Glial cells expressing neuron-glial antigen 2 (NG2), also known as oligodendrocyte progenitor cells (OPCs), play a critical role in maintaining brain health. However, their ability to differentiate after ischemic injury is poorly understood. The aim of this study was to investigate the properties and functions of NG2 glia in the ischemic brain. Using transgenic mice, we selectively labeled NG2-expressing cells and their progeny in both healthy brain and after focal cerebral ischemia (FCI). Using single-cell RNA sequencing, we classified the labeled glial cells into five distinct subpopulations based on their gene expression patterns. Additionally, we examined the membrane properties of these cells using the patch-clamp technique. Of the identified subpopulations, three were identified as OPCs, whereas the fourth subpopulation had characteristics indicative of cells likely to develop into oligodendrocytes. The fifth subpopulation of NG2 glia showed astrocytic markers and had similarities to neural progenitor cells. Interestingly, this subpopulation was present in both healthy and post-ischemic tissue; however, its gene expression profile changed after ischemia, with increased numbers of genes related to neurogenesis. Immunohistochemical analysis confirmed the temporal expression of neurogenic genes and showed an increased presence of NG2 cells positive for Purkinje cell protein-4 at the periphery of the ischemic lesion 12 days after FCI, as well as NeuN-positive NG2 cells 28 and 60 days after injury. These results suggest the potential development of neuron-like cells arising from NG2 glia in the ischemic tissue. Our study provides insights into the plasticity of NG2 glia and their capacity for neurogenesis after stroke.
- MeSH
- antigeny metabolismus MeSH
- astrocyty metabolismus MeSH
- ischemie mozku * metabolismus MeSH
- mozek metabolismus MeSH
- myši transgenní MeSH
- myši MeSH
- nervové kmenové buňky * metabolismus MeSH
- neuroglie metabolismus MeSH
- oligodendroglie metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Trophoblastic cell surface antigen 2 (TROP2) is a membrane glycoprotein overexpressed in many solid tumors with a poor prognosis, including intestinal neoplasms. In our study, we show that TROP2 is expressed in preneoplastic lesions, and its expression is maintained in most colorectal cancers (CRC). High TROP2 positivity correlated with lymph node metastases and poor tumor differentiation and was a negative prognostic factor. To investigate the role of TROP2 in intestinal tumors, we analyzed two mouse models with conditional disruption of the adenomatous polyposis coli (Apc) tumor-suppressor gene, human adenocarcinoma samples, patient-derived organoids, and TROP2-deficient tumor cells. We found that Trop2 is produced early after Apc inactivation and its expression is associated with the transcription of genes involved in epithelial-mesenchymal transition, the regulation of migration, invasiveness, and extracellular matrix remodeling. A functionally similar group of genes was also enriched in TROP2-positive cells from human CRC samples. To decipher the driving mechanism of TROP2 expression, we analyzed its promoter. In human cells, this promoter was activated by β-catenin and additionally by the Yes1-associated transcriptional regulator (YAP). The regulation of TROP2 expression by active YAP was verified by YAP knockdown in CRC cells. Our results suggest a possible link between aberrantly activated Wnt/β-catenin signaling, YAP, and TROP2 expression.
- Publikační typ
- časopisecké články MeSH
The use of low sub-perceptual doses of psychedelics ("microdosing") has gained popularity in recent years. Although anecdotal reports claim multiple benefits associated with this practice, the lack of placebo-controlled studies severely limits our knowledge of microdosing and its effects. Moreover, research conducted in standard laboratory settings could fail to capture the motivation of individuals engaged or planning to engage in microdosing protocols, thus underestimating the likelihood of positive effects on creativity and cognitive function. We recruited 34 individuals starting to microdose with psilocybin mushrooms (Psilocybe cubensis), one of the materials most frequently used for this purpose. Following a double-blind placebo-controlled experimental design, we investigated the acute and short-term effects of 0.5 g of dried mushrooms on subjective experience, behavior, creativity (divergent and convergent thinking), perception, cognition, and brain activity. The reported acute effects were significantly more intense for the active dose compared to the placebo, but only for participants who correctly identified their experimental condition. These changes were accompanied by reduced EEG power in the theta band, together with preserved levels of Lempel-Ziv broadband signal complexity. For all other measurements there was no effect of microdosing except for few small changes towards cognitive impairment. According to our findings, low doses of psilocybin mushrooms can result in noticeable subjective effects and altered EEG rhythms, but without evidence to support enhanced well-being, creativity and cognitive function. We conclude that expectation underlies at least some of the anecdotal benefits attributed to microdosing with psilocybin mushrooms.
