Biology subjects

Wu, X.-R.

Publications and source records attributed to Wu, X.-R..

6 recordsLinked to original sources

bioRxiv2024

Hijacking a dedicated entorhinal-hippocampal extinction circuit to remove traumatic memory

Effective psychotherapy of post-traumatic stress disorder (PTSD) remains challenging due to the fragile nature of fear extinction, for which ventral hippocampal CA1 (vCA1) region is considered as a central hub. However, neither the core pathway nor the cellular mechanisms involved in implementing extinction are known. Here, we unveil a direct pathway, where layer 2a fan cells in the lateral entorhinal cortex (LEC) target parvalbumin-expressing interneurons (PV-INs) in the vCA1 region to propel low gamma-band synchronization of the LEC-vCA1 activity during extinction learning. Bidirectional manipulations of either hippocampal PV-INs or LEC fan cells suffice fear extinction. Gamma entrainment of vCA1 by deep brain stimulation (DBS) or noninvasive transcranial alternating current stimulation (tACS) of LEC persistently enhances the PV-IN activity in vCA1, thereby promoting fear extinction. These results demonstrate that the LEC-vCA1 pathway forms a top-down motif to empower low gamma-band oscillations that facilitate fear extinction. Finally, application of low gamma DBS and tACS to a mouse model with persistent PTSD shows potent efficacy, suggesting that the dedicated LEC-vCA1 pathway can be hijacked for therapy to remove traumatic memory trace. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=199 SRC="FIGDIR/small/593830v1_ufig1.gif" ALT="Figure 1"> View larger version (57K): org.highwire.dtl.DTLVardef@ca6768org.highwire.dtl.DTLVardef@4ae574org.highwire.dtl.DTLVardef@11e4ff5org.highwire.dtl.DTLVardef@1136cc2_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2023

Urothelium-specific expression of mutationally activated Pik3ca initiates early lesions of non-invasive bladder cancer

Despite the fact that [~]70% of bladder cancers are non-invasive and have high recurrence rates, early stage disease is understudied. The relative lack of models to validate the contribution of molecular drivers of bladder tumorigenesis is a significant issue. While mutations in PIK3CA are frequent in human bladder cancer, an in vivo model for understanding their contribution to bladder tumorigenesis is unavailable. Therefore, a Upk2-Cre/Pik3caH1047R mouse model expressing one or two R26-Pik3caH1047R alleles in a urothelium-specific manner was created. Pik3caH1047R functionality was confirmed by quantifying Akt phosphorylation and mice were characterized by assessing urothelial thickness, nuclear atypia, and expression of luminal and basal markers at 6 and 12 months of age. At 6 months, Pik3caH1047R mice developed increased urothelial thickness and nuclear atypia, however, at 12 months, Pik3caH1047R mice did not exhibit progressive disease. Immunohistochemistry shows urothelium maintained luminal differentiation characterized by high Foxa1 and Ppar{gamma} expression. In addition, mice were subjected to low-dose carcinogen exposure (N-Butyl-N-(4-hydroxybutyl)nitrosamine (BBN)). Surprisingly, Pik3caH1047R mice exhibited no significant differences after exposure relative to mice without exposure. Furthermore, ssGSEA analysis of invasive human tumors showed those with mutant PIK3CA do not exhibit significantly increased PI3K/AKT pathway activity compared to wildtype PIK3CA tumors. Overall, these data suggest that Pik3caH1047R can elicit early tumorigenic changes in the urothelium, but progression to invasion may require additional genetic alterations.

cancer biology↗

bioRxiv2023

The Complexity of Functional Connectivity Profiles of the Subgenual Anterior Cingulate Cortex and Dorsal Lateral Prefrontal Cortex in Major Depressive Disorder: a DIRECT Consortium Study

BackgroundThe subgenual anterior cingulate cortex (sgACC) plays a central role in the pathophysiology of major depressive disorder (MDD), and its functional interactive profile with the left dorsal lateral prefrontal cortex (DLPFC) is associated with transcranial magnetic stimulation (TMS) treatment outcomes. Nevertheless, previous research on sgACC functional connectivity (FC) in MDD has yielded inconsistent results, partly due to small sample sizes and limited statistical power. Furthermore, calculating sgACC-FC to target TMS individually is challenging. MethodsLeveraging a large multi-site cross-sectional sample (1660 MDD patients vs. 1341 healthy controls) from Phase II of the Depression Imaging REsearch ConsorTium (DIRECT), we systematically delineated case-control difference maps of sgACC-FC. Then, we explored the potential impact of such group-level abnormality profiles on the TMS target localization and clinical efficacy. Next, we developed an MDD big data-guided individualized TMS targeting algorithm to integrate group-level statistical maps with individual-level brain activity to localize TMS targets individually. ResultsWe found an enhanced sgACC-DLPFC FC in MDD patients compared to healthy controls (HC). Such group differences altered the position of the sgACC anti-correlation peak in the left DLPFC. In two independent clinical samples, we showed that the magnitude of TMS targets case-control differences in sgACC FC was related to clinical improvement. The MDD big data-guided individualized TMS targeting algorithm may generate individualized TMS targets that are clinically superior to group-level targets. InterpretationWe reliably delineated MDD-related abnormalities of sgACC-FC profiles in a large, independently ascertained sample and demonstrated the potential impact of such case-control differences on FC-guided localization of TMS targets. FundingMinistry of Science and Technology of the Peoples Republic of China, National Natural Science Foundation of China, and Chinese Academy of Sciences

neuroscience↗

bioRxiv2022

Dynamic tripartite construct of interregional engram circuits underlies forgetting of extinction memory

