Cells
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Preprints posted in the last 30 days, ranked by how well they match Cells's content profile, based on 232 papers previously published here. The average preprint has a 0.18% match score for this journal, so anything above that is already an above-average fit.
Gomez, A.; Logsdon, A. F.; Bailoo, J. D.; Cornwall, G. A.
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Cystatin-related epididymal spermatogenic (CRES) is a member of a reproductive subgroup of family 2 cystatins and part of a functional amyloid-containing extracellular matrix (ECM) with host defense functions in the epididymal lumen. CRES and the endogenous epididymal amyloid matrix exhibit high plasticity, forming distinct amyloid structures, with antimicrobial functions tailored to specific bacterial strains. We recently demonstrated that CRES/CRES amyloid is also present in the mammalian brain ECM. In this study, we utilized a CRES knockout (KO) mouse model to determine if the loss of CRES altered the structure of the hippocampal and cortical ECM and impacted brain function. We report that CRES KO male and female mice exhibited sex-specific structural changes in both the loose/interstitial and perineuronal net (PNN) ECM. Additionally, young CRES KO males--but not females--displayed deficits in learning, memory and executive functioning when compared to WT controls. In contrast, older CRES KO males did not exhibit behavioral deficits, a finding that correlated with the observation of a similar PNN ECM structure when compared to WT mice. Our data suggest that CRES functions as a regulatory or structural component of the brain ECM, contributing to its sex-specific structural organization and plasticity, affecting sex-specific behaviors of learning and memory.
Varma, P.; Saintilus, M.; Nessim, M.; Todd, J. J.; Mohassel, P.; Lawal, T. A.
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Pathogenic RYR1 variants are associated with a set of rare neuromuscular disorders termed RYR1-related disorders (RYR1-RD). Clinical manifestations of RYR1-RD include proximal/axial muscle weakness, delayed motor milestones, impaired mobility, muscle pain, and fatigue. Muscle-specific microRNAs (miRNAs) are mostly expressed in muscle tissue and can be detected peripherally in plasma. Using a digital detection system, here we identified and quantified differential amounts of miRNAs in six adult (four monoallelic and two biallelic) RYR1-RD patient plasma samples compared to controls. Overall, 51 differentially expressed miRNAs were identified and hsa-miR-4454+hsa-miR-7975, in particular, was significantly overexpressed relative to controls (+ 39-fold, P=0.00285). Exploration of these differentially expressed miRNAs warrant further investigation as potential biomarkers of RYR1-RD.
Lara Ordonez, A. J.; Annicotte, C.; Behrends, E.; Morez, M.; Burin, A.; Goveas, L.; Van Mele, F.; Galicia, C.; Versees, W.; Taymans, J.-M.
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Leucine-Rich Repeat Kinase 2 (LRRK2) is a signaling molecule involved in Parkinsons disease pathomechanisms. In disease, the LRRK2 protein displays both a toxic gain of kinase function and a loss of phosphorylation at heterophosphosites found in an extended loop of the LRR domain. RAB GTPases, such as RAB29, have been identified as upstream activators of LRRK2. Indeed, co-expression of LRRK2 with RAB29 induces a hyperactivation of LRRK2 kinase activity, however the role of the LRRK2 heterologous phosphorylation status in its activation remains unknown. Here, our aim was to determine the role of LRRK2 heterologous phosphorylation on its activation by RAB29. Using single and compound phosphodead or phosphomimetic mutants of LRRK2 we show differential sensitivity of LRRK2 phosphomutants to activation by RAB29, with phosphodead mutants being more susceptible to be activated than phosphomimetic mutants. Interestingly, we find that the single phosphodead S910A LRRK2 mutant displays an activation of LRRK2 kinase activity similar to that observed for the compound phosphodead 6xS>A LRRK2 mutant (S860A/S910A/S935A/S955A/S973A/S976A). Time-course analysis revealed that phosphodead mutants displayed higher but also faster activation by RAB29. In addition, both physical interaction between LRRK2 and RAB29 as well as RAB29-induced recruitment of LRRK2 to the trans-Golgi network (TGN) was enhanced by phosphodead compared to phosphomimetic mutants. To confirm effects on native LRRK2, we tested a panel of ten nanobodies targeting LRRK2 that stabilized LRRK2 phosphorylation at varying levels. Nanobodies stabilizing LRRK2 at low S935 phosphorylation levels showed enhanced RAB29-induced activation compared to nanobodies not affecting pS935 LRRK2. Finally, we tested whether LRRK2 heterologous phosphorylation could affect centrosome cohesion deficits, a phenotype that has been linked to LRRK2 hyperactivation, and found that both the phosphodead LRRK2 as well as a nanobody stabilizing dephosphorylated LRRK2 enhanced the centrosome cohesion deficit. Our findings indicate that hyperactivability of LRRK2 is directly related to its heterologous phosphorylation status, with dephosphorylation leading to strong hyperactivation of LRRK2 by upstream activating RABs, and phosphorylated LRRK2 showing the opposite. This implies that strategies favoring LRRK2 phosphorylation will have therapeutic benefit.
