scholarly journals Chloride channels regulate differentiation and barrier functions of the mammalian airway

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Mu He ◽  
Bing Wu ◽  
Wenlei Ye ◽  
Daniel D Le ◽  
Adriane W Sinclair ◽  
...  

The conducting airway forms a protective mucosal barrier and is the primary target of airway disorders. The molecular events required for the formation and function of the airway mucosal barrier, as well as the mechanisms by which barrier dysfunction leads to early onset airway diseases, remain unclear. In this study, we systematically characterized the developmental landscape of the mouse airway using single-cell RNA sequencing and identified remarkably conserved cellular programs operating during human fetal development. We demonstrated that in mouse, genetic inactivation of chloride channel Ano1/Tmem16a compromises airway barrier function, results in early signs of inflammation, and alters the airway cellular landscape by depleting epithelial progenitors. Mouse Ano1-/-mutants exhibited mucus obstruction and abnormal mucociliary clearance that resemble the airway defects associated with cystic fibrosis. The data reveal critical and non-redundant roles for Ano1 in organogenesis, and show that chloride channels are essential for mammalian airway formation and function.

2019 ◽  
Author(s):  
Mu He ◽  
Bing Wu ◽  
Daniel D. Le ◽  
Wenlei Ye ◽  
Adriane W. Sinclair ◽  
...  

SUMMARYThe conducting airway forms a protective mucosal barrier and is the primary target of airway disorders. To better understand how airway developmental programs are established to support air breathing and barrier functions, we constructed a single-cell atlas of the human and mouse developing trachea. In this study, we uncover hitherto unrecognized heterogeneity of cell states with distinct differentiation programs and immune features of the developing airway. In addition, we find ubiquitous expression of CFTR and ANO1/TMEM16A chloride channels in the embryonic airway epithelium. We show that genetic inactivation of TMEM16A leads to airway defects commonly seen in cystic fibrosis patients with deficient CFTR, alters the differentiation trajectory of airway basal progenitors, and results in mucus cell hyperplasia and aberrant epithelial antimicrobial expression. Together, our study illuminates conserved developmental features of the mammalian airway and implicates chloride homeostasis as a key player in regulating mucosal barrier formation and function relevant to early onset airway diseases.


Antioxidants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 303
Author(s):  
Haiwei Liang ◽  
Ning Liu ◽  
Renjie Wang ◽  
Yunchang Zhang ◽  
Jingqing Chen ◽  
...  

Apoptosis of intestinal epithelial cells following oxidative stress is a major cause of mucosal barrier dysfunction and is associated with the pathogenesis of various gastrointestinal diseases. Although L-tryptophan (Trp) is known to improve intestinal integrity and function, a beneficial effect of N-acetyl serotonin (NAS), a metabolite of Trp, on the apoptosis of enterocytes and the underlying mechanisms remain largely unknown. In the present study, we showed that porcine enterocytes treated with 4-hydroxy-2-nonenal (4-HNE), a metabolite of lipid peroxidation, led to upregulation of apoptotic proteins, including Bax and cleaved caspase-3, and reduction of tight junction proteins. These effects of 4-HNE were significantly abrogated by NAS. In addition, NAS reduced ROS accumulation while increasing the intracellular concentration of glutathione (GSH), and the abundance of the Nrf2 protein in the nucleus and its downstream target proteins. Importantly, these protective effects of NAS were abrogated by Atra, an inhibitor of Nrf2, indicating a dependence on Nrf2 signaling. Taken together, we demonstrated that NAS attenuated oxidative stress-induced cellular injury in porcine enterocytes by regulating Nrf2 signaling. These findings provide new insights into a functional role of NAS in maintaining intestinal homeostasis.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Monica Sala-Rabanal ◽  
Zeynep Yurtsever ◽  
Kayla N. Berry ◽  
Tom J. Brett

Chloride transport proteins play critical roles in inflammatory airway diseases, contributing to the detrimental aspects of mucus overproduction, mucus secretion, and airway constriction. However, they also play crucial roles in contributing to the innate immune properties of mucus and mucociliary clearance. In this review, we focus on the emerging novel roles for a chloride channel regulator (CLCA1), a calcium-activated chloride channel (TMEM16A), and two chloride exchangers (SLC26A4/pendrin and SLC26A9) in chronic inflammatory airway diseases.


2021 ◽  
Vol 11 (2) ◽  
pp. 87-98
Author(s):  
Frederick Berro Rivera ◽  
Pia Alfonso ◽  
Jem Marie Golbin ◽  
Kevin Lo ◽  
Edgar Lerma ◽  
...  

Clinical guidelines include diuretics for the treatment of heart failure (HF), not to decrease mortality but to decrease symptoms and hospitalizations. More attention has been paid to the worse outcomes, including mortality, associated with continual diuretic therapy due to hypochloremia. Studies have revealed a pivotal role for serum chloride in the pathophysiology of HF and is now a target of treatment to decrease mortality. The prognostic value of serum chloride in HF has been the subject of much attention. Mechanistically, the macula densa, a region in the renal juxtaglomerular apparatus, relies on chloride levels to sense salt and volume status. The recent discovery of with-no-lysine (K) (WNK) protein kinase as an intracellular chloride sensor sheds light on the possible reason of diuretic resistance in HF. The action of chloride on WNKs results in the upregulation of the sodium-potassium-chloride cotransporter and sodium-chloride cotransporter receptors, which could lead to increased electrolyte and fluid reabsorption. Genetic studies have revealed that a variant of a voltage-sensitive chloride channel (CLCNKA) gene leads to almost a 50% decrease in current amplitude and function of the renal chloride channel. This variant increases the risk of HF. Several trials exploring the prognostic value of chloride in both acute and chronic HF have shown mostly positive results, some even suggesting a stronger role than sodium. However, so far, interventional trials exploring serum chloride as a therapeutic target have been largely inconclusive. This study is a review of the pathophysiologic effects of hypochloremia in HF, the genetics of chloride channels, and clinical trials that are underway to investigate novel approaches to HF management.