Fear extinction allows for adaptive control of learned fear responses but often fails, resulting in a renewal or spontaneous recovery of the extinguished fear, i.e., forgetting of the extinction memory readily occurs. Using an activity-dependent neuronal labeling strategy, we demonstrate that engram neurons for fear extinction memory are dynamically positioned in the medial prefrontal cortex (mPFC), basolateral amygdala (BLA), and ventral hippocampus (vHPC), which constitute an engram construct in the term of directional engram synaptic connectivity from the BLA or vHPC to mPFC, but not that in the opposite direction, for retrieval of extinction memory. Fear renewal or spontaneous recovery switches the extinction engram construct from an accessible to inaccessible state, whereas additional extinction learning or optogenetic induction of long-term potentiation restores the directional engram connectivity and prevents the return of fear. Thus, the plasticity of engram construct underlies forgetting of extinction memory.

neuroscience↗

bioRxiv2021

The kidney protects against sepsis by enhancing the systemic release of Uromodulin to stimulate macrophage function

Sepsis is a significant cause of mortality in hospitalized patients. Concomitant development of acute kidney injury (AKI) increases sepsis mortality through unclear mechanisms. While electrolyte disturbances and toxic metabolite buildup during AKI could be important, it is possible that the kidney produces a protective molecule lost during sepsis with AKI. We previously demonstrated that systemic Tamm-Horsfall Protein (THP, uromodulin), a kidney-derived protein with immunomodulatory properties, falls in AKI. Using a mouse sepsis model without severe kidney injury, we show that the kidney increases circulating THP by enhancing basolateral release of THP from medullary thick ascending limb cells. In sepsis patients, changes in circulating THP are positively associated with critical illness. THP is also found de novo in injured lungs. Genetic ablation of THP in mice leads to increased mortality and bacterial burden during sepsis. Consistent with the increased bacterial burden, the presence of THP in vitro and in vivo leads macrophages and monocytes to upregulate a transcriptional program promoting cell migration, phagocytosis and chemotaxis and treatment of macrophages with purified THP increases phagocytosis. Rescue of septic THP-/- mice with exogenous systemic THP improves survival. Together, these findings suggest that through releasing THP, the kidney modulates the immune response in sepsis by enhancing mononuclear phagocyte function and systemic THP has therapeutic potential in sepsis. Significance StatementSepsis is a significant contributor to kidney injury as well as morbidity and mortality worldwide. Specific therapies to improve outcomes in sepsis with kidney injury have largely been limited to symptom management and infectious agent control, in part because it is unclear how kidney injury increases sepsis mortality. This paper describes the identification of Tamm-Horsfall protein, previously known to protect in ischemic models of AKI, as protective in preclinical models of sepsis. It demonstrates how the loss of THP leads to decreased mononuclear phagocyte function and diversity, increased pathogen burden and decreased survival. THP also increases in sepsis without severe kidney injury and concentrates in injured organs. Further study of THP in sepsis could lead to novel sepsis therapeutics.

immunology↗

bioRxiv2018

Reduced but not Enhanced Default Mode Network Functional Connectivity in Major Depressive Disorder: Evidence from 25 Cohorts in the REST-meta-MDD Project

Major Depressive Disorder (MDD) is common and disabling, but its neural pathophysiology remains unclear. Functional brain network studies in MDD have largely had limited statistical power and data analysis approaches have varied widely. The REST-meta-MDD Project of resting-state fMRI (R-fMRI) addresses these issues. The 25 research groups in China composing the REST-meta-MDD Project contributed R-fMRI data of 1,300 patients with MDD and 1,128 normal controls (NCs). The data were preprocessed locally with a standardized protocol prior to aggregated group analyses. We focused on functional connectivity (FC) within the default mode network (DMN), frequently reported to show increased FC in MDD. We found decreased instead of increased DMN FC when comparing 848 MDDs with 794 NCs from 17 sites after data exclusion. We found FC reduction only in recurrent MDD, not in first-episode drug-naive MDD. Decreased DMN FC was associated with medication usage but not with MDD duration. DMN FC was also positively related to symptom severity but only in recurrent MDDs. Exploratory analyses also revealed alterations of local intrinsic activity in MDD. We confirmed the key role of DMN in MDD but found reduced rather than increased FC within the DMN. Future studies should test whether decreased DMN FC mediates treatment response. This manuscript announces the publicly available resting-state fMRI indices of the REST-meta-MDD consortium shared via the R-fMRI Maps Project.\n\nSIGNIFICANCE STATEMENTFunctional connectivity within the default mode network in major depressive disorder patients has been frequently reported abnormal but with contradicting directions in previous small sample size studies. By creating the REST-meta-MDD consortium containing neuroimaging data of 1,300 depressed patients and 1,128 normal controls from 25 research groups in China, we found decreased default mode network functional connectivity in depressed patients, driven by patients with recurrent depression, and associated with current medication treatment but not with disease duration. These findings suggest that default mode network functional connectivity remains a prime target for understanding the pathophysiology of depression, with particular relevance to revealing mechanisms of effective treatments.

neuroscience↗