Nav1.7 as a chondrocyte regulator and therapeutic target for osteoarthritis.

Osteoarthritis (OA) is the most common joint disease. Currently there are no effective methods that simultaneously prevent joint degeneration and reduce pain1. Although limited evidence suggests the existence of voltage-gated sodium channels (VGSCs) in chondrocytes2, their expression and function in chondrocytes and in OA remain essentially unknown. Here we identify Nav1.7 as an OA-associated VGSC and demonstrate that human OA chondrocytes express functional Nav1.7 channels, with a density of 0.1 to 0.15 channels per µm2 and 350 to 525 channels per cell. Serial genetic ablation of Nav1.7 in multiple mouse models demonstrates that Nav1.7 expressed in dorsal root ganglia neurons is involved in pain, whereas Nav1.7 in chondrocytes regulates OA progression. Pharmacological blockade of Nav1.7 with selective or clinically used pan-Nav channel blockers significantly ameliorates the progression of structural joint damage, and reduces OA pain behaviour. Mechanistically, Nav1.7 blockers regulate intracellular Ca2+ signalling and the chondrocyte secretome, which in turn affects chondrocyte biology and OA progression. Identification of Nav1.7 as a novel chondrocyte-expressed, OA-associated channel uncovers a dual target for the development of disease-modifying and non-opioid pain relief treatment for OA.

PGRN deficiency exacerbates, whereas a brain penetrant PGRN derivative protects, GBA1 mutation-associated pathologies and diseases.

Mutations in GBA1, encoding glucocerebrosidase (GCase), cause Gaucher disease (GD) and are also genetic risks in developing Parkinson's disease (PD). Currently, the approved therapies are only effective for directly treating visceral symptoms, but not for primary neuronopathic involvement in GD (nGD). Progranulin (PGRN), encoded by GRN, is a novel modifier of GCase, but the impact of PGRN in GBA1 mutation-associated pathologies in vivo remains unknown. Herein, Grn-/- mice crossed into Gba9v/9v mice, a Gba1 mutant line homozygous for the Gba1 D409V mutation, generating Grn-/-Gba9v/9v (PG9V) mice. PG9V mice exhibited neurobehavioral deficits, early onset, and more severe GD phenotypes compared to Grn-/- and Gba9v/9v mice. Moreover, PG9V mice also displayed PD-like phenotype. Mechanistic analysis revealed that PGRN deficiency caused severe neuroinflammation with microgliosis and astrogliosis, along with impaired autophagy associated with the Gba1 mutation. A PGRN-derived peptide, termed ND7, ameliorated the disease phenotype in GD patient fibroblasts ex vivo. Unexpectedly, ND7 penetrated the blood-brain barrier (BBB) and effectively ameliorated the nGD manifestations and PD pathology in Gba9v/null and PG9V mice. Collectively, this study not only provides the first line of in vivo but also ex vivo evidence demonstrating the crucial role of PGRN in GBA1/Gba1 mutation-related pathologies, as well as a clinically relevant mouse model for mechanistic and potential therapeutics studies for nGD and PD. Importantly, a BBB penetrant PGRN-derived biologic was developed that may provide treatment for rare lysosomal storage diseases and common neurodegenerative disorders, particularly nGD and PD.

Propagation of radially polarized beams with a Hermite non-uniformly correlated array in free space and turbulent atmosphere.

We introduce what we believe to be a novel class of radially polarized partially coherent beams in which the correlation function possesses a Hermite non-uniformly correlated array. The source parameter conditions required to generate a physical beam are derived. The statistical properties of such beam propagating in free space and turbulent atmosphere are thoroughly examined using the extended Huygens-Fresnel principle. It is shown that the intensity profile of such beams presents a controllable periodic grid distribution due to its multi-self-focusing propagation property and can keep the shape in free space while propagating in turbulent atmosphere, it exhibits self-combining properties over a long-ranges. Owing to the interaction between the non-uniform correlation structure and the non-uniform polarization, this beam can locally self-recover the polarization state after propagating a long distance in a turbulent atmosphere. Furthermore, the source parameters play essential roles in determining the distribution of spectral intensity, the state of polarization, and the degree of polarization of the RPHNUCA beam. Our results may benefit multi-particle manipulation and free-space optical communication applications.

