Influence of different commercial scaffolds on the in vitro differentiation of human mesenchymal stem cells to nucleus pulposus-like cells

Introduction: Cell-based therapies for regeneration of the degenerated intervertebral disc (IVD) are an alternative to current surgical intervention. Mesenchymal stem cells (MSCs), in combination with a scaffold, might be ideal candidates for regenerating nucleus pulposus (NP), the pressure-distributing part of the IVD. While the use of growth factors for MSCs differentiation currently receives major attention, in this study we compare the performance of sponge-like matrixes in supporting cell differentiation into NP-like cells. Materials and methods: Four types matrixes approved as medical devices for other applications were tested as scaffolds for MSCs: two made of equine or porcine collagen, one of gelatin and one of chitosan. Bone marrow-derived human MSCs were seeded in these scaffolds or embedded in alginate, as a three-dimensional control. After five weeks in culture, NP-like differentiation of the cell-scaffold constructs was analyzed by qRT-PCR, histology, total DNA quantification, proteoglycan accumulation and immunohistochemistry. Results: MSCs in collagen matrixes and gelatin produced more mRNA and proteins of the chondrogenic markers collagen type I, collagen type II (COL2) and aggrecan (ACAN), when compared with cells embedded in alginate or chitosan. Proteoglycan accumulation and cell survival were also higher in collagen and gelatin matrixes. Gene expression results were also confirmed by histological and immunohistochemical staining. In contrast to alginate control, the gene expression of the undesired bone marker osteopontin was lower in all tested groups. In porcine collagen supports, MSC expression ratio between COL2/ACAN closely resembled the expression of nucleus pulposus cells, but gene expression of recently described NP markers keratin19, PAX1 and FOXF1 was lower. Conclusions: Collagen supports provide a readily available, medically approved and effective scaffold for chondrogenic differentiation in vitro, but the phenotype of differentiated MSCs is not yet completely equivalent to that of NP cell

Cell Invasion in Collagen Scaffold Architectures Characterized by Percolation Theory.

The relationship between biological scaffold interconnectivity and cell migration is an important but poorly understood factor in tissue regeneration. Here a scale-independent technique for characterization of collagen scaffold interconnectivity is presented, using a combination of X-ray microcomputed tomography and percolation theory. Confocal microscopy of connective tissue cells reveals this technique as highly relevant for determining the extent of cell invasion.The authors acknowledge financial support from EPSRC, Geistlich Pharma AG and ERC Advanced Grant 320598 3D-E.This is the final version of the article. It first appeared from Wiley at http://dx.doi.org/10.1002/adhm.201500197

A Research and Development (R&D) roadmap for influenza vaccines: Looking toward the future

Improved influenza vaccines are urgently needed to reduce the burden of seasonal influenza and to ensure a rapid and effective public-health response to future influenza pandemics. The Influenza Vaccines Research and Development (R&D) Roadmap (IVR) was created, through an extensive international stakeholder engagement process, to promote influenza vaccine R&D. The roadmap covers a 10-year timeframe and is organized into six sections: virology; immunology; vaccinology for seasonal influenza vaccines; vaccinology for universal influenza vaccines; animal and human influenza virus infection models; and policy, finance, and regulation. Each section identifies barriers, gaps, strategic goals, milestones, and additional R&D priorities germane to that area. The roadmap includes 113 specific R&D milestones, 37 of which have been designated high priority by the IVR expert taskforce. This report summarizes the major issues and priority areas of research outlined in the IVR. By identifying the key issues and steps to address them, the roadmap not only encourages research aimed at new solutions, but also provides guidance on the use of innovative tools to drive breakthroughs in influenza vaccine R&D.publishedVersio

Human MMP28 expression is unresponsive to inflammatory stimuli and does not correlate to the grade of intervertebral disc degeneration

BACKGROUND: MMP28 (epilysin) is a recently discovered member of the MMP (matrix metalloproteinase) family that is, amongst others, expressed in osteoarthritic cartilage and intervertebral disc (IVD) tissue. In this study the hypothesis that increased expression of MMP28 correlates with higher grades of degeneration and is stimulated by the presence of proinflammatory molecules was tested. Gene expression levels of MMP28 were investigated in traumatic and degenerative human IVD tissue and correlated to the type of disease and the degree of degeneration (Thompson grade). Quantification of MMP28 gene expression in human IVD tissue or in isolated cells after stimulation with the inflammatory mediators lipopolysaccharide (LPS), interleukin (IL)-1β, tumor necrosis factor (TNF)-α or the histondeacetylase inhibitor trichostatin A was performed by real-time RT PCR. RESULTS: While MMP28 expression was increased in individual cases with trauma or disc degeneration, there was no significant correlation between the grade of disease and MMP28 expression. Stimulation with LPS, IL-1β, TNF-α or trichostatin A did not alter MMP28 gene expression at any investigated time point or any concentration. CONCLUSIONS: Our results demonstrate that gene expression of MMP28 in the IVD is not regulated by inflammatory mechanisms, is donor-dependent and cannot be positively or negatively linked to the grade of degeneration and only weakly to the occurrence of trauma. New hypotheses and future studies are needed to find the role of MMP28 in the intervertebral disc

B cell receptor silencing reveals origin and dependencies of high-grade B cell lymphomas with MYC and BCL2 rearrangements

