MYCL-mediated reprogramming expands pancreatic insulin-producing cells

Nature metabolism

2022 Feb 01

Hirano, M;So, Y;Tsunekawa, S;Kabata, M;Ohta, S;Sagara, H;Sankoda, N;Taguchi, J;Yamada, Y;Ukai, T;Kato, M;Nakamura, J;Ozawa, M;Yamamoto, T;Yamada, Y;
PMID: 35145326 | DOI: 10.1038/s42255-022-00530-y

β cells have a limited capacity for regeneration, which predisposes towards diabetes. Here, we show that, of the MYC family members, Mycl plays a key role in proliferation of pancreatic endocrine cells. Genetic ablation of Mycl causes a reduction in the proliferation of pancreatic endocrine cells in neonatal mice. By contrast, the expression of Mycl in adult mice stimulates the proliferation of β and α cells, and the cells persist after withdrawal of Mycl expression. A subset of the expanded α cells give rise to insulin-producing cells after this withdrawal. Transient Mycl expression in vivo is sufficient to normalize the hyperglycaemia of diabetic mice. In vitro expression of Mycl similarly provokes active replication in islet cells, even in those from aged mice. Finally, we show that MYCL stimulates the division of human adult cadaveric islet cells. Our results demonstrate that the induction of Mycl alone expands the functional β-cell population, which may provide a regenerative strategy for β cells.

Optical tools to study the subcellular organization of GPCR neuromodulation

Journal of neuroscience methods

2021 Nov 08

Jullié, D;Valbret, Z;Stoeber, M;
PMID: 34763022 | DOI: 10.1016/j.jneumeth.2021.109408

Modulation of neuronal circuit activity is key to information processing in the brain. G protein-coupled receptors (GPCRs), the targets of most neuromodulatory ligands, show extremely diverse expression patterns in neurons and receptors can be localized in various sub-neuronal membrane compartments. Upon activation, GPCRs promote signaling cascades that alter the level of second messengers, drive phosphorylation changes, modulate ion channel function, and influence gene expression, all of which critically impact neuron physiology. Because of its high degree of complexity, this form of interneuronal communication has remained challenging to integrate into our conceptual understanding of brain function. Recent technological advances in fluorescence microscopy and the development of optical biosensors now allow investigating neuromodulation with unprecedented resolution on the level of individual cells. In this review, we will highlight recent imaging techniques that enable determining the precise localization of GPCRs in neurons, with specific focus on the subcellular and nanoscale level. Downstream of receptors, we describe novel conformation-specific biosensors that allow for real-time monitoring of GPCR activation and of distinct signal transduction events in neurons. Applying these new tools has the potential to provide critical insights into the function and organization of GPCRs in neuronal cells and may help decipher the molecular and cellular mechanisms that underlie neuromodulation.

The beginning of the era of precision medicine for gastric cancer with fibroblast growth factor receptor 2 aberration

Gastric cancer : official journal of the International Gastric Cancer Association and the Japanese Gastric Cancer Association

2021 Aug 16

Ooki, A;Yamaguchi, K;
PMID: 34398359 | DOI: 10.1007/s10120-021-01235-z

Despite recent advances in the systemic treatment of metastatic gastric cancer (GC), prognostic outcomes remain poor. Considerable research effort has been invested in characterizing the genomic landscape of GC and identifying potential therapeutic targets. FGFR2 is one of the most attractive targets because aberrations in this gene are frequently associated with GC, particularly the diffuse type in Lauren's classification, which confers an unfavorable prognosis. Based on the preclinical data, the FGFR2 signaling pathway plays a key role in the development and progression of GC, and several FGFR inhibitors have been clinically assessed. However, the lack of robust treatment efficacy has hampered precision medicine for patients with FGFR2-aberrant GC. Recently, the clinical benefits of the FGFR2-IIIb-selective monoclonal antibody bemarituzumab for FGFR2b-positive GC patients were shown in a randomized phase II FIGHT trial of bemarituzumab combined with the first-line chemotherapy. This trial demonstrates proof of concept, suggesting that FGFR2 is a relevant therapeutic target for patients with FGFR2b-positive GC and that bemarituzumab brings new hope for diffuse-type GC patients. In this review, we summarize the oncogenic roles of FGFR2 signaling and highlight the most recent advances in FGFR inhibitors based on the findings of pivotal clinical trials for patients with FGFR2-aberrant GC. Thus, the era of precision medicine for patients with FGFR2-aberrant GC will be opened.