Kaemperfol Protects Dopaminergic Neurons by Promoting mTOR-Mediated Autophagy in Parkinson's Disease Models.

We previously showed that kaempferol (KAE) could exert neuroprotective effects against PD. It has been demonstrated that abnormal autophagy plays a key role in the development of PD. Mitochondrial dysfunction, involved in the development of PD, can damage dopaminergic neurons. Whether the protective effects of KAE were exerted via regulating autophagy remains largely undefined, however. This study aimed to investigate whether KAE could protect dopaminergic neurons via autophagy and the underlying mechanisms using a MPTP/MPP+-stimulated PD model. Cell viability was detected by cell counting kit-8 (CCK-8) assay, and protein levels of autophagy mediators along with mTOR signaling pathway molecules were investigated by immunohistochemistry and Western blot analyses. The results showed that KAE could ameliorate the behavioral impairments of mice, reduce the loss of tyrosine hydroxylase (TH)-positive neurons in the substantia nigra pars compacta, and reduce α-synuclein (α-syn) levels. Furthermore, KAE upregulated levels of autophagy effector protein of Beclin-1 and autophagy microtubule associated protein of light chain 3 (LC3) in the substantia nigra (SN) while rescuing mitochondrial integrity, and downregulated levels of ubiquitin binding protein p62 and cleaved caspase-3, probably by decreasing the mammalian target of rapamycin (mTOR) signaling pathway. Further in vitro experiments demonstrated similar results. In conclusion, KAE exerts neuroprotective effects against PD potentially by promoting autophagy via inhibiting the mTOR signaling pathway.

Modeling by disruption and a selected-for partner for the nude locus.

A long-standing problem in biology is how to dissect traits for which no tractable model exists. Here, we screen for genes like the nude locus (Foxn1)-genes central to mammalian hair and thymus development-using animals that never evolved hair, thymi, or Foxn1. Fruit flies are morphologically disrupted by the FOXN1 transcription factor and rescued by weak reductions in fly gene function, revealing molecules that potently synergize with FOXN1 to effect dramatic, chaotic change. Strong synergy/effectivity in flies is expected to reflect strong selection/functionality (purpose) in mammals; the more disruptive a molecular interaction is in alien contexts (flies), the more beneficial it will be in its natural, formative contexts (mammals). The approach identifies Aff4 as the first nude-like locus, as murine AFF4 and FOXN1 cooperatively induce similar cutaneous/thymic phenotypes, similar gene expression programs, and the same step of transcription, pre-initiation complex formation. These AFF4 functions are unexpected, as AFF4 also serves as a scaffold in common transcriptional-elongation complexes. Most likely, the approach works because an interaction's power to disrupt is the inevitable consequence of its selected-for power to benefit.

Silver-mediated radical oxytrifluoromethylation of unsaturated carboxylic acids for the synthesis of γ-trifluoromethylthio lactones.

An efficient silver-mediated oxidative trifluoromethylthiolation of unsaturated carboxylic acids to construct trifluoromethylthiol-containing lactones has been disclosed. In this protocol no metal-catalysts was added, and preliminary mechanism investigations suggested that a free-radical pathway should be involved in the process. High functional group tolerance and excellent yields were demonstrated by the efficient preparation of a wide range of γ-trifluoromethylthiolated phthalides.

14-3-3 epsilon is an intracellular component of TNFR2 receptor complex and its activation protects against osteoarthritis.

