Biology subjects

Roberts, J. L.

Publications and source records attributed to Roberts, J. L..

4 recordsLinked to original sources

bioRxiv2025

Wnt5a gain- and loss-of-function present distinctly in craniofacial bone

IntroductionRobinow syndrome has characteristic craniofacial and dental features and can be caused by gain- or loss-of-function variants in Wnt family member 5A (WNT5A) non-canonical signaling. The craniofacial and dental manifestation of Robinow syndrome is heterogenous, as is the effect of altered Wnt5a in animal models. The relationship between Wnt5a and craniofacial and dental phenotypes is not fully understood. MethodsTo investigate the role of Wnt5a in craniofacial and dental development, we utilized a Wnt5a conditional loss-of-function (LOF: Wnt5afl/fl;Ctskcre) and a Wnt5a conditional gain-of-function (GOF: Rosa26-LSL-Wnt5a;Ctskcre) model to determine the effect of both LOF and GOF of Wnt5a in bone cells during craniofacial and dental development. Postnatal day 10 conditional LOF Wnt5a, GOF Wnt5a, and control skulls were scanned by micro-computed tomography and assessed using traditional and geometric morphometrics. Mandibular bone apoptosis was further assessed by TUNEL staining. ResultsConditional Wnt5a LOF resulted in midface hypoplasia, increased maxillary intermolar width, increased rostral basisphenoid width, and delayed molar eruption. Wnt5a LOF mandibles did not have altered bone mineral density or bone microarchitecture unlike our previous study examining Wnt5a LOF femurs. In contrast, conditional Wnt5a GOF results in macrocephaly, shortened hard palate, increased zygomatic length, micrognathia, and mandibular process morphology changes. The micrognathia and mandibular process morphology changes in the Wnt5a GOF mice were not due to increased apoptosis. A partially penetrant snout deviation was present in both the Wnt5a LOF and GOF mice. ConclusionsCraniofacial and dental phenotype differed between mice with conditional GOF and LOF of Wnt5a, consistent with the craniofacial phenotype heterogeneity in Wnt5a-associated Robinow syndrome. We detected tooth eruption delay, mandibular condyle dysmorphology, and facial asymmetry in mice with altered Wnt5a that have not been previously reported in patients. Our data suggest precise regulation of Wnt5a is essential for proper craniofacial and dental development. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=82 SRC="FIGDIR/small/665966v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@971284org.highwire.dtl.DTLVardef@40d5f6org.highwire.dtl.DTLVardef@9f0caforg.highwire.dtl.DTLVardef@1f9ba9b_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

bioRxiv2025

Dried Blood Spot Lipidomics in Diabetes

Comprehensive lipidomic profiling in diabetes has identified disease-associated lipid signatures that may support more personalised monitoring beyond routine glycaemic control. Dried blood spot (DBS) microsampling offers a minimally invasive method for collecting and storing small blood volumes (<50 {micro}L), enabling decentralised and longitudinal sampling. However, its application in lipidomics for cardiometabolic phenotyping remains underexplored. In this study, 34 participants (17 diabetics, 17 non-diabetic controls) self-collected DBS samples using advanced microsampling devices (10 {micro}L, Capitainer(R)B). Lipid extracts were analysed using a validated liquid chromatography-trapped ion mobility-time-of-flight mass spectrometry method optimised for semi-quantitative DBS lipidomics. Multivariate analysis revealed significant differences in lipidomic profiles (n = 432 lipids) between diabetic and non-diabetic individuals (R{superscript 2}Y = 0.82, Q{superscript 2}Y = 0.50, p = 0.05). Key discriminatory lipids (all VIP > 1.44), including HexCer(18:1;O2/24:0), HexCer(18:1;O2/22:0), LPC(16:0), PC(O-34:3), TG(18:0_18:1_20:3), and TG(18:1_18:1_22:6), were consistent with matched venous and capillary plasma samples. Lipid class and structural differences, including elevated long-chain triacylglycerols and reduced lysophosphatidylcholines reflected known dyslipidaemia in diabetes and demonstrate the capacity of DBS to capture biologically meaningful lipid perturbations. Participant-reported outcomes from Problem Areas In Diabetes (PAID-20), Patient Activation Measure (PAM-13), and microsampling perception questionnaires highlighted psychosocial and behavioural insights, and indicated strong support for DBS sampling over venepuncture, citing ease of use and reduced burden. These findings establish DBS lipidomics as a feasible and informative approach for stratifying cardiometabolic disease, supporting broader implementation in remote, personalised monitoring frameworks (Figure 1). O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=77 SRC="FIGDIR/small/656742v1_fig1.gif" ALT="Figure 1"> View larger version (13K): org.highwire.dtl.DTLVardef@c53b4org.highwire.dtl.DTLVardef@14b507forg.highwire.dtl.DTLVardef@191e563org.highwire.dtl.DTLVardef@16af172_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 1.C_FLOATNO Graphical abstract - Chapter 5. C_FIG

biochemistry↗

bioRxiv2024

Targeting of SUMOylation leads to cBAF complex stabilization and disruption of the SS18::SSX transcriptome in Synovial Sarcoma

