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Biology subjects

Lai, C.-H.

Publications and source records attributed to Lai, C.-H..

3 recordsLinked to original sources

Different Emotional States Engage Distinct Descending Pathways from the Prefrontal Cortex

Effective emotional processing, crucial for adaptive behavior, is mediated by the medial prefrontal cortex (mPFC) via connections to the basolateral amygdala (BLA) and nucleus accumbens (NAc), traditionally considered functionally similar in modulating reward and aversion responses. However, the functional specialization of the mPFC[->]BLA and mPFC[->]NAc pathways in representing affective states remains unclear. We found that while overall firing patterns appeared consistent across emotional states, deeper analysis revealed distinct variabilities. Specifically, mPFC[->]BLA neurons, especially "center-ON" neurons, exhibited heightened activity during behaviors classically associated with anxiety-like states, suggesting their involvement in aversive behavioral regulation. Conversely, mPFC[->]NAc neurons were more active during exploratory and approach-related behaviors, implicating them in the processing of positively valenced behavioral states. Notably, mPFC[->]NAc neurons showed significant pattern decorrelation during social interactions, suggesting a pivotal role in processing social preference. Additionally, repeated win/loss outcomes in the tube test produced distinct hierarchy-dependent behavioral changes and elevated corticosterone levels in loser mice, supporting the biological relevance of these behaviorally defined states. Together, these findings reveal pathway-specific representations of affect-related behavioral states in mPFC circuits and provide a framework for understanding how prefrontal outputs organize adaptive behavior across environmental contexts.

neuroscience↗

Parkin coordinates mitochondrial lipid remodeling to execute mitophagy

Mitochondrial failure caused by Parkin mutations contributes to Parkinsons disease. Parkin binds, ubiquitinates, and targets impaired mitochondria for autophagic destruction. Robust mitophagy involves peri-nuclear concentration of Parkin-tagged mitochondria, followed by dissemination of juxtanuclear mitochondrial aggregates, and efficient sequestration of individualized mitochondria by autophagosomes. Here, we report that the execution of complex mitophagic events requires active mitochondrial lipid remodeling. Parkin recruits phospholipase D2 to the depolarized mitochondria and generate phosphatidic acid (PA). Mitochondrial PA is subsequently converted to diacylglycerol (DAG) by Lipin-1 phosphatase-a process that further requires mitochondrial ubiquitination and ubiquitin-binding autophagic receptors, NDP52 and Optineurin. We show that Optineurin transports, via Golgi-derived vesicles, a PA-binding factor EndoB1 to ubiquitinated mitochondria, thereby facilitating DAG production. Mitochondrial DAG activates both F-actin assembly to drive mitochondrial individualization, and autophagosome biogenesis to efficiently restrict impaired mitochondria. Thus Parkin, autophagic receptors and the Golgi complex orchestrate mitochondrial lipid remodeling to execute robust mitophagy.

cell biology↗

IFN-γ induces epithelial-to-mesenchymal transition of cancer cells via an unique microRNA processing

Interferon-{gamma} (IFN{gamma}) is a potent cytokine in modulating tumor immunity and tumoricidal effects. We demonstrate a new function of IFN{gamma} in inducing epithelial-to-mesenchymal transition (EMT) in normal and cancer cells from different cell types. IFN{gamma} activates JAK-STAT signaling pathway leading to the transcription of IFN-stimulated genes (ISGs), such as interferon-induced tetratricopeptide repeat 5 (IFIT5). We unveil a new function of IFIT5 complex in degrading precursor microRNAs (pre-miRNA) that include pre-miR-363 from the miR-106a-363 cluster, as well as pre-miR-101 and pre-miR-128 with a similar 5-end structure with pre-miR-363. Noticeably, these suppressive miRNAs have similar functions by targeting EMT transcription factors in prostate cancer (PCa) cells. We further demonstrated that IFIT5 plays a critical role in IFN{gamma}-induced cell invasiveness in vitro and lung metastasis in vivo. Clinically, IFIT5 is highly elevated in high-grade PCa and its expression inversely correlates with these suppressive miRNAs. Altogether, this study unveils pro-tumorigenic role of the IFN pathway via a new mechanism of action, which certainly raises concern about its clinical application.

cancer biology↗