OBJECTIVES: Osteoarthritis (OA) is the most common joint disease; however, the indeterminate nature of mechanisms by which OA develops has restrained advancement of therapeutic targets. TNF signalling has been implicated in the pathogenesis of OA. TNFR1 primarily mediates inflammation, whereas emerging evidences demonstrate that TNFR2 plays an anti-inflammatory and protective role in several diseases and conditions. This study aims to decipher TNFR2 signalling in chondrocytes and OA. METHODS: Biochemical copurification and proteomics screen were performed to isolate the intracellular cofactors of TNFR2 complex. Bulk and single cell RNA-seq were employed to determine 14-3-3 epsilon (14-3-3ε) expression in human normal and OA cartilage. Transcription factor activity screen was used to isolate the transcription factors downstream of TNFR2/14-3-3ε. Various cell-based assays and genetically modified mice with naturally occurring and surgically induced OA were performed to examine the importance of this pathway in chondrocytes and OA. RESULTS: Signalling molecule 14-3-3ε was identified as an intracellular component of TNFR2 complexes in chondrocytes in response to progranulin (PGRN), a growth factor known to protect against OA primarily through activating TNFR2. 14-3-3ε was downregulated in OA and its deficiency deteriorated OA. 14-3-3ε was required for PGRN regulation of chondrocyte metabolism. In addition, both global and chondrocyte-specific deletion of 14-3-3ε largely abolished PGRN's therapeutic effects against OA. Furthermore, PGRN/TNFR2/14-3-3ε signalled through activating extracellular signal-regulated kinase (ERK)-dependent Elk-1 while suppressing nuclear factor kappa B (NF-κB) in chondrocytes. CONCLUSIONS: This study identifies 14-3-3ε as an inducible component of TNFR2 receptor complex in response to PGRN in chondrocytes and presents a previously unrecognised TNFR2 pathway in the pathogenesis of OA.

Polyphenols from Toona sinensiss Seeds Alleviate Neuroinflammation Induced by 6-Hydroxydopamine Through Suppressing p38 MAPK Signaling Pathway in a Rat Model of Parkinson's Disease.

Polyphenols from Toona sinensis seeds (PTSS) have demonstrated anti-inflammatory effects in various diseases, while the anti-neuroinflammatory effects still remain to be investigated. We aimed to investigate the effects of PTSS on Parkinson's disease and underlying mechanisms using a rat model. We employed 6-hydroxydopamine (6-OHDA) to male Sprague Dawley (SD) rats and PC12 cells to construct the in vivo and vitro models of PD and dopaminergic (DA) neuron injury, respectively. Cell viability was detected by cell counting kit-8 (CCK-8) assay and protein levels of inflammatory mediators and some p38 MAPK pathway molecules were investigated by immunohistochemistry and Western blot analyses. The results showed that 6-OHDA significantly increased protein levels of inflammatory mediators, such as cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and tumor necrosis factor α (TNF-α), which could be reversed by PTSS through suppressing the p38 MAPK pathway. The anti-inflammatory effects of PTSS were significantly enhanced by the specific p38 inhibitor of SB203580 in vitro. The present work suggests that PTSS can exert anti-inflammatory effects on PD models, which may be attributed to the suppression of p38 MAPK signaling pathway.

Fexofenadine inhibits TNF signaling through targeting to cytosolic phospholipase A2 and is therapeutic against inflammatory arthritis.

OBJECTIVE: Tumour necrosis factor alpha (TNF-α) signalling plays a central role in the pathogenesis of various autoimmune diseases, particularly inflammatory arthritis. This study aimed to repurpose clinically approved drugs as potential inhibitors of TNF-α signalling in treatment of inflammatory arthritis. METHODS: In vitro and in vivo screening of an Food and Drug Administration (FDA)-approved drug library; in vitro and in vivo assays for examining the blockade of TNF actions by fexofenadine: assays for defining the anti-inflammatory activity of fexofenadine using TNF-α transgenic (TNF-tg) mice and collagen-induced arthritis in DBA/1 mice. Identification and characterisation of the binding of fexofenadine to cytosolic phospholipase A2 (cPLA2) using drug affinity responsive target stability assay, proteomics, cellular thermal shift assay, information field dynamics and molecular dynamics; various assays for examining fexofenadine inhibition of cPLA2 as well as the dependence of fexofenadine's anti-TNF activity on cPLA2. RESULTS: Serial screenings of a library composed of FDA-approved drugs led to the identification of fexofenadine as an inhibitor of TNF-α signalling. Fexofenadine potently inhibited TNF/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB) signalling in vitro and in vivo, and ameliorated disease symptoms in inflammatory arthritis models. cPLA2 was isolated as a novel target of fexofenadine. Fexofenadine blocked TNF-stimulated cPLA2 activity and arachidonic acid production through binding to catalytic domain 2 of cPLA2 and inhibition of its phosphorylation on Ser-505. Further, deletion of cPLA2 abolished fexofenadine's anti-TNF activity. CONCLUSION: Collectively, these findings not only provide new insights into the understanding of fexofenadine action and underlying mechanisms but also provide new therapeutic interventions for various TNF-α and cPLA2-associated pathologies and conditions, particularly inflammatory rheumatic diseases.

