Treatment of human T-cell acute lymphoblastic leukemia cells with CFTR inhibitor CFTRinh-172

Evaluation of aspartame effects at environmental concentration on early development of zebrafish: Morphology and transcriptome1

The use of aspartame as an artificial sweetener is prevalent in a wide range of everyday food products, potentially leading to health complications such as obesity, diabetes mellitus, autism spectrum disorders, and neurodegeneration. Aspartame has also been detected in natural water bodies at a concentration of 0.49 μg/L, yet research on its ecotoxicological effects on aquatic life remains scarce. This study aimed to investigate the potential negative effects of environmentally relevant concentrations of aspartame on the development of various tissues and organs in zebrafish embryos. We used a zebrafish model to treat embryos with aspartame at environmental concentration and those higher than in the environment-up to 1000 times. We observed that after exposure to aspartame body length increased, pigmentation was delayed, and neutrophil production inhibited in zebrafish. Furthermore, transcriptome analysis revealed that early exposure of zebrafish embryos to aspartame affected the transcriptomics of various systems, primarily by downregulating genes related to immune cell production, eye and optic nerve development, nervous system development, and growth hormone-related transcription. Most of the genes associated with ferroptosis were upregulated. This study provides new insights into the ecotoxicological effects of aspartame on aquatic environments.

RCAN family member 3 deficiency contributes to noncompaction of the ventricular myocardium

Noncompaction of the ventricular myocardium (NVM), the third most diagnosed cardiomyopathy, is characterized by prominent trabeculae and intratrabecular recesses. However, the genetic etiology of 40%-60% of NVM cases remains unknown. Here, we identify two infants with NVM, in a nonconsanguineous family, with a typical clinical presentation of persistent bradycardia since the prenatal period. A homozygous missense variant (R223L) of RCAN family member 3 (RCAN3) is detected in both infants using whole-exome sequencing. In the zebrafish model, marked cardiac dysfunction is detected in rcan3 deficiency (MO-rcan3ATG-injected) and rcan-/- embryos. Developmental dysplasia of both endocardial and myocardial layers is also detected in rcan3-deficient embryos. RCAN3 R223L variant mRNAs can not rescue heart defects caused by rcan3 knockdown or knockout; however, hRCAN3 mRNAs rescue these phenotypes. RNA-seq experiments show that several genes involved in cardiomyopathies are significantly regulated through multiple signaling pathways in the rcan3-knockdown zebrafish model. In human cardiomyocytes, RCAN3 deficiency results in reduced proliferation and increased apoptosis, together with an abnormal mitochondrial ultrastructure. Thus, we suggest that RCAN3 is a susceptibility gene for cardiomyopathies, especially NVM and that the R223L mutation is a potential loss-of-function variant.

Cell membrane-camouflaged bufalin targets NOD2 and overcomes multidrug resistance in pancreatic cancer

AIMS

Multidrug resistance in pancreatic cancer poses a significant challenge in clinical treatment. Bufalin (BA), a compound found in secretions from the glands of toads, may help overcome this problem. However, severe cardiotoxicity thus far has hindered its clinical application. Hence, the present study aimed to develop a cell membrane-camouflaged and BA-loaded polylactic-co-glycolic acid nanoparticle (CBAP) and assess its potential to counter chemoresistance in pancreatic cancer.

METHODS

The toxicity of CBAP was evaluated by electrocardiogram, body weight, distress score, and nesting behavior of mice. In addition, the anticarcinoma activity and underlying mechanism were investigated both in vitro and in vivo.

RESULTS

CBAP significantly mitigated BA-mediated acute cardiotoxicity and enhanced the sensitivity of pancreatic cancer to several clinical drugs, such as gemcitabine, 5-fluorouracil, and FOLFIRINOX. Mechanistically, CBAP directly bound to nucleotide-binding and oligomerization domain containing protein 2 (NOD2) and inhibited the expression of nuclear factor kappa-light-chain-enhancer of activated B cells. This inhibits the expression of ATP-binding cassette transporters, which are responsible for chemoresistance in cancer cells.

CONCLUSIONS

Our findings indicate that CBAP directly inhibits NOD2. Combining CBAP with standard-of-care chemotherapeutics represents a safe and efficient strategy for the treatment of pancreatic cancer.

