Accumulation of environmental chitin in the lungs can lead to pulmonary fibrosis, characterized by inflammatory infiltration and fibrosis in acidic chitinase (Chia)-deficient mice. Transgenic expression of Chia in these mice ameliorated the symptoms, indicating the potential of enzyme supplementation as a promising therapeutic strategy for related lung diseases. This study focuses on utilizing hyperactivated human Chia, which exhibits low activity. We achieved significant activation of human Chia by incorporating nine amino acids derived from the crab-eating monkey (Macaca fascicularis) Chia, known for its robust chitin-degrading activity. The modified human Chia retained high activity across a broad pH spectrum and exhibited enhanced thermal stability. The amino acid substitutions associated with hyperactivation of human Chia activity occurred species specifically in monkey Chia. This discovery highlights the potential of hyperactivated Chia in treating pulmonary diseases resulting from chitin accumulation in human lungs.
- MeSH
- Enzyme Activation drug effects MeSH
- Chitin metabolism chemistry MeSH
- Chitinases * metabolism genetics chemistry MeSH
- Hydrogen-Ion Concentration MeSH
- Humans MeSH
- Macaca fascicularis MeSH
- Mice MeSH
- Lung metabolism pathology enzymology MeSH
- Enzyme Stability MeSH
- Amino Acid Substitution MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
OBJECTIVE: The aim of this work was to study the differences at the whole-brain level between self-paced and cued movement processing in Parkinson's disease (PD). METHODS: High density electroencephalogram (HD-EEG) was recorded during the performance of self-paced movements (Bereitschaftspotential - BP) and visually cued movements (VMT) in PD patients (n = 38) and in a group of healthy controls (HC, n = 23). Oscillatory changes in the alpha, beta, and gamma frequencies were evaluated and correlated to the clinical scales- MDS-UPDRS and Freezing of Gait Questionnaire (FOGQ). RESULTS: The main difference in the alpha range was an activation in the basal ganglia area during VMT performance as compared to BP performance; this activation was present only in HC. The most important finding was observed in the high beta range: a higher activation of the right postcentral area during BP performance in PD subjects as compared to HC, correlating to the severity of FOG. Moreover, PD patients had lower gamma activation of the right frontal areas. CONCLUSION: A simplification of motor circuits and a hyperactivation of the right somatosensory cortex were observed in PD subjects. SIGNIFICANCE: Future studies should be focused on this area to confirm or disprove its role in FOG.
- MeSH
- Electroencephalography * methods MeSH
- Middle Aged MeSH
- Humans MeSH
- Parkinson Disease * physiopathology MeSH
- Cues MeSH
- Movement physiology MeSH
- Aged MeSH
- Somatosensory Cortex * physiopathology MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
BACKGROUND: Prostate cancer ranks as the second most frequently diagnosed cancer in men worldwide. Recent research highlights the crucial roles IL6ST-mediated signaling pathways play in the development and progression of various cancers, particularly through hyperactivated STAT3 signaling. However, the molecular programs mediated by IL6ST/STAT3 in prostate cancer are poorly understood. METHODS: To investigate the role of IL6ST signaling, we constitutively activated IL6ST signaling in the prostate epithelium of a Pten-deficient prostate cancer mouse model in vivo and examined IL6ST expression in large cohorts of prostate cancer patients. We complemented these data with in-depth transcriptomic and multiplex histopathological analyses. RESULTS: Genetic cell-autonomous activation of the IL6ST receptor in prostate epithelial cells triggers active STAT3 signaling and significantly reduces tumor growth in vivo. Mechanistically, genetic activation of IL6ST signaling mediates senescence via the STAT3/ARF/p53 axis and recruitment of cytotoxic T-cells, ultimately impeding tumor progression. In prostate cancer patients, high IL6ST mRNA expression levels correlate with better recurrence-free survival, increased senescence signals and a transition from an immune-cold to an immune-hot tumor. CONCLUSIONS: Our findings demonstrate a context-dependent role of IL6ST/STAT3 in carcinogenesis and a tumor-suppressive function in prostate cancer development by inducing senescence and immune cell attraction. We challenge the prevailing concept of blocking IL6ST/STAT3 signaling as a functional prostate cancer treatment and instead propose cell-autonomous IL6ST activation as a novel therapeutic strategy.