Goeke, M.; Serrano, N.; Koopmans, P. J.; Murach, K. A.
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A hallmark of damaged skeletal muscle fibers is displaced myonuclei that are no longer peripherally positioned. Displaced myonuclei are dogmatically thought to be derived exclusively from muscle stem cell (satellite cell) fusion. Using a surgical resection muscle injury model and in vivo recombination-independent resident myonuclear labeling, we detail the prevalence, time course, and origin of displaced myonuclei in response to a non-chemically-mediated muscle trauma. We found that: 1) non-satellite cell-derived (resident) displaced myonuclei emerge seven days after surgical injury in similar proportion to exogenous (satellite cell-derived) displaced myonuclei in intact muscle fibers, with a biased prevalence in myosin heavy chain IIB muscle fibers, 2) muscle fibers with multiple ([≥]2) displaced resident myonuclei was an unexpected but noteworthy feature of muscle fibers 7 days after injury, 3) embryonic myosin-expressing fibers at seven days post-surgery expectedly contain predominantly satellite-cell derived displaced myonuclei, but a subset have displaced resident myonuclei, and 4) satellite cell numbers in intact muscle do not increase until 7 days post-surgery. These data may help inform whether to target satellite cell-initiated processes, myonuclear-initiated processes, or both to facilitate muscle fiber injury repair. This information could lead to more effective therapeutic strategies for treating muscle trauma.
Sian, V.; Roos, A.; Hentschel, A.; Sarparanta, J.; Jonson, P. H.; Valente, S.; Mai, A.; Altucci, L.; Udd, B.; Nebbioso, A.; Savarese, M.
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Epigenetic regulation, particularly histone acetylation, plays a critical role in skeletal muscle differentiation by modulating gene expression programs without altering DNA sequence. Histone deacetylases (HDACs) tightly regulate myogenesis by controlling the timing of differentiation. Pharmacological inhibition of HDACs has shown context-dependent effects on muscle cells. We investigated the effects of 1 {micro}M SAHA (suberoylanilide hydroxamic acid) on C2C12 and L6 myoblasts during differentiation using morphological, immunofluorescence, transcriptomic, and proteomic analyses. SAHA delayed early differentiation, reducing myotube formation with partial recovery at later stages. Transcriptomic analysis revealed time-dependent changes in pathways related to cytoskeleton, cell cycle, and chromatin regulation. Proteomics showed increased mitochondrial metabolism and reduced cytoskeletal components in C2C12 cells, while L6 cells displayed alterations in muscle structural and extracellular matrix proteins. SAHA induces stage- and model-dependent reprogramming of myogenesis, highlighting the importance of timing and cellular context in HDAC-targeted therapies.
Palinkas, J.; Jezso, B.; Nagy-Kanta, E.; Nemeth, R.; Aman, U. A.; Takacs, G.; Szikriszt, B.; Hosszu, A. T.; Ecsedi, P.; Szakacs, G.; Szuts, D.; Fekete, A.; Kovacs, M.
