Pflugers Archiv : European journal of physiology
Heinl, ES;Broeker, KA;Lehrmann, C;Heydn, R;Krieger, K;Ortmaier, K;Tauber, P;Schweda, F;
PMID: 36480070 | DOI: 10.1007/s00424-022-02774-9
The natriuretic peptides (NPs) ANP (atrial natriuretic peptide) and BNP (B-type natriuretic peptide) mediate their widespread effects by activating the natriuretic peptide receptor-A (NPR-A), while C-type natriuretic peptide (CNP) acts via natriuretic peptide receptor-B (NPR-B). NPs are removed from the circulation by internalization via the natriuretic peptide clearance receptor natriuretic peptide receptor-C (NPR-C). In addition to their well-known functions, for instance on blood pressure, all three NPs confer significant cardioprotection and renoprotection. Since neither the NP-mediated renal functions nor the renal target cells of renoprotection are completely understood, we performed systematic localization studies of NP receptors using in situ hybridization (RNAscope) in mouse kidneys. NPR-A mRNA is highly expressed in glomeruli (mainly podocytes), renal arterioles, endothelial cells of peritubular capillaries, and PDGFR-receptor β positive (PDGFR-β) interstitial cells. No NPR-A mRNA was detected by RNAscope in the tubular system. In contrast, NPR-B expression is highest in proximal tubules. NPR-C is located in glomeruli (mainly podocytes), in endothelial cells and PDGFR-β positive cells. To test for a possible regulation of NPRs in kidney diseases, their distribution was studied in adenine nephropathy. Signal intensity of NPR-A and NPR-B mRNA was reduced while their spatial distribution was unaltered compared with healthy kidneys. In contrast, NPR-C mRNA signal was markedly enhanced in cell clusters of myofibroblasts in fibrotic areas of adenine kidneys. In conclusion, the primary renal targets of ANP and BNP are glomerular, vascular, and interstitial cells but not the tubular compartment, while the CNP receptor NPR-B is highly expressed in proximal tubules. Further studies are needed to clarify the function and interplay of this specific receptor expression pattern.
Lotun, A;Li, D;Xu, H;Su, Q;Tuncer, S;Sanmiguel, J;Mooney, M;Baer, CE;Ulbrich, R;Eyles, SJ;Strittmatter, L;Hayward, LJ;Gessler, DJ;Gao, G;
PMID: 37149081 | DOI: 10.1016/j.pneurobio.2023.102460
Myelinating oligodendrocytes are essential for neuronal communication and homeostasis of the central nervous system (CNS). One of the most abundant molecules in the mammalian CNS is N-acetylaspartate (NAA), which is catabolized into L-aspartate and acetate by the enzyme aspartoacylase (ASPA) in oligodendrocytes. The resulting acetate moiety is thought to contribute to myelin lipid synthesis. In addition, affected NAA metabolism has been implicated in several neurological disorders, including leukodystrophies and demyelinating diseases such as multiple sclerosis. Genetic disruption of ASPA function causes Canavan disease, which is hallmarked by increased NAA levels, myelin and neuronal loss, large vacuole formation in the CNS, and early death in childhood. Although NAA's direct role in the CNS is inconclusive, in peripheral adipose tissue, NAA-derived acetate has been found to modify histones, a mechanism known to be involved in epigenetic regulation of cell differentiation. We hypothesize that a lack of cellular differentiation in the brain contributes to the disruption of myelination and neurodegeneration in diseases with altered NAA metabolism, such as Canavan disease. Our study demonstrates that loss of functional Aspa in mice disrupts myelination and shifts the transcriptional expression of neuronal and oligodendrocyte markers towards less differentiated stages in a spatiotemporal manner. Upon re-expression of ASPA, these oligodendrocyte and neuronal lineage markers are either improved or normalized, suggesting that NAA breakdown by Aspa plays an essential role in the maturation of neurons and oligodendrocytes. Also, this effect of ASPA re-expression is blunted in old mice, potentially due to limited ability of neuronal, rather than oligodendrocyte, recovery.
Ling KK, Jackson M, Alkam D, Liu D, Allaire N, Sun C, Kiaei M, McCampbell A, Rigo F.