Drug-induced eRF1 degradation promotes readthrough and reveals a new branch of ribosome quality control

Suppression of premature termination codons (PTCs) by translational readthrough is a promising strategy to treat a wide variety of severe genetic diseases caused by nonsense mutations. Here, we present two potent readthrough promoters-NVS1.1 and NVS2.1-that restore substantial levels of functional full-length CFTR and IDUA proteins in disease models for cystic fibrosis and Hurler syndrome, respectively. In contrast to other readthrough promoters that affect stop codon decoding, the NVS compounds stimulate PTC suppression by triggering rapid proteasomal degradation of the translation termination factor eRF1. Our results show that this occurs by trapping eRF1 in the terminating ribosome, causing ribosome stalls and subsequent ribosome collisions, and activating a branch of the ribosome-associated quality control network, which involves the translational stress sensor GCN1 and the catalytic activity of the E3 ubiquitin ligases RNF14 and RNF25.

Toxicology evaluation of overdose hydroxychloroquine on zebrafish (Danio rerio) embryos

Potential risks of treatment with hydroxychloroquine (HCQ) include QT interval prolongation, hypoglycemia, a wide range of neuropsychiatric manifestations, hematotoxicity, and potential genetic defects. HCQ is extremely toxic when used in overdose and can lead to tachycardia, hypotension, known central nervous system, transmission defects, hypokalemia and other manifestations in individuals. The mechanism of excessive HCQ leading to these manifestations is still unclear. In this paper, overdose HCQ at different concentrations was used to treat zebrafish embryos, and the phenomena like human beings were obtained, such as increased heart rate and nervous system inhibition. With the increase of concentration to 100 μM, embryo mortality and malformation rate increased and hatching rate decreased, in situ hybridization showed abnormal differentiation of embryo germ layers and formation of vital organs. We selected embryos treated with 50 μM HCQ, in which concentration the mortality rate, hatching rate and malformation rate of the embryos were like those of the control group, for transcriptome analysis. Although the above indexes did not change significantly, the molecular changes related to the development of the heart, eye, nerve and other important organs were significant. This study provides useful information for further research on the toxicity mechanism of HCQ overdose, and provides some insight that can guide future studies in humans.

Cystic fibrosis transmembrane conductance regulator (CFTR): beyond cystic fibrosis

Background

The cystic fibrosis transmembrane conductance regulator (CFTR) gene has been traditionally linked to cystic fibrosis (CF) inheritance in an autosomal recessive manner. Advances in molecular biology and genetics have expanded our understanding of the CFTR gene and its encoding products expressed in different tissues.

Aim

The study’s aim consists of reviewing the different pathological CF phenotypes using the existing literature. We know that alterations of the CFTR protein’s structure may result in different pathological phenotypes.

Methods

Open sources such as PubMed and Science Direct databases have been used for this review. We focused our selection on articles published within the last 15 years. Critical terms related to the CFTR protein have been used: “CFTR AND cancer,” “CFTR AND celiac disease,” “CFTR AND pancreatitis,” “children,” “adults,” “genotype,” “phenotype,” “correlation,” “mutation,”  “CFTR,” “diseases,” “disorders,” and “no cystic fibrosis.”

Results

We analyzed 1,115 abstracts in total. Moreover, only 189 were suitable for the topic. We focused on the role of CFTR in cancer, gastrointestinal disorders, respiratory diseases, reproductive system, and systemic hypertension.

Conclusions

Mutations in CFTR gene are often associated with CF. In this review, we highlighted the broad spectrum of alterations reported for this gene, which may be involved in the pathogenesis of other diseases. The importance of these new insights in the role of CFTR relies on the possibility of considering this protein/gene as a novel therapeutic target for CF- and CFTR-related diseases.

Cystic fibrosis transmembrane conductance regulator prevents ischemia/reperfusion induced intestinal apoptosis via inhibiting PI3K/AKT/NF-κB pathway

BACKGROUND

Intestinal ischemia/reperfusion (I/R) injury is a fatal syndrome that occurs under many clinical scenarios. The apoptosis of intestinal cells caused by ischemia can cause cell damage and provoke systemic dysfunction during reperfusion. However, the mechanism of I/R-induced apoptosis remains unclear. Cystic fibrosis transmembrane conductance regulator (CFTR) is a cAMP-activated chloride channel. Few researchers have paid attention to its role in intestinal I/R injury, or the relationship between CFTR and intestinal apoptosis induced by hypoxia/reoxygenation (H/R).

