Biology subjects

Chermakani, P.

Publications and source records attributed to Chermakani, P..

3 recordsLinked to original sources

bioRxiv2026

Combinatorial Control of Corticospinal Axon Growth by Retinoic Acid Receptors

Regeneration of central nervous system (CNS) axons depends on Transcription Factors (TFs) that reactivate developmental growth programs, yet most such factors remain unknown. By intersecting developmental chromatin binding with pro-growth gene networks, we identified two retinoic acid receptor transcription factors, RARA and RARG, whose occupancy at growth-associated genes is progressively lost as neurons mature. Restoring both factors together increased neurite outgrowth beyond either alone in two independent systems, the Neuro-2a cell line and primary cortical neurons. In vivo, the same combination drove cross-midline sprouting after pyramidotomy and long-tract regeneration after thoracic spinal cord crush, with concordant recovery of hindlimb gait and grip strength. Interestingly, neither receptor alone was sufficient, hinting at combinatorial regulation. Single-nucleus transcriptomics delineated that only the combination reactivated relevant cytoskeletal and gene-expression programs, while genome-wide binding maps showed that RARA and RARG partition the regulatory landscape, with RARG dominating promoters and RARA occupying distal enhancers, so that neither receptor reconstitutes the developmental growth state alone. Intriguingly, this cooperative requirement was specific to the CNS: in peripheral sensory neurons, RARG alone was sufficient and RARA was dispensable. These data identify RARA and RARG as novel cooperative regulators of regenerative axon growth in mammalian CNS and PNS neurons and potential targets for therapeutic intervention.

neuroscience↗

bioRxiv2025

Targeting RARβ With a Stable Retinoic Acid Mimic Promotes Neurite Outgrowth, Neurogenesis, and Behavioral Recovery

Injury to the adult central nervous system triggers minimal axonal regeneration, partly due to the limited activation of intrinsic growth programs. Retinoic acid (RA) signaling has been shown to promote modest regenerative responses, but its clinical utility is restricted by poor biochemical stability and short-lived receptor engagement. Here, we report a tribenzamide-based small molecule DM04, that recapitulates RA-like transcriptional and phenotypic effects and enhances regenerative outcomes, independent of canonical RARE-dependent transactivation. DM04 promoted neurite outgrowth in primary neurons, upregulated canonical RA-responsive genes, and supported neural induction from human iPSCs. In a murine spinal injury model, DM04 treatment improved motor recovery. Transcriptomic analysis revealed shared target gene activation between RA and DM04, along with unique enrichment of extracellular matrix remodeling pathways. These findings establish DM04 as a small molecule based approach with dual efficacy in injury and developmental contexts, acting through a mechanism distinct from canonical RAR transactivation, and highlight its promise as a candidate for further preclinical investigation in neural repair.

neuroscience↗

bioRxiv2025

Nuclear Receptor Transcription factors promote axon regeneration in the Adult Corticospinal Tract

Transcription factors are potent levers for neural repair, but which factors govern regenerative capacity in the corticospinal tract remains largely unknown. By intersecting developmental RNA-seq with ATAC-seq footprinting, we identified two nuclear-receptor transcription factors, NR2F1 and NR2F6, neither previously linked to CNS axon growth, whose chromatin occupancy at pro-growth enhancers is progressively lost as neurons mature. Forced expression of either factor significantly increased neurite outgrowth in single-neuron tracing assays, and each drove strong cross-midline sprouting after pyramidotomy and long-tract CST regeneration after complete thoracic crush, with concordant recovery of hip-rise kinematics and grip strength. Parallel multi-omic profiling (CUT&RUN, snRNA-seq and Ribo-seq) of both factors together with NR2F6 Hi-C revealed distinct mechanisms: NR2F1 reactivated chromatin-remodeling and cytoskeletal programs, whereas NR2F6, via a conserved corepressor domain, re-occupied developmental enhancers, reorganized three-dimensional chromatin architecture into new topologically associating domains, and imposed a transient translational down-shift in which growth-relevant modules were selectively preserved through translational buffering. Together, these data identify NR2F nuclear receptors as regulators of corticospinal regeneration, acting through enhancer redeployment, translational reprogramming and three-dimensional genome reorganization.

neuroscience↗