Biology subjects

Hussain, I.

Publications and source records attributed to Hussain, I..

3 recordsLinked to original sources

bioRxiv2026

Aging reprograms the response to chronic stress

Chronic stress is thought to accelerate brain aging. We find this to be true in the brains of young mice, but reversed in the old. Using chronic variable stress in young (2-month) and aged (24-month) mice, we show that aged animals perceive stress physiologically but exhibit stress-responses that differ from those of young mice on behavioral, synaptic, and molecular levels. Multi-Omics profiling of prefrontal cortex and nucleus accumbens and 3D vasculature measurements reveals that stress in aged mice activates angiogenic programs that oppose aging-related patterns. Our results demonstrate that stress cannot be universally conceptualized as an aging accelerator, but instead engages age-specific programs with opposite directionality in young and old animals.

neuroscience↗

bioRxiv2024

Transthyretin orchestrates vitamin B12-induced stress resilience

Chronic stress significantly contributes to mood- and anxiety disorders. Previous and current data suggest a correlative connection between vitamin B12 supplementation, depression, and stress resilience. However, the underlying mechanisms are still poorly understood. This study reveals a molecular pathway that functionally connects vitamin B12, DNA methylation (DNAme), and stress resilience. We identified Transthyretin (Ttr) as a sex-specific key target of vitamin B12 action in chronic stress. Accordingly, TTR expression was increased postmortem in the prefrontal cortex of male, but not female, depressed patients. Virally altered Ttr in the prefrontal cortex functionally contributed to stress- and depression-related behaviors, changes in dendritic spine morphology and gene expression. In stressed mice, vitamin B12 reduced DNAme in the Ttr promoter region. Importantly, using in vivo epigenome editing to alter DNAme in the brains of living mice for the first time, we establish a direct causal link between DNAme on Ttr and stress-associated behaviors. In summary, using state-of-the-art techniques, this study uncovers a mechanistic link between cobalamin supplementation and markers of chronic stress and depression, encouraging further studies into environmental interventions for mood disorders.

neuroscience↗

bioRxiv2023

Prioritization of The Zinc finger domain within BCL11A gene by the Amelioration capability of hemoglobinopathies using CRISPR-Cas9 technology

BCL11A/EVI9, a zinc-finger protein primarily expressed in brain and hematopoietic cells, plays a central role in lymphocyte development, gamma-globin suppression, spinal neuron development, sensory innervation, neuronal polarity, migration, and is associated with microcephaly and dysregulated brain-related genes, offering therapeutic potential for sickle cell disease. The function of the transcriptional regulator is intricately linked to its structural organization, which determines its ability to interact with specific DNA sequences and modulate gene expression. BCL11A boasts multiple domains, including six C2H2 zinc fingers, a C2HC zinc finger, a NuRD-interacting domain, an acidic domain, and a proline-rich domain. In the present study, we delve into the intricate structure and function of the zinc finger domains located in the BCL11A gene, which plays a crucial role in regulating the expression of gamma-globin gene. Specifically, three C2H2-type zinc finger domains, Znf4, Znf5, and Znf6, within BCL11A, are known to bind to DNA. Znf4 and Znf5 demonstrate a significant interaction with the TGACCA motif in the gamma-globin -115 HPFH region sequence, contributing substantially to DNA binding specificity. Although Znf3 and Znf6 also interact with DNA, their contributions are comparatively minor. Employing CRISPR-Cas9 technology, targeted genomic deletions of Znf4 exhibit high efficiency, opening doors for further research. Edited CD34+ cells successfully differentiate into erythrocytes without impairments, underscoring CRISPR-Cas9s suitability for studying gene functions in erythropoiesis. Furthermore, BCL11A knockdown via sgRNAs results in elevated gamma-globin expression, offering a promising therapeutic avenue for beta-hemoglobinopathies. HPLC analysis reveals a substantial increase in HbF levels, particularly upon Znf4 deletion, emphasizing BCL11A gene potential as a therapeutic target. These findings also highlight the connection between the function of BCL11A and its structural organization, which can be modulated, and this insight can potentially be extended to uncover its roles in various other domains.

molecular biology↗