The B cell receptor (BCR) is critical for mature B cell lymphomas, serving as a therapeutic target. We show that high-grade B cell lymphomas with MYC and BCL2 rearrangements (HGBCL-DH-BCL2) predominantly exhibit immunoglobulin heavy (IGH) chain silencing, leading to BCR shutdown. IGH-silenced HGBCL-DH-BCL2 (IGHUND) differ from IGH+ counterparts in germinal center-zone programs, MYC expression, and immune infiltrate. While IGH+ HGBCL-DH-BCL2 favor IGM/IG-Kappa expression, IGHUND counterparts complete IGH isotype switching and IG-Lambda rearrangements. IGHUND lymphomas retain productive IGHV rearrangements and require IGH for optimal fitness. BCR silencing, caused by accelerated IGH turnover and reduced IGH expression, precedes HGBCL-DH-BCL2 onset, inducing RAG1/2-dependent IG light chain editing and facilitating t(8;22)/IGL::MYC translocations. IGHUND HGBCL-DH-BCL2 models exhibit reduced sensitivity to the CD79B-targeting antibody-drug conjugate Polatuzumab-vedotin. Collectively, HGBCL-DH-BCL2 commonly arises from isotype-switched t(14;18)+ germinal center B cells, which edit IG light chains, fueling intra-clonal diversification, BCR extinction, and t(8;22) while maintaining IGH dependence, with clinical implications

In situ estimation of ice crystal properties at the South Pole using LED calibration data from the IceCube Neutrino Observatory

The IceCube Neutrino Observatory instruments about 1 km3 of deep, glacial ice at the geographic South Pole. It uses 5160 photomultipliers to detect Cherenkov light emitted by charged relativistic particles. An unexpected light propagation effect observed by the experiment is an anisotropic attenuation, which is aligned with the local flow direction of the ice. We examine birefringent light propaga- tion through the polycrystalline ice microstructure as a pos- sible explanation for this effect. The predictions of a first- principles model developed for this purpose, in particular curved light trajectories resulting from asymmetric diffusion, provide a qualitatively good match to the main features of the data. This in turn allows us to deduce ice crystal properties. Since the wavelength of the detected light is short compared to the crystal size, these crystal properties include not only the crystal orientation fabric, but also the average crystal size and shape, as a function of depth. By adding small empiri- cal corrections to this first-principles model, a quantitatively accurate description of the optical properties of the IceCube glacial ice is obtained. In this paper, we present the exper- imental signature of ice optical anisotropy observed in Ice- Cube light-emitting diode (LED) calibration data, the theory and parameterization of the birefringence effect, the fitting procedures of these parameterizations to experimental data, and the inferred crystal propertie

Three-year performance of the IceAct telescopes at the IceCube Neutrino Observatory

IceAct is an array of compact Imaging Air Cherenkov Telescopes at the ice surface as part of the IceCube Neutrino Observatory. The telescopes, featuring a camera of 61 silicon photomultipliers and fresnel-lens-based optics, are optimized to be operated in harsh environmental conditions, such as at the South Pole. Since 2019, the first two telescopes have been operating in a stereoscopic configuration in the center of IceCube\u27s surface detector IceTop. With an energy threshold of about 10 TeV and a wide field-of-view, the IceAct telescopes show promising capabilities of improving current cosmic-ray composition studies: measuring the Cherenkov light emissions in the atmosphere adds new information about the shower development not accessible with the current detectors. First simulations indicate that the added information of a single telescope leads, e.g., to an improved discrimination between flux contributions from different primary particle species in the sensitive energy range. We review the performance and detector operations of the telescopes during the past 3 years (2020-2022) and give an outlook on the future of IceAct

Highlights from the IceCube Neutrino Observatory

As IceCube surpasses a decade of operation in the full detector configuration, results that drive forward the fields of neutrino astronomy, cosmic ray physics, multi-messenger astronomy, particle physics, and beyond continue to emerge at an accelerated pace. IceCube data is dominated by background events, and thus teasing out the signal is the common challenge to most analyses. Statistical accumulation of data, along with better understanding of the background fluxes, the detector, and continued development of our analysis tools have produced many profound results that were presented at ICRC2023. Highlights covered here include the first neutrino observation of the Galactic Plane, the first observation of a steady emission neutrino point source NGC1068, new characterizations of the cosmic ray flux and its secondary particles, and a possible new era in measuring the energy spectrum of the diffuse astrophysical flux. IceCube is poised to make more discoveries and drive fields forward in the near future with many novel analyses coming online

Search for the rare interactions of neutrinos from distant point sources with the IceCube Neutrino Telescope

The recent discovery and evidence of neutrino signals from distant sources, TXS 0506+056 and NGC 1068 respectively, provide opportunities to search for rare interactions of neutrinos that they might encounter on their paths. One potential scenario of interest is the interaction between neutrinos and dark matter, which is invisible and expected to be abundantly spread over the Universe. Various astrophysical observations have implied the existence of dark matter. When high-energy neutrinos from extragalactic sources interact with dark matter during their propagation, their spectra might show suppressions at specific energy ranges, where such interactions occur. These attenuation signatures from the interaction might be measurable on Earth with large neutrino telescopes such as the IceCube Neutrino Observatory. This analysis is focused on the search for rare interactions of high-energy neutrinos from the IceCube-identified astrophysical neutrino sources with dark matter in sub-GeV masses and several benchmark mediator cases using the upgoing track-like events. In this poster, sensitivity studies about the interaction of neutrinos and dark matter are presented