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Mammalian single-stranded DNA binding protein 1 (SSB1) has been established as an essential component of genome stability in both human cells and mice. Moreover, SSB1 was recently implicated in cytoplasmic stress response by its involvement in Ras GTPase-activating protein-binding protein 1 (G3BP1)-containing cytoplasmic stress granules (SGs) upon various forms of stress. Here, we generated and analyzed human cellular knockout and rodent ischemia-reperfusion (I/R) models to define SSB1s roles in cytoplasmic stress response. Analysis of wild-type as well as SSB1 and G3BP1 knockout human retinal pigment epithelial (RPE-1) cells shows stress-specific incorporation of SSB1 into SGs and a negative regulator role for SSB1 in SG dynamics under sublethal stress conditions. We find that SSB1 knockout measurably increases cellular sensitivity to oxidative stress but does not alter cell proliferation following mild acute stress. Moreover, we detect SSB1 efflux from the nucleus upon stress that is dependent upon the presence of G3BP1 in a stress-specific manner. In addition, using mouse and rat models we observe significant upregulation and robust cytoplasmic granulation of SSB1 upon renal ischemia-reperfusion stress, establishing SSB1s involvement in complex organismal stress response in vivo. Together, our data demonstrate active involvement of SSB1 in cytoplasmic response to cellular stress and acute kidney injury, with implications for targeting stress response functions in cancerous versus non-cancerous contexts. HIGHLIGHTSO_LISSB1 is incorporated into cytoplasmic stress granules and negatively regulates stress granule assembly under sublethal stress conditions C_LIO_LISSB1 shows stress- and G3BP1-dependent nuclear efflux C_LIO_LISSB1 is upregulated and undergoes apical granulation in renal epithelial cells during renal ischemia-reperfusion injury C_LI
Fedele, L.; Maurer, M.; Tinker, A.; Andersson, D. A.
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Postganglionic sympathetic neurons not only regulate target organs but also their own intrinsic activity and can be further modulated by parasympathetic neurons. This crosstalk and automodulatory signalling have been implicated in cardiovascular disorders, with the majority of earlier work employing rodent models. Here, we have used human sympathetic neurons derived from induced pluripotent stem cells (hiPSCs), as a scalable human in vitro system with the aim to investigate these pathways. Efficient differentiation of hiPSCs into sympathetic neurons was confirmed using molecular characterisation for the expression of PHOX2B, DBH, TH, PRPH. We employed Ca2+ imaging and whole-cell patch-clamp electrophysiology, to examine the neuronal functional properties and found that hiPSC-derived sympathetic neurons recapitulate key physiological features of the rodent native counterparts. Most cells responded to nicotine and expressed functional 2 adrenergic and muscarinic receptors, involved in sympathetic autoregulation and parasympathetic crosstalk. We further demonstrated that 2 adrenergic and muscarinic receptors inhibit membrane excitability (increased rheobase, hyperpolarisation, reduced input resistance) and that both types of receptors converge on inwardly rectifying K+ channels (GIRK) as effectors. The GIRK blocker Tertiapin-Q significantly reduced the 2 adrenergic and muscarinic responses, while the activator ML297 mimicked their action. Analysis of mouse stellate scRNA-seq confirmed that the receptors and GIRK subtypes studied here are prominently expressed in native sympathetic neurons. Overall, our data show that GIRK channels play an important role in the regulation of sympathetic neurons excitability and that hiPSC-derived neurons provide an attractive in vitro tool for drug discovery to study sympathetic autoregulation and parasympathetic-sympathetic crosstalk. KEY POINTSO_LIhiPSC-sympathetic neurons recapitulate key cellular pathways of native counterparts C_LIO_LIThey express relevant receptors and ion channels involved in the inhibitory autoregulatory feedback and parasympathetic-sympathetic crosstalk C_LIO_LIUsing a combination of RT-qPCR and functional recordings we identified inwardly rectifying K+ channels as downstream effectors of both 2 adrenergic and M2 muscarinic receptors. We cross-validated our findings with a mouse transcriptomic dataset from thoracic sympathetic ganglia. C_LIO_LIOverall, our data suggest that hiPSC-sympathetic neurons can be employed as a human in vitro platform to study cellular pathways and for drug discovery purposes. C_LI O_FIG O_LINKSMALLFIG WIDTH=119 HEIGHT=200 SRC="FIGDIR/small/727423v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@14e37ddorg.highwire.dtl.DTLVardef@35c534org.highwire.dtl.DTLVardef@260837org.highwire.dtl.DTLVardef@e57af6_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphic abstract.C_FLOATNO Summary of proposed modulation of sympathetic neuron activity via 2ARs and muscarinic receptors via GIRK channels Functional recordings showed that muscarinic receptors and 2 adrenergic receptors reduce neuronal excitability, this effect was mimicked by activation of inwardly rectifying K+ channels (GIRK). Blockade of GIRK abolished the effects of both types of receptors, demonstrating that they converge on GIRK as a common effector. The muscarinic response was blocked by pertussis toxin, indicating an involvement of Gi/o downstream of the receptor, consistent with the high expression of CHRM2 by RT-qPCR. C_FIG
Welle, van der, R. E. N.; Jark, R.; Jans, J. J. M.; Verhoeven-Duif, N. M.; Klumperman, J.