IQGAP3, a YAP Target, Is Required for Proper Cell-Cycle Progression and Genome Stability

Molecular cancer research : MCR

2021 Jun 28

Leone, M;Cazorla-Vázquez, S;Ferrazzi, F;Wiederstein, JL;Gründl, M;Weinstock, G;Vergarajauregui, S;Eckstein, M;Krüger, M;Gaubatz, S;Engel, FB;
PMID: 34183451 | DOI: 10.1158/1541-7786.MCR-20-0639

Controlling cell proliferation is critical for organism development, tissue homeostasis, disease, and regeneration. IQGAP3 has been shown to be required for proper cell proliferation and migration, and is associated to a number of cancers. Moreover, its expression is inversely correlated with the overall survival rate in the majority of cancers. Here, we show that IQGAP3 expression is elevated in cervical cancer and that in these cancers IQGAP3 high expression is correlated with an increased lethality. Furthermore, we demonstrate that IQGAP3 is a target of YAP, a regulator of cell cycle gene expression. IQGAP3 knockdown resulted in an increased percentage of HeLa cells in S phase, delayed progression through mitosis, and caused multipolar spindle formation and consequentially aneuploidy. Protein-protein interaction studies revealed that IQGAP3 interacts with MMS19, which is known in Drosophila to permit, by competitive binding to Xpd, Cdk7 to be fully active as a Cdk-activating kinase (CAK). Notably, IQGAP3 knockdown caused decreased MMS19 protein levels and XPD knockdown partially rescued the reduced proliferation rate upon IQGAP3 knockdown. This suggests that IQGAP3 modulates the cell cycle via the MMS19/XPD/CAK axis. Thus, in addition to governing proliferation and migration, IQGAP3 is a critical regulator of mitotic progression and genome stability. IMPLICATIONS: Our data indicate that, while IQGAP3 inhibition might be initially effective in decreasing cancer cell proliferation, this approach harbors the risk to promote aneuploidy and, therefore, the formation of more aggressive cancers.

What do we know about porcine circovirus 3 (PCV3) diagnosis so far?: A review

Transboundary and emerging diseases

2021 Jun 10

Tan, CY;Lin, CN;Ooi, PT;
PMID: 34110095 | DOI: 10.1111/tbed.14185

Porcine circovirus 3 (PCV3) was first discovered in 2016, almost concomitantly by two groups of researchers in the United States. The novel case was reported in a group of sows with chronic reproductive problems with clinical presentation alike porcine dermatitis and nephropathy syndrome (PDNS), where metagenomic sequencing revealed a genetically divergent porcine circovirus designated PCV3. The discovery of PCV3 in a PDNS case, which used to be considered as part of PCVAD attributed to PCV2 (porcine circovirus 2), has garnered attention and effort in further research of the novel virus. Just when an infectious molecular DNA clone of PCV3 has been developed and successfully used in an in vivo pathogenicity study, yet another novel PCV strain surfaced, designated PCV4 (porcine circovirus 4). So far, PCV3 has been reported in domestic swine population globally at low to moderate prevalence, from almost all sample types including organ tissues, faecal, semen and colostrum samples. PCV3 has been associated with a myriad of clinical presentations, from PDNS to porcine respiratory disease complex (PRDC). This review paper summarizes the studies on PCV3 to date, with focus on diagnosis.

