Till, A;Fries, C;Fenske, WK;
PMID: 36552107 | DOI: 10.3390/brainsci12121646
The body of mammals harbors two distinct types of adipose tissue: while cells within the white adipose tissue (WAT) store surplus energy as lipids, brown adipose tissue (BAT) is nowadays recognized as the main tissue for transforming chemical energy into heat. This process, referred to as 'non-shivering thermogenesis', is facilitated by the uncoupling of the electron transport across mitochondrial membranes from ATP production. BAT-dependent thermogenesis acts as a safeguarding mechanism under reduced ambient temperature but also plays a critical role in metabolic and energy homeostasis in health and disease. In this review, we summarize the evolutionary structure, function and regulation of the BAT organ under neuronal and hormonal control and discuss its mutual interaction with the central nervous system. We conclude by conceptualizing how better understanding the multifaceted communicative links between the brain and BAT opens avenues for novel therapeutic approaches to treat obesity and related metabolic disorders.
Pediatric and developmental pathology : the official journal of the Society for Pediatric Pathology and the Paediatric Pathology Society
Terry, J;
PMID: 36571293 | DOI: 10.1177/10935266221144083
The pathogenesis of chronic intervillositis of unknown etiology (CIUE) may involve IFNγ overexpression. This study assesses the extent of IFNγ expression in CIUE by immunohistochemistry and compares it to spontaneous pregnancy losses. C4d deposition is also assessed to see whether IFNγ and C4d might represent separate diagnostic categories. Placenta from first to early second trimester with high grade CIUE (CHG; 17 cases) and low grade CIUE (CLG; 12 cases) is compared to euploid (SPLN; 18 cases), aneuploid spontaneous pregnancy losses (SPLA, 17 cases), normal placenta (NP, 13 cases). Protein level expression of IFNγ and C4d is assessed on whole tissue sections by immunohistochemistry. 35% of CHG and 42% of CLG show some level of IFNγ expression localized to the luminal surface of syncytiotrophoblast. 12% of SPLA and no SPLN or NP cases are IFNγ positive. C4d deposition is seen in 100% of CIUE, 88% of SPLA, 83% of SPLN, and 46% of NP samples. IFNγ overexpression occurs in approximately 40% of CIUE-related pregnancy losses. IFNγ expression restricted to a subgroup of CIUE implies that IFNγ may define a distinct disease process. The non-discriminatory pattern of C4d deposition suggests it is a non-specific phenomenon possibly related to placental damage.
International journal of molecular sciences
Oku, Y;Madia, F;Lau, P;Paparella, M;McGovern, T;Luijten, M;Jacobs, MN;
PMID: 36361516 | DOI: 10.3390/ijms232112718
With recent rapid advancement of methodological tools, mechanistic understanding of biological processes leading to carcinogenesis is expanding. New approach methodologies such as transcriptomics can inform on non-genotoxic mechanisms of chemical carcinogens and can be developed for regulatory applications. The Organisation for the Economic Cooperation and Development (OECD) expert group developing an Integrated Approach to the Testing and Assessment (IATA) of Non-Genotoxic Carcinogens (NGTxC) is reviewing the possible assays to be integrated therein. In this context, we review the application of transcriptomics approaches suitable for pre-screening gene expression changes associated with phenotypic alterations that underlie the carcinogenic processes for subsequent prioritisation of downstream test methods appropriate to specific key events of non-genotoxic carcinogenesis. Using case studies, we evaluate the potential of gene expression analyses especially in relation to breast cancer, to identify the most relevant approaches that could be utilised as (pre-) screening tools, for example Gene Set Enrichment Analysis (GSEA). We also consider how to address the challenges to integrate gene panels and transcriptomic assays into the IATA, highlighting the pivotal omics markers identified for assay measurement in the IATA key events of inflammation, immune response, mitogenic signalling and cell injury.
