Mitoregulin self-associates to form likely homo-oligomeric pore-like complexes.

We and others previously found that a misannotated long noncoding RNA encodes for a conserved mitochondrial transmembrane microprotein named Mitoregulin (Mtln). Beyond an established role for Mtln in lipid metabolism, Mtln has been shown to broadly influence mitochondria, boosting respiratory efficiency and Ca retention capacity, while lowering ROS, yet the underlying mechanisms remain unresolved. Prior studies have identified possible Mtln protein interaction partners; however, a lack of consensus persists, and no claims have been made about Mtln's structure.

Upstream alternative polyadenylation in produces a short transcript isoform encoding a mitochondria-localized NaV1.5 N-terminal fragment that influences cardiomyocyte respiration.

encodes the cardiac voltage-gated Na+ channel, NaV1.5, that initiates action potentials. gene variants cause arrhythmias and increased heart failure risk.

MIRO1 controls energy production and proliferation of smooth muscle cells.

Background: The outer mitochondrial Rho GTPase 1, MIRO1, mediates mitochondrial motility within cells, but implications for vascular smooth muscle cell (VSMC) physiology and its roles invascular diseases, such as neointima formation following vascular injury are widely unknown.

Methods: An in vivo model of selective Miro1 deletion in VSMCs was generated, and the animals were subjected to carotid artery ligation. The molecular mechanisms relevant to VSMC proliferation were then explored in explanted VSMCs by imaging mitochondrial positioning and cristae structure and assessing the effects on ATP production, metabolic function and interactions with components of the electron transport chain (ETC).

Mitoregulin self-associates to form likely homo-oligomeric pore-like structures.

We and others previously found that a misannotated long noncoding RNA encodes for a conserved mitochondrial transmembrane microprotein named Mitoregulin (Mtln). Beyond an established role for Mtln in lipid metabolism, Mtln has also been shown to more broadly influence mitochondria, boosting respiratory efficiency and Ca retention capacity, while lowering ROS, yet the underlying mechanisms remain unresolved. Prior studies have identified possible Mtln protein interaction partners; however, a lack of consensus persists, and no claims have been made about Mtln's structure.

Mitoregulin supports mitochondrial membrane integrity and protects against cardiac ischemia-reperfusion injury.

We and others discovered a highly-conserved mitochondrial transmembrane microprotein, named Mitoregulin (Mtln), that supports lipid metabolism. We reported that Mtln strongly binds cardiolipin (CL), increases mitochondrial respiration and Ca retention capacities, and reduces reactive oxygen species (ROS). Here we extend our observation of Mtln-CL binding and examine Mtln influence on cristae structure and mitochondrial membrane integrity during stress.

A Specialized Centrosome-Proteasome Axis Mediates Proteostasis and Influences Cardiac Stress through Txlnb.

Background: Centrosomes localize to perinuclear foci where they serve multifunctional roles, arranging the microtubule organizing center (MTOC) and anchoring ubiquitin-proteasome system (UPS) machinery. In mature cardiomyocytes, centrosomal proteins redistribute into a specialized perinuclear cage-like structure, and a potential centrosome-UPS interface has not been studied. Taxilin-beta (Txlnb), a cardiomyocyte-enriched protein, belongs to a family of centrosome adapter proteins implicated in protein quality control.

Neuronal genetic rescue normalizes brain network dynamics in a lysosomal storage disorder despite persistent storage accumulation.

Although neurologic symptoms occur in two-thirds of lysosomal storage disorders (LSDs), for most we do not understand the mechanisms underlying brain dysfunction. A major unanswered question is if the pathogenic hallmark of LSDs, storage accumulation, induces functional defects directly or is a disease bystander. Also, for most LSDs we do not know the impact of loss of function in individual cell types.

Modulation of miR-181 influences dopaminergic neuronal degeneration in a mouse model of Parkinson's disease.

Parkinson's disease (PD) is caused by the loss of dopaminergic (DA) neurons in the substantia nigra (SN). Although PD pathogenesis is not fully understood, studies implicate perturbations in gene regulation, mitochondrial function, and neuronal activity. MicroRNAs (miRs) are small gene regulatory RNAs that inhibit diverse subsets of target mRNAs, and several studies have noted miR expression alterations in PD brains.