PPAR-gamma induced AKT3 expression increases levels of mitochondrial biogenesis driving prostate cancer

Oncogene

2021 Mar 02

Galbraith, LCA;Mui, E;Nixon, C;Hedley, A;Strachan, D;MacKay, G;Sumpton, D;Sansom, OJ;Leung, HY;Ahmad, I;
PMID: 33654198 | DOI: 10.1038/s41388-021-01707-7

Peroxisome Proliferator-Activated Receptor Gamma (PPARG) is one of the three members of the PPAR family of transcription factors. Besides its roles in adipocyte differentiation and lipid metabolism, we recently demonstrated an association between PPARG and metastasis in prostate cancer. In this study a functional effect of PPARG on AKT serine/threonine kinase 3 (AKT3), which ultimately results in a more aggressive disease phenotype was identified. AKT3 has previously been shown to regulate PPARG co-activator 1 alpha (PGC1α) localisation and function through its action on chromosome maintenance region 1 (CRM1). AKT3 promotes PGC1α localisation to the nucleus through its inhibitory effects on CRM1, a known nuclear export protein. Collectively our results demonstrate how PPARG over-expression drives an increase in AKT3 levels, which in turn has the downstream effect of increasing PGC1α localisation within the nucleus, driving mitochondrial biogenesis. Furthermore, this increase in mitochondrial mass provides higher energetic output in the form of elevated ATP levels which may fuel the progression of the tumour cell through epithelial to mesenchymal transition (EMT) and ultimately metastasis.

White matter aging drives microglial diversity

Neuron

2021 Feb 11

Safaiyan, S;Besson-Girard, S;Kaya, T;Cantuti-Castelvetri, L;Liu, L;Ji, H;Schifferer, M;Gouna, G;Usifo, F;Kannaiyan, N;Fitzner, D;Xiang, X;Rossner, MJ;Brendel, M;Gokce, O;Simons, M;
PMID: 33606969 | DOI: 10.1016/j.neuron.2021.01.027

Aging results in gray and white matter degeneration, but the specific microglial responses are unknown. Using single-cell RNA sequencing from white and gray matter separately, we identified white matter-associated microglia (WAMs), which share parts of the disease-associated microglia (DAM) gene signature and are characterized by activation of genes implicated in phagocytic activity and lipid metabolism. WAMs depend on triggering receptor expressed on myeloid cells 2 (TREM2) signaling and are aging dependent. In the aged brain, WAMs form independent of apolipoprotein E (APOE), in contrast to mouse models of Alzheimer's disease, in which microglia with the WAM gene signature are generated prematurely and in an APOE-dependent pathway similar to DAMs. Within the white matter, microglia frequently cluster in nodules, where they are engaged in clearing degenerated myelin. Thus, WAMs may represent a potentially protective response required to clear degenerated myelin accumulating during white matter aging and disease.

Targeting barrel field spiny stellate cells using a vesicular monoaminergic transporter 2-Cre mouse line

Scientific reports

2021 Feb 05

Freitag, FB;Ahemaiti, A;Weman, HM;Ambroz, K;Lagerström, MC;
PMID: 33547358 | DOI: 10.1038/s41598-021-82649-8

Rodent primary somatosensory cortex (S1) is organized in defined layers, where layer IV serves as the main target for thalamocortical projections. Serotoninergic signaling is important for the organization of thalamocortical projections and consequently proper barrel field development in rodents, and the vesicular monoamine transporter 2 (VMAT2) can be detected locally in layer IV S1 cortical neurons in mice as old as P10, but the identity of the Vmat2-expressing neurons is unknown. We here show that Vmat2 mRNA and also Vmat2-Cre recombinase are still expressed in adult mice in a sub-population of the S1 cortical neurons in the barrel field. The Vmat2-Cre cells showed a homogenous intrinsically bursting firing pattern determined by whole-cell patch-clamp, localized radial densely spinous basal dendritic trees and almost exclusively lack of apical dendrite, indicative of layer IV spiny stellate cells. Single cell mRNA sequencing analysis showed that S1 cortical Vmat2-Cre;tdTomato cells express the layer IV marker Rorb and mainly cluster with layer IV neurons, and RNAscope analysis revealed that adult Vmat2-Cre neurons express Vmat2 and vesicular glutamate transporter 1 (Vglut1) and Vglut2 mRNA to a high extent. In conclusion, our analysis shows that cortical Vmat2 expression is mainly confined to layer IV neurons with morphological, electrophysiological and transcriptional characteristics indicative of spiny stellate cells.

