The Journal of clinical investigation
Chen, X;Dong, T;Hu, Y;De Pace, R;Mattera, R;Eberhardt, K;Ziegler, M;Pirovolakis, T;Sahin, M;Bonifacino, JS;Ebrahimi-Fakhari, D;Gray, SJ;
PMID: 36951961 | DOI: 10.1172/JCI164575
Spastic paraplegia 50 (SPG50) is an ultrarare childhood-onset neurological disorder caused by biallelic loss-of-function variants in the AP4M1 gene. SPG50 is characterized by progressive spastic paraplegia, global developmental delay and subsequent intellectual disability, secondary microcephaly, and epilepsy. Preclinical studies evaluated an adeno-associated virus (AAV)/AP4M1 gene therapy for SPG50. In vitro studies demonstrated that transduction of patient-derived fibroblasts with AAV2/AP4M1 resulted in phenotypic rescue. To evaluate efficacy in vivo, Ap4m1 knockout mice were intrathecally (IT) injected with 5E11, 2.5E11, or 1.25E11 vg doses of AAV9/AP4M1 at postnatal day p7-10 (pre-manifesting cohorts) or p90 (early manifesting cohorts). Age- and dose-dependent effects were observed, with early intervention and higher doses achieving the best therapeutic benefits. In parallel, three toxicology studies in wild-type mice, rats, and non-human primates (NHPs) demonstrated that AAV9/AP4M1 had an acceptable safety profile up to a target human dose of 1E15 vg. Of note, similar degrees of minimal to mild dorsal root ganglia (DRG) toxicity were observed in both rats and NHPs, supporting the use of rats to monitor DRG toxicity in future IT AAV studies. These preclinical results identify an acceptably safe and efficacious dose of IT-administered AAV9/AP4M1, supporting an investigational gene transfer clinical trial to treat SPG50.
bioRxiv : the preprint server for biology
Du, W;Ergin, V;Loeb, C;Huang, M;Silver, S;Armstrong, AM;Huang, Z;Gurumurthy, CB;Staecker, H;Liu, X;Chen, ZY;
PMID: 36865298 | DOI: 10.1101/2023.02.25.530035
Patients with mutations in the TMPRSS3 gene suffer from recessive deafness DFNB8/DFNB10 for whom cochlear implantation is the only treatment option. Poor cochlear implantation outcomes are seen in some patients. To develop biological treatment for TMPRSS3 patients, we generated a knock-in mouse model with a frequent human DFNB8 TMPRSS3 mutation. The Tmprss3 A306T/A306T homozygous mice display delayed onset progressive hearing loss similar to human DFNB8 patients. Using AAV2 as a vector to carry a human TMPRSS3 gene, AAV2-h TMPRSS3 injection in the adult knock-in mouse inner ears results in TMPRSS3 expression in the hair cells and the spiral ganglion neurons. A single AAV2-h TMPRSS3 injection in aged Tmprss3 A306T/A306T mice leads to sustained rescue of the auditory function, to a level similar to the wildtype mice. AAV2-h TMPRSS3 delivery rescues the hair cells and the spiral ganglions. This is the first study to demonstrate successful gene therapy in an aged mouse model of human genetic deafness. This study lays the foundation to develop AAV2-h TMPRSS3 gene therapy to treat DFNB8 patients, as a standalone therapy or in combination with cochlear implantation.
Noh, YW;Yook, C;Kang, J;Lee, S;Kim, Y;Yang, E;Kim, H;Kim, E;
PMID: 35982261 | DOI: 10.1038/s42003-022-03813-y
IRSp53 (or BAIAP2) is an abundant excitatory postsynaptic scaffolding/adaptor protein that is involved in actin regulation and has been implicated in autism spectrum disorders, schizophrenia, and attention-deficit/hyperactivity disorder. IRSp53 deletion in mice leads to enhanced NMDA receptor (NMDAR) function and social deficits that are responsive to NMDAR inhibition. However, it remains unclear whether IRSp53 re-expression in the adult IRSp53-mutant mouse brain after the completion of brain development could reverse these synaptic and behavioral dysfunctions. Here we employed a brain-blood barrier (BBB)-penetrant adeno-associated virus (AAV) known as PHP.eB to drive adult IRSp53 re-expression in IRSp53-mutant mice. The adult IRSp53 re-expression normalized social deficits without affecting hyperactivity or anxiety-like behavior. In addition, adult IRSp53 re-expression normalized NMDAR-mediated excitatory synaptic transmission in the medial prefrontal cortex. Our results suggest that adult IRSp53 re-expression can normalize synaptic and behavioral deficits in IRSp53-mutant mice and that BBB-penetrant adult gene re-expression has therapeutic potential.