Synovial Sarcoma (SS) is driven by the SS18::SSX fusion oncoprotein. and is ultimately refractory to therapeutic approaches. SS18::SSX alters ATP-dependent chromatin remodeling BAF (mammalian SWI/SNF) complexes, leading to the degradation of canonical (cBAF) complex and amplified presence of an SS18::SSX-containing non-canonical BAF (ncBAF or GBAF) that drives an SS-specific transcription program and tumorigenesis. We demonstrate that SS18::SSX activates the SUMOylation program and SSs are sensitive to the small molecule SAE1/2 inhibitor, TAK-981. Mechanistically, TAK-981 de-SUMOylates the cBAF subunit SMARCE1, stabilizing and restoring cBAF on chromatin, shifting away from SS18::SSX-ncBAF-driven transcription, associated with DNA damage and cell death and resulting in tumor inhibition across both human and mouse SS tumor models. TAK-981 synergized with cytotoxic chemotherapy through increased DNA damage, leading to tumor regression. Targeting the SUMOylation pathway in SS restores cBAF complexes and blocks the SS18::SSX-ncBAF transcriptome, identifying a therapeutic vulnerability in SS, positioning the in-clinic TAK-981 to treat SS.

cancer biology↗

bioRxiv2019

Scavenging dicarbonyls with 5'-O-pentyl-pyridoxamine improves insulin sensitivity and reduces atherosclerosis through modulating inflammatory Ly6Chi monocytosis and macrophage polarization

ObjectiveOxidative stress contributes to the development of insulin resistance (IR) and atherosclerosis. Peroxidation of lipids produces reactive dicarbonyls such as Isolevuglandins (IsoLG) and malondialdehyde (MDA) that covalently bind plasma/cellular proteins, phospholipids, and DNA leading to altered function and toxicity. We examined whether scavenging reactive dicarbonyls with 5-O-pentyl-pyridoxamine (PPM) protects against the development of IR and atherosclerosis in Ldlr-/- mice. MethodsMale or female Ldlr-/- mice were fed a western diet (WD) for 16 weeks and treated with PPM versus vehicle alone. Plaque extent, dicarbonyl-lysyl adducts, efferocytosis, apoptosis, macrophage inflammation, and necrotic area were measured. Plasma MDA-LDL adducts and the in vivo and in vitro effects of PPM on the ability of HDL to reduce macrophage cholesterol were measured. Blood Ly6Chi monocytes and ex vivo 5-ethynyl-2-deoxyuridine (EdU) incorporation into bone marrow CD11b+ monocytes and CD34+ hematopoietic stem and progenitor cells (HSPC) were also examined. IR was examined by measuring fasting glucose/insulin levels and tolerance to insulin/glucose challenge. ResultsPPM reduced the proximal aortic atherosclerosis by 48% and by 46% in female and male Ldlr-/- mice, respectively. PPM also decreased IR and hepatic fat and inflammation in male Ldlr-/- mice. Importantly, PPM decreased plasma MDA-LDL adducts and prevented the accumulation of plaque MDA- and IsoLG-lysyl adducts in Ldlr-/- mice. In addition, PPM increased the net cholesterol efflux capacity of HDL from Ldlr-/- mice and prevented both the in vitro impairment of HDL net cholesterol efflux capacity and apoAI crosslinking by MPO generated hypochlorous acid. Moreover, PPM decreased features of plaque instability including decreased proinflammatory M1-like macrophages, IL-1{beta} expression, myeloperoxidase, apoptosis, and necrotic core. In contrast, PPM increased M2-like macrophages, Tregs, fibrous cap thickness, and efferocytosis. Furthermore, PPM reduced inflammatory monocytosis as evidenced by decreased blood Ly6Chi monocytes and proliferation of bone marrow monocytes and HSPC from Ldlr-/- mice. ConclusionsPPM has pleotropic atheroprotective effects in a murine model of familial hypercholesterolemia, supporting the therapeutic potential of reactive dicarbonyl scavenging in the treatment of IR and atherosclerotic cardiovascular disease.

pharmacology and toxicology↗