The hippocampus is pivotal in integrating emotional processing, learning, memory, and reward-related behaviors. The dorsal hippocampus (dHPC) is particularly crucial for episodic, spatial, and ...associative memory, and has been shown to be necessary for context- and cue-associated reward behaviors. The nucleus accumbens (NAc), a central structure in the mesolimbic reward pathway, integrates the salience of aversive and rewarding stimuli. Despite extensive research on dHPC→NAc direct projections, their sufficiency in driving reinforcement and reward-related behavior remains to be determined. Our study establishes that activating excitatory neurons in the dHPC is sufficient to induce reinforcing behaviors through its direct projections to the dorso-medial subregion of the NAc shell (dmNAcSh). Notably, dynorphin-containing neurons specifically contribute to dHPC-driven reinforcing behavior, even though both dmNAcSh dynorphin- and enkephalin-containing neurons are activated with dHPC stimulation. Our findings unveil a pathway governing reinforcement, advancing our understanding of the hippocampal circuity's role in reward-seeking behaviors.
Abstract
The evidence for the impact of benzodiazepine (BZD) use on infection or clinical outcomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is limited. We evaluated the ...association of BZD use with SARS-CoV-2 infection and the clinical outcomes of coronavirus disease 2019 (COVID-19) using a nationwide COVID-19 database from South Korea. This nationwide cohort study was performed using the COVID-19 database from the Health Insurance Review and Assessment Service of Korea, and SARS-CoV-2 positivity was investigated according to BZD use. SARS-CoV-2-positive adult patients were assessed in three groups, those who needed hospitalization, those with severe symptoms requiring intensive care, and those who died. A multivariate logistic regression model was used for all the analyses. After adjusting for potential confounding factors, there was no association between BZD use and SARS-CoV-2 positivity. SARS-CoV-2-positive patients with BZD use showed an increased risk of need for hospitalization from COVID-19 compared to those without BZD use (odds ratio OR: 1.33, 95% confidence interval CI 1.07–1.65). In addition, there was a higher risk for long-term users (OR: 2.64, 95% CI 1.08–6.47). Chronic BZD use contributed to a higher risk of the need for hospitalization among COVID-19 patients, whereas BZD use did not increase the risk of SARS-CoV-2 test positivity, severe outcomes, or mortality.
Live-cell single mRNA imaging is a powerful tool but has been restricted in higher eukaryotes to artificial cell lines and reporter genes. We describe an approach that enables live-cell imaging of ...single endogenous labeled mRNA molecules transcribed in primary mammalian cells and tissue. We generated a knock-in mouse line with an MS2 binding site (MBS) cassette targeted to the 3' untranslated region of the essential β-actin gene. As β-actin-MBS was ubiquitously expressed, we could uniquely address endogenous mRNA regulation in any tissue or cell type. We simultaneously followed transcription from the β-actin alleles in real time and observed transcriptional bursting in response to serum stimulation with precise temporal resolution. We tracked single endogenous labeled mRNA particles being transported in primary hippocampal neurons. The MBS cassette also enabled high-sensitivity fluorescence in situ hybridization (FISH), allowing detection and localization of single β-actin mRNA molecules in various mouse tissues.
Biomolecular condensates, often assembled through phase transition mechanisms, play key roles in organizing diverse cellular activities. The material properties of condensates, ranging from liquid ...droplets to solid-like glasses or gels, are key features impacting the way resident components associate with one another. However, it remains unclear whether and how different material properties would influence specific cellular functions of condensates. Here, we combine optogenetic control of phase separation with single-molecule mRNA imaging to study relations between phase behaviors and functional performance of condensates. Using light-activated condensation, we show that sequestering target mRNAs into condensates causes translation inhibition. Orthogonal mRNA imaging reveals highly transient nature of interactions between individual mRNAs and condensates. Tuning condensate composition and material property towards more solid-like states leads to stronger translational repression, concomitant with a decrease in molecular mobility. We further demonstrate that β-actin mRNA sequestration in neurons suppresses spine enlargement during chemically induced long-term potentiation. Our work highlights how the material properties of condensates can modulate functions, a mechanism that may play a role in fine-tuning the output of condensate-driven cellular activities.
Background
Obesity is increasing worldwide, potentially influencing surgical outcomes in colorectal cancer (CRC) patients. We analyzed the effects of obesity indexes on lymph node (LN) retrieval in ...CRC patients.
Method
We applied obesity indexes of body mass index (BMI) and visceral (VAT) and subcutaneous (SAT) adipose tissue volumes to stage I‐III CRC patients. The primary outcome was the effect of these indexes on the number of retrieved LNs (12 > LNs ≥ 12).