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The tight regulation of iron homeostasis is of great importance for cellular health. An increase in intracellular iron levels results in the formation of free radicals, which damages macromolecules and membranes, eventually resulting in cell death by Ferroptosis. Recently, we showed that patients with mutations in VPS41 display a severe neurodegenerative phenotype with iron deposition in the brain. VPS41 is well known as subunit of the HOPS complex required for fusion of late endosomes and autophagosomes with lysosomes. However, VPS41 has also been identified as inhibitor of Ferroptosis and regulator of redox homeostasis. How VPS41 exerts these functions and if these are dependent on the HOPS complex is unknown. Here we show that depletion of VPS41 results in increased intracellular iron levels, ROS formation and mitochondrial fission. Our findings indicate an important role for VPS41 in the regulation of iron homeostasis and mitochondrial fission and suggest Ferroptosis as a possible cause for neurodegeneration in VPS41 patients.
Galli, C.; Colleluori, G.; Perugini, J.; Scopini, E.; Severi, I.; Grandin, G.; Giordano, A.
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Administration of ciliary neurotrophic factor (CNTF) reduces food intake and body weight in both humans and experimental animals, where it also ameliorates hyperglycemia, hyperinsulinemia, and dyslipidemia. To exert its anti-obesogenic and anti-diabetogenic effects, CNTF targets brain feeding centers as well as multiple peripheral organs inducing the phosphorylation of the transcription factor signal transducer and activator of transcription 3 (p-STAT3). However, data showing which peripheral cytotypes are specifically targeted by exogenous CNTF in vivo in metabolically relevant organs are currently lacking. Here, we first evaluated the gene expression levels of the subunits of the tripartite CNTF receptor (Cntfr) complex, i.e., the Cntfr, the leukemia inhibitory factor receptor {beta} (Lifr{beta}) and the glycoprotein 130 (gp130), by quantitative real-time PCR in metabolically relevant organs of adult male mice: gastrointestinal (GI) tract, pancreas, liver, visceral and subcutaneous white (WAT) and interscapular brown adipose tissue (iBAT), skeletal muscle and the sciatic nerve. We then quantified p-STAT3 by Western blotting in these organs after intraperitoneal administration of CNTF (0.3 mg/kg) or saline. Finally, we mapped CNTF-responsive cells by immunohistochemistry, followed by morphometric quantification and confocal microscopy in both CNTF- and saline-treated mice. Lifr{beta} and gp130 were ubiquitously detected across all the investigated organs; the Cntfr showed the highest expression levels in the skeletal muscle, sciatic nerve, and iBAT, whereas it was found to be expressed to a lesser extent in the other sites. Administration of CNTF led to a significant increase of p-STAT3/STAT3 protein ratio in all organs examined, except the duodenum, and induced a distinctive pattern of cell nuclear p-STAT3 immunoreactivity. Notably, along the analyzed GI tract CNTF induced nuclear STAT3 phosphorylation in neurons of the submucosal and myenteric plexuses of the enteric nervous system and in contractile cells of the muscularis externa, where the response peaked in the mesenteric gut and colon. In the pancreas, CNTF triggered a higher activation within the endocrine component compared to the exocrine parenchyma. In the liver, CNTF induced STAT3 phosphorylation not only in parenchymal cells but also in sinusoids and resident macrophages. The cytokine activated p-STAT3 in subcutaneous and visceral white adipocytes, but also in brown adipocytes, with a prominent response observed in the beige subcutaneous adipocytes; adipose resident macrophages and endothelial cells of numerous blood vessels were also CNTF-responsive. Lastly, in skeletal muscle, a major site for glucose/lipid utilization, CNTF induced widespread nuclear p-STAT3 immunoreactivity in muscle fibers and in connective and Schwann cells of the peripheral nerves, including the sciatic nerve, supplying the gastrocnemius. In conclusion, our data indicate that CNTF acts across diverse cytotypes within metabolically relevant organs and tissues, likely fostering its peripheral metabolic effects through this cellular heterogeneity.