Brahma-Related Gene-1 (BRG1) promotes the malignant phenotype of glioblastoma cells

Journal of cellular and molecular medicine

2021 Feb 02

Wang, Y;Yang, CH;Schultz, AP;Sims, MM;Miller, DD;Pfeffer, LM;
PMID: 33528916 | DOI: 10.1111/jcmm.16330

Glioblastoma multiforme (GBM) is an aggressive malignant brain tumour that is resistant to existing therapeutics. Identifying signalling pathways deregulated in GBM that can be targeted therapeutically is critical to improve the present dismal prognosis for GBM patients. In this report, we have identified that the BRG1 (Brahma-Related Gene-1) catalytic subunit of the SWI/SNF chromatin remodelling complex promotes the malignant phenotype of GBM cells. We found that BRG1 is ubiquitously expressed in tumour tissue from GBM patients, and high BRG1 expression levels are localized to specific brain tumour regions. Knockout (KO) of BRG1 by CRISPR-Cas9 gene editing had minimal effects on GBM cell proliferation, but significantly inhibited GBM cell migration and invasion. BRG1-KO also sensitized GBM cells to the anti-proliferative effects of the anti-cancer agent temozolomide (TMZ), which is used to treat GBM patients in the clinic, and selectively altered STAT3 tyrosine phosphorylation and gene expression. These results demonstrate that BRG-1 promotes invasion and migration, and decreases chemotherapy sensitivity, indicating that it functions in an oncogenic manner in GBM cells. Taken together, our findings suggest that targeting BRG1 in GBM may have therapeutic benefit in the treatment of this deadly form of brain cancer.

Low-dose decitabine priming endows CAR T cells with enhanced and persistent antitumour potential via epigenetic reprogramming

Nature communications

2021 Jan 18

Wang, Y;Tong, C;Dai, H;Wu, Z;Han, X;Guo, Y;Chen, D;Wei, J;Ti, D;Liu, Z;Mei, Q;Li, X;Dong, L;Nie, J;Zhang, Y;Han, W;
PMID: 33462245 | DOI: 10.1038/s41467-020-20696-x

Insufficient eradication capacity and dysfunction are common occurrences in T cells that characterize cancer immunotherapy failure. De novo DNA methylation promotes T cell exhaustion, whereas methylation inhibition enhances T cell rejuvenation in vivo. Decitabine, a DNA methyltransferase inhibitor approved for clinical use, may provide a means of modifying exhaustion-associated DNA methylation programmes. Herein, anti-tumour activities, cytokine production, and proliferation are enhanced in decitabine-treated chimeric antigen receptor T (dCAR T) cells both in vitro and in vivo. Additionally, dCAR T cells can eradicate bulky tumours at a low-dose and establish effective recall responses upon tumour rechallenge. Antigen-expressing tumour cells trigger higher expression levels of memory-, proliferation- and cytokine production-associated genes in dCAR T cells. Tumour-infiltrating dCAR T cells retain a relatively high expression of memory-related genes and low expression of exhaustion-related genes in vivo. In vitro administration of decitabine may represent an option for the generation of CAR T cells with improved anti-tumour properties.

TIGIT blockade elicits potent anti-tumor immunity in naturally occurring hepatitis B virus-related hepatocellular carcinoma in mice

Hepatology (Baltimore, Md.)

2022 Aug 08

Wu, Y;Hao, X;Wei, H;Sun, R;Chen, Y;Tian, Z;
PMID: 35938354 | DOI: 10.1002/hep.32715

Chronic hepatitis B virus (HBV) infection is the leading cause of hepatocellular carcinoma (HCC) and is a serious health problem in China, East Asia, and North African countries. Effective treatment of HBV-related HCC is currently unavailable. This study evaluated the therapeutic potential of TIGIT blockade in HBV-related HCC.A mouse model of spontaneous HBV-related HCC was generated by replacing wild-type hepatocytes with HBsAg+ hepatocytes (namely HBs-HepR mice). The tumors in HBs-HepR mice were inflammation-associated HCC, similar to HBV-related HCC in patients, which was distinguished from other HCC mouse models, such as diethylnitrosamine (DEN)-induced HCC, Tak1-knockout-induced HCC, HCC in stelic animal model (STAM), or nonalcoholic steatohepatitis (NASH)-induced HCC. HCC in HBs-HepR mice was characterized by an increased number of CD8+ T cells whereas the production of IL-2, TNF-α, and IFN-γ by intrahepatic CD8+ T cells was decreased. Increased expression of TIGIT on CD8+ T cells was responsible for functional exhaustion. The therapeutic effect of TIGIT blockade was investigated at the early and middle stages of HCC progression in HBs-HepR mice. TIGIT blockade reinvigorated intrahepatic CD8+ T cells with increased TNF-α and IFN-γ production and an increased number of CD8+ T cells in tumors, thereby slowing the development of HCC in HBs-HepR mice. Blocking PD-L1 did not show direct therapeutic effects or synergize with TIGIT blockade.Blockade of TIGIT alone enhanced the anti-tumor activity of CD8+ T cells during the progression of HBV-related HCC in a spontaneous HCC mouse model.This article is protected by

