Probes for INS

The incidence of non-alcoholic fatty liver disease (NAFLD) increases with age. Cellular senescence refers to a state of irreversible cell-cycle arrest combined with the secretion of proinflammatory cytokines and mitochondrial dysfunction. Senescent cells contribute to age-related tissue degeneration. Here we show that the accumulation of senescent cells promotes hepatic fat accumulation and steatosis. We report a close correlation between hepatic fat accumulation and markers of hepatocyte senescence. The elimination of senescent cells by suicide gene-meditated ablation of p16Ink4a-expressing senescent cells in INK-ATTAC mice or by treatment with a combination of the senolytic drugs dasatinib and quercetin (D+Q) reduces overall hepatic steatosis. Conversely, inducing hepatocyte senescence promotes fat accumulation in vitro and in vivo. Mechanistically, we show that mitochondria in senescent cells lose the ability to metabolize fatty acids efficiently. Our study demonstrates that cellular senescence drives hepatic steatosis and elimination of senescent cells may be a novel therapeutic strategy to reduce steatosis.

Sparse populations of neurons in the dentate gyrus (DG) of the hippocampus are causally implicated in the encoding of contextual fear memories. However, engram-specific molecular mechanisms underlying memory consolidation remain largely unknown. Here we perform unbiased RNA sequencing of DG engram neurons 24 h after contextual fear conditioning to identify transcriptome changes specific to memory consolidation. DG engram neurons exhibit a highly distinct pattern of gene expression, in which CREB-dependent transcription features prominently (P = 6.2 × 10-13), including Atf3 (P = 2.4 × 10-41), Penk (P = 1.3 × 10-15), and Kcnq3 (P = 3.1 × 10-12). Moreover, we validate the functional relevance of the RNAseq findings by establishing the causal requirement of intact CREB function specifically within the DG engram during memory consolidation, and identify a novel group of CREB target genes involved in the encoding of long-term memory

Abstract

BACKGROUND:

Programmed death receptor and programmed death ligand (PD-L1) are immunoregulatory proteins. Nonsmall cell lung cancer bypasses the immune system through the induction of protumorigenic immunosuppressive changes. The better understanding of immunology and antitumor immune responses has brought the promising development of novel immunotherapy agents like programmed death receptor checkpoint inhibitors. The aim of this study was to investigate the expression of PD-L1 in lung adenocarcinoma (ADC), comparing 2 different technologies: immunohistochemistry (IHC) by 2 methods versus RNA in situ hybridization (RISH).

METHODOLOGY:

In total, 20 cases of ADC of the lung and 4 samples of metastatic colon ADC were selected. Evaluation of PD-L1 expression was performed by IHC and RISH. RISH was performed using RNAscope. Both methods were scored in tumor cells and quantified using combined intensity and proportion scores.

RESULTS:

Eight of 20 (40%) lung ADC and 2 of 4 (50%) colon ADC were positive for PD-L1 with Cell Signaling IHC, and 65% lung ADC were positive by Dako IHC (13/20). All 4 cases of colon ADC were negative. When evaluated by RISH, 12 lung ADC (60%) and 1 colon ADC (25%) were PD-L1 positive.

CONCLUSIONS:

RNAscope probes provide sensitive and specific detection of PD-L1 in lung ADC. Both IHC methods (Cell Signaling and Dako) show PD-L1 expression, with the Dako method more sensitive (40% vs. 65%). This study illustrates the utility of RISH and Cell Signaling IHC as complementary diagnostic tests, and Food and Drug Administration approved Dako IHC as a companion diagnostic test.

The lateral central nucleus of the amygdala (CeAL) and the dorsolateral bed nucleus of the stria terminalis (BNSTDL) coordinate the expression of shorter- and longer-lasting fears, respectively. Less is known about how these structures communicate with each other during fear acquisition. One pathway, from the CeAL to the BNSTDL, is thought to communicate via corticotropin-releasing factor (CRF), but studies have yet to examine its function in fear learning and memory. Thus, we developed an adeno-associated viral-based strategy to selectively target CRF neurons with the optogenetic silencer archaerhodopsin tp009 (CRF-ArchT) to examine the role of CeAL CRF neurons and projections to the BNSTDL during the acquisition of contextual fear. Expression of our CRF-ArchT vector injected into the amygdala was restricted to CeAL CRF neurons. Furthermore, CRF axonal projections from the CeAL clustered around BNSTDL CRF cells. Optogenetic silencing of CeAL CRF neurons during contextual fear acquisition disrupted retention test freezing 24 h later, but only at later time points (>6 min) during testing. Silencing CeAL CRF projections in the BNSTDL during contextual fear acquisition produced a similar effect. Baseline contextual freezing, the rate of fear acquisition, freezing in an alternate context after conditioning and responsivity to foot shock were unaffected by optogenetic silencing. Our results highlight how CeAL CRF neurons and projections to the BNSTDL consolidate longer-lasting components of a fear memory. Our findings have implications for understanding how discrete amygdalar CRF pathways modulate longer-lasting fear in anxiety- and trauma-related disorders.

Postnatal cells expressing PRX1 (pnPRX1+) present with qualities of skeletal stem cells are identified in the calvaria and axial skeleton. Here we characterize the location and functional capacity of the calvarial pnPRX1+ cells. We found that pnPRX1+ reside exclusively in the calvarial suture niche and decrease in number with age. They are distinct from preosteoblasts and osteoblasts of the sutures, respond to WNT signaling in vitro and in vivo by differentiating into osteoblasts and upon heterotopic transplantation, are able to regenerate bone. Diphtheria toxin A (DTA)-mediated lineage ablation of pnPRX1+ cells and suturectomy perturb regeneration of calvarial bone defects and confirm that pnPRX1+ cells of the sutures are required for bone regeneration. Orthotopic transplantation of sutures with traceable pnPRX1+ cells into wild-type animals show that pnPRX1+ cells of the suture contribute to calvarial bone defect regeneration. DTA-mediated lineage ablation of pnPRX1+ does not however interfere with calvarial development.