Xlcaax-1 is localized to the basolateral membrane of kidney tubule and other polarized epithelia during Xenopus development.
Cornish J A,Kloc M,Decker G L,Reddy B A,Etkin L D
Developmental biology
Xlcaax-1 is a novel, maternally expressed, 110-kDa, CAAX box containing protein that undergoes isoprenylation and palmitoylation through which it associates with the plasma membrane. We report here the cellular and subcellular localization of the xlcaax-1 protein during development of Xenopus laevis. Whole-mount immunocytochemistry and immunoperoxidase staining of tissue sections show that during development the xlcaax-1 protein accumulation is coincident with the differentiation of the epidermis, pronephros, and mesonephros. In the pronephros and mesonephros the xlcaax-1 protein is localized to the basolateral membrane of differentiated tubule epithelial cells. Thus, the xlcaax-1 protein serves as a marker for tubule formation and polarization during Xenopus kidney development. Xlcaax-1 may also be used as a marker for the functional differentiation of the epidermis and the epidermally derived portions of the lens and some cranial nerves. Western blot analysis shows that in the adult the xlcaax-1 protein is most abundant in kidney. Immunogold EM analysis shows that the xlcaax-1 protein is highly enriched in the basal infoldings of the basolateral membrane of the epithelial cells in adult kidney distal tubules. In addition, immunoperoxidase staining of tissue sections detected low levels of xlcaax-1 protein in the epithelial cells of skin, urinary bladder, gall bladder, and parietal glands of the stomach. The localization pattern of xlcaax-1 suggests that the protein may function in association with an ion transport channel or pump.
10.1016/0012-1606(92)90011-5
Downregulation of Paralemmin-3 Ameliorates Lipopolysaccharide-Induced Acute Lung Injury in Rats by Regulating Inflammatory Response and Inhibiting Formation of TLR4/MyD88 and TLR4/TRIF Complexes.
Chen Xuxin,Tang Lu,Feng Jian,Wang Yi,Han Zhihai,Meng Jiguang
Inflammation
Previous studies have demonstrated paralemmin-3 (PALM3) participates in Toll-like receptor (TLR) signaling. This study investigated the effect of PALM3 knockdown on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and its underlying mechanisms. We constructed a recombinant adenoviral vector containing short hairpin RNA for PALM3 to knockdown PALM3 expression. A transgene-free adenoviral vector was used as a negative control. The ALI rat model was established by LPS peritoneal injection at 48-h post-transfection. Results showed that downregulation of PALM3 improved the survival rate, attenuated lung pathological changes, alleviated pulmonary edema, lung vascular leakage and neutrophil infiltration, inhibited the production of proinflammatory cytokines and activation of nuclear factor κB and interferon β regulatory factor 3, and promoted the secretion of anti-inflammatory cytokine interleukin-10 and expression of suppressor of cytokine signaling-3 in the ALI rat model. However, PALM3 knockdown had no effect on TLR4, myeloid differentiation factor 88 (MyD88), and Toll-interleukin-1 receptor domain-containing adaptor inducing interferon β (TRIF) expression. Moreover, PALM3 knockdown reduced the interaction of TLR4 with MyD88 or TRIF induced by LPS in rat lungs. Therefore, the downregulation of PALM3 protected rats from LPS-induced ALI and its mechanisms were partially associated with the modulation of inflammatory responses and inhibition of TLR4/MyD88 and TLR4/TRIF complex formation.
10.1007/s10753-017-0639-9
Paralemmin-3 augments lipopolysaccharide-induced acute lung injury with M1 macrophage polarization via the notch signaling pathway.