Boender, AJ;Boon, M;Albers, HE;Eck, SR;Fricker, BA;Kelly, AM;LeDoux, JE;Motta, SC;Shrestha, P;Taylor, JH;Trainor, BC;Triana-Del Rio, R;Young, LJ;
PMID: 37256960 | DOI: 10.1126/sciadv.adf4950
A major issue in neuroscience is the poor translatability of research results from preclinical studies in animals to clinical outcomes. Comparative neuroscience can overcome this barrier by studying multiple species to differentiate between species-specific and general mechanisms of neural circuit functioning. Targeted manipulation of neural circuits often depends on genetic dissection, and use of this technique has been restricted to only a few model species, limiting its application in comparative research. However, ongoing advances in genomics make genetic dissection attainable in a growing number of species. To demonstrate the potential of comparative gene editing approaches, we developed a viral-mediated CRISPR/Cas9 strategy that is predicted to target the oxytocin receptor (Oxtr) gene in >80 rodent species. This strategy specifically reduced OXTR levels in all evaluated species (n = 6) without causing gross neuronal toxicity. Thus, we show that CRISPR/Cas9-based tools can function in multiple species simultaneously. Thereby, we hope to encourage comparative gene editing and improve the translatability of neuroscientific research.
Leithead, AB;Godino, A;Barbier, M;Harony-Nicolas, H;
PMID: 37245781 | DOI: 10.1016/j.biopsych.2023.05.016
The posterior intralaminar (PIL) complex of the thalamus is a multimodal nucleus that has been implicated in maternal behaviors and conspecific social behaviors in male and female rodents. Glutamatergic neurons are a major component of the PIL; however, their specific activity and role during social interactions has not yet been assessed.We used immunohistochemistry for the immediate early gene c-fos as a proxy for neuronal activity in the PIL of mice exposed to a novel social stimulus, a novel object stimulus, or no stimulus. We then used fiber photometry to record neural activity of glutamatergic neurons in the PIL in real-time during social and non-social interactions. Finally, we used inhibitory DREADDs in glutamatergic PIL neurons and tested social preference and social habituation-dishabituation.We observed significantly more c-fos-positive cells in the PIL of mice exposed to social versus object or no stimuli. Neural activity of PIL glutamatergic neurons was increased when male and female mice were engaged in social interaction with a same-sex juvenile or opposite-sex adult, but not a toy mouse. Neural activity positively correlated with social investigation bout length and negatively correlated with chronological order of bouts. Social preference was unaffected by inhibition; however, inhibiting activity of glutamatergic neurons in the PIL delayed the time it took female mice to form social habituation.Together these findings suggest that glutamatergic PIL neurons respond to social stimuli in both male and female mice and may regulate perceptual encoding of social information to facilitate recognition of social stimuli.
Rashnonejad, A;Amini-Chermahini, G;Taylor, N;Fowler, A;Kraus, E;King, O;Harper, S;
| DOI: 10.1016/j.nmd.2022.07.255
Facioscapulohumeral muscular dystrophy (FSHD) is among the most prevalent muscular dystrophies, ranging from 1 in 8,333 to 1 in 20,000. Currently no treatment exists that alters the course of FSHD, and therapy development remains an unmet need in the field. Abnormal reactivation of the DUX4 gene in skeletal muscle has emerged as an underlying cause of muscle weakness and wasting in FSHD. We propose that DUX4 silencing is the most direct route to FSHD therapy. Toward this goal, we developed an AAV6-CRISPR-Cas13 strategy to silence DUX4 mRNA. Cas13 targets and cleaves RNA instead of DNA, and avoids potential risks of permanent off-target genome editing that could arise with DNA-targeting systems. Intramuscular delivery of an AAV6 vector encoding a PspCas13b enzyme and DUX4-targeting guide RNAs reduced DUX4 mRNA by >50% and improved histopathological outcomes in FSHD mice. To investigate possible off-target effects, we performed RNA-seq of treated versus control or untreated human myoblasts and also examined potential collateral RNA cleavage activity using a dual reporter system. Although we did not detect collateral cleavage, our RNA-sequencing results suggested some guide RNAs could induce potential off-target gene expression changes. We are currently exploring mechanisms to explain these differential off-target effects. To address whether PspCas13b can activate a mammalian host immune response, we injected wild-type mice with AAV-Cas13b and investigated immune cell infiltration and pro-inflammatory cytokine profiles. We find evidence of an immune response against PspCas13b in injected mouse muscles. Importantly, transient immunosuppression reduced immune responses to Cas13b in treated animals. In conclusion, our data support that Cas13b can target and reduce DUX4 expression in FSHD muscles, but minimizing cellular immune response may be necessary to translate AAV-Cas13b therapy.
Molecular Therapy - Methods & Clinical Development
Khoja, S;Lambert, J;Nitzahn, M;Eliav, A;Zhang, Y;Tamboline, M;Le, C;Nasser, E;Li, Y;Patel, P;Zhuravka, I;Lueptow, L;Tkachyova, I;Xu, S;Nissim, I;Schulze, A;Lipshutz, G;
| DOI: 10.1016/j.omtm.2022.03.015
Creatine deficiency disorders are inborn errors of creatine metabolism, an energy homeostasis molecule. One of these, guanidinoacetate N-methyltransferase (GAMT) deficiency, has clinical characteristics that include features of autism, self-mutilation, intellectual disability and seizures with approximately 40% having a disorder of movement; failure to thrive can also be a component. Along with low creatine levels, guanidinoacetic acid (GAA) toxicity has been implicated in the pathophysiology of the disorder. Present-day therapy with oral creatine to control GAA lacks efficacy; seizures can persist. Dietary management and pharmacological ornithine treatment are challenging. Utilizing an AAV-based gene therapy approach to express human codon-optimized GAMT in hepatocytes, in situ hybridization and immunostaining demonstrated pan-hepatic GAMT expression. Serial collection of blood demonstrated a marked early and sustained reduction of GAA with normalization of plasma creatine; urinary GAA levels also markedly declined. The terminal time point demonstrated marked improvement in cerebral and myocardial creatine levels. In conjunction with the biochemical findings, treated mice gained weight to nearly match their wild type littermates, while behavioral studies demonstrated resolution of abnormalities; PET-CT imaging demonstrated improvement in brain metabolism. In conclusion, a gene therapy approach can result in long-term normalization of GAA with increased creatine in guanidinoacetate N-methyltransferase deficiency and at the same time resolves the behavioral phenotype in a murine model of the disorder. These findings have important implications for the development of a new therapy for this abnormality of creatine metabolism.
Investigative Ophthalmology & Visual Science
Sudharsan, R;Aguirre, GD;
RESULTS : PR-specific expression of _PRLΔE1_ was observed in the following canine models of progressive inherited retinal degeneration (IRD): _RPGR_-XLPRA1 and _NPHP5_-LCA. In _RPGR_-XLPRA2 carrier retinas that undergo random X-inactivation, patches of_ PRLΔE1 _expression correlated with patches of PR degeneration. However, we did not observe expression of _PRLΔE1_ 24 hrs and 2 wks after light exposure that triggers acute rod loss in the canine RHO-T4R model of adRP. No _PRLΔE1 _expression was seen either in the _CNGB3_-ACHM3 retina that undergoes extremely slow cone degeneration. In _RPGR-_XLPRA1 and _RPGR-_XLPRA2 dogs subretinally-injected with an AAV-_RPGR_ vector, _PRLΔE1 _was completely absent in treated PRs while robust expression was seen in diseased/untreated areas.
Vectorology for Optogenetics and Chemogenetics
Bohlen, M;Tremblay, S;
| DOI: 10.1007/978-1-0716-2918-5_16
The development of new genetic tools has revolutionized our ability to study the functional role of specific neuronal populations and circuits generating behavior. Although this revolution has already taken place in small animal models such as mice, adoption of these techniques has been relatively slow for animals more closely related to humans, such as nonhuman primates. Current challenges include effective delivery to much larger structural targets in the primate brain, cell-type specific transduction, and immunological responses. In this chapter, we will review some of the challenges and considerations that are specific to using these viral technologies in the nonhuman primate brain. Ultimately, these challenges can be met with new advances in surgical technique and gene therapy that will spin out new viral vectors with enhanced features able to compensate for the limitations of current vectors. As the existing challenges are circumvented, this will lead to a revolution in primate neuroscientific research and a greater understanding of the functional role circuits play in complex behaviors relevant to human neurological and psychiatric diseases.
Becker, K;Weigelt, CM;Fuchs, H;Viollet, C;Rust, W;Wyatt, H;Huber, J;Lamla, T;Fernandez-Albert, F;Simon, E;Zippel, N;Bakker, RA;Klein, H;Redemann, NH;
PMID: 36371417 | DOI: 10.1038/s41598-022-23065-4
Retinopathies are multifactorial diseases with complex pathologies that eventually lead to vision loss. Animal models facilitate the understanding of the pathophysiology and identification of novel treatment options. However, each animal model reflects only specific disease aspects and understanding of the specific molecular changes in most disease models is limited. Here, we conducted transcriptome analysis of murine ocular tissue transduced with recombinant Adeno-associated viruses (AAVs) expressing either human VEGF-A, TNF-α, or IL-6. VEGF expression led to a distinct regulation of extracellular matrix (ECM)-associated genes. In contrast, both TNF-α and IL-6 led to more comparable gene expression changes in interleukin signaling, and the complement cascade, with TNF-α-induced changes being more pronounced. Furthermore, integration of single cell RNA-Sequencing data suggested an increase of endothelial cell-specific marker genes by VEGF, while TNF-α expression increased the expression T-cell markers. Both TNF-α and IL-6 expression led to an increase in macrophage markers. Finally, transcriptomic changes in AAV-VEGF treated mice largely overlapped with gene expression changes observed in the oxygen-induced retinopathy model, especially regarding ECM components and endothelial cell-specific gene expression. Altogether, our study represents a valuable investigation of gene expression changes induced by VEGF, TNF-α, and IL-6 and will aid researchers in selecting appropriate animal models for retinopathies based on their agreement with the human pathophysiology.