RATIONALE: Serotonergic psychedelics are being studied as novel treatments for mental health disorders and as facilitators of improved well-being, mental function, and creativity. Recent studies have found mixed results concerning the effects of low doses of psychedelics ("microdosing") on these domains. However, microdosing is generally investigated using instruments designed to assess larger doses of psychedelics, which might lack sensitivity and specificity for this purpose. OBJECTIVES: Determine whether unconstrained speech contains signatures capable of identifying the acute effects of psilocybin microdoses. METHODS: Natural speech under psilocybin microdoses (0.5 g of psilocybin mushrooms) was acquired from thirty-four healthy adult volunteers (11 females: 32.09 ± 3.53 years; 23 males: 30.87 ± 4.64 years) following a double-blind and placebo-controlled experimental design with two measurement weeks per participant. On Wednesdays and Fridays of each week, participants consumed either the active dose (psilocybin) or the placebo (edible mushrooms). Features of interest were defined based on variables known to be affected by higher doses: verbosity, semantic variability, and sentiment scores. Machine learning models were used to discriminate between conditions. Classifiers were trained and tested using stratified cross-validation to compute the AUC and p-values. RESULTS: Except for semantic variability, these metrics presented significant differences between a typical active microdose and the inactive placebo condition. Machine learning classifiers were capable of distinguishing between conditions with high accuracy (AUC [Formula: see text] 0.8). CONCLUSIONS: These results constitute first evidence that low doses of serotonergic psychedelics can be identified from unconstrained natural speech, with potential for widely applicable, affordable, and ecologically valid monitoring of microdosing schedules.
- MeSH
- dospělí MeSH
- duševní poruchy * MeSH
- dvojitá slepá metoda MeSH
- halucinogeny * farmakologie MeSH
- jazyk (prostředek komunikace) MeSH
- kreativita MeSH
- lidé MeSH
- psilocybin farmakologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Modulating endogenous regenerative processes may represent a suitable treatment for central nervous system (CNS) injuries, such as stroke or trauma. Neural stem/progenitor cells (NS/PCs), which naturally reside in the subventricular zone (SVZ) of the adult brain, proliferate and differentiate to other cell types, and therefore may compensate the negative consequences of ischemic injury. The fate of NS/PCs in the developing brain is largely influenced by Wingless/Integrated (Wnt) signaling; however, its role in the differentiation of adult NS/PCs under ischemic conditions is still enigmatic. In our previous study, we identified the Wnt/β-catenin signaling pathway as a factor promoting neurogenesis at the expense of gliogenesis in neonatal mice. In this study, we used adult transgenic mice in order to assess the impact of the canonical Wnt pathway modulation (inhibition or hyper-activation) on NS/PCs derived from the SVZ, and combined it with the middle cerebral artery occlusion (MCAO) to disclose the effect of focal cerebral ischemia (FCI). Based on the electrophysiological properties of cultured cells, we first identified three cell types that represented in vitro differentiated NS/PCs - astrocytes, neuron-like cells, and precursor cells. Following FCI, we detected fewer neuron-like cells after Wnt signaling inhibition. Furthermore, the immunohistochemical analysis revealed an overall higher expression of cell-type-specific proteins after FCI, indicating increased proliferation and differentiation rates of NS/PCs in the SVZ. Remarkably, Wnt signaling hyper-activation increased the abundance of proliferating and neuron-like cells, while Wnt pathway inhibition had the opposite effect. Finally, the expression profiling at the single cell level revealed an increased proportion of neural stem cells and neuroblasts after FCI. These observations indicate that Wnt signaling enhances NS/PCs-based regeneration in the adult mouse brain following FCI, and supports neuronal differentiation in the SVZ.