2021 ◽  
Author(s):  
Xuemeng Si ◽  
Ning Liu ◽  
Hai Jia ◽  
Jiaqi Wang ◽  
Lina Pan ◽  
...  

Gut relief formula administration alleviated mucosal inflammation and mucosal barrier dysfunction by inhibiting STAT3 and NF-κB activity and upregulating abundances of Lactobacillus in DSS-induced colitis.


2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Xia Liu ◽  
Yiwen Cheng ◽  
Li Shao ◽  
Zongxin Ling

Growing evidence indicated that the gut microbiota was the intrinsic and essential component of the cancer microenvironment, which played vital roles in the development and progression of colorectal cancer (CRC). In our present study, we investigated the alterations of fecal abundant microbiota with real-time quantitative PCR and the changes of indicators of gut mucosal barrier from 53 early-stage CRC patients and 45 matched healthy controls. We found that the traditional beneficial bacteria such as Lactobacillus and Bifidobacterium decreased significantly and the carcinogenic bacteria such as Enterobacteriaceae and Fusobacterium nucleatum were significantly increased in CRC patients. We also found gut mucosal barrier dysfunction in CRC patients with increased levels of endotoxin (LPS), D-lactate, and diamine oxidase (DAO). With Pearson’s correlation analysis, D-lactate, LPS, and DAO were correlated negatively with Lactobacillus and Bifidobacterium and positively with Enterobacteriaceae and F. nucleatum. Our present study found dysbiosis of the fecal microbiota and dysfunction of the gut mucosal barrier in patients with early-stage CRC, which implicated that fecal abundant bacteria and gut mucosal barrier indicators could be used as targets to monitor the development and progression of CRC in a noninvasive and dynamic manner.


2019 ◽  
Author(s):  
Ru-pin Alicia Chi ◽  
Tianyuan Wang ◽  
Nyssa Adams ◽  
San-pin Wu ◽  
Steven L. Young ◽  
...  

ABSTRACTContextPoor uterine receptivity is one major factor leading to pregnancy loss and infertility. Understanding the molecular events governing successful implantation is hence critical in combating infertility.ObjectiveTo define PGR-regulated molecular mechanisms and epithelial roles in receptivity.DesignRNA-seq and PGR-ChIP-seq were conducted in parallel to identify PGR-regulated pathways during the WOI in endometrium of fertile women.SettingEndometrial biopsies from the proliferative and mid-secretory phases were analyzed.Patients or Other ParticipantsParticipants were fertile, reproductive aged (18-37) women with normal cycle length; and without any history of dysmenorrhea, infertility, or irregular cycles. In total, 42 endometrial biopsies obtained from 42 women were analyzed in this study.InterventionsThere were no interventions during this study.Main Outcome MeasuresHere we measured the alterations in gene expression and PGR occupancy in the genome during the WOI, based on the hypothesis that PGR binds uterine chromatin cycle-dependently to regulate genes involved in uterine cell differentiation and function.Results653 genes were identified with regulated PGR binding and differential expression during the WOI. These were involved in regulating inflammatory response, xenobiotic metabolism, EMT, cell death, interleukin/STAT signaling, estrogen response, and MTORC1 response. Transcriptome of the epithelium identified 3,052 DEGs, of which 658 were uniquely regulated. Transcription factors IRF8 and MEF2C were found to be regulated in the epithelium during the WOI at the protein level, suggesting potentially important functions that are previously unrecognized.ConclusionPGR binds the genomic regions of genes regulating critical processes in uterine receptivity and function.PrécisUsing a combination of RNA-seq and PGR ChIP-seq, novel signaling pathways and epithelial regulators were identified in the endometrium of fertile women during the window of implantation.


2020 ◽  
Vol 5 (43) ◽  
pp. eaay3994 ◽  
Author(s):  
Mindy M. Miller ◽  
Preeyam S. Patel ◽  
Katherine Bao ◽  
Thomas Danhorn ◽  
Brian P. O’Connor ◽  
...  

A transitory, interleukin-25 (IL-25)–responsive, group 2 innate lymphoid cell (ILC2) subset induced during type 2 inflammation was recently identified as iILC2s. This study focuses on understanding the significance of this population in relation to tissue-resident nILC2s in the lung and intestine. RNA-sequencing and pathway analysis revealed the AP-1 superfamily transcription factor BATF (basic leucine zipper transcription factor, activating transcription factor–like) as a potential modulator of ILC2 cell fate. Infection of BATF-deficient mice with Nippostrongylus brasiliensis showed a selective defect in IL-25–mediated helminth clearance and a corresponding loss of iILC2s in the lung characterized as IL-17RBhigh, KLRG1high, BATFhigh, and Arg1low. BATF deficiency selectively impaired iILC2s because it had no impact on tissue-resident nILC2 frequency or function. Pulmonary-associated iILC2s migrated to the lung after infection, where they represented an early source of IL-4 and IL-13. Although the composition of ILC2s in the small intestine was distinct from those in the lung, their frequency and IL-13 expression remained dependent on BATF, which was also required for optimal goblet and tuft cell hyperplasia. Findings support IL-25–responsive ILC2s as early sentinels of mucosal barrier integrity.


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