Results
Among 519 patients, 35.6% had a BMI ≥ 25 kg/m2. After adjusting for gender, age, tumor location, resected colon length, and local invasion and LN statuses, patients in the highest VAT quartile showed a 5.848 decrease in the number of retrieved LNs, with an odds ratio of 0.483 (95% confidence interval CI 0.260‐0.8979) for adequate LN retrieval (≥12), compared with those in the lowest quartile (P < 0.001 for both). Analysis of the model predicting LN retrieval revealed VAT as the only obesity index (area under the curve AUC = 0.721) providing significant additional predictive power (P = 0.037) to the model including age, gender, staging, tumor location, and resected colon length (AUC = 0.707).
Conclusion
Increased VAT may cause inadequate LN retrieval in CRC patients. In viscerally obese patients, VAT volumes should be considered when clinically interpreting LN status.
Leucine-rich repeat kinase 2 (LRRK2), a multi-domain protein, is a key causative factor in Parkinson's disease (PD). Identification of novel substrates and the molecular mechanisms underlying the ...effects of LRRK2 are essential for understanding the pathogenesis of PD. In this study, we showed that LRRK2 played an important role in neuronal cell death by directly phosphorylating and activating apoptosis signal-regulating kinase 1 (ASK1). LRRK2 phosphorylated ASK1 at Thr832 that is adjacent to Thr845, which serves as an autophosphorylation site. Moreover, results of binding and kinase assays showed that LRRK2 acted as a scaffolding protein by interacting with each components of the ASK1–MKK3/6–p38 MAPK pathway through its specific domains and increasing the proximity to downstream targets. Furthermore, LRRK2-induced apoptosis was suppressed by ASK1 inhibition in neuronal stem cells derived from patients with PD. These results clearly indicate that LRRK2 acts as an upstream kinase in the ASK1 pathway and plays an important role in the pathogenesis of PD.
•LRRK2 Acts as an Upstream Kinase and Regulates the ASK1 Pathway.•LRRK2 Physically Interacts with ASK1 Signaling Kinases and Acts as a Scaffolding Protein.•LRRK2 Interacts with ASK1 in a JIP1-Independent Manner.•LRRK2 Promotes Neuronal Cell Death by Phosphorylating ASK1 at Thr832.•LRRK2 Induces Apoptosis of Patient-Derived NSCs in an ASK1-Dependent Manner.
The comorbid association of autoimmune diseases with cancers has been a major obstacle to successful anti-cancer treatment. Cancer survival rate decreases significantly in patients with preexisting ...autoimmunity. However, to date, the molecular and cellular profiles of such comorbidities are poorly understood. We used Aicardi-Goutières syndrome (AGS) as a model autoimmune disease and explored the underlying mechanisms of genome instability in AGS-associated-gene-deficient patient cells. We found that R-loops are highly enriched at transcription-replication conflict regions of the genome in fibroblast of patients bearing SAMHD1 mutation, which is the AGS-associated-gene mutation most frequently reported with tumor and malignancies. In SAMHD1-depleted cells, R-loops accumulated with the concomitant activation of DNA damage responses. Removal of R-loops in SAMHD1 deficiency reduced cellular responses to genome instability. Furthermore, downregulation of SAMHD1 expression is associated with various types of cancer and poor survival rate. Our findings suggest that SAMHD1 functions as a tumor suppressor by resolving R-loops, and thus, SAMHD1 and R-loop may be novel diagnostic markers and targets for patient stratification in anti-cancer therapy.
There are few prospective studies on the correlations between MRI features and whole RNA-sequencing data in breast cancer according to molecular subtypes. The purpose of our study was to explore the ...association between genetic profiles and MRI phenotypes of breast cancer and to identify imaging markers that influences the prognosis and treatment according to subtypes.
From June 2017 to August 2018, MRIs of 95 women with invasive breast cancer were prospectively analyzed, using the breast imaging-reporting and data system and texture analysis. Whole RNA obtained from surgical specimens was analyzed using next-generation sequencing. The association between MRI features and gene expression profiles was analyzed in the entire tumor and subtypes. Gene networks, enriched functions, and canonical pathways were analyzed using Ingenuity Pathway Analysis. The P value for differential expression was obtained using a parametric F test comparing nested linear models and adjusted for multiple testing by reporting Q value.