Espericueta, N. V.; Neel, M. J.; Wang, Y.; Soo, T. J.; Porahang, P.; Goyokpin, F. A.; Salehi, R. S.; Khan, S.; Lee, J.; Maramica, N. B.; Flores, G.; Kulkarni, A.; Plaha, S. S.; Ghahremani, S.; Huang, W.; Smith, Q.; Chang, P.; Johnson, B. A.; Monuki, E. S.
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Cells that store lipids for other cells or organs can contain "giant" or large lipid droplets (LLDs) greater than 2 {micro}m in diameter. In this study, human postmortem choroid plexus was evaluated for lipid droplets. Staining with hematoxylin and eosin (H&E), the lipophilic dye Oil red O, and anti-adipophilin antibodies established the presence of LLDs exceeding 10 {micro}m in diameter in choroid plexus epithelial cells (CPECs). Manual annotation of H&E stains from 105 cases revealed a significant association between age and the percentage of CPECs containing LLDs (reaching up to 69%) and involving LLDs in our largest annotated category (>5 {micro}m in diameter). The LLD association with age was replicated and extended to a total of 245 cases using a trained convolutional neural network, which further showed significant associations with body mass index at time of death (increasing with BMI), sex (higher in females >65 years old), and a near-significant association with Alzheimers Disease (lower in AD). Like HepG2 and derived hepatocytes, excess fatty acids in culture media readily induced LLDs and steatosis in human embryonic stem cell-derived CPECs. Akin to hepatocytes for the human body, we propose that CPECs store lipids for the human brain and become steatotic in the setting of excess adiposity.
Nathan Kochen, N.; Zafari, S.; Renaud, A.; Schneider, N.; Vunam, N.; Liao, E. E.; Dutton, J. R.; Braun, A. R.; Sachs, J. N.
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Recently, we showed that ketoconazole, a known anti-fungal inhibitor of CYP51, stabilized TAR DNA-binding protein 43 (TDP-43) native self-interactions, reduced TDP-43 pathology and rescued TDP-43-induced SREBP2 downregulation. Despite its promising effects, ketoconazole is not viable for repurposing for ALS due to liver toxicity side effects that occur when orally delivered. To address this, we tested the activities of seven additional known azole-based CYP51 inhibitors in order identify a viable alternative to ketoconazole. Using our established TDP-43 mislocalization and aggregation assay in HEK293T cells, we identified posaconazole, an FDA-approved, CNS-penetrant and orally delivered anti-fungal, as the strongest inhibitor of TDP-43 pathology. Posaconazole was able to reduce insoluble TDP-43 and restore SREBP2 levels, outperforming ketoconazole. Mechanism of action (MOA) experiments suggest posaconazole is able to outperform ketoconazole by inducing a significantly stronger activation of autophagy and upregulation of heat shock proteins known to clear TDP-43. Further MOA experiments show that the effects of posaconazole on TDP-43 are dependent on its known ability to lower cellular cholesterol levels. By correlating our experimental results on the eight CYP51 inhibitors tested, we show that predicted affinity towards human CYP51 strongly correlates with the inhibitors ability to lower TDP-43 aggregation and mislocalization. Finally, we tested posaconazole in a low dose sodium arsenite ALS model in iPSC-derived motor neurons, showing that it is efficacious at inhibiting TDP-43 pathology in the nanomolar range. Altogether, these results support the repurposing of posaconazole for ALS/FTD as a means to prevent TDP-43 pathology.
Dlaskova, A.; Bazila, B.; Krepelka, P.; Victor, R. C.; Jhala, D. J.; Jezek, P.