AIM

To investigate the effects of CFTR on I/R-induced intestinal apoptosis and its underlying molecular mechanisms.

METHODS

An intestinal I/R injury model was established in mice with superior mesenteric artery occlusion, and Caco2 cells were subjected to H/R for the simulation of I/R in vivo.

RESULTS

The results suggested that CFTR overexpression significantly increased the Caco2 cell viability and decreased cell apoptosis induced by the H/R. Interestingly, we found that the translocation of p65, an NF-κB member, from the cytoplasm to the nucleus after H/R treatment can be reversed by the overexpression of CFTR, the NF-κB P65 would return from the nucleus to the cytoplasm as determined by immunostaining. We also discovered that CFTR inhibited cell apoptosis in the H/R-treated cells, and this effect was significantly curbed by the NF-κB activator BA, AKT inhibitor GSK690693 and the PI3K inhibitor LY294002. Moreover, we demonstrated that CFTR overexpression could reverse the decreased PI3K/AKT expression induced by the I/R treatment in vivo or H/R treatment in vitro.

CONCLUSION

The results of the present study indicate that the overexpression of CFTR protects Caco2 cells from H/R-induced apoptosis; furthermore, it also inhibits H/R-induced apoptosis through the PI3K/AKT/NF-κB signaling pathway in H/R-treated Caco2 cells and intestinal tissues.

CFTR is a negative regulator of γδ T cell IFN-γ production and antitumor immunity

CFTR, a chloride channel and ion channel regulator studied mostly in epithelial cells, has been reported to participate in immune regulation and likely affect the risk of cancer development. However, little is known about the effects of CFTR on the differentiation and function of γδ T cells. In this study, we observed that CFTR was functionally expressed on the cell surface of γδ T cells. Genetic deletion and pharmacological inhibition of CFTR both increased IFN-γ release by peripheral γδ T cells and potentiated the cytolytic activity of these cells against tumor cells both in vitro and in vivo. Interestingly, the molecular mechanisms underlying the regulation of γδ T cell IFN-γ production by CFTR were either TCR dependent or related to Ca2+ influx. CFTR was recruited to TCR immunological synapses and attenuated Lck-P38 MAPK-c-Jun signaling. In addition, CFTR was found to modulate TCR-induced Ca2+ influx and membrane potential (Vm)-induced Ca2+ influx and subsequently regulate the calcineurin-NFATc1 signaling pathway in γδ T cells. Thus, CFTR serves as a negative regulator of IFN-γ production in γδ T cells and the function of these cells in antitumor immunity. Our investigation suggests that modification of the CFTR activity of γδ T cells may be a potential immunotherapeutic strategy for cancer.

Role of Autophagy and Apoptosis in Acute Lymphoblastic Leukemia

Background:

Acute lymphoblastic leukemia (ALL) is a malignant disease characterized by an excessive number of immature lymphocytes, including immature precursors of both B- and T cells. ALL affects children more often than adults. Immature lymphocytes lead to arrested differentiation and proliferation of cells. Its conventional treatments involve medication with dexamethasone, vincristine, and other anticancer drugs. Although the current first-line drugs can achieve effective treatment, they still cannot prevent the recurrence of some patients with ALL. Treatments have high risk of recurrence especially after the first remission. Currently, novel therapies to treat ALL are in need. Autophagy and apoptosis play important roles in regulating cancer development. Autophagy involves degradation of proteins and organelles, and apoptosis leads to cell death. These phenomena are crucial in cancer progression. Past studies reported that many potential anticancer agents regulate intracellular signaling pathways.

Methods:

The authors discuss the recent research findings on the role of autophagy and apoptosis in ALL.

Results:

The autophagy and apoptosis are widely used in the treatment of ALL. Most studies showed that many agents regulate autophagy and apoptosis in ALL cell models, clinical trials, and ALL animal models.

Conclusions:

In summary, activating autophagy and apoptosis pathways are the main strategies for ALL treatments. For ALL, combining new drugs with traditional chemotherapy and glucocorticoids treatments can achieve the greatest therapeutic effect by activating autophagy and apoptosis.