PMID: 29518482 | DOI: 10.1016/j.nbd.2018.03.002
Amyotrophic lateral sclerosis (ALS) is a fatal adult onset motor neuron disease characterized by progressive denervation and subsequent motor impairment. EphA4, a negative regulator of axonal growth, was recently identified as a genetic modifier in fish and rodent models of ALS. To evaluate the therapeutic potential of EphA4 for ALS, we examined the effect of CNS-directed EphA4 reduction in preclinical mouse models of ALS, and assessed if the levels of EPHA4 mRNA in blood correlate with disease onset and progression in human ALS patients. We developed antisense oligonucleotides (ASOs) to specifically reduce the expression of EphA4 in the central nervous system (CNS) of adult mice. Intracerebroventricular administration of an Epha4-ASO in wild-type mice inhibited Epha4 mRNA and protein in the brain and spinal cord, and promoted re-innervation and functional recovery after sciatic nerve crush. In contrast, lowering of EphA4 in the CNS of two mouse models of ALS (SOD1G93A and PFN1G118V) did not improve their motor function or survival. Furthermore, the level of EPHA4 mRNA in human blood correlated weakly with age of disease onset, and it was not a significant predictor of disease progression as measured by ALS Functional Rating Scores (ALSFRS). Our data demonstrates that lowering EphA4 in the adult CNS may not be a stand-alone viable strategy for treating ALS.
Liu, QR;Zhu, M;Zhang, P;Mazucanti, CH;Huang, NS;Lang, DL;Chen, Q;Auluck, P;Marenco, S;O'Connell, JF;Ferrucci, L;Chia, CW;Egan, JM;
PMID: 34649926 | DOI: 10.2337/db21-0198
Human insulin (INS) gene diverged from the ancestral genes of invertebrate and mammalian species millions of years ago. We previously found that mouse insulin gene (Ins2) isoforms are expressed in brain choroid plexus (ChP) epithelium cells where insulin secretion is regulated by serotonin and not by glucose. We further compared human INS isoform expression in postmortem ChP and islets of Langerhans. We uncovered novel INS upstream open reading frame (uORF) isoforms and their protein products. In addition, we found a novel alternatively spliced isoform that translates to a 74-amino acid (AA) proinsulin containing a shorter 19-AA C-peptide sequence, herein designated Cα-peptide. The middle portion of the conventional C-peptide contains β-sheet (GQVEL) and hairpin (GGGPG) motifs that are not present in Cα-peptide. Islet amyloid polypeptide (IAPP) is not expressed in ChP and its amyloid formation was inhibited in vitro by Cα-peptide more efficiently than by C-peptide. Of clinical relevance, the ratio of the 74-AA proinsulin to proconvertase processed Cα-peptide was significantly increased in islets from type 2 diabetes mellitus (T2DM) autopsy donors. Intriguingly, 100 years after the discovery of insulin we found that INS isoforms are present in ChP from insulin-deficient autopsy donors.
Forrest, SL;Lee, S;Nassir, N;Martinez-Valbuena, I;Sackmann, V;Li, J;Ahmed, A;Tartaglia, MC;Ittner, LM;Lang, AE;Uddin, M;Kovacs, GG;
PMID: 37354322 | DOI: 10.1007/s00401-023-02604-x
Microtubule-associated protein tau (MAPT) aggregates in neurons, astrocytes and oligodendrocytes in a number of neurodegenerative diseases, including progressive supranuclear palsy (PSP). Tau is a target of therapy and the strategy includes either the elimination of pathological tau aggregates or reducing MAPT expression, and thus the amount of tau protein made to prevent its aggregation. Disease-associated tau affects brain regions in a sequential manner that includes cell-to-cell spreading. Involvement of glial cells that show tau aggregates is interpreted as glial cells taking up misfolded tau assuming that glial cells do not express enough MAPT. Although studies have evaluated MAPT expression in human brain tissue homogenates, it is not clear whether MAPT expression is compromised in cells accumulating pathological tau. To address these perplexing aspects of disease pathogenesis, this study used RNAscope combined with immunofluorescence (AT8), and single-nuclear(sn) RNAseq to systematically map and quantify MAPT expression dynamics across different cell types and brain regions in controls (n = 3) and evaluated whether tau cytopathology affects MAPT expression in PSP (n = 3). MAPT transcripts were detected in neurons, astrocytes and oligodendrocytes, and varied between brain regions and within each cell type, and were preserved in all cell types with tau aggregates in PSP. These results propose a complex scenario in all cell types, where, in addition to the ingested misfolded tau, the preserved cellular MAPT expression provides a pool for local protein production that can (1) be phosphorylated and aggregated, or (2) feed the seeding of ingested misfolded tau by providing physiological tau, both accentuating the pathological process. Since tau cytopathology does not compromise MAPT gene expression in PSP, a complete loss of tau protein expression as an early pathogenic component is less likely. These observations provide rationale for a dual approach to therapy by decreasing cellular MAPT expression and targeting removal of misfolded tau.
Journal for immunotherapy of cancer
Michels, KR;Sheih, A;Hernandez, SA;Brandes, AH;Parrilla, D;Irwin, B;Perez, AM;Ting, HA;Nicolai, CJ;Gervascio, T;Shin, S;Pankau, MD;Muhonen, M;Freeman, J;Gould, S;Getto, R;Larson, RP;Ryu, BY;Scharenberg, AM;Sullivan, AM;Green, S;
PMID: 36918221 | DOI: 10.1136/jitc-2022-006292
Chimeric antigen receptor (CAR) T-cell therapies have demonstrated transformational outcomes in the treatment of B-cell malignancies, but their widespread use is hindered by technical and logistical challenges associated with ex vivo cell manufacturing. To overcome these challenges, we developed VivoVec, a lentiviral vector-based platform for in vivo engineering of T cells. UB-VV100, a VivoVec clinical candidate for the treatment of B-cell malignancies, displays an anti-CD3 single-chain variable fragment (scFv) on the surface and delivers a genetic payload that encodes a second-generation CD19-targeted CAR along with a rapamycin-activated cytokine receptor (RACR) system designed to overcome the need for lymphodepleting chemotherapy in supporting successful CAR T-cell expansion and persistence. In the presence of exogenous rapamycin, non-transduced immune cells are suppressed, while the RACR system in transduced cells converts rapamycin binding to an interleukin (IL)-2/IL-15 signal to promote proliferation.UB-VV100 was administered to peripheral blood mononuclear cells (PBMCs) from healthy donors and from patients with B-cell malignancy without additional stimulation. Cultures were assessed for CAR T-cell transduction and function. Biodistribution was evaluated in CD34-humanized mice and in canines. In vivo efficacy was evaluated against normal B cells in CD34-humanized mice and against systemic tumor xenografts in PBMC-humanized mice.In vitro, administration of UB-VV100 resulted in dose-dependent and anti-CD3 scFv-dependent T-cell activation and CAR T-cell transduction. The resulting CAR T cells exhibited selective expansion in rapamycin and antigen-dependent activity against malignant B-cell targets. In humanized mouse and canine studies, UB-VV100 demonstrated a favorable biodistribution profile, with transduction events limited to the immune compartment after intranodal or intraperitoneal administration. Administration of UB-VV100 to humanized mice engrafted with B-cell tumors resulted in CAR T-cell transduction, expansion, and elimination of systemic malignancy.These findings demonstrate that UB-VV100 generates functional CAR T cells in vivo, which could expand patient access to CAR T technology in both hematological and solid tumors without the need for ex vivo cell manufacturing.