- Publikační typ
- časopisecké články MeSH
The canonical Wnt signaling pathway is mediated by interaction of β-catenin with the T-cell factor/lymphoid enhancer-binding factor (TCF/LEF) transcription factors and subsequent transcription activation of Wnt-target genes. In the hematopoietic system, the function of the pathway has been mainly investigated by rather unspecific genetic manipulations of β-catenin that yielded contradictory results. Here, we used a mouse expressing a truncated dominant negative form of the human TCF4 transcription factor (dnTCF4) that specifically abrogates β-catenin-TCF/LEF interaction. Disruption of the β-catenin-TCF/LEF interaction resulted in the accumulation of immature cells and reduced granulocytic differentiation. Mechanistically, dnTCF4 progenitors exhibited downregulation of the Csf3r gene, reduced granulocyte colony-stimulating factor (G-CSF) receptor levels, attenuation of downstream Stat3 phosphorylation after G-CSF treatment, and impaired G-CSF-mediated differentiation. Chromatin immunoprecipitation assays confirmed direct binding of TCF/LEF factors to the promoter and putative enhancer regions of CSF3R. Inhibition of β-catenin signaling compromised activation of the emergency granulopoiesis program, which requires maintenance and expansion of myeloid progenitors. Consequently, dnTCF4 mice were more susceptible to Candida albicans infection and more sensitive to 5-fluorouracil-induced granulocytic regeneration. Importantly, genetic and chemical inhibition of β-catenin-TCF/LEF signaling in human CD34+ cells reduced granulocytic differentiation, whereas its activation enhanced myelopoiesis. Altogether, our data indicate that the β-catenin-TCF/LEF complex directly regulates G-CSF receptor levels, and consequently controls proper differentiation of myeloid progenitors into granulocytes in steady-state and emergency granulopoiesis. Our results uncover a role for the β-catenin signaling pathway in fine tuning the granulocytic production, opening venues for clinical intervention that require enhanced or reduced production of neutrophils.
- MeSH
- beta-katenin genetika metabolismus MeSH
- Candida albicans MeSH
- granulocyty metabolismus MeSH
- kandidóza genetika metabolismus MeSH
- myelopoéza * MeSH
- myši transgenní MeSH
- myši MeSH
- protein 2 podobný transkripčnímu faktoru 7 metabolismus MeSH
- receptory faktoru stimulujícího kolonie biosyntéza genetika MeSH
- signální transdukce * MeSH
- transkripční faktory TCF genetika metabolismus MeSH
- upregulace * MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Úvod: Akutní pankreatitida (AP) je poměrně vzácnou, ale závažnou komplikací, která se může objevit u pacientů po transplantaci orgánů. V populaci pacientů po transplantaci jater je její incidence popisovaná v rozmezí od 1,5 do 8 % a je spojená s významnou mortalitou. Cíl a metody: Cílem naší studie bylo stanovit incidenci, identifikovat rizikové faktory a posoudit průběh AP u pacientů po transplantaci jater v Institutu klinické a experimentální medicíny. Provedli jsme retrospektivní analýzu lékařských záznamů všech pacientů, kteří podstoupili transplantaci jater mezi zářím 1996 a prosincem 2019. Výsledky: Celkem podstoupilo ve sledovaném období transplantaci jater 1 740 pacientů. AP byla diagnostikována u 50 pacientů (2,9 %), ve 40 případech (80 %) bylo onemocnění lehké, těžká AP byla zaznamenána u 10 pacientů (20 %), celková mortalita byla 10 %. Časná AP (< 30 dní od transplantace), vzniklá v průměru s 10denním odstupem od transplantace, se vyskytla u 14 pacientů (28 %); u většiny z nich byla AP těžká (9 pacientů, 64 %) s úmrtím ve čtyřech případech (44%). Pozdní AP byla diagnostikována u 36 pacientů (72 %) v průměru po 40 měsících od transplantace; v naprosté většině případů byl průběh pankreatitidy lehký (35 pacientů, 97 %), jediný pacient s těžkou AP na onemocnění zemřel. Nejčastější etiologie AP byly: post-endoskopická retrográdní cholangiopankreatografie (38 %), idiopatická (26 %), pooperační (14 %) a poléková (12 %). Komplikace byly zaznamenány u devíti pacientů. Tři pacienti podstoupili chirurgickou léčbu. Chronická infekce virem hepatitidy B (HBV) jako příčina jaterního onemocnění vedoucího k transplantaci byla rizikovým faktorem vzniku AP (p = 0,012). Závěr: AP se vyskytuje u pacientů po transplantaci jater relativně vzácně, avšak častěji než v běžné populaci. Celková mortalita onemocnění byla ve srovnání s obecnou populací vyšší i přes obdobné zastoupení těžké a lehké formy AP. Nepříznivý průběh byl spojen zejména s výskytem onemocnění v časném potransplantačním období. Rizikovým faktorem vzniku AP byla transplantace jater pro komplikace HBV infekce.