Aging changes in bladder HCN are associated with increasing heterogeneity of adrenergic/mucosal influence on detrusor control in the mouse

The journals of gerontology. Series A, Biological sciences and medical sciences

2021 Mar 08

Hardy, CC;Al-Naggar, IM;Kuo, CL;Kuchel, GA;Smith, PP;
PMID: 33693872 | DOI: 10.1093/gerona/glab070

A geroscience-informed approach to the increasing prevalence of bladder control problems in older adults requires understanding the impact of aging on dynamic mechanisms that ensure resilience in response to stressors challenging asymptomatic voluntary control over urine storage and voiding. Bladder control is predicated on sensory neural information about bladder volume. Modulation of volume-induced bladder wall tensions by autonomic and mucosal factors controls neural sensitivity to bladder volume. We hypothesized that HCN (hyperpolarization-activated cyclic nucleotide-gated) channels integrate these factors and thereby mediate adrenergic detrusor tension control. Furthermore, loss of HCN expression compromises that integration, and could result in loss of precision of detrusor control. Using a lifespan mouse model, RT-qPCR and pharmacologic studies in pre-tensioned intact and mucosa-denuded bladder strips were made. The dominant hcn1 expression declines with maturation and aging, however aging is also associated with increased variance around mean values. In strips from mature animals, isoproterenol had less effect in denuded muscle strips than in intact strips, and HCN blockade diminished isoproterenol responsiveness. With aging, variances about mean response values significantly increased, paralleling hcn1 expression. Our findings support a role for HCN in providing neuroendocrine/paracrine integration and suggest an association of increased heterogeneity of HCN expression in aging with reductions in response precision to neuroendocrine control. The functional implication is an increased risk of dysfunction of brainstem/bladder regulation of neuronal sensitivity to bladder volume. This supports the clinical model of the aging bladder phenotype as an expression of loss of resilience, and not as emerging bladder pathology with aging.

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	Description
sense Example: Hs-LAG3-sense	Standard probes for RNA detection are in antisense. Sense probe is reverse complent to the corresponding antisense probe.
Intron# Example: Mm-Htt-intron2	Probe targets the indicated intron in the target gene, commonly used for pre-mRNA detection
Pool/Pan Example: Hs-CD3-pool (Hs-CD3D, Hs-CD3E, Hs-CD3G)	A mixture of multiple probe sets targeting multiple genes or transcripts
No-XSp Example: Hs-PDGFB-No-XMm	Does not cross detect with the species (Sp)
XSp Example: Rn-Pde9a-XMm	designed to cross detect with the species (Sp)
O# Example: Mm-Islr-O1	Alternative design targeting different regions of the same transcript or isoforms
CDS Example: Hs-SLC31A-CDS	Probe targets the protein-coding sequence only
EnEm	Probe targets exons n and m
En-Em	Probe targets region from exon n to exon m
Retired Nomenclature
tvn Example: Hs-LEPR-tv1	Designed to target transcript variant n
ORF Example: Hs-ACVRL1-ORF	Probe targets open reading frame
UTR Example: Hs-HTT-UTR-C3	Probe targets the untranslated region (non-protein-coding region) only
5UTR Example: Hs-GNRHR-5UTR	Probe targets the 5' untranslated region only
3UTR Example: Rn-Npy1r-3UTR	Probe targets the 3' untranslated region only
Pan Example: Pool	A mixture of multiple probe sets targeting multiple genes or transcripts

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