Labbaf, Z;Petratou, K;Ermlich, L;Backer, W;Tarbashevich, K;Reichman-Fried, M;Luschnig, S;Schulte-Merker, S;Raz, E;
PMID: 35914525 | DOI: 10.1016/j.devcel.2022.07.008
Cell ablation is a key method in the research fields of developmental biology, tissue regeneration, and tissue homeostasis. Eliminating specific cell populations allows for characterizing interactions that control cell differentiation, death, behavior, and spatial organization of cells. Current methodologies for inducing cell death suffer from relatively slow kinetics, making them unsuitable for analyzing rapid events and following primary and immediate consequences of the ablation. To address this, we developed a cell-ablation system that is based on bacterial toxin/anti-toxin proteins and enables rapid and cell-autonomous elimination of specific cell types and organs in zebrafish embryos. A unique feature of this system is that it uses an anti-toxin, which allows for controlling the degree and timing of ablation and the resulting phenotypes. The transgenic zebrafish generated in this work represent a highly efficient tool for cell ablation, and this approach is applicable to other model organisms as demonstrated here for Drosophila.
Journal of controlled release : official journal of the Controlled Release Society
Xue, B;Ge, M;Fan, K;Huang, X;Yan, X;Jiang, W;Jiang, B;Yang, Z;
PMID: 35987352 | DOI: 10.1016/j.jconrel.2022.08.026
Retinal neovascularization is typically accompanied by hypoxia-induced oxidative injury in the vascular system. This study developed an ultrasmall (6-8 nm) platinum (Pt) nanozyme loaded mitochondria-targeted liposome (Pt@MitoLipo) to alleviate hypoxia and eliminate excess reactive oxygen species (ROS) for effective retinal neovascularization disease therapy. Pt nanozymes possess superoxide dismutase (SOD) and catalase (CAT) cascade enzyme-like activities, which convert cytotoxic O2•- and H2O2 into nontoxic H2O and O2. Triphenylphosphonium (TPP)-conjugated liposomes were coated on the surface of Pt nanozymes to increase their biocompatibility and help them penetrate the cell membrane, escape from the lysosomal barrier, and target mitochondria, thus achieving precise scavenging of mitochondrial O2•- and relief from hypoxia. Using an oxygen-induced retinopathy (OIR) mouse model, we demonstrated that Pt@MitoLipo nanozymes significantly suppressed hypoxia-induced abnormal neovascularization and facilitated avascular normalization of the retina in vivo without any noticeable toxicity. This study provides a promising way to break through cellular barriers and target scavenging mitochondrial O2•- and illustrates the potential of ROS-scavenging and hypoxia relief in retinal neovascularization disease therapy.
Development (Cambridge, England)
Price, JD;Lindtner, S;Ypsilanti, A;Binyameen, F;Johnson, JR;Newton, BW;Krogan, NJ;Rubenstein, JLR;
PMID: 35695185 | DOI: 10.1242/dev.199508
In the developing subpallium, the fate decision between neurons and glia is driven by expression of Dlx1/2 or Olig1/2, respectively, two sets of transcription factors with a mutually repressive relationship. The mechanism by which Dlx1/2 repress progenitor and oligodendrocyte fate, while promoting transcription of genes needed for differentiation, is not fully understood. We identified a motif within DLX1 that binds RBBP4, a NuRD complex subunit. ChIP-seq studies of genomic occupancy of DLX1 and six different members of the NuRD complex show that DLX1 and NuRD colocalize to putative regulatory elements enriched near other transcription factor genes. Loss of Dlx1/2 leads to dysregulation of genome accessibility at putative regulatory elements near genes repressed by Dlx1/2, including Olig2. Consequently, heterozygosity of Dlx1/2 and Rbbp4 leads to an increase in the production of OLIG2+ cells. These findings highlight the importance of the interplay between transcription factors and chromatin remodelers in regulating cell-fate decisions.
ACS chemical neuroscience
Dai, D;Li, W;Chen, A;Gao, XF;Xiong, L;
PMID: 35412792 | DOI: 10.1021/acschemneuro.2c00067
The lateral habenula (LHb) is a tiny structure that acts as a hub, relaying signals from the limbic forebrain structures and basal ganglia to the brainstem modulatory area. Facilitated by updated knowledge and more precise manipulation of circuits, the progress in figuring out the neural circuits and functions of the LHb has increased dramatically over the past decade. Importantly, LHb is found to play an integrative role and has profound effects on a variety of behaviors associated with pain, including depression-like and anxiety-like behaviors, antireward or aversion, aggression, defensive behavior, and substance use disorder. Thus, LHb is a potential target for improving pain management and related disorders. In this review, we focused on the functions, related circuits, and neurotransmissions of the LHb in pain processing and related behaviors. A comprehensive understanding of the relationship between the LHb and pain will help to find new pain treatments.
Lloyd-Lewis, B;Gobbo, F;Perkins, M;Jacquemin, G;Huyghe, M;Faraldo, MM;Fre, S;
PMID: 35263603 | DOI: 10.1016/j.celrep.2022.110461
Real-time in vivo imaging provides an essential window into the spatiotemporal cellular events contributing to tissue development and pathology. By coupling longitudinal intravital imaging with genetic lineage tracing, here we capture the earliest cellular events arising in response to active Wnt/β-catenin signaling and the ensuing impact on the organization and differentiation of the mammary epithelium. This enables us to interrogate how Wnt/β-catenin regulates the dynamics of distinct subpopulations of mammary epithelial cells in vivo and in real time. We show that β-catenin stabilization, when targeted to either the mammary luminal or basal epithelial lineage, leads to cellular rearrangements that precipitate the formation of hyperplastic lesions that undergo squamous transdifferentiation. These results enhance our understanding of the earliest stages of hyperplastic lesion formation in vivo and reveal that, in mammary neoplastic development, β-catenin activation dictates a hair follicle/epidermal differentiation program independently of the targeted cell of origin.
Advanced Functional Materials
Shen, H;Fan, C;You, Z;Xiao, Z;Zhao, Y;Dai, J;
| DOI: 10.1002/adfm.202110628
Spinal cord injury (SCI) often leads to the loss of motor and sensory functions and is a major challenge in neurological clinical practice. Understanding the pathophysiological changes and the inhibitory microenvironment is crucial to enable the identification of potential mechanisms for functional restoration and to provide guidance for the development of efficient treatment and repair strategies. To date, the implantation of specifically functionalized biomaterials in the lesion area has been shown to help promote axon regeneration and facilitate neuronal circuit generation by remolding SCI microenvironments. Moreover, structural and functional restoration of the spinal cord through the transplantation of naive spinal cord tissue grafts from adult donors, artificial spinal cord-like tissue developed from tissue engineering, and 3D printing will open up new avenues for SCI treatment. This review focuses on the dynamic pathophysiological changes in SCI microenvironments, biomaterials for SCI repairs, strategies for restoring spinal cord structure and function, experimental animal models, regenerative mechanisms, and clinical studies for SCI repair. The current status, recent advances, challenges, and prospects of scaffold-based SCI repair from basic to clinical settings are summarized and discussed, to provide a reference that will help to guide the future exploration and development of spinal cord regeneration strategies.