- MeSH
- Cyclin-Dependent Kinase Inhibitor p16 metabolism genetics MeSH
- Humans MeSH
- Disease Models, Animal MeSH
- Mice MeSH
- Cell Line, Tumor MeSH
- Tumor Microenvironment * MeSH
- Tumor Suppressor Protein p53 * metabolism genetics MeSH
- Prostatic Neoplasms * pathology metabolism genetics MeSH
- Gene Expression Regulation, Neoplastic MeSH
- Signal Transduction * MeSH
- Cellular Senescence * MeSH
- STAT3 Transcription Factor * metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
The eIF4F translation initiation complex plays a critical role in melanoma resistance to clinical BRAF and MEK inhibitors. In this study, we uncover a function of eIF4F in the negative regulation of the rat sarcoma (RAS)/rapidly accelerated fibrosarcoma (RAF)/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) signaling pathway. We demonstrate that eIF4F is essential for controlling ERK signaling intensity in treatment-naïve melanoma cells harboring BRAF or NRAS mutations. Specifically, the dual-specificity phosphatase DUSP6/MKP3, which acts as a negative feedback regulator of ERK activity, requires continuous production in an eIF4F-dependent manner to limit excessive ERK signaling driven by oncogenic RAF/RAS mutations. Treatment with small-molecule eIF4F inhibitors disrupts the negative feedback control of MAPK signaling, leading to ERK hyperactivation and EGR1 overexpression in melanoma cells in vitro and in vivo. Furthermore, our quantitative analyses reveal a high spare signaling capacity in the ERK pathway, suggesting that eIF4F-dependent feedback keeps the majority of ERK molecules inactive under normal conditions. Overall, our findings highlight the crucial role of eIF4F in regulating ERK signaling flux and suggest that pharmacological eIF4F inhibitors can disrupt the negative feedback control of MAPK activity in melanomas with BRAF and NRAS activating mutations.
- MeSH
- Eukaryotic Initiation Factor-4F * metabolism genetics MeSH
- Extracellular Signal-Regulated MAP Kinases metabolism MeSH
- Dual Specificity Phosphatase 6 metabolism genetics MeSH
- GTP Phosphohydrolases * metabolism genetics MeSH
- Humans MeSH
- MAP Kinase Signaling System * genetics MeSH
- Melanoma * genetics metabolism pathology MeSH
- Membrane Proteins * metabolism genetics MeSH
- Mutation * MeSH
- Mice MeSH
- Cell Line, Tumor MeSH
- Proto-Oncogene Proteins B-raf * genetics metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
... activation 84 -- 3.2.1 Role of adipokines 84 -- 3.2.2 Renin-angiotensin-aldosterone system 86 -- 3.2.3 Hyperactivation ...
Učební texty Univerzity Karlovy
First edition 241 stran : ilustrace ; 23 cm
- Conspectus
- Patologie. Klinická medicína
- Učební osnovy. Vyučovací předměty. Učebnice
- NML Fields
- biochemie
- patologie
- NML Publication type
- učebnice vysokých škol
Acute myeloid leukemia (AML) is a malignant neoplasia of the hematopoietic system characterized by the accumulation of immature and nonfunctional leukemic blasts in the bone marrow and peripheral tissues. Mechanistically, the development of AML is explained by the "two-hit" theory, which is based on the accumulation of driver mutations that will cooperate to induce transformation. However, a significant percentage of patients with AML exhibit only one driver mutation, and thus, how leukemic transformation occurs in these cases is unclear. Accumulating evidence suggests that nongenetic factors, such as chronic inflammation, might influence AML development, and accordingly, clinical data have reported that patients with chronic inflammatory disorders have an increased risk of developing hematological malignancies. Here, using a mouse model of chronic inflammation, we demonstrate that systemic elevated levels of cytokines and chemokines and hyperactivation of the Jak/Stat3 signaling pathway may substitute "second hit" mutations and accelerate tumorigenesis. Altogether, our data highlight chronic inflammation as an additional factor in the development of AML, providing additional understanding of the mechanisms of transformation and opening new avenues for the treatment of this disease.