Respiratory physiology & neurobiology
BACKGROUND:Acute lung injury (ALI) involves severe lung damage and respiratory failure, which are accompanied by alveolar macrophage (AM) activation. The aim of this article is to verify the influence of paralemmin-3 (PALM3) on alveolar macrophage (AM) polarization in ALI and the underlying mechanism of action. METHODS:An ALI rat model was established by successive lipopolysaccharide (LPS) inhalations. The influence of PALM3 on the survival rate, severity of lung injury, and macrophage polarization was analyzed. Furthermore, we explored the underlying mechanism of PALM3 in regulating macrophage polarization. RESULTS:PALM3 overexpression increased mortality of ALI rats, augmented lung pathological damage, and promoted AM polarization toward M1 cells. Conversely, PALM3 knockdown had the opposite effects. Mechanistically, PALM3 might promote M1 polarization by acting as an adaptor to facilitate transduction of Notch signaling. CONCLUSION:PALM3 aggravates lung injury and induces macrophage polarization toward M1 cells by activating the Notch signaling pathway in LPS-induced ALI, which may shed light on ALI/ARDS treatments.
10.1016/j.resp.2023.104203
A novel binding protein of single immunoglobulin IL-1 receptor-related molecule: Paralemmin-3.
Chen Xuxin,Wu Xueling,Zhao Yunfeng,Wang Guansong,Feng Jian,Li Qi,Qian Guisheng
Biochemical and biophysical research communications
Previous studies have shown that single immunoglobulin IL-1 receptor-related molecule (SIGIRR) is a negative regulator of Toll-Interleukin-1 receptor signaling. Nevertheless, the molecular mechanism of the negatively regulatory effect of SIGIRR remains unknown. Using a yeast two-hybrid screen, we identified paralemmin-3 (PALM3) as a novel binding protein of SIGIRR. This interaction of SIGIRR with PALM3 was confirmed by coimmunoprecipitation in mammalian cells. In addition, the PALM3 mRNA expression was upregulated by lipopolysaccharide (LPS)-stimulation in a human alveolar epithelial cell line (A549 cells). Furthermore, silencing PALM3 by RNA interference inhibited the release of inflammatory cytokines in A549 cells after LPS-stimulation. These results suggest that PALM3 may function as an adaptor in the LPS- Toll-like receptor 4 signaling and the interaction of SIGIRR with PALM3 may partly account for the mechanism of the negatively regulatory effect of SIGIRR.
10.1016/j.bbrc.2010.12.104
Silencing of Paralemmin-3 Protects Mice from lipopolysaccharide-induced acute lung injury.
Li Shaoying,Guo Liang,Zhao Yunfeng,Qian Pin,Lv Xuejun,Qian Lanlan,Wang Qin,Qian Guisheng,Yao Wei,Wu Xueling
Peptides
Excessive inflammatory response induced by lipopolysaccharide (LPS) plays a critical role in the development of acute lung injury (ALI). Paralemmin-3 (PALM3) is a novel protein that can modulate LPS-stimulated inflammatory responses in alveolar epithelial A549 cells. However, it remains unclear whether it is involved in the progression of ALI in vivo. Therefore, we studied the role of PALM3 in the pathogenesis of ALI induced by LPS. ALI was induced by LPS peritoneal injection in C57BL/6J mice. Lentivirus-mediated small interfering RNA (siRNA) targeting the mouse PALM3 gene and a negative control siRNA were intranasally administered to the mice. We found that the expression of PALM3 was up-regulated in the lung tissues obtained from the mouse model of LPS-induced ALI. The LPS-evoked inflammatory response (neutrophils and the concentrations of proinflammatory cytokines [IL-6, IL-1β, TNF-α, MIP-2] in the bronchoalveolar lavage fluid [BALF]), histologic lung injury (lung injury score), permeability of the alveolar capillary barrier (lung wet/dry weight ratio and BALF protein concentration) and mortality rates were attenuated in the PALM3 siRNA-treated mice. These results indicate that PALM3 contributes to the development of ALI in mice challenged with LPS. Inhibiting PALM3 through the intranasal application of specific siRNA protected against LPS-induced ALI.
10.1016/j.peptides.2016.01.001
Paralemmin-3 contributes to lipopolysaccharide-induced inflammatory response and is involved in lipopolysaccharide-Toll-like receptor-4 signaling in alveolar macrophages.