Foxo4- and Stat3-dependent IL-10 production by progranulin in regulatory T cells restrains inflammatory arthritis.

Progranulin (PGRN) restrains inflammation and is therapeutic against inflammatory arthritis; however, the underlying immunological mechanism remains unknown. In this study, we demonstrated that anti-inflammatory cytokine IL-10 was a critical mediator for PGRN-mediated anti-inflammation in collagen-induced arthritis by using PGRN and IL-10 genetically modified mouse models. IL-10 green fluorescent protein reporter mice revealed that regulatory T (Treg) cells were the predominant source of IL-10 in response to PGRN. In addition, PGRN-mediated expansion and activation of Treg cells, as well as IL-10 production, depends on JNK signaling, but not on known PGRN-activated ERK and PI3K pathways. Furthermore, microarray and chromatin immunoprecipitation sequencing screens led to the discovery of forkhead box protein O4 and signal transducer and activator of transcription 3 as the transcription factors required for PGRN induction of IL-10 in Treg cells. These findings define a previously unrecognized signaling pathway that underlies IL-10 production by PGRN in Treg cells and present new insights into the mechanisms by which PGRN resolves inflammation in inflammatory conditions and autoimmune diseases, particularly inflammatory arthritis.-Fu, W., Hu, W., Shi, L., Mundra, J. J. Xiao, G., Dustin, M. L., Liu, C. Foxo4- and Stat3-dependent IL-10 production by progranulin in regulatory T cells restrains inflammatory arthritis.

[Numerical simulation of the effect of virtual stent release pose on the expansion results].

The current finite element analysis of vascular stent expansion does not take into account the effect of the stent release pose on the expansion results. In this study, stent and vessel model were established by Pro/E. Five kinds of finite element assembly models were constructed by ABAQUS, including 0 degree without eccentricity model, 3 degree without eccentricity model, 5 degree without eccentricity model, 0 degree axial eccentricity model and 0 degree radial eccentricity model. These models were divided into two groups of experiments for numerical simulation with respect to angle and eccentricity. The mechanical parameters such as foreshortening rate, radial recoil rate and dog boning rate were calculated. The influence of angle and eccentricity on the numerical simulation was obtained by comparative analysis. Calculation results showed that the residual stenosis rates were 38.3%, 38.4%, 38.4%, 35.7% and 38.2% respectively for the 5 models. The results indicate that the pose has less effect on the numerical simulation results so that it can be neglected when the accuracy of the result is not highly required, and the basic model as 0 degree without eccentricity model is feasible for numerical simulation.

Therapeutic effects of intranigral transplantation of mesenchymal stem cells in rat models of Parkinson's disease.

Stem cell transplantation is a promising tool for the treatment of neurodegenerative disorders, including Parkinson's disease (PD); however, the therapeutic routes and mechanisms of mechanical approaches to stem cell transplantation must be explored. This study tests the therapeutic effect of transplantation of rat bone marrow mesenchymal stem cells (MSCs) into the substantia nigra (SN) of the PD rat. 5-Bromo-2-deoxyuridine-labeled rat MSCs were transplanted into the SN of the 6-hydroxydopamine-injected side of PD rat brains. The behavioral changes in PD rats were examined before and 4 and 8 weeks after MSC transplantation. The expression of tyrosine hydroxylase (TH) in the SN and the striatum and the survival and differentiation of MSCs were assessed by immunohistochemical and double immunofluorescence techniques. Abnormal behavior of PD rats was significantly improved by the administration of bone marrow MSCs, and the number of TH-positive cells in the SN and the optical density of TH-positive fibers in the striatum were markedly increased. Transplanted MSCs can survive and migrate in the brain and differentiate into nestin-, neuron-specific enolase-, and GFAP-positive cells. Our findings suggest that transplantation of rat bone marrow MSCs into the SN of PD rats may provide therapeutic effects. © 2016 Wiley Periodicals, Inc.

Second-order statistics of a radially polarized partially coherent twisted beam in a uniaxial crystal.

