Biology subjects
Publications and source records attributed to Jia, J.-M..
Withdrawal statementThe authors have withdrawn this manuscript due to a duplicate posting of manuscript number BIORXIV/2023/570712. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author. The correct preprint can be found at doi: 10.1101/2023.12.07.570712.
How mature neurons survive under homeostasis is a question of utmost importance and is known to be different from developing neurons. However, the understanding of this regard remains largely unknown. Here, based on the relationship between the sympathetic cervical ganglia (SCG) and the arterial networks of projecting and targeting organs, we report that the secretome of cerebral, but not peripheral, arterial smooth muscles (SMC) was required for the survival of sympathetic neurons. Among the secretome, we further identified that netrin-4, encoded by the ntn-4 gene, only entered neurons and not glia and played a crucial role both in vitro and in vivo. This was demonstrated with three independent lines of tamoxifen-inducible SMC-specific conditional knockout mice (cKO). Notably, in cKO mice, the local supply of exogenous netrin-4 confined to SCG selectively rescued neuronal necroptosis, which otherwise consistently occurred in a specific subgroup of SCG neurons that innervate cerebral SMCs. Mechanistically, we demonstrated that cerebral netrin-4 was endocytosed at the neurovascular interface and retrogradely long transported to peripheral soma in SCG, where it differentially regulated mRNA translations. This regulation suppressed vacuolization and neuronal necrosis, both of which took place spontaneously in cKO mice. The former is immediately followed by the latter when we injured axons using two-photon laser ablation. The findings revealed a new principle of neurovascular interactions vital for mature neuron survival, implying that under circumstances of cerebral SMC insufficient secretion, such as natural aging, may initiate mature neuronal loss due to uncontrolled vacuolization.
Ischemic stroke produces the highest adult disability. Despite successful recanalization, no-reflow, or the futile restoration of the cerebral perfusion after ischemia, is a major cause of brain lesion expansion. However, the vascular mechanism underlying this hypoperfusion is largely unknown, and no approach is available to actively promote optimal reperfusion to treat no-reflow. Here, by combining two-photon laser scanning microscopy (2PLSM) and a mouse middle cerebral arteriolar occlusion (MCAO) model, we found myogenic vasomotion deficits correlated with post-ischemic cerebral circulation interruptions and no-reflow. Transient occlusion-induced transient loss of mitochondrial membrane potential ({Delta}{Psi}m) permanently impaired mitochondria-endoplasmic reticulum (ER) contacts and abolished Ca2+ oscillation in smooth muscle cells (SMCs), the driving force of myogenic spontaneous vasomotion. Furthermore, tethering mitochondria and ER by specific overexpression of ME-Linker in SMCs restored cytosolic Ca2+ homeostasis, remotivated myogenic spontaneous vasomotion, achieved optimal reperfusion, and ameliorated neurological injury. Collectively, the maintaining of arteriolar myogenic vasomotion and mitochondria-ER contacts in SMCs, are of critical importance in preventing post-ischemic no-reflow.
Spontaneous cerebral vasomotion, characterized by [~]0.1 Hz rhythmic contractility, is crucial for brain homeostasis. However, our understanding of vasomotion is limited due to a lack of high-precision analytical methods to determine single vasomotion events at basal levels. Here, we developed a novel strategy that integrates a baseline smoothing algorithm, allowing precise measurements of vasodynamics and concomitant Ca2+ dynamics in mouse cerebrovasculature imaged by two-photon microscopy. We identified several previously unrecognized vasomotion properties under different physiological and pathological conditions, especially in ischemic stroke, which is a highly harmful brain disease that results from vessel occlusion. First, the dynamic characteristics between SMCs Ca2+ and corresponding arteriolar vasomotion are interplayed. Second, compared to previous diameter-based estimations, our radius-based measurements reveal nonisotropic vascular movements, enabling a more precise determination of the latency between smooth muscle cell (SMC) Ca2+ activity and vasocontraction. Third, we characterized single vasomotion event kinetics at scales of less than 4 seconds. Finally, following pathological vasoconstrictions induced by ischemic stroke, vasoactive arterioles transitioned to an inert state and persisted despite recanalization. In summary, we developed a highly accurate technique for analyzing spontaneous vasomotion, and we suggest a potential strategy to reduce stroke damage by promoting vasomotion recovery.
Emotion induces changes in regional cerebral blood flow (CBF), a manifestation of neurovascular coupling (NVC), yet whether NVC might feed back to modulate emotion actively remains unexplored. Here, we demonstrate that NVC actively and bidirectionally modulates stress-induced negative emotions. We established bidirectional manipulations of NVC in freely moving mice by employing integrated pharmacological, genetic, and arteriolar optogenetic approaches. Our results showed that both systemic and basolateral amygdala (BLA) region-specific NVC deficiencies heightened emotional responses when mice transitioned from a safe, familiar environment to anxiogenic environments, and local restoration of NVC in the BLA normalized these responses. Mechanistically, NVC dysfunction impairs the capacity of BLA neuronal scaling during state transitions, manifesting as a characteristic biphasic pattern of c-Fos topology. Namely, the NVC-deficient animal aberrantly adopts high-stress configurations under mild stress but regresses to low-stress templates during high-demand survival threats, thereby compromising defensive sustainability. Notably, the genetic NVC-enhancement model counteracts NVC impairments caused by chronic stress, thereby alleviating stress-driven emotional distress. These findings established NVC in the BLA as an allostatic program that fine-tunes neural circuit activity for emotional responses, with implications for understanding and treating emotional disorders.
White matter abnormalities are an emerging feature of schizophrenia, yet the underlying pathophysiological mechanisms are largely unknown. Disruption of ErbB signaling that is essential for peripheral myelination has been genetically associated with schizophrenia and white matter lesions in schizophrenic patients. However, the roles of ErbB signaling in oligodendrocytes remain elusive. Here, we used a pan-ErbB inhibition strategy and demonstrated the synergistic functions of endogenous ErbB receptors in oligodendrocytes. Through analyses of the cellular, histological, biochemical, behavioral, and electrophysiological differences in mice with manipulation of ErbB activities in oligodendrocytes at different differentiation stages, we found that ErbB signaling regulates myelination and aerobic glycolysis in oligodendrocytes, and both functions are required for working memory. ErbB inhibition in oligodendrocytes at early differentiation stages induces hypomyelination by suppressing the differentiation of newly-formed oligodendrocytes. In contrast, ErbB inhibition in mature oligodendrocytes alters neither myelination nor oligodendrocyte numbers, but accelerates axonal conduction decline under energy stress. Mechanistically, mature oligodendrocytes with ErbB inhibition reduce the expression of lactate dehydrogenase A, failing to provide lactate to electrically active axons. Supplementation of L-lactate restores axonal conduction and working memory capacity that are suppressed by ErbB inhibition in mature oligodendrocytes. These findings reveal the indispensable roles of ErbB signaling in white matter integrity and function, and provide insights into the multifaceted contributions of white matter abnormalities to cognitive impairment.