Serafini, RA;Frere, JJ;Zimering, J;Giosan, IM;Pryce, KD;Golynker, I;Panis, M;Ruiz, A;tenOever, BR;Zachariou, V;
PMID: 37159520 | DOI: 10.1126/scisignal.ade4984
Although largely confined to the airways, SARS-CoV-2 infection has been associated with sensory abnormalities that manifest in both acute and chronic phenotypes. To gain insight on the molecular basis of these sensory abnormalities, we used the golden hamster model to characterize and compare the effects of infection with SARS-CoV-2 and influenza A virus (IAV) on the sensory nervous system. We detected SARS-CoV-2 transcripts but no infectious material in the cervical and thoracic spinal cord and dorsal root ganglia (DRGs) within the first 24 hours of intranasal virus infection. SARS-CoV-2-infected hamsters exhibited mechanical hypersensitivity that was milder but prolonged compared with that observed in IAV-infected hamsters. RNA sequencing analysis of thoracic DRGs 1 to 4 days after infection suggested perturbations in predominantly neuronal signaling in SARS-CoV-2-infected animals as opposed to type I interferon signaling in IAV-infected animals. Later, 31 days after infection, a neuropathic transcriptome emerged in thoracic DRGs from SARS-CoV-2-infected animals, which coincided with SARS-CoV-2-specific mechanical hypersensitivity. These data revealed potential targets for pain management, including the RNA binding protein ILF3, which was validated in murine pain models. This work elucidates transcriptomic signatures in the DRGs triggered by SARS-CoV-2 that may underlie both short- and long-term sensory abnormalities.
The Journal of clinical investigation
Alter, C;Henseler, AS;Owenier, C;Hesse, J;Ding, Z;Lautwein, T;Bahr, J;Hayat, S;Kramann, R;Kostenis, E;Scheller, J;Schrader, J;
PMID: 36943408 | DOI: 10.1172/JCI163799
Plasma IL-6 is elevated after myocardial infarction (MI) and is associated with increased morbidity and mortality. Which cardiac cell type preferentially contributes to IL-6 and how its production is regulated is largely unknown. Here, we studied the cellular source and purinergic regulation of IL-6 formation in a murine MI model. IL-6, measured in various cell types in post MI hearts by qPCR, RNAscope and at protein level, was preferentially formed by fibroblasts (CFs). scRNAseq in infarcted mouse and human hearts confirmed this finding. Adenosine stimulated fibroblast IL-6 formation via A2bR in a Gq-dependent manner. CFs highly expressed Adora2b, rapidly degraded extracellular ATP to AMP but lacked CD73. In mice and humans Adora2B was also mainly expressed by fibroblasts (scRNAseq). Global IL-6 formation was assessed in isolated hearts in mice lacking CD73 on T-cells (CD4CD73-/-) a condition known to be associated with adverse cardiac remodeling. The ischemia-induced release of IL-6 was strongly attenuated in CD4CD73-/- mice, suggesting adenosine-mediated modulation. Together this demonstrates that post-MI IL-6 is mainly derived from activated CFs and is controlled by T-cell derived adenosine. Purinergic metabolic cooperation between CFs and T-cells is a novel mechanism with therapeutic potential which modulates IL6 formation by the heart.
Stein LM, Lhamo R, Cao A, Workinger J, Tinsley I, Doyle RP, Grill HJ, Hermann GE, Rogers RC, Hayes MR
PMID: 32152264 | DOI: 10.1038/s41398-020-0767-0
Previous studies identify a role for hypothalamic glia in energy balance regulation; however, a narrow hypothalamic focus provides an incomplete understanding of how glia throughout the brain respond to and regulate energy homeostasis. We examined the responses of glia in the dorsal vagal complex (DVC) to the adipokine leptin and high fat diet-induced obesity. DVC astrocytes functionally express the leptin receptor; in vivo pharmacological studies suggest that DVC astrocytes partly mediate the anorectic effects of leptin in lean but not diet-induced obese rats. Ex vivo calcium imaging indicated that these changes were related to a lower proportion of leptin-responsive cells in the DVC of obese versus lean animals. Finally, we investigated DVC microglia and astroglia responses to leptin and energy balance dysregulation in vivo: obesity decreased DVC astrogliosis, whereas the absence of leptin signaling in Zucker rats was associated with extensive astrogliosis in the DVC and decreased hypothalamic micro- and astrogliosis. These data uncover a novel functional heterogeneity of astrocytes in different brain nuclei of relevance to leptin signaling and energy balance regulation