Mitoregulin: A lncRNA-Encoded Microprotein that Supports Mitochondrial Supercomplexes and Respiratory Efficiency.

Mitochondria are composed of many small proteins that control protein synthesis, complex assembly, metabolism, and ion and reactive oxygen species (ROS) handling. We show that a skeletal muscle- and heart-enriched long non-coding RNA, LINC00116, encodes a highly conserved 56-amino-acid microprotein that we named mitoregulin (Mtln). Mtln localizes to the inner mitochondrial membrane, where it binds cardiolipin and influences protein complex assembly.

Modulating membrane fluidity corrects Batten disease phenotypes in vitro and in vivo.

The neuronal ceroid lipofuscinoses are a class of inherited neurodegenerative diseases characterized by the accumulation of autofluorescent storage material. The most common neuronal ceroid lipofuscinosis has juvenile onset with rapid onset blindness and progressive degeneration of cognitive processes. The juvenile form is caused by mutations in the CLN3 gene, which encodes the protein CLN3.

CLN3 deficient cells display defects in the ARF1-Cdc42 pathway and actin-dependent events.

Juvenile Batten disease (juvenile neuronal ceroid lipofuscinosis, JNCL) is a devastating neurodegenerative disease caused by mutations in CLN3, a protein of undefined function. Cell lines derived from patients or mice with CLN3 deficiency have impairments in actin-regulated processes such as endocytosis, autophagy, vesicular trafficking, and cell migration. Here we demonstrate the small GTPase Cdc42 is misregulated in the absence of CLN3, and thus may be a common link to multiple cellular defects.

CLN3 loss disturbs membrane microdomain properties and protein transport in brain endothelial cells.

Juvenile neuronal ceroid lipofuscinosis (JNCL) is a fatal childhood-onset neurodegenerative disorder caused by mutations in ceroid lipofuscinosis neuronal-3 (CLN3), a hydrophobic transmembrane protein of unresolved function. Previous studies indicate blood-brain barrier (BBB) defects in JNCL, and our earlier report showed prominent Cln3 expression in mouse brain endothelium. Here we find that CLN3 is necessary for normal trafficking of the microdomain-associated proteins caveolin-1, syntaxin-6, and multidrug resistance protein 1 (MDR1) in brain endothelial cells.

MiR-34a represses Numbl in murine neural progenitor cells and antagonizes neuronal differentiation.

MicroRNA (miRNA) function is required for normal animal development, in particular in differentiation pathways from stem cell and precursor populations. In neurogenesis, it is becoming increasingly appreciated that miRNAs act at many stages to ensure proper progression. In this study we examined the role of miR-34a in neural progenitor cells (NPC) derived from murine embryonic cortex.

A knock-in reporter mouse model for Batten disease reveals predominant expression of Cln3 in visual, limbic and subcortical motor structures.

Juvenile neuronal ceroid lipofuscinosis (JNCL) or Batten disease is an autosomal recessive neurodegenerative disorder of children caused by mutation in CLN3. JNCL is characterized by progressive visual impairment, cognitive and motor deficits, seizures and premature death. Information about the localization of CLN3 expressing neurons in the nervous system is limited, especially during development.

Osmoregulation of ceroid neuronal lipofuscinosis type 3 in the renal medulla.

Recessive inheritance of mutations in ceroid neuronal lipofuscinosis type 3 (CLN3) results in juvenile neuronal ceroid lipofuscinosis (JNCL), a childhood neurodegenerative disease with symptoms including loss of vision, seizures, and motor and mental decline. CLN3p is a transmembrane protein with undefined function. Using a Cln3 reporter mouse harboring a nuclear-localized bacterial beta-galactosidase (beta-Gal) gene driven by the native Cln3 promoter, we detected beta-Gal most prominently in epithelial cells of skin, colon, lung, and kidney.

Rho GTPases modulate entry of Ebola virus and vesicular stomatitis virus pseudotyped vectors.