Frontiers in bioengineering and biotechnology
Pietersz, KL;Plessis, FD;Pouw, SM;Liefhebber, JM;van Deventer, SJ;Martens, GJM;Konstantinova, PS;Blits, B;
PMID: 34414171 | DOI: 10.3389/fbioe.2021.679483
Of the adeno-associated viruses (AAVs), AAV9 is known for its capability to cross the blood-brain barrier (BBB) and can, therefore, be used as a noninvasive method to target the central nervous system. Furthermore, the addition of the peptide PhP.B to AAV9 increases its transduction across the BBB by 40-fold. Another neurotropic serotype, AAV5, has been shown as a gene therapeutic delivery vehicle to ameliorate several neurodegenerative diseases in preclinical models, but its administration requires invasive surgery. In this study, AAV9-PhP.B and AAV5-PhP.B were designed and produced in an insect cell-based system. To AAV9, the PhP.B peptide TLAVPFK was added, whereas in AAV5-PhP.B (AQTLAVPFKAQAQ), with AQ-AQAQ sequences used to swap with the corresponding sequence of AAV5. The addition of PhP.B to AAV5 did not affect its capacity to cross the mouse BBB, while increased transduction of liver tissue was observed. Then, intravenous (IV) and intrastriatal (IStr) delivery of AAV9-PhP.B and AAV5 were compared. For AAV9-PhP.B, similar transduction and expression levels were achieved in the striatum and cortex, irrespective of the delivery method used. IStr administration of AAV5 resulted in significantly higher amounts of vector DNA and therapeutic miRNA in the target regions such as striatum and cortex when compared with an IV administration of AAV9-PhP.B. These results illustrate the challenge in developing a vector that can be delivered noninvasively while achieving a transduction level similar to that of direct administration of AAV5. Thus, for therapeutic miRNA delivery with high local expression requirements, intraparenchymal delivery of AAV5 is preferred, whereas a humanized AAV9-PhP.B may be useful when widespread brain (and peripheral) transduction is needed.
Yang, X;Yang, C;Friesel, RE;Liaw, L;
PMID: 37121163 | DOI: 10.1016/j.atherosclerosis.2023.04.007
Sprouty1 (Spry1) regulates the differentiation of vascular smooth muscle cells (VSMC), and our aim was to determine its role in atherogenesis. A significant proportion of cells within atherosclerotic lesions are derived from migration and pathological adaptation of medial VSMC.We used global Spry1 null mouse, and Myh11-CreERT2, ROSA26-STOPfl/fl-tdTomato-Spry1fl/fl mice to allow for lineage tracing and conditional Spry1 deletion in VSMC. Atherosclerosis was induced by injection of a mutant form of mPCSK9D377Y-AAV followed by Western diet. Human aortic VSMC (hVSMC) with shRNA targeting of Spry1 were also analyzed.Global loss of Spry1 increased inflammatory markers ICAM1 and Cox2 in VSMC. Conditional deletion of Spry1 in VSMC had no effect on early lesion development, despite increased Sca1high cells. After 26 weeks of Western diet, mice with VSMC deletion of Spry1 had increased plaque burden, with reduced collagen content and smooth muscle alpha actin (SMA) in the fibrous cap. Lineage tracing via tdTomato marking Cre-recombined cells indicated that VSMC with loss of Spry1 had decreased migration into the lesion, noted by decreased proportions of tdTomato+ and tdTomato+/SMA + cells. Loss-of-function of Spry1 in hVSMC increased mesenchymal and activation markers, including KLF4, PDGFRb, ICAM1, and Cox2. Loss of Spry1 enhanced the effects of PDGFBB and TNFa on hVSMC.Loss of Spry1 in VSMC aggravated plaque formation at later stages, and increased markers of instability. Our results indicate that Spry1 suppresses the mesenchymal and inflammatory phenotype of VSMC, and its expression in VSMC is protective against chronic atherosclerotic disease.