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The endoplasmic reticulum (ER) and mitochondria maintain a dynamic structural partnership essential for pancreatic {beta}-cell homeostasis, yet the high-resolution 3D remodeling of these networks under stress conditions remains poorly defined. We employed Focused Ion Beam Scanning Electron Microscopy (FIB-SEM) to perform 3D reconstructions of INS1E cells subjected to mitochondrial respiratory chain inhibition, uncoupling, and exogenous oxidative stress. Quantitative analysis revealed that mitochondrial dysfunction induces profound ultrastructural transitions, characterized by significant luminal swelling of the ER, expansion of the perinuclear space, and mitochondrial diameter enlargement. 3D volume imaging identified a coordinated fragmentation of both ER and mitochondrial networks into discrete, spatially separated structures--a phenomenon distinct from the reticular morphology observed in control cells. The similarity between respiratory inhibition- and H2O2-induced phenotypes, together with preservation of ER structure following mitochondrial uncoupling, suggests a potential contribution of reactive oxygen species to the observed remodeling process. Despite this extensive organelle breakdown, interorganelle membrane contact sites were not only preserved but expanded under stress conditions. We further provide a quantitative description of nuclear envelope-mitochondria contact sites (NAMs), demonstrating their selective remodeling during mitochondrial dysfunction. Our findings provide a high-resolution structural framework for organelle remodeling in {beta}-cells, demonstrating that membrane contact sites are actively preserved and reorganized despite profound organelle fragmentation. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=110 SRC="FIGDIR/small/727587v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@4f63b5org.highwire.dtl.DTLVardef@1b3dc8org.highwire.dtl.DTLVardef@7527fcorg.highwire.dtl.DTLVardef@1944f2c_HPS_FORMAT_FIGEXP M_FIG C_FIG
Vann, C. G.; Bareja, A.; Hubal, M. J.; Naz, S. I.; Ma, S.; Orenduff, M. C.; Ross, L. M.; Bennett, W. C.; Huffman, K. M.; Aliferis, C. F.; Kraus, W.; Kraus, V. B.
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We investigated effects of three aerobic exercise interventions, varying in amount and intensity with durations of 8-9-months on small RNA (smRNA) expression and regulatory pathways in skeletal muscle and plasma from 120 participants. Using untargeted smRNA sequencing focused on miRNAs and piRNAs, adjusting for demographics and bodyweight, we identified 124 muscle smRNAs altered by exercise amount and 15 by intensity, and 47 plasma smRNAs altered by intensity and one by amount. These smRNAs were enriched in metabolic, transcriptional, translational, and cell cycle pathways. Exercise-induced changes in several smRNAs-six from muscle and five from plasma-and exercise-induced reduction in body weight, aligned with improvement in insulin sensitivity (p<0.05). These findings demonstrate tissue-specific regulation of smRNAs by exercise and identify potential candidates for exercise mimetics to modulate muscle insulin sensitivity.
Otsuki, S.; Miyaki, S.; Lotz, M. K.
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We performed a new set of experiments to confirm findings reported in our previous publication regarding the role of Sulf-1 and Sulf-2 in regulating BMP-7 and FGF-2 signaling in human articular chondrocytes. Using primary chondrocytes from five independent human donors, we examined the effects of Sulf knockdown on Smad1/5 and Erk1/2 phosphorylation. Sulf-1 and Sulf-2 knockdown consistently reduced BMP-7-induced Smad1/5 phosphorylation and enhanced FGF-2-induced Erk1/2 phosphorylation. Although the magnitude of Erk1/2 activation was somewhat lower than originally reported, the direction and statistical significance of the effects were preserved. These results confirm the original conclusions and support the role of Sulfs as dual regulators of BMP-7 and FGF-2 signaling pathways in human chondrocytes.
Jones, E.; Adams, H.; Chen, K.-E.; Maroof, F.; Ibbotson, T. M.; Nakamura, Y.; Banks, P. J.; Healy, M. D.; Lewis, P. A.; Heesom, K. J.; Collins, B. M.; Wilkinson, K. A.; Cullen, P. J.; McMillan, K. J.
