Disrupting the LINC complex by AAV mediated gene transduction prevents progression of Lamin induced cardiomyopathy

Mutations in the LaminA gene are a common cause of monogenic dilated cardiomyopathy. Here we show that mice with a cardiomyocyte-specific Lmna deletion develop cardiac failure and die within 3–4 weeks after inducing the mutation. When the same Lmna mutations are induced in mice genetically deficient in the LINC complex protein SUN1, life is extended to more than one year. Disruption of SUN1’s function is also accomplished by transducing and expressing a dominant-negative SUN1 miniprotein in Lmna deficient cardiomyocytes, using the cardiotrophic Adeno Associated Viral Vector 9. The SUN1 miniprotein disrupts binding between the endogenous LINC complex SUN and KASH domains, displacing the cardiomyocyte KASH complexes from the nuclear periphery, resulting in at least a fivefold extension in lifespan. Cardiomyocyte-specific expression of the SUN1 miniprotein prevents cardiomyopathy progression, potentially avoiding the necessity of developing a specific therapeutic tailored to treating each different LMNA cardiomyopathy-inducing mutation of which there are more than 450.

HOXA9 promotes MYC-mediated leukemogenesis by maintaining gene expression for multiple anti-apoptotic pathways

HOXA9 is often highly expressed in leukemias. However, its precise roles in leukemogenesis remain elusive. Here, we show that HOXA9 maintains gene expression for multiple anti-apoptotic pathways to promote leukemogenesis. In MLL fusion-mediated leukemia, MLL fusion directly activates the expression of MYC and HOXA9. Combined expression of MYC and HOXA9 induced leukemia, whereas single gene transduction of either did not, indicating a synergy between MYC and HOXA9. HOXA9 sustained expression of the genes implicated in the hematopoietic precursor identity when expressed in hematopoietic precursors, but did not reactivate it once silenced. Among the HOXA9 target genes, BCL2 and SOX4 synergistically induced leukemia with MYC. Not only BCL2, but also SOX4 suppressed apoptosis, indicating that multiple anti-apoptotic pathways underlie cooperative leukemogenesis by HOXA9 and MYC. These results demonstrate that HOXA9 is a crucial transcriptional maintenance factor that promotes MYC-mediated leukemogenesis, potentially explaining why HOXA9 is highly expressed in many leukemias.

A mosaic adeno-associated virus vector as a versatile tool that exhibits high levels of transgene expression and neuron specificity in primate brain

Recent emphasis has been placed on gene transduction mediated through recombinant adeno-associated virus (AAV) vector to manipulate activity of neurons and their circuitry in the primate brain. In the present study, we created a novel AAV vector of which capsid was composed of capsid proteins derived from the serotypes 1 and 2 (AAV1 and AAV2). Following the injection into the frontal cortex of macaque monkeys, this mosaic vector, termed AAV2.1 vector, was found to exhibit the excellence in transgene expression (for the AAV1 vector) and neuron specificity (for the AAV2 vector) simultaneously. To explore its applicability to chemogenetic manipulation and in vivo calcium imaging, the AAV2.1 vector expressing excitatory DREADDs or GCaMP was injected into the striatum or the visual cortex of macaque monkeys, respectively. Our results have defined that such vectors secure intense and stable expression of the target proteins and yield conspicuous modulation and imaging of neuronal activity.

Decitabine Reactivation of FoxM1-Dependent Endothelial Regeneration and Vascular Repair for Potential Treatment of Elderly ARDS and COVID-19 Patients

Aging is a major risk factor of high incidence and increased mortality of acute respiratory distress syndrome (ARDS) and COVID-19. We repot that aging impairs the intrinsic FoxM1-dependent endothelial regeneration and vascular repair program and causes persistent lung injury and high mortality following sepsis. Therapeutic gene transduction of FOXM1 in vascular endothelium or treatment with FDA-approved drug Decitabine was sufficient to reactivate FoxM1-dependent lung endothelial regeneration in aged mice, reverse aging-impaired resolution of inflammatory injury, and promote survival. In COVID-19 lung autopsy samples, FOXM1 expression was not induced in vascular endothelial cells of elderly patients in contrast to mid-age patients. Thus, Decitabine reactivation of FoxM1-dependent vascular repair represents a potential effective therapy for elderly COVID-19 and non-COVID-19 ARDS patients.

Supramolecular Peptide Nanofibrils with Optimized Sequences and Molecular Structures for Efficient Retroviral Transduction

Amyloid-like peptide nanofibrils (PNFs) are abundant in nature providing rich bioactivities and playing both functional and pathological roles. The structural features responsible for their unique bioactivities are, however, still elusive. Supramolecular nanostructures are notoriously challenging to optimize, as sequence changes affect self-assembly, fibril morphologies and biorecognition. Herein, we report the first sequence optimization of PNFs for enhanced retroviral gene transduction via a multiparameter and a multiscale approach. Retroviral gene transfer is the method of choice for stable delivery of genetic information into cells offering great perspectives for the treatment of genetic disorders. Single fibril imaging, zeta potential, vibrational spectroscopy and quantitative retroviral transduction assays provided the structure parameters responsible for PNF assembly, fibril morphologies and PNF-virus-cell interactions. Optimized peptide sequences have been obtained quantitatively forming supramolecular nanofibrils with high intermolecular beta-sheet content that efficiently bound virions and attached to cellular membranes revealing efficient retroviral gene transfer

Supramolecular Peptide Nanofibrils with Optimized Sequences and Molecular Structures for Efficient Retroviral Transduction

Amyloid-like peptide nanofibrils (PNFs) are abundant in nature providing rich bioactivities and playing both functional and pathological roles. The structural features responsible for their unique bioactivities are, however, still elusive. Supramolecular nanostructures are notoriously challenging to optimize, as sequence changes affect self-assembly, fibril morphologies and biorecognition. Herein, we report the first sequence optimization of PNFs for enhanced retroviral gene transduction via a multiparameter and a multiscale approach. Retroviral gene transfer is the method of choice for stable delivery of genetic information into cells offering great perspectives for the treatment of genetic disorders. Single fibril imaging, zeta potential, vibrational spectroscopy and quantitative retroviral transduction assays provided the structure parameters responsible for PNF assembly, fibril morphologies and PNF-virus-cell interactions. Optimized peptide sequences have been obtained quantitatively forming supramolecular nanofibrils with high intermolecular beta-sheet content that efficiently bound virions and attached to cellular membranes revealing efficient retroviral gene transfer

HOXA9 promotes MYC-mediated leukemogenesis by maintaining gene expression for multiple anti-apoptotic pathways

HOXA9 is often highly expressed in leukemias. However, its precise roles in leukemogenesis remain elusive. Here, we show that HOXA9 maintains gene expression for multiple anti-apoptotic pathways to promote leukemogenesis. In MLL-rearranged leukemia, MLL fusion directly activates the expression of MYC and HOXA9. Combined expression of MYC and HOXA9 induced leukemia, whereas single gene transduction of either did not, indicating a synergy between MYC and HOXA9. HOXA9 sustained expression of the genes implicated to the hematopoietic precursor identity when expressed in hematopoietic precursors, but did not reactivate it once silenced. Among the HOXA9 target genes, BCL2 and SOX4 synergistically induced leukemia with MYC. Not only BCL2, but also SOX4 suppressed apoptosis, indicating that multiple anti-apoptotic pathways underlie cooperative leukemogenesis by HOXA9 and MYC. These results demonstrate that HOXA9 is a key transcriptional maintenance factor which promotes MYC-mediated leukemogenesis, potentially explaining why HOXA9 is highly expressed in many leukemias.

Dilated cardiomyopathy mutations in thin-filament regulatory proteins reduce contractility, suppress systolic Ca2+, and activate NFAT and Akt signaling

Dilated cardiomyopathy (DCM) is a frequently occurring cardiac disorder with a degree of genetic inheritance. We have found that DCM mutations in proteins that regulate the contractile machinery cause alterations to contraction, calcium-handling, and some new signaling pathways that provide stimuli for disease development. We have used guinea pig cells that recapitulate human calcium-handling and introduced the mutations using adenovirus gene transduction to look at the initial triggers of disease before remodeling.