- MeSH
- Leukemia, Myeloid, Acute * genetics drug therapy MeSH
- Hematologic Neoplasms * MeSH
- Bone Marrow pathology MeSH
- Humans MeSH
- Cell Transformation, Neoplastic genetics MeSH
- Inflammation MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
Somatic JAK2 mutations are the main molecular cause of the vast majority of polycythemia vera (PV) cases. According to a recent structural model, the prevalent acquired V617F mutation improves the stability of the JAK2 dimer, thereby enhancing the constitutive JAK2 kinase activity. Germline JAK2 mutations usually do not largely alter JAK2 signaling, although they may modulate the impact of V617F. We found an unusual germline JAK2 mutation L604F in homozygous form in a young PV patient, along with a low allele burden JAK2 V617F mutation, and in her apparently healthy sister. Their father with a PV-like disease had L604F in a heterozygous state, without V617F. The functional consequences of JAK2 L604Fmutation were compared with those induced by V617F in two different in vitro model systems: (i) HEK293T cells were transfected with plasmids for exogenous JAK2-GFP expression, and (ii) endogenous JAK2 modifications were introduced into HeLa cells using CRISPR/Cas9. Both mutations significantly increased JAK2 constitutive activity in transfected HEK293T cells. In the second model, JAK2 modification resulted in reduced total JAK2 protein levels. An important difference was also detected: as described previously, the effect of V617F on JAK2 kinase activity was abrogated in the absence of the aromatic residue F595. In contrast, JAK2 hyperactivation by L604F was only partially inhibited by the F595 change to alanine. We propose that the L604F mutation increases the probability of spontaneous JAK2 dimer formation, which is physiologically mediated by F595. In addition, L604F may contribute to dimer stabilization similarly to V617F.
- MeSH
- HEK293 Cells MeSH
- HeLa Cells MeSH
- Janus Kinase 2 genetics MeSH
- Humans MeSH
- Mutation MeSH
- Germ Cells * MeSH
- Germ-Line Mutation * MeSH
- Check Tag
- Humans MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
The cytokine interleukin-6 (IL-6) has considerable pro-inflammatory properties and is a driver of many physiological and pathophysiological processes. Cellular responses to IL-6 are mediated by membrane-bound or soluble forms of the IL-6 receptor (IL-6R) complexed with the signal-transducing subunit gp130. While expression of the membrane-bound IL-6R is restricted to selected cell types, soluble IL-6R (sIL-6R) enables gp130 engagement on all cells, a process termed IL-6 trans-signalling and considered to be pro-inflammatory. sIL-6R is predominantly generated through proteolytic processing by the metalloproteinase ADAM17. ADAM17 also liberates ligands of the epidermal growth factor receptor (EGFR), which is a prerequisite for EGFR activation and results in stimulation of proliferative signals. Hyperactivation of EGFR mostly due to activating mutations drives cancer development. Here, we reveal an important link between overshooting EGFR signalling and the IL-6 trans-signalling pathway. In epithelial cells, EGFR activity induces not only IL-6 expression but also the proteolytic release of sIL-6R from the cell membrane by increasing ADAM17 surface activity. We find that this derives from the transcriptional upregulation of iRhom2, a crucial regulator of ADAM17 trafficking and activation, upon EGFR engagement, which results in increased surface localization of ADAM17. Also, phosphorylation of the EGFR-downstream mediator ERK mediates ADAM17 activity via interaction with iRhom2. In sum, our study reveals an unforeseen interplay between EGFR activation and IL-6 trans-signalling, which has been shown to be fundamental in inflammation and cancer.
- MeSH
- Cytokine Receptor gp130 genetics MeSH
- Epithelial Cells metabolism MeSH
- ErbB Receptors genetics metabolism MeSH
- Interleukin-6 * genetics metabolism MeSH
- Humans MeSH
- ADAM17 Protein * MeSH
- Signal Transduction * genetics MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Much of the burgeoning research on adult attachment in organizational settings has utilized assessment methods developed for personal or social relationships contexts. Here, we propose and test a novel framework for assessing attachment orientations in the workplace, the Experiences in Work Relationships-Individual (EWR-I), based on a conceptualization of the regulatory functions of attachment dynamics. Using data from two samples comprising early career starters and employees in the Czech Republic (N = 588 and N = 633) analyses confirmed the bifactorial structure of the new scale corresponding to "interpersonal hyperactivation" (involving emotional instability, negative emotionality, and lack of appreciation in work relationships) and a second factor termed "interpersonal deactivation" (involving distancing from others and relationships at work, mistrust and inhibition of positive emotionality). Evidence of convergent and discriminant validity against general relational assessments of adult attachment, and predictive and construct validity against measures of workplace personality, organizational citizenship behavior and counterproductive work behavior further documented the nature and utility of the new scale. We argue that interpersonal hyperactivation and deactivation represent two distinct and measurable key components of attachment behavior dynamics at work.