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Efficient transport of membrane proteins through the endosomal network is essential for brain development and function, with perturbation implicated in disease. Deficiencies in Retromer, a key regulator of endosomal transport, have been linked to aging-related neurodegenerative disorders including Alzheimers and Parkinsons disease. To better define the neuroprotective role of Retromer, we have applied cell surface restricted proteomics to identify those integral membrane proteins whose recycling to the plasma membrane is mediated by Retromer and associated cargo adaptors, sorting nexin 3 (SNX3), its paralogue sorting nexin 12 (SNX12), and sorting nexin 27 (SNX27) (data available via ProteomeXchange: PXD078277). By comparing primary rat cortical neurons and astrocytes we have identified several cargoes that require either SNX3/SNX12- or SNX27-Retromer complexes for endosomal recycling, including proteins involved in synapse organisation, synaptic signalling and Alzheimers disease pathology. We highlight that perturbed Retromer function leads to endosomal enlargement, and we establish a key role of SNX27-Retromer in modulating transport of glutamate across both neuronal and astrocytic membranes via recycling of glutamate transporters EAAT3 (SLC1A1) and EAAT1 (SLC1A3) respectively. Our study provides further mechanistic insight into the consequences of Retromer deficiency for neuronal and astrocytic function, offering new avenues of research in the treatment of neurodegenerative disease. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=194 SRC="FIGDIR/small/724903v1_ufig1.gif" ALT="Figure 1"> View larger version (59K): org.highwire.dtl.DTLVardef@98277forg.highwire.dtl.DTLVardef@1490534org.highwire.dtl.DTLVardef@f4a9feorg.highwire.dtl.DTLVardef@c48402_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphical AbstractC_FLOATNO Suppression of Retromer and the sorting nexins (SNX27, SNX3/SNX12) leads to a significant change in the surface proteome of rat cortical neurons and astrocytes. Focusing on the glutamate transporters, SLC1A1 and SLC1A3, we have validated that SNX27-Retromer is required for their trafficking, with SNX27-Retromer suppression in astrocytes leading to a loss of glutamate uptake. C_FIG
Manrique-Maldonado, G.; Sun, X.; Daugherty, S. L.; Beckel, J. M.; Carattino, M. D.
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Normal urinary bladder function relies on afferent fibers that detect and integrate mechanical and chemical cues related to bladder distension. Though, the molecular identity and function of the various sensory neuron types involved in bladder function have yet to be fully elucidated. Here, we introduce a novel framework for the functional classification of mechanosensitive bladder afferents based on their differential responses to physiological (15 l/min) and noxious filling (30 s at intravesical pressures of 10, 20, 30, 40, 50, and 60 cmH2O). Our data reveal the presence of three distinct types of mechanosensitive bladder afferents, two that respond to physiological distension (type I and II) and one that is activated by noxious stimulation (type III). Of the two populations that respond to physiological filling, one displays a linear increase in firing with bladder filling (type I), while the firing of the other plateaus as intravesical pressure increases (type II). Fast filling (130 l/min) increases the discharge of all three afferent types, with the effect being most pronounced in those responding to noxious stimulation (type III). Corroborating the existence of three functionally distinct bladder afferent populations, Yoda1, a selective PIEZO1 channel activator, significantly increased the firing rate of types I and III during slow filling and of type III during noxious stimulation. In summary, we present a reliable and reproducible method for studying and classifying bladder afferents, while providing compelling evidence for the existence of functionally distinct populations of mechanosensitive afferents, each activated and regulated by distinct mechanisms. New & NoteworthyUsing a novel approach, we identify three types of mechanosensitive afferents innervating the urinary bladder, two that respond to slow filling and one that is activated only by noxious distension. The three afferent types display distinct firing patterns during rapid filling and in response to the PIEZO1 channel agonist Yoda1.
Roth-Carter, R.; Helms, E.; Saldivar, J. C.; Podrabsky, J.
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Hypoxia and anoxia are known to suppress cell proliferation due to an increase in replication stress and activation of DNA damage checkpoints. Embryos of the annual killifish Austrofundulus limnaeus show a strong tolerance to extended anoxic exposure, indicating an improved genomic stability under oxygen starvation. Here we investigate the cell cycle regulation of the anoxia tolerant killifish embryonic cell line PSU-AL-WS40NE during anoxic exposure. Live cell imaging confirms continued cell proliferation of WS40NE cells for the first 24 hours of anoxic exposure with minimal cell death. Fluorescent imaging shows that cells begin to accumulate in G1 after the first day in anoxia with a pronounced and rapid entry into the S phase upon reoxygenation. Pharmacological inhibition tests show that this response appears to be reliant more on ATR signaling then ATM, suggesting that increased {gamma}H2AX levels are driven by increased replication stress instead of DNA damage. This conclusion is further supported by an apparent lack of induction of a G2 checkpoint in these cells suggesting that DNA damage during anoxic replication is minimal. Maintaining cellular proliferation during initial exposure to anoxia and accumulating cells in the G1 phase for extended anoxic exposure is likely one way that embryos of the annual killifish are able to survive prolonged anoxia and provides insight into mechanisms that enable cells to proliferate under metabolic stress.
Kostareva, O. S.; Eliseeva, I. A.; Buyan, A. I.; Lyabin, D. N.; Tishchenko, S. V.; Mikhaylina, A. O.
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Nucleobindin 1 (NUCB1) is a multifunctional conserved protein located in Golgi luminal, nucleus, extracellular and cytosolic pools. NUCB1 is multidomain protein comprised of a signal peptide, a DNA-binding domain, a leucine zipper and Ca2+ -binding domain. The multiple domains and localization of NUCB1 potentiates its interactions with various partners, such as DNA, Gi3 protein, cyclooxygenase 2, LRP10 and RNA suggests its importance in the regulation of many cellular events. We revealed that NUCB1 contains three RNA-binding regions and able to interact with two RNA fragments. It was suggested possible variants of the participation of NUCB1 in the interaction of the two partially complementary RNAs. The RNA-binding properties of the NUCB1 were also confirmed in vivo experiments.
Diaz-Franco, M. V.; Caniuqueo-Vargas, A.; Lasekan, O. A.; Castillo-Sarmiento, C. A.; Rodriguez-Martin, B.
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Background: Childhood and adolescent hearing loss affects not only communication and cognitive development but also motor skills and school participation. Consequently, it generates inequalities in learning and educational inclusion. Nevertheless, no systematic review has yet analyzed these differences from an inclusive education perspective. Methods: A systematic review with meta-analysis was conducted following PRISMA guidelines and registered in PROSPERO. Observational studies comparing physical fitness between children and adolescents with hearing loss and their hearing peers were included. Methodological quality was assessed using the Newcastle--Ottawa Scale, and standardized effect sizes were calculated with a random-effects model. Results: Five studies (n=404) were analyzed. Findings revealed significant differences in strength, agility, speed, and balance. Moreover, the meta-analysis showed a large standardized effect favoring hearing children (ES=-2.35; 95% CI: -3.34 to -1.37). Conclusions: Children and adolescents with hearing loss present significantly lower physical fitness, which may affect the planning of physical education activities if their capacities are misinterpreted. Implementing inclusive and adapted strategies within the school curriculum is essential to ensure equal opportunities, improve physical fitness, and promote educational equity.
Hoang, N.; Yang, H.; Uddin, M. N.; Zhong, J.; Faiyaz, A.; Singh, M. V.; Boodoo, Z. D.; Sutton, K. R.; Wang, H. Z.; Sahin, B.; Khan, M. W.; Weber, M. T.; Yuan, C.; Chen, L.; Schifitto, G.
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Background: Despite the success of combination antiretroviral therapy (cART), vascular comorbidities, including cerebrovascular disease, are more prominent in people living with HIV (PLWH) compared to people without HIV (PWOH). However, quantitative assessments of cerebrovascular morphometry and their associations with cognitive outcomes in the context of HIV are still limited. In this study, we explore this missing link. Methods: Magnetic Resonance Angiography (MRA) data, blood markers, and neurocognitive assessments were collected from 73 PWOH subjects (male: 57, female: 16; age: 53 {+/-} 16) and 99 PLWH subjects (male: 66, female: 30, age: 53 {+/-} 11). Vessel morphometric features were quantified using intraCranial Artery Feature Extraction (iCafe) to investigate associations between vessel morphometry, markers of monocytes, endothelial cell activation, and cognitive performance. Results: HIV status predicted a lower total number of branches ({beta} = -0.224, p = 0.001, d = -0.517) and shorter total distal length ({beta} = -0.173, p = 0.021, d = -0.370) with a moderate effect size. Total branch number was found to be negatively associated with plasma levels of monocyte markers (sCD14: r = -0.167, p = 0.033; sCD163: r = -0.157, p = 0.045) and positively correlated with white matter cerebral blood flow (r = 0.550; p [≤] 0.05). HIV status was the strongest predictor of overall cognitive performance in ANCOVA model ({beta} = -0.219, p = 0.006, d = -0.453). Conclusions: Our results suggest that cognitive impairment in PLWH is associated with vessel morphology metrics. Monocyte immune activation may contribute to changes in vessel morphology.