Biology subjects

Jajoo, A.

Publications and source records attributed to Jajoo, A..

3 recordsLinked to original sources

bioRxiv2026

Revealing the convergence of disease- and risk-associated circular RNAs in schizophrenia and bipolar disorder

Circular RNAs (circRNAs) remain an underexplored layer of transcriptomic regulation in psychiatric disorders. We quantified circRNA expression from 1,022 [518 neurotypical, 365 schizophrenia (SCZ) and 139 bipolar disorder (BIP)] postmortem cortex samples from PsychENCODE consortium cohorts and integrated these profiles with matched linear RNA and genotype profiles. We identified 23 SCZ-associated and 3 BIP-associated differentially expressed circRNAs (FDR<0.05; FDR-circDEG). We trained genetically regulated circRNA expression (circGReX) models using neurotypicals and applied them to SCZ and BIP GWAS to perform Transcriptomic Wide association analysis (TWAS) which identified 22 and 4 circGReX trait associations (circGTAs), respectively. Pathway enrichment of circDEGs and circGTAs implicated neuronal and synaptic processes for both disorders. In UK Biobank, circGReX-imaging associations were predominantly negatively correlated with SCZ and BIP circGTAs, but positively correlated with Alzheimers disease circGTAs. circKLHL24 isoforms showed the most prominent imaging associations. Many co-expression modules containing our FDR-circDEGs were enriched for psychiatric and neurodegenerative risk genes, including our identified circGTAs, and these modules were enriched for cognitive and neurodevelopmental traits. To conclude, circRNAs represent a distinct regulatory layer in psychiatric disorders, linking genetic risk to synaptic biology, brain structure and cognition through disease-specific expression, TWAS prioritization, and imaging associations.

neuroscience↗

bioRxiv2026

Mapping spatially organized molecular and genetic signatures of schizophrenia across multiple scales in human prefrontal cortex

The dorsolateral prefrontal cortex (dlPFC) is central to cognitive dysfunction in schizophrenia (SCZ), yet how molecular changes are organized across cortex remains unclear. Here, we applied complementary spatial transcriptomic approaches spanning laminar domains, microenvironments, and cell types in postmortem human dlPFC. At the laminar level, SCZ-associated transcriptional changes were strongest in glia-enriched domains (layer 1/meninges and white matter), including down-regulation of microglia-associated genes, whereas genetic risk localized to neuronal-rich gray matter. We next analyzed SCZ-linked microenvironments including neuropil, neuronal, perineuronal net, and vascular compartments. Within these, neuronal and synaptic transcriptional changes were most prominent in neuropil, showing down-regulation of activity-dependent synaptic genes and inhibitory neuron markers. At the cellular level, these signals reflected intrinsic alterations localized to cell types. Across analyses, patterns converged on altered BDNF-TrkB signaling and inhibitory circuit dysfunction. Together, our findings highlight spatial scale as a key determinant in resolving neuronal and non-neuronal aspects of SCZ-associated biology.

neuroscience↗

bioRxiv2024

Modulation of photosystem II heterogeneity and stomatal functioning contribute to sustaining photochemistry and photoprotection in mangroves exposed to a cold wave

Cold waves restrict the distribution of mangroves. This study examined the contribution of PSII heterogeneity and stomatal functioning to sustaining photochemistry and photoprotection in mangroves during a cold wave. We exposed eight populations of Kandelia obovata (cold-tolerant) and, Bruguiera gymnorhiza (cold-susceptible) from different latitudes to 27/20{degrees}C (favorable) and 10/3{degrees}C (chilling; simulated cold wave) day and night temperatures. Multiple trait responses imply that cold waves affected K. obovata the least. Significant changes in chlorophyll fluorescence transients (photosystem II [PSII]) with a slight decrease in the redox status of P700 (photosystem I [PSI]) imply a greater impact of a cold wave on PSII. During the cold wave, photochemical efficiency of PSII, efficiency of the water-splitting complex, light absorptance, stomatal pore area, cyclic electron flow, nonphotochemical quenching, and number of active PSII and PSII QB reducing centers decreased, while light transmittance, night respiration, and inactive PSII QB nonreducing, PSII{beta}, and {gamma} centers increased in both species. The population of K. obovata from the coldest latitudinal site (Fujian, China) was least affected by cold wave due to local evolutionary adaptations. Modulation of PSII heterogeneity and stomatal functioning is important to sustaining photochemistry and photoprotection in mangroves to cope with cold waves. HighlightsPSII heterogeneity and stomatal functioning support mangroves to cope with cold waves. Local evolutionary adaptations promote the cold tolerance of mangrove populations.

plant biology↗