Chen Xu-Xin,Tang Lu,Fu Yu-Mei,Wang Yi,Han Zhi-Hai,Meng Ji-Guang
International journal of molecular medicine
Alveolar macrophages (AMs) are the first line of defense against foreign stimulation in alveoli, and they participate in inflammatory responses during acute lung injury (ALI). Previous studies indicated that paralemmin-3 (PALM3) expression is induced by lipopolysaccharides (LPS) and may be involved in LPS-Toll-like receptor 4 (TLR4) signaling in alveolar epithelial cells. The aim of the present study was to investigate the effect of PALM3 on LPS-induced inflammation and its underlying mechanisms in rat AMs. For this purpose, the authors detected the expression of PALM3 in AMs by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting following LPS stimulation. Following this, a recombinant adenovirus expressing short hairpin RNA (shRNA) for PALM3 was constructed, as well as a recombinant adenovirus carrying the rat PALM3 gene to modulate the expression of PALM3 in rat AMs. At 48 h after transfection, the PALM3 expression in AMs was detected by RT-qPCR and western blotting. The levels of several cytokines and the activity of nuclear factor-κB and interferon regulatory factor 3 in AMs were measured after LPS stimulation. The localization of PALM3 and LPS-TLR4 signaling adaptor molecules in AMs was analyzed by confocal microscopy, and the physical interactions of PALM3 with these adaptors were assessed by co-immunoprecipitation assays. LPS induced PALM3 expression in AMs and that PALM3 expression promoted the LPS-induced inflammatory response, while PALM3 downregulation suppressed the LPS-induced inflammatory response in AMs. In addition, the results demonstrated that PALM3 could interact with TLR4, myeloid differentiation factor 88, interleukin (IL)-1 receptor associated kinase-1, tumor necrosis factor receptor associated factor-6, and Toll-IL-1 receptor containing adapter molecule-2 in AMs after LPS stimulation. These results suggested that PALM3 contributes to the LPS-induced inflammatory response and participates in LPS-TLR4 signaling in AMs. These data may provide the basis for the development of novel targeted therapeutic strategies of treating ALI.
10.3892/ijmm.2017.3161
Let-7b-5p in vesicles secreted by human airway cells reduces biofilm formation and increases antibiotic sensitivity of .
Koeppen Katja,Nymon Amanda,Barnaby Roxanna,Bashor Laura,Li Zhongyou,Hampton Thomas H,Liefeld Amanda E,Kolling Fred W,LaCroix Ian S,Gerber Scott A,Hogan Deborah A,Kasetty Swetha,Nadell Carey D,Stanton Bruce A
Proceedings of the National Academy of Sciences of the United States of America
is an opportunistic pathogen that forms antibiotic-resistant biofilms, which facilitate chronic infections in immunocompromised hosts. We have previously shown that secretes outer-membrane vesicles that deliver a small RNA to human airway epithelial cells (AECs), in which it suppresses the innate immune response. Here, we demonstrate that interdomain communication through small RNA-containing membrane vesicles is bidirectional and that microRNAs (miRNAs) in extracellular vesicles (EVs) secreted by human AECs regulate protein expression, antibiotic sensitivity, and biofilm formation by Specifically, human EVs deliver miRNA let-7b-5p to , which systematically decreases the abundance of proteins essential for biofilm formation, including PpkA and ClpV1-3, and increases the ability of beta-lactam antibiotics to reduce biofilm formation by targeting the beta-lactamase AmpC. Let-7b-5p is bioinformatically predicted to target not only PpkA, ClpV1, and AmpC in but also the corresponding orthologs in , another notorious opportunistic lung pathogen, suggesting that the ability of let-7b-5p to reduce biofilm formation and increase beta-lactam sensitivity is not limited to Here, we provide direct evidence for transfer of miRNAs in EVs secreted by eukaryotic cells to a prokaryote, resulting in subsequent phenotypic alterations in the prokaryote as a result of this interdomain communication. Since let-7-family miRNAs are in clinical trials to reduce inflammation and because chronic lung infections are associated with a hyperinflammatory state, treatment with let-7b-5p and a beta-lactam antibiotic in nanoparticles or EVs may benefit patients with antibiotic-resistant infections.