Qian, X;DeGennaro, EM;Talukdar, M;Akula, SK;Lai, A;Shao, DD;Gonzalez, D;Marciano, JH;Smith, RS;Hylton, NK;Yang, E;Bazan, JF;Barrett, L;Yeh, RC;Hill, RS;Beck, SG;Otani, A;Angad, J;Mitani, T;Posey, JE;Pehlivan, D;Calame, D;Aydin, H;Yesilbas, O;Parks, KC;Argilli, E;England, E;Im, K;Taranath, A;Scott, HS;Barnett, CP;Arts, P;Sherr, EH;Lupski, JR;Walsh, CA;
PMID: 36228617 | DOI: 10.1016/j.devcel.2022.09.011
Kinesins are canonical molecular motors but can also function as modulators of intracellular signaling. KIF26A, an unconventional kinesin that lacks motor activity, inhibits growth-factor-receptor-bound protein 2 (GRB2)- and focal adhesion kinase (FAK)-dependent signal transduction, but its functions in the brain have not been characterized. We report a patient cohort with biallelic loss-of-function variants in KIF26A, exhibiting a spectrum of congenital brain malformations. In the developing brain, KIF26A is preferentially expressed during early- and mid-gestation in excitatory neurons. Combining mice and human iPSC-derived organoid models, we discovered that loss of KIF26A causes excitatory neuron-specific defects in radial migration, localization, dendritic and axonal growth, and apoptosis, offering a convincing explanation of the disease etiology in patients. Single-cell RNA sequencing in KIF26A knockout organoids revealed transcriptional changes in MAPK, MYC, and E2F pathways. Our findings illustrate the pathogenesis of KIF26A loss-of-function variants and identify the surprising versatility of this non-motor kinesin.
Zhu H, Meissner LE, Byrnes C, Tuymetova G, Tifft CJ, Proia RL
PMID: 32179479 | DOI: 10.1016/j.isci.2020.100957
The SUSD4 (Sushi domain-containing protein 4) gene encodes a complement inhibitor that is frequently deleted in 1q41q42 microdeletion syndrome, a multisystem congenital disorder that includes neurodevelopmental abnormalities. To understand SUSD4's role in the mammalian nervous system, we analyzed Susd4 knockout (KO) mice. Susd4 KO mice exhibited significant defects in motor performance and significantly higher levels of anxiety-like behaviors. Susd4 KO brain had abnormal "hairy" basket cells surrounding Purkinje neurons within the cerebellum and significantly reduced dendritic spine density in hippocampal pyramidal neurons. Neurons and oligodendrocyte lineage cells of wild-type mice were found to express Susd4 mRNA. Protein expression of the complement component C1q was increased in the brains of Susd4 KO mice. Our data indicate that SUSD4 plays an important role in neuronal functions, possibly via the complement pathway, and that SUSD4 deletion may contribute to the nervous system abnormalities in patients with 1q41q42 deletions
Nuclear isoform of FGF13 regulates post-natal neurogenesis in the hippocampus through an epigenomic mechanism
Yang, QQ;Zhai, YQ;Wang, HF;Cai, YC;Ma, XY;Yin, YQ;Li, YD;Zhou, GM;Zhang, X;Hu, G;Zhou, JW;
PMID: 34010636 | DOI: 10.1016/j.celrep.2021.109127
The hippocampus is one of two niches in the mammalian brain with persistent neurogenesis into adulthood. The neurogenic capacity of hippocampal neural stem cells (NSCs) declines with age, but the molecular mechanisms of this process remain unknown. In this study, we find that fibroblast growth factor 13 (FGF13) is essential for the post-natal neurogenesis in mouse hippocampus, and FGF13 deficiency impairs learning and memory. In particular, we find that FGF13A, the nuclear isoform of FGF13, is involved in the maintenance of NSCs and the suppression of neuronal differentiation during post-natal hippocampal development. Furthermore, we find that FGF13A interacts with ARID1B, a unit of Brahma-associated factor chromatin remodeling complex, and suppresses the expression of neuron differentiation-associated genes through chromatin modification. Our results suggest that FGF13A is an important regulator for maintaining the self-renewal and neurogenic capacity of NSCs in post-natal hippocampus, revealing an epigenomic regulatory function of FGFs in neurogenesis.