Introduction: Acute pancreatitis (AP) is relatively rare but serious complication that may occur after organ transplantation. In the group of patients with liver transplantation, the reported incidence ranges from 1.5 to 8 % and is associated with significant mortality. Aim and methods: The aim of this study was to assess the incidence, identify potential risk factors and evaluate the course of acute pancreatitis in patients after liver transplantation in the Institute for Clinical and Experimental Medicine. We performed a retrospective analysis of the medical records of all patients who underwent liver transplantation during the period between September 1996 and December 2019. Results: A total of 1,740 patients underwent liver transplantation during the study period. AP was diagnosed in 50 patients (2.9%), a mild form was present in 40 cases (80%) and a severe form was found in 10 patients (20%), the overall mortality was 10%. An early form of AP (< 30 days from transplantation), arising with an average 10-day delay from transplantation, occurred in 14 patients (28%); most of these patients presented with severe AP (9 patients, 64%) and four of them died (44%). Late form of AP was diagnosed in 36 patients (72%) with a mean delay of 40 months from transplantation; in most of the cases, the course of AP was mild (35 patients, 97%), one patient with severe AP died. The most common etiology of AP were post-endoscopic retrograde cholangio pancreatography (38%), idiopathic (26%), post-operative (14%) and drug-induced (12%). Complications occurred in nine patients. Three patients underwent surgical treatment. Chronic hepatitis B virus (HBV) infection as the cause of the liver disease leading to liver transplantation was a risk factor for the development of AP (P = 0.012). Conclusion: AP occurs relatively rarely in liver transplant recipients, but more frequently than in the general population. The overall mortality of the disease was higher compared to the general population despite similar representation of severe and mild form of AP. The unfavorable course was mainly associated with the occurrence of the disease in the early post-transplant period. Liver transplantation for complications of HBV infection was a risk factor for the development of AP. Conflict of Interest: The authors declare that the article/ manuscript complies with ethical standards, patien
Wnt signaling plays an important role in the self-renewal, fate-commitment and survival of the neural stem/progenitor cells (NS/PCs) of the adult central nervous system (CNS). Ischemic stroke impairs the proper functioning of the CNS and, therefore, active Wnt signaling may prevent, ameliorate, or even reverse the negative effects of ischemic brain injury. In this review, we provide the current knowledge of Wnt signaling in the adult CNS, its status in diverse cell types, and the Wnt pathway's impact on the properties of NS/PCs and glial cells in the context of ischemic injury. Finally, we summarize promising strategies that might be considered for stroke therapy, and we outline possible future directions of the field.
- MeSH
- buněčná diferenciace genetika MeSH
- cílená molekulární terapie metody trendy MeSH
- dospělí MeSH
- ischemie mozku genetika metabolismus patologie patofyziologie MeSH
- lidé MeSH
- mozek cytologie patologie fyziologie MeSH
- nervové kmenové buňky patologie fyziologie MeSH
- neurogeneze fyziologie MeSH
- neuroglie patologie fyziologie MeSH
- signální dráha Wnt genetika fyziologie MeSH
- tranzitorní ischemická ataka genetika metabolismus patologie terapie MeSH
- zdraví MeSH
- zvířata MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Protein phosphatase magnesium-dependent 1 delta (PPM1D) terminates cell response to genotoxic stress by negatively regulating the tumor suppressor p53 and other targets at chromatin. Mutations in the exon 6 of the PPM1D result in production of a highly stable, C-terminally truncated PPM1D. These gain-of-function PPM1D mutations are present in various human cancers but their role in tumorigenesis remains unresolved. Here we show that truncated PPM1D impairs activation of the cell cycle checkpoints in human non-transformed RPE cells and allows proliferation in the presence of DNA damage. Next, we developed a mouse model by introducing a truncating mutation in the PPM1D locus and tested contribution of the oncogenic PPM1DT allele to colon tumorigenesis. We found that p53 pathway was suppressed in colon stem cells harboring PPM1DT resulting in proliferation advantage under genotoxic stress condition. In addition, truncated PPM1D promoted tumor growth in the colon in Apcmin mice and diminished survival. Moreover, tumor organoids derived from colon of the ApcminPpm1dT/+ mice were less sensitive to 5-fluorouracil when compared to ApcminPpm1d+/+and the sensitivity to 5-fluorouracil was restored by inhibition of PPM1D. Finally, we screened colorectal cancer patients and identified recurrent somatic PPM1D mutations in a fraction of colon adenocarcinomas that are p53 proficient and show defects in mismatch DNA repair. In summary, we provide the first in vivo evidence that truncated PPM1D can promote tumor growth and modulate sensitivity to chemotherapy.
- MeSH
- chromatin účinky léků MeSH
- exony genetika MeSH
- fluoruracil farmakologie MeSH
- karcinogeneze účinky léků MeSH
- kontrolní body buněčného cyklu genetika MeSH
- lidé MeSH
- mutace genetika MeSH
- myši MeSH
- nádorový supresorový protein p53 genetika MeSH
- nádory tračníku farmakoterapie genetika patologie MeSH
- oprava DNA účinky léků MeSH
- poškození DNA účinky léků MeSH
- proliferace buněk účinky léků MeSH
- protein familiární adenomatózní polypózy genetika MeSH
- proteinfosfatasa 2C genetika MeSH
- regulace genové exprese u nádorů účinky léků MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Colorectal cancer (CRC) is a heterogeneous disease that includes both hereditary and sporadic types of tumors. Tumor initiation and growth is driven by mutational or epigenetic changes that alter the function or expression of multiple genes. The genes predominantly encode components of various intracellular signaling cascades. In this review, we present mouse intestinal cancer models that include alterations in the Wnt, Hippo, p53, epidermal growth factor (EGF), and transforming growth factor β (TGFβ) pathways; models of impaired DNA mismatch repair and chemically induced tumorigenesis are included. Based on their molecular biology characteristics and mutational and epigenetic status, human colorectal carcinomas were divided into four so-called consensus molecular subtype (CMS) groups. It was shown subsequently that the CMS classification system could be applied to various cell lines derived from intestinal tumors and tumor-derived organoids. Although the CMS system facilitates characterization of human CRC, individual mouse models were not assigned to some of the CMS groups. Thus, we also indicate the possible assignment of described animal models to the CMS group. This might be helpful for selection of a suitable mouse strain to study a particular type of CRC.
- MeSH
- epidermální růstový faktor genetika MeSH
- geny p53 genetika MeSH
- karcinogeneze genetika MeSH
- kolorektální nádory klasifikace metabolismus patofyziologie MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- nádorová transformace buněk genetika MeSH
- nádory tračníku genetika MeSH
- oprava chybného párování bází DNA genetika MeSH
- protein-serin-threoninkinasy genetika MeSH
- regulace genové exprese u nádorů genetika MeSH
- signální dráha Wnt genetika MeSH
- transformující růstový faktor beta genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