The Wigner function (WDF) has been used to study the second-order moments for a radially polarized partially coherent twisted (RPPCT) beam (i.e., a RPPC beam with a twist phase) propagating in a uniaxial crystal. With the help of the extended Huygens-Fresnel integral formula and definition of the WDF, the analytical formulas for propagation factor (M2-factor), effective radius of curvature (ERC), and Rayleigh range of a RPPCT beam propagating in a uniaxial crystal have been derived. Our numerical results show that the M2-factor of a RPPCT beam with larger absolute value of the twist factor or lower coherence is less affected by anisotropic diffraction in a uniaxial crystal. The dependence of the ERC and Rayleigh range of a RPPCT beam propagating in a uniaxial crystal on the parameter e along the x direction is much different from that along the y direction due to anisotropic diffraction. We can judge how much a RPPCT beam carries the twist factor by measuring the deviation percentage of the M2-factor of a RPPCT beam propagating in a uniaxial crystal and even can modulate the properties of a RPPCT beam by varying the beam parameters, which will be useful in some applications where a RPPCT beam is required.

The Computational Fluid Dynamics Rupture Challenge 2013--Phase II: Variability of Hemodynamic Simulations in Two Intracranial Aneurysms.

With the increased availability of computational resources, the past decade has seen a rise in the use of computational fluid dynamics (CFD) for medical applications. There has been an increase in the application of CFD to attempt to predict the rupture of intracranial aneurysms, however, while many hemodynamic parameters can be obtained from these computations, to date, no consistent methodology for the prediction of the rupture has been identified. One particular challenge to CFD is that many factors contribute to its accuracy; the mesh resolution and spatial/temporal discretization can alone contribute to a variation in accuracy. This failure to identify the importance of these factors and identify a methodology for the prediction of ruptures has limited the acceptance of CFD among physicians for rupture prediction. The International CFD Rupture Challenge 2013 seeks to comment on the sensitivity of these various CFD assumptions to predict the rupture by undertaking a comparison of the rupture and blood-flow predictions from a wide range of independent participants utilizing a range of CFD approaches. Twenty-six groups from 15 countries took part in the challenge. Participants were provided with surface models of two intracranial aneurysms and asked to carry out the corresponding hemodynamics simulations, free to choose their own mesh, solver, and temporal discretization. They were requested to submit velocity and pressure predictions along the centerline and on specified planes. The first phase of the challenge, described in a separate paper, was aimed at predicting which of the two aneurysms had previously ruptured and where the rupture site was located. The second phase, described in this paper, aims to assess the variability of the solutions and the sensitivity to the modeling assumptions. Participants were free to choose boundary conditions in the first phase, whereas they were prescribed in the second phase but all other CFD modeling parameters were not prescribed. In order to compare the computational results of one representative group with experimental results, steady-flow measurements using particle image velocimetry (PIV) were carried out in a silicone model of one of the provided aneurysms. Approximately 80% of the participating groups generated similar results. Both velocity and pressure computations were in good agreement with each other for cycle-averaged and peak-systolic predictions. Most apparent "outliers" (results that stand out of the collective) were observed to have underestimated velocity levels compared to the majority of solutions, but nevertheless identified comparable flow structures. In only two cases, the results deviate by over 35% from the mean solution of all the participants. Results of steady CFD simulations of the representative group and PIV experiments were in good agreement. The study demonstrated that while a range of numerical schemes, mesh resolution, and solvers was used, similar flow predictions were observed in the majority of cases. To further validate the computational results, it is suggested that time-dependent measurements should be conducted in the future. However, it is recognized that this study does not include the biological aspects of the aneurysm, which needs to be considered to be able to more precisely identify the specific rupture risk of an intracranial aneurysm.

Ion channels in osteoarthritis: emerging roles and potential targets.