ALKBH5-mediated m6A-demethylation of USP1 regulated T-cell acute lymphoblastic leukemia cell glucocorticoid resistance by Aurora B

Recent studies evidence that ubiquitin-specific proteases (USPs) are associated with the occurrence and chemoresistance of T-cell acute lymphoblastic leukemia (T-ALL). N⁶ -methyladenosine (m6A) demethylase AlkB homolog 5 (ALKBH5) exerts a carcinogenic effect in human cancers and improves the mRNA stability of USPs. Whether ubiquitin-specific protease 1 (USP1) controls chemoresistance of T-ALL is unknown. Our study demonstrated that USP1 expression was upregulated in glucocorticoid (GC)-resistant T-ALL patients and cells (CEM-C1). High expression of USP1 was correlated to the poor prognosis in T-ALL patients. Silencing USP1 increased CEM-C1 cell sensitivity to dexamethasone (Dex), reduced cell invasion, promoted cell apoptosis, and ameliorated glucocorticoid receptor (GR) expression. USP1 mediated T-ALL chemoresistance by interacting with and deubiquitination of Aurora B. Overexpression of USP1 reversed the amelioration effect of Aurora B inhibitor on CEM-C1 cell resistance to Dex. Mechanistically, ALKBH5 enhanced USP1 expression by reducing m6A level and mRNA stability in USP1 mRNA transcript. Downregulation of ALKBH5 reduced the levels of USP1 and Aurora B, facilitated CEM-C1 cell sensitivity to Dex, apoptosis, and GR expression, suppressed cell invasion. However, overexpression of USP1 reversed all the effects of ALKBH5 on CEM-C1 cells. In vivo results showed that tail vein injection of sh-USP1 resulted in a significant prolongation of mouse survival, suppressed tumor growth, maintained the normal weight of mice, reduced USP1 expression and facilitated GR expression. In conclusion, inhibition of ALKBH5-mediated m6A modification decreased USP1 expression and downregulation of USP1 ameliorated GC resistance of T-ALL through suppressing Aurora B expression and elevating GR level.

CFTR regulates embryonic T lymphopoiesis via Wnt signaling in zebrafish

The number and function of T cells are abnormal as observed in cystic fibrosis (CF) patients and CF mouse models, and our previous work shows that the CFTR mutant leads to deficiency of primitive and definitive hematopoietic in zebrafish. However, the functions and underlying mechanisms of CFTR in T cell development during early embryogenesis have not been explored. Here, we report that the genetic ablation of CFTR in zebrafish resulted in abrogated embryonic T lymphopoiesis, which was ascribed to impaired thymic homing and expansion of hematopoietic stem cells (HSCs). Transcriptome analysis of isolated HSCs in zebrafish embryos at 48 hpf showed a significant alteration of key factors essential for T cell development and Wnt signaling, consistent with our previous work on CFTR regulating hematopoiesis. In brief, we uncovered the function of CFTR in embryonic T cell development and suggest that the immune deficiency of CF patients may originate from an early embryonic stage.

CFTR deficiency causes cardiac dysplasia during zebrafish embryogenesis and is associated with dilated cardiomyopathy

Mutations in the CFTR gene cause cystic fibrosis (CF) with myocardial dysfunction. However, it remains unknown whether CF-related heart disease is a secondary effect of pulmonary disease, or an intrinsic primary defect in the heart. Here, we used zebrafish, which lack lung tissue, to investigate the role of CFTR in cardiogenesis. Our findings demonstrated that the loss of CFTR impairs cardiac development from the cardiac progenitor stage, resulting in cardiac looping defects, a dilated atrium, pericardial edema, and a decrease in heart rate. Furthermore, we found that cardiac development was perturbed in wild-type embryos treated with a gating-specific CFTR channel inhibitor, CFTRinh-172, at the blastula stage of development, but not at later stages. Gene expression analysis of blastulas indicated that transcript levels, including mRNAs associated with cardiovascular diseases, were significantly altered in embryos derived from cftr mutants relative to controls. To evaluate the role of CFTR in human heart failure, we performed a genetic association study on individuals with dilated cardiomyopathy and found that the I556V mutation in CFTR, which causes a channel defect, was associated with the disease. Similar to other well-studied channel-defective CFTR mutants, CFTR I556V mRNA failed to restore cardiac dysplasia in mutant embryos. The present study revealed an important role for the CFTR ion channel in regulating cardiac development during early embryogenesis, supporting the hypothesis that CF-related heart disease results from an intrinsic primary defect in the heart.