To explore mechanisms of entry for Ebola virus (EBOV) glycoprotein (GP) pseudotyped virions, we used comparative gene analysis to identify genes whose expression correlated with viral transduction. Candidate genes were identified by using EBOV GP pseudotyped virions to transduce human tumor cell lines that had previously been characterized by cDNA microarray. Transduction profiles for each of these cell lines were generated, and a significant positive correlation was observed between RhoC expression and permissivity for EBOV vector transduction.

A knock-in reporter model of Batten disease.

Juvenile neuronal ceroid lipofuscinosis is a severe inherited neurodegenerative disease resulting from mutations in CLN3 (ceroid-lipofuscinosis, neuronal 3, juvenile). CLN3 function, and where and when it is expressed during development, is not known. In this study, we generated a knock-in reporter mouse to elucidate CLN3 expression during embryogenesis and after birth and to correlate expression and behavior in a CLN3-deficient mouse.

Persistent expression of factor VIII in vivo following nonprimate lentiviral gene transfer.

Hemophilia A is a clinically important coagulation disorder caused by the lack or abnormality of plasma coagulation factor VIII (FVIII). Gene transfer of the FVIII cDNA to hepatocytes using lentiviral vectors is a potential therapeutic approach. We investigated the efficacy of feline immunodeficiency virus (FIV)-based vectors in targeting hepatocytes and correcting FVIII deficiency in a hemophilia A mouse model.

The lymphocytic choriomeningitis virus envelope glycoprotein targets lentiviral gene transfer vector to neural progenitors in the murine brain.

Feline immunodeficiency virus (FIV)-based lentiviral vectors can be targeted to restricted cell types by pseudotyping with envelopes from other viruses. An FIV vector expressing bacterial beta-galactosidase (beta-gal) and pseudotyped with lymphocytic choriomeningitis virus (LCMV) envelope glycoprotein was injected into postnatal mouse brain striatum to determine neural cell-type transduction. After 3 or 7.

Identification of PDGFR as a receptor for AAV-5 transduction.

Understanding the process of vector transduction has important implications for the application and optimal use of a vector system for human gene therapy. Recent studies with vectors based on adeno-associated virus type 5 (AAV-5) have shown utility of this vector system in the lung, central nervous system, muscle and eye. To understand the natural tropism of this virus and to identify proteins necessary for AAV-5 transduction, we characterized 43 cell lines as permissive or nonpermissive for AAV-5 transduction and compared the gene expression profiles derived from cDNA microarray analyses of those cell lines.

Platelet-mediated modulation of adaptive immunity. A communication link between innate and adaptive immune compartments.

Platelets are highly reactive components of the circulatory system with well-documented hemostatic function. Recent studies extend platelet function to modulation of local inflammatory events through the release of chemokines, cytokines, and a number of immunomodulatory ligands, including CD154. We hypothesized that platelet-derived CD154 modulates adaptive immunity.

In vivo gene transfer using a nonprimate lentiviral vector pseudotyped with Ross River Virus glycoproteins.

Vectors derived from lentiviruses provide a promising gene delivery system. We examined the in vivo gene transfer efficiency and tissue or cell tropism of a feline immunodeficiency virus (FIV)-based lentiviral vector pseudotyped with the glycoproteins from Ross River Virus (RRV). RRV glycoproteins were efficiently incorporated into FIV virions, generating preparations of FIV vector, which after concentration attain titers up to 1.

Functional correction of established central nervous system deficits in an animal model of lysosomal storage disease with feline immunodeficiency virus-based vectors.

Gene transfer vectors based on lentiviruses can transduce terminally differentiated cells in the brain; however, their ability to reverse established behavioral deficits in animal models of neurodegeneration has not previously been tested. When recombinant feline immunodeficiency virus (FIV)-based vectors expressing beta-glucuronidase were unilaterally injected into the striatum of adult beta-glucuronidase deficient [mucopolysaccharidosis type VII (MPS VII)] mice, an animal model of lysosomal storage disease, there was bihemispheric correction of the characteristic cellular pathology. Moreover, after the injection of FIV-based vectors expressing beta-glucuronidase into brains of beta-glucuronidase-deficient mice with established impairments in spatial learning and memory, there was dramatic recovery of behavioral function.