In 95 participants (mean age, 53 years ± 11 standard deviation), mass lesion type was associated with upregulation of CCL3L1 (sevenfold) and irregular mass shape was associated with downregulation of MIR421 (sixfold). In estrogen receptor-positive cancer with mass lesion type, CCL3L1 (21-fold), SNHG12 (11-fold), and MIR206 (sevenfold) were upregulated, and MIR597 (265-fold), MIR126 (12-fold), and SOX17 (fivefold) were downregulated. In triple-negative breast cancer with increased standard deviation of texture analysis on precontrast T1-weighted imaging, CLEC3A (23-fold), SRGN (13-fold), HSPG2 (sevenfold), KMT2D (fivefold), and VMP1 (fivefold) were upregulated, and IGLC2 (73-fold) and PRDX4 (sevenfold) were downregulated (all, P < 0.05 and Q < 0.1). Gene network and functional analysis showed that mass type estrogen receptor-positive cancers were associated with cell growth, anti-estrogen resistance, and poor survival.
MRI characteristics are associated with the different expressions of genes related to metastasis, anti-drug resistance, and prognosis, depending on the molecular subtypes of breast cancer.
d‐Alanylation of the teichoic acids of the Gram‐positive bacterial cell wall plays crucial roles in bacterial physiology and virulence. Deprivation of d‐alanine from the teichoic acids of ...Staphylococcus aureus impairs biofilm and colony formation, induces autolysis and ultimately renders methicillin‐resistant S. aureus highly susceptible to antimicrobial agents and host defense peptides. Hence, the d‐alanylation pathway has emerged as a promising antibacterial target against drug‐resistant S. aureus. d‐Alanylation of teichoic acids is mediated via the action of four proteins encoded by the dlt operon, DltABCD, all four of which are essential for the process. In order to develop novel antimicrobial agents against S. aureus, the d‐alanyl carrier protein ligase DltA, which is the first protein in the d‐alanylation pathway, was focused on. Here, the crystal structure of DltA from the methicillin‐resistant S. aureus strain Mu50 is presented, which reveals the unique molecular details of the catalytic center and the role of the P‐loop. Kinetic analysis shows that the enantioselectivity of S. aureus DltA is much higher than that of DltA from other species. In the presence of DltC, the enzymatic activity of DltA is increased by an order of magnitude, suggesting a new exploitable binding pocket. This discovery may pave the way for a new generation of treatments for drug‐resistant S. aureus.
The crystal structure and functional characterization of DltA from Staphylococcus aureus, a d‐alanyl carrier protein ligase that is the first protein in the d‐alanylation pathway, are reported.
Adiponectin exerts renoprotective effects against diabetic nephropathy (DN) by activating the AMP-activated protein kinase (AMPK)/peroxisome proliferative-activated receptor-
(PPAR
) pathway through ...adiponectin receptors (AdipoRs). AdipoRon is an orally active synthetic adiponectin receptor agonist. We investigated the expression of AdipoRs and the associated intracellular pathways in 27 patients with type 2 diabetes and examined the effects of AdipoRon on DN development in male C57BLKS/J
mice, glomerular endothelial cells (GECs), and podocytes. The extent of glomerulosclerosis and tubulointerstitial fibrosis correlated with renal function deterioration in human kidneys. Expression of AdipoR1, AdipoR2, and Ca
/calmodulin-dependent protein kinase kinase-
(CaMKK
) and numbers of phosphorylated liver kinase B1 (LKB1)- and AMPK-positive cells significantly decreased in the glomeruli of early stage human DN. AdipoRon treatment restored diabetes-induced renal alterations in
mice. AdipoRon exerted renoprotective effects by directly activating intrarenal AdipoR1 and AdipoR2, which increased CaMKK
, phosphorylated Ser
LKB1, phosphorylated Thr
AMPK, and PPAR
expression independently of the systemic effects of adiponectin. AdipoRon-induced improvement in diabetes-induced oxidative stress and inhibition of apoptosis in the kidneys ameliorated relevant intracellular pathways associated with lipid accumulation and endothelial dysfunction. In high-glucose-treated human GECs and murine podocytes, AdipoRon increased intracellular Ca
levels that activated a CaMKK
/phosphorylated Ser
LKB1/phosphorylated Thr
AMPK/PPAR
pathway and downstream signaling, thus decreasing high-glucose-induced oxidative stress and apoptosis and improving endothelial dysfunction. AdipoRon further produced cardioprotective effects through the same pathway demonstrated in the kidney. Our results show that AdipoRon ameliorates GEC and podocyte injury by activating the intracellular Ca
/LKB1-AMPK/PPAR
pathway, suggesting its efficacy for treating type 2 diabetes-associated DN.