- MeSH
- Affective Symptoms MeSH
- Adult MeSH
- Interpersonal Relations * MeSH
- Humans MeSH
- Personality * MeSH
- Personality Disorders MeSH
- Workplace MeSH
- Object Attachment MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Publication type
- Journal Article MeSH
Východiska: Endoplazmatické retikulum (ER), organela tvořená soustavou cisteren a tubulů, je esenciální pro řadu buněčných dějů, mj. pro syntézu a transport proteinů. Pokud se chybně složené proteiny hromadí v lumen ER, dochází k rozvoji stresu ER, přičemž následnou odpovědí na narušení homeostázy je aktivace signální dráhy UPR (z angl. unfolded protein response, tj. odpověď na přítomnost nesbalených proteinů). Cílem procesu je obnovit homeostázu zvyšováním kapacity ER a jeho schopnosti skládat proteiny. K aktivaci homeostatické UPR dochází prostřednictvím některého ze tří transmembránových proteinů, kterými jsou enzym vyžadující inositol 1a (inositol-requiring enzyme 1a – IRE1a), kináza ER podobná R kináze (proteine kinase R-like ER kinase – PERK) a aktivující transkripční faktor 6 (activating transcription factor 6 – ATF6). V případě selhání pokusu o obnovu homeostázy naopak dochází prostřednictvím hyperaktivace týchž proteinů k rozvoji terminální UPR a apoptóze. Aktivace různých větví UPR byla popsána u mnoha nádorových onemocnění vč. mnohočetného myelomu (MM), který se vyznačuje maligní transformaci plazmatických buněk a zvýšenou syntézou monoklonálního imunoglobulinu, kdy je role ER zvláště podstatná. Navzdory pokrokům v léčbě MM zůstává onemocnění jen obtížně léčitelné a cílení na signální dráhy spojené s UPR by mohlo např. podpořit účinek inhibitorů proteazomu. Cíl: Tato práce si klade za cíl představit molekulární odpověď na stres ER za fyziologických okolností i v kontextu nádorových onemocnění, a to zejména s přihlédnutím k potenciálním terapeutickým cílům u MM.
Background: The endoplasmic reticulum (ER), an organelle composed of a system of cisternae and tubules, is essential for many cellular processes, including protein synthesis and transport. When misfolded proteins accumulate in the ER lumen, ER stress is induced, and the subsequent response to the disruption of homeostasis is the activation of the unfolded protein response (UPR). The purpose of this process is to restore homeostasis by increasing the capacity of the ER and its ability to fold proteins. Activation of the homeostatic UPR occurs via one of three transmembrane proteins, inositol-requiring enzyme 1a (IRE1a), protein kinase R-like ER kinase (PERK) and activating transcription factor 6 (ATF6). Failure of the attempt to restore homeostasis, on the other hand, leads to the development of terminal UPR and apoptosis via hyperactivation of the same proteins. Activation of UPR has been described in many malignancies, including multiple myeloma (MM), which is characterized by malignant transformation of plasma cells and increased monoclonal immunoglobulin synthesis, where the role of the ER is of particular importance. Despite advances in the treatment of MM, the disease remains difficult to treat and targeting signaling pathways associated with the UPR could, for example, enhance the effect of proteasome inhibitors. Purpose: This review intends to present the molecular response to ER stress under physiological circumstances and in the context of cancer, particularly with regard to potential therapeutic targets in MM.
- MeSH
- Molecular Targeted Therapy methods MeSH
- Endoplasmic Reticulum * genetics drug effects MeSH
- Proteasome Inhibitors pharmacology classification therapeutic use MeSH
- Humans MeSH
- Multiple Myeloma * drug therapy genetics MeSH
- Unfolded Protein Response drug effects MeSH
- Endoplasmic Reticulum Stress drug effects MeSH
- X-Box Binding Protein 1 analysis drug effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH