Biology subjects

Jensen, B. K.

Publications and source records attributed to Jensen, B. K..

4 recordsLinked to original sources

bioRxiv2026

Engineered Chimeric Proteins Functionally Replace ALS-causing Endogenous FUS and TDP-43 to Improve Neuronal Health

Mislocalization and aggregation of the RNA-binding proteins (RBPs) FUS and TDP-43 are pathological hallmarks of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), contributing to combined loss- and gain-of-function toxicity. Here, we present a protein engineering strategy that appends optimized anti-aggregation motifs to FUS and TDP-43, thereby enhancing their nuclear localization and solubility, and enabling functional replacement of disease-associated proteins. We show that these engineered chimeric RBPs reduce levels of aggregation-prone endogenous proteins through autoregulatory mechanisms. In addition, chimeric FUS and TDP-43 recapitulate key nuclear functions, including DNA repair and mRNA processing. Notably, chimeric FUS restores neurite outgrowth in diseased iPSC-derived neurons, while chimeric TDP-43 suppresses cryptic exon inclusion in patient-derived fibroblasts. Collectively, these results demonstrate that engineered chimeric RBPs can rebalance RBP homeostasis by simultaneously addressing protein aggregation and mislocalization, thus mitigating RBP-associated loss- and gain-of-function toxicity, highlighting a generalizable strategy for therapeutic protein replacement in neurodegenerative disease.

neuroscience↗

bioRxiv2026

Intrathecal (G4C2)149 delivery in C9orf72-deficient mice yields mild motor dysfunction and ALS/FTD pathological hallmarks

A repeat expansion in C9orf72 is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), yet existing mouse models incompletely engage spinal regions implicated in disease. Here, an adeno-associated virus encoding (G4C2)149 repeats was delivered via neonatal intrathecal injection, achieving widespread CNS expression with robust spinal cord targeting. This approach was applied to mice with graded loss of endogenous C9orf72 to interrogate both gain- and loss-of-function mechanisms. Longitudinal motor, behavioral, and pathological analyses revealed that repeat expression primarily drives mild, progressive muscle weakness, whereas coordination deficits were largely genotype dependent. Subtle gait abnormalities and hyperactivity were also observed. Within spinal motor regions, repeat-expressing mice exhibited dipeptide repeat protein accumulation, reduced NeuN-positive area, glial activation, and sparse phosphorylated TDP-43 pathology. Cross-domain correlations further linked repeat expression, spinal pathology, and motor dysfunction. Collectively, these findings establish that CNS-wide repeat expression combined with reduced C9orf72 produces a coherent, mild ALS/FTD model.

neuroscience↗

bioRxiv2024

Short RNA chaperones promote aggregation-resistant TDP-43 conformers to mitigate neurodegeneration

Aberrant aggregation of the prion-like, RNA-binding protein TDP-43 underlies several debilitating neurodegenerative proteinopathies, including amyotrophic lateral sclerosis (ALS). Here, we define how short, specific RNAs antagonize TDP-43 aggregation. Short, specific RNAs engage and stabilize the TDP-43 RNA-recognition motifs, which allosterically destabilizes a conserved helical region in the prion-like domain, thereby promoting aggregation-resistant conformers. By mining sequence space, we uncover short RNAs with enhanced activity against TDP-43 and diverse disease-linked variants. The solubilizing activity of enhanced short RNA chaperones corrects aberrant TDP-43 phenotypes in optogenetic models and ALS patient-derived neurons. Remarkably, an enhanced short RNA chaperone mitigates TDP-43 proteinopathy and neurodegeneration in mice. Our studies reveal mechanisms of short RNA chaperones and pave the way for the development of short RNA therapeutics for fatal TDP-43 proteinopathies.

biochemistry↗

bioRxiv2021

Astrocytic expression of ALS-causative mutant FUS leads to TNFa-dependent neurodegeneration in vivo

Genetic mutations that cause Amyotrophic Lateral Sclerosis (ALS), a progressively lethal motor neuron disease, are commonly found in ubiquitously expressed genes. In addition to direct defects within motor neurons, growing evidence suggests that dysfunction of non-neuronal cells is also an important driver of disease. Previously, we demonstrated that mutations in DNA/RNA binding protein Fused in Sarcoma (FUS) induce neurotoxic phenotypes in astrocytes in vitro, via activation of the NF-{kappa}B pathway and release of pro-inflammatory cytokine TNF. Here, we developed an intraspinal cord injection model to test whether astrocyte-specific expression of ALS-causative FUSR521G variant (mtFUS) causes neuronal damage in vivo. We show that mtFUS expression causes TNF upregulation, motor function deficits, and spinal motor neuron loss. We further demonstrate a lack of phenotype in TNF knockout animals expressing mtFUS, and prevention of neurodegeneration in mtFUS-transduced animals through administration of TNF neutralizing antibodies. Together, these studies strengthen evidence that astrocytes contribute to disease in ALS, establish that FUS-ALS astrocytes induce pathogenic changes to motor neurons in vivo, and provide insights identifying FUS-ALS specific potential therapeutic targets.

neuroscience↗