Osteoarthritis (OA) is a highly prevalent joint disease that causes substantial disability, yet effective approaches to disease prevention or to the delay of OA progression are lacking. Emerging evidence has pinpointed ion channels as pivotal mediators in OA pathogenesis and as promising targets for disease-modifying treatments. Preclinical studies have assessed the potential of a variety of ion channel modulators to modify disease pathways involved in cartilage degeneration, synovial inflammation, bone hyperplasia and pain, and to provide symptomatic relief in models of OA. Some of these modulators are currently being evaluated in clinical trials. This review explores the structures and functions of ion channels, including transient receptor potential channels, Piezo channels, voltage-gated sodium channels, voltage-dependent calcium channels, potassium channels, acid-sensing ion channels, chloride channels and the ATP-dependent P2XR channels in the osteoarthritic joint. The discussion spans channel-targeting drug discovery and potential clinical applications, emphasizing opportunities for further research, and underscoring the growing clinical impact of ion channel biology in OA.

Comparative analysis of structural dynamics and allosteric mechanisms of RecA/Rad51 family proteins: Integrated atomistic MD simulation and network-based analysis.

Homologous recombination plays a key role in double-strand break repair, stalled replication fork repair, and meiosis. The RecA/Rad51 family recombinases catalyze the DNA strand invasion reaction that occurs during homologous recombination. However, the high sequence differences between homologous groups have hindered the thoroughly studies of this ancient protein family. The dynamic mechanisms of the family, particularly at the residual level, remain poorly understood. In this work, five representative RecA/Rad51 recombinase family members from all major kingdoms of living organisms: prokaryotes, eukaryotes, archaea, and viruses, were selected to explore the molecular mechanisms behind their conserved biological significance. A variety of techniques, including all-atom molecular dynamics simulation, perturbation response scanning, and protein structure network analysis, were used to examine the flexibility and correlation of protein domains, distribution of sensors and effectors and conserved hub residues. Furthermore, the potential communication routes between the ATP-binding region and the DNA-binding region of each recombinase were identified. Our results demonstrate the conserved molecular dynamics of these recombinases in the early stage of homologous recombination, including cooperative motions between regions, conserved sensing and effecting functional residue distribution, and conserved hub residues. Meanwhile, the unique ATP-DNA communication routes of each recombinase was also revealed. These results provide new insights into the mechanism of RecA/Rad51 family proteins, and provide new theoretical guidance for the development of allosteric inhibitors and the application of RecA/Rad51 family proteins.

Numerical Investigation of Tree-Type Hydraulic Fracturing for Balanced Permeability Enhancement of Heterogenous Coal Seams Based on the Finite-Discrete Element Method Model.

Tree-type hydraulic fracturing (TTHF) is a new technology that can enhance the permeability of coal seams in a balanced manner and increase the coalbed methane production rate. However, the heterogeneity of coal seams is a major challenge in achieving balanced permeability enhancement by TTHF. Traditional methods based on digital image processing are difficult to apply in practice. To address these challenges, we proposed a 2D numerical model of coal seams based on the combined finite-discrete element method (FDEM). The elastic modulus of the coal seams obeys a Weibull distribution, and the coal heterogeneity was quantified by an index m. The effects on the fracture initiation pressure, the fracturing influence range, and displacements of TTHF were analyzed from four aspects, including the homogeneity index of coal, the arrangement angle of branch boreholes, the horizontal stress difference, and the injection rate of the fracturing fluid. The results show that TTHF has a significant effect on the balanced permeability enhancement in coal reservoirs, particularly with strong heterogeneity, and the best permeability enhancement for TTHF is achieved when the branch boreholes are arranged at 45°. The branch boreholes are prefabricated in advance to create a pressure relief area around the injection point, and the hydraulic fracture propagation is affected by the horizontal stress difference only when the fracturing influence range exceeds this area. When the horizontal stress difference increases from 0 to 4 MPa, its fracture initiation pressure increases from 8.93 to 10.86 MPa, with an increase of 21.61%. In addition, the initial stage of fluid injection was found to be crucial for achieving balanced permeability enhancement in TTHF, and a higher injection rate can expand the fracturing influence range. The numerical model has profound implications for the field application of TTHF technology.

TNFR1-mediated senescence and lack of TNFR2-signaling limit human intervertebral disc cell repair in back pain conditions.

Poor intervertebral disc (IVD) healing causes IVD degeneration (IVDD) and progression to herniation and back pain. This study identified distinct roles of TNFα-receptors (TNFRs) in contributing to poor healing in painful IVDD. We first isolated IVDD tissue of back pain subjects and determined the complex pro-inflammatory mixture contained many chemokines for recruiting inflammatory cells. Single-cell RNA-sequencing of human IVDD tissues revealed these pro-inflammatory cytokines were dominantly expressed by a small macrophage-population. Human annulus fibrosus (hAF) cells treated with IVDD-conditioned media (CM) underwent senescence with greatly reduced metabolic rates and limited inflammatory responses. TNFR1 inhibition partially restored hAF cell metabolism sufficiently to enable a robust chemokine and cytokine response to CM. We showed that the pro-reparative TNFR2 was very limited on hIVD cell membranes so that TNFR2 inhibition with blocking antibodies or activation using Atsttrin had no effect on hAF cells with CM challenge. However, TNFR2 was expressed in high levels on macrophages identified in scRNA-seq analyses, suggesting their role in repair responses. Results therefore point to therapeutic strategies for painful IVDD involving immunomodulation of TNFR1 signaling in IVD cells to enhance metabolism and enable a more robust inflammatory response including recruitment or delivery of TNFR2 expressing immune cells to enhance IVD repair.

Variability of computational fluid dynamics solutions for pressure and flow in a giant aneurysm: the ASME 2012 Summer Bioengineering Conference CFD Challenge.

Stimulated by a recent controversy regarding pressure drops predicted in a giant aneurysm with a proximal stenosis, the present study sought to assess variability in the prediction of pressures and flow by a wide variety of research groups. In phase I, lumen geometry, flow rates, and fluid properties were specified, leaving each research group to choose their solver, discretization, and solution strategies. Variability was assessed by having each group interpolate their results onto a standardized mesh and centerline. For phase II, a physical model of the geometry was constructed, from which pressure and flow rates were measured. Groups repeated their simulations using a geometry reconstructed from a micro-computed tomography (CT) scan of the physical model with the measured flow rates and fluid properties. Phase I results from 25 groups demonstrated remarkable consistency in the pressure patterns, with the majority predicting peak systolic pressure drops within 8% of each other. Aneurysm sac flow patterns were more variable with only a few groups reporting peak systolic flow instabilities owing to their use of high temporal resolutions. Variability for phase II was comparable, and the median predicted pressure drops were within a few millimeters of mercury of the measured values but only after accounting for submillimeter errors in the reconstruction of the life-sized flow model from micro-CT. In summary, pressure can be predicted with consistency by CFD across a wide range of solvers and solution strategies, but this may not hold true for specific flow patterns or derived quantities. Future challenges are needed and should focus on hemodynamic quantities thought to be of clinical interest.

Neural metabolite changes in corpus striatum after rat multipotent mesenchymal stem cells transplanted in hemiparkinsonian rats by magnetic resonance spectroscopy.

OBJECTIVE: To investigate the biochemical changes in striatum after rat bone marrow mesenchymal stem cells (MSCs) were transplanted into hemiparkinsonian rats and to further confirm the therapeutic effects of rat MSCs for Parkinson's disease (PD). METHODS: 5-bromo-2-deoxyuridine (BrdU)-labeled MSCs were transplanted into the corpus striatum of the 6-hydroxydopamine (6-OHDA)-injected side of six PD model rats. Before and 8 weeks after MSC transplantation, ethological changes in PD rats were assessed. The expression of tyrosine hydroxylase (TH) in substantia nigra (SN) and striatum were measured using immunohistochemical methods. The differentiation of MSCs was detected by double immunofluorescence techniques. The concentrations of neural metabolites of N-acetylaspartate (NAA), choline (Cho) and creatine (Cr) were measured by ¹H-magnetic resonance spectroscopy (MRS). Relative concentrations of NAA/Cr and Cho/Cr were calculated. RESULTS: The behavior of PD rats in rotarod tests improved, and there were statistical differences in TH-positive cells in SN and TH-positive terminals in striatum after the transplantation of BrdU-labeled MSCs. Transplanted MSCs differentiated into MAP-2-positive neurons. Especially compared with pre-MSC transplantation, the neural metabolite NAA/Cr ratio of the 6-OHDA-injected side of the striatum increased (P < 0.05) and the Cho/Cr ratio decreased (P < 0.05). CONCLUSION: MSCs transplantation apparently improves neuronal function in the striatum of PD rats.