10.1073/pnas.2105370118
Let-7b-5p is involved in the response of endoplasmic reticulum stress in acute pulmonary embolism through upregulating the expression of stress-associated endoplasmic reticulum protein 1.
Liu Ting-Wei,Liu Fan,Kang Jian
IUBMB life
The endogenous non-coding microRNA (miRNA) let-7b-5p is highly expressed in the blood of patients with acute pulmonary embolism (PE). However, the mechanism underlying the involvement of let-7b-5p in acute PE remains unclear. To address this, we investigated the role of let-7b-5p in acute PE in both in vitro and in vivo experimental models. The results showed that let-7b-5p upregulated the expression of stress-associated endoplasmic reticulum protein 1 (SERP1) at the post-transcriptional level. SERP1 activation leads to modulation of its chaperone protein SEC61B in the response of endoplasmic reticulum (ER) stress. Furthermore, our data show that the unfolded protein response was triggered and activation of unfolded proteins GRP78, PERK, RNF121, and CHOP occurred through the PERK-CHOP pathway, resulting in an inflammatory response and apoptosis of lung epithelial cells. These characteristics were promoted by the in vitro expression of a let-7b-5p mimic; conversely, transfection with a let-7b-5p inhibitor decreased the response of ER stress in acute PE. The results from this study thus provide evidence that let-7b-5p promotes protein processing during ER stress response by upregulating SERP1 expression, ultimately resulting in an inflammatory response and apoptosis of lung cells, cumulatively playing a critical role in the pathogenesis of acute PE.
10.1002/iub.2306
Exosomes derived from M1 macrophages inhibit the proliferation of the A549 and H1299 lung cancer cell lines via the miRNA-let-7b-5p-GNG5 axis.
PeerJ
Background:Almost all cells are capable of secreting exosomes (Exos) for intercellular communication and regulation. Therefore, Exos can be used as a natural therapeutic platform to regulate genes or deliver drugs to treat diseases. M1 macrophages inhibit tumor growth by releasing pro-inflammatory factors. This study explored the applicability of M1 macrophage exosomes (M1-Exos) as gene carriers and the effects on GNG5 protein, and further examined whether macrophage repolarization could inhibit tumor activity. Methods:M0 macrophages were polarized toward M1 using vitexin. Exos were obtained from M1 macrophages by ultra-centrifugation. The transwell non-contact co-culture system was used to co-culture M1 macrophages with HLF- human lung epithelial cells or A549 or H1299 lung cancer cells. MTT, scratch, and transwell assays were used to detect the cell viability, migration, and invasion ability of cells in the four groups. Flow cytometry was used to detect the apoptosis rate of each group, and western blot (WB) analysis was performed to detect the change in the expression of proliferation- and apoptosis-related proteins. We screened the differentially expressed microRNAs using quantitative polymerase chain reaction technology. Luciferase reporter analysis was performed to explore the interaction between miRNA and protein. We used Xenografted A549 tumors in nude mice to study the effect of M1-Exos on tumor cell growth in vivo. Results:The results showed that, under the M1 macrophage co-culture system, lung cancer cell viability, invasion, and migration ability decreased, and the number of apoptotic cells increased, will all indicators being statistically significant ( < 0.05). The expression levels of PCNA, KI67, and Bcl-2 decreased significantly, but that of Bax increased ( < 0.05). Exosomes can have the same effect on tumor cells as M1 macrophages. Exosomes can transport miR-let-7b-5p to tumor cells, and miR-let-7b-5p can inhibit tumor cell proliferation and promote tumor cell apoptosis by regulating the GNG5 protein level. Conclusions:M1-Exos inhibit the proliferation, invasion, and metastasis of lung cancer cells through miRNA-let-7b-5p and GNG5 signaling pathways and inhibit the anti-apoptotic ability of lung cancer cells.
10.7717/peerj.14608