile and common signalling pathways implicated in hMSC lineage fate. Undifferentiated hMSC SDC-1 KD cultures exhibited a pro-adipogenic phenotype with subsequent osteogenic differentiation demonstrating enhanced maturation of osteoblasts. In cultures where SDC-1 KD was performed following initiation of differentiation, increased adipogenic gene and protein marker expression along with increased Oil Red O staining identified enhanced adipogenesis, with impaired osteogenesis also observed in these cultures. These findings implicate SDC-1 as a facilitator of the hMSC osteo-adipogenic balance during early induction of lineage differentiation.

An investigation of genetic polymorphisms in heparan sulfate proteoglycan core proteins and key modification enzymes in an Australian Caucasian multiple sclerosis population.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease affecting the central nervous system in young adults. Heparan sulfate proteoglycans (HSPGs) are ubiquitous to the cell surface and the extracellular matrix. HSPG biosynthesis is a complex process involving enzymatic attachment of heparan sulfate (HS) chains to a core protein. HS side chains mediate specific ligand and growth factor interactions directing cellular processes including cell adhesion, migration and differentiation. Two main families of HSPGs exist, the syndecans (SDC1-4) and glypicans (GPC1-6). The SDCs are transmembrane proteins, while the GPC family are GPI linked to the cell surface. SDC1 has well-documented interactions with numerous signalling pathways. Genome-wide association studies (GWAS) have identified regions of the genome associated with MS including a region on chromosome 13 containing GPC5 and GPC6. International studies have revealed significant associations between this region and disease development. The exostosin-1 (EXT1) and sulfatase-1 (SULF1) are key enzymes contributing to the generation of HS chains. EXT1, with documented tumour suppressor properties, is involved in the initiation and polymerisation of the growing HS chain. SULF1 removes 6-O-sulfate groups from HS chains, affecting protein-ligand interactions and subsequent downstream signalling with HS modification potentially having significant effects on MS progression. In this study, we identified significant associations between single nucleotide polymorphisms in SDC1, GPC5 and GPC6 and MS in an Australian Caucasian case-control population. Further significant associations in these genes were identified when the population was stratified by sex and disease subtype. No association was found for EXT1 or SULF1.