Cui, L;Guo, J;Cranfill, SL;Gautam, M;Bhattarai, J;Olson, W;Beattie, K;Challis, RC;Wu, Q;Song, X;Raabe, T;Gradinaru, V;Ma, M;Liu, Q;Luo, W;
PMID: 34986325 | DOI: 10.1016/j.neuron.2021.12.007
Whether glutamate or itch-selective neurotransmitters are used to confer itch specificity is still under debate. We focused on an itch-selective population of primary afferents expressing MRGPRA3, which highly expresses Vglut2 and the neuropeptide neuromedin B (Nmb), to investigate this question. Optogenetic stimulation of MRGPRA3+ afferents triggers scratching and other itch-related avoidance behaviors. Using a combination of optogenetics, spinal cord slice recordings, Vglut2 conditional knockout mice, and behavior assays, we showed that glutamate is essential for MRGPRA3+ afferents to transmit itch. We further demonstrated that MRGPRA3+ afferents form monosynaptic connections with both NMBR+ and NMBR- neurons and that NMB and glutamate together can enhance the activity of NMBR+ spinal DH neurons. Moreover, Nmb in MRGPRA3+ afferents and NMBR+ DH neurons are required for chloroquine-induced scratching. Together, our results establish a new model in which glutamate is an essential neurotransmitter in primary afferents for itch transmission, whereas NMB signaling enhances its activities.
Steiner, I;Flores-Tellez, T;Mevel, R;Ali, A;Wang, P;Schofield, P;Forsythe, N;Ashton, G;Taylor, C;Mills, I;Oliveira, P;McDade, S;Zeiss, D;Choudhury, A;Lacaud, G;Baena, E;
| DOI: 10.2139/ssrn.3966640
The emergence of castration resistant prostate cancer is associated with a high mortality and remains an area of unmet clinical need. We recently identified a rare subpopulation of normal prostate progenitor cells, characterized by an intrinsic resistance to androgen-deprivation and marked by the expression of LY6D. We here describe the underlying mechanisms driving castration-resistance of LY6D+ luminal progenitors and their contribution to advanced prostate cancer. We demonstrate that conditional deletion of PTEN in the murine prostate epithelium causes an expansion of transformed LY6D+ progenitor cells in proximal and distal regions of the prostate without impairing stem cell properties. Transcriptomic analyses of LY6D+ luminal cells identified an autocrine positive feed-back loop, based on the secretion of amphiregulin (AREG), further increasing cellular fitness and organoid formation. Pharmacological interference with AREG-activated MAPK-signaling overcomes the castration-resistant properties of LY6D+ cells with a near complete suppression of organoid formation. Notably, LY6D+ tumor cells are enriched in prostate specimens from high-grade and androgen-resistant prostate cancer, providing clinical evidence for their contribution to advanced and also metastatic disease. Our data indicate that the prospective identification of LY6D+ cells could allow for an early interference with MAPK-inhibitors to prevent the emergence of castration-resistant prostate cancer.
Functional coordination of non-myocytes plays a key role in adult zebrafish heart regeneration
Ma, H;Liu, Z;Yang, Y;Feng, D;Dong, Y;Garbutt, TA;Hu, Z;Wang, L;Luan, C;Cooper, CD;Li, Y;Welch, JD;Qian, L;Liu, J;
PMID: 34523214 | DOI: 10.15252/embr.202152901
Cardiac regeneration occurs primarily through proliferation of existing cardiomyocytes, but also involves complex interactions between distinct cardiac cell types including non-cardiomyocytes (non-CMs). However, the subpopulations, distinguishing molecular features, cellular functions, and intercellular interactions of non-CMs in heart regeneration remain largely unexplored. Using the LIGER algorithm, we assemble an atlas of cell states from 61,977 individual non-CM scRNA-seq profiles isolated at multiple time points during regeneration. This analysis reveals extensive non-CM cell diversity, including multiple macrophage (MC), fibroblast (FB), and endothelial cell (EC) subpopulations with unique spatiotemporal distributions, and suggests an important role for MC in inducing the activated FB and EC subpopulations. Indeed, pharmacological perturbation of MC function compromises the induction of the unique FB and EC subpopulations. Furthermore, we developed computational algorithm Topologizer to map the topological relationships and dynamic transitions between functional states. We uncover dynamic transitions between MC functional states and identify factors involved in mRNA processing and transcriptional regulation associated with the transition. Together, our single-cell transcriptomic analysis of non-CMs during cardiac regeneration provides a blueprint for interrogating the molecular and cellular basis of this process.