Roles of lysosomal proteolytic systems in AQP5 degradation in the submandibular gland of rats following chorda tympani parasympathetic denervation

2010 ◽  
Vol 299 (5) ◽  
pp. G1106-G1117 ◽  
Author(s):  
Ahmad Azlina ◽  
Purevjav Javkhlan ◽  
Yuka Hiroshima ◽  
Takahiro Hasegawa ◽  
Chenjuan Yao ◽  
...  

Chorda tympani denervation (CTD) of rats was earlier shown to result in loss of submandibular gland (SMG) weight (at only 1 wk) and in continued reduction in aquaporin 5 (AQP5) protein expression (until 4 wk), without affecting its mRNA synthesis (Li X, Azlina A, Karabasil MR, Purwanti N, Hasegawa T, Yao C, Akamatsu T, Hosoi K. Am J Physiol Gastrointest Liver Physiol 295: G112–G123, 2008). The present study indicated that despite elevation of bax, a proapoptosis protein, by CTD, the operation also increased the level of bcl-2, an antiapoptosis protein, in the SMG. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL assay) showed no increase in the number of apoptotic cells in the SMG. CTD, however, induced strongly and transiently (at 1–3 days) the protein expression of LC3B-II, a marker protein of autophagosomes, suggesting that the reduction in the gland weight was due to onset of autophagy by CTD. Upon CTD, Lamp2, a lysosomal marker, gradually increased in amount, reaching a peak at the 14th day. Immunohistochemical analysis revealed an increase in the number of lysosome-like structures positive for both AQP5 and Lamp2 in the acinar cells of the SMG after CTD; similar changes were observed also for AQP5 and LC3Bs. These data suggest that AQP5 in the SMG entered autophagosomes and/or lysosomes for degradation upon CTD. In vitro AQP5-degrading activity was found in the SMG extracts, and such activity was shown to be increased by CTD. Inhibitor experiments implied cathepsins B and L to be candidate enzymes for this degradation under normal and CTD conditions, respectively.

2008 ◽  
Vol 295 (1) ◽  
pp. G112-G123 ◽  
Author(s):  
Xuefei Li ◽  
Ahmad Azlina ◽  
Mileva Ratko Karabasil ◽  
Nunuk Purwanti ◽  
Takahiro Hasegawa ◽  
...  

By chorda tympani denervation (CTD, parasympathectomy), the aquaporin 5 (AQP5), but not AQP1, protein level in the rat submandibular gland (SMG) was significantly decreased, dropping to 37% of that of the contralateral gland at 4 wk. The protein levels of AQP5 and AQP1 were not significantly affected by denervation of the cervical sympathetic trunk (sympathectomy). Administration of cevimeline hydrochloride, an M3 muscarinic receptor agonist (10 mg/kg for 7 days po), but not pilocarpine (0.3 mg/kg for 7 days po), recovered the AQP5 protein level reduced by CTD and increased the AQP1 protein level above the control one. The mRNA level of AQP5 was scarcely affected by CTD and cevimeline hydrochloride administration. Administration of chloroquine (50 mg/kg for 7 days po), a denaturant of lysosomes, increased the AQP5 protein level reduced by CTD. An extract obtained from the submandibular lysosomal fraction degraded the AQP5 protein in the total membrane fraction in vitro. These results suggest the possible regulation of the AQP5 protein level in the SMG by the parasympathetic nerves/M3 muscarinic receptor agonist and imply the involvement of lysosomal enzymes, but not a transcriptional mechanism, in this regulation.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Qingsong Cao ◽  
Jie Zhang ◽  
Tao Zhang

Nasopharyngeal carcinoma (NPC) is a head and neck tumor with high degree of malignancy and with high incidence especially in southern China. AIMP2-DX2, one isoform of the aminoacyl-tRNA synthetase interacting multifunctional proteins (AIMPs), is shown to be a potential target in many cancers. However, the detailed mechanisms of AIMP2-DX2 in NPC development remain to be elucidated. Here, we found that the mRNA expression level of AIMP2-DX2 was significantly increased in NPC specimens, compared with normal nasopharyngeal tissues. Microarray immunohistochemical analysis of NPC specimens and Kaplan–Meier analysis showed that patients with high AIMP2-DX2 protein expression had shorter overall survival than those with low AIMP2-DX2 level. Furthermore, mRNA and protein expression levels of AIMP2-DX2 were both increased in cultured NPC cell lines (5-8F, CNE-2Z, and CNE-1), by being compared with normal nasopharyngeal cell line NP69. Overexpression of AIMP2-DX2 remarkably promoted the cell viability, cell migration, and invasion of cultured NPC cells. Genetic knockdown of AIMP2-DX2 by shRNA lentiviruses significantly suppressed the proliferation, migration, and invasion and induced apoptosis of NPC cells. Inhibition of AIMP2-DX2 decreased the highly expressed level of matrix metalloproteinase- (MMP-) 2 and MMP-9, further suppressed proliferation, migration, and invasion in cultured NPC cells in vitro, and inhibited tumor growth in a xenograft mouse model in vivo. Taken together, these results suggest that AIMP2-DX2 plays an important role in the regulation of NPC and could be a potential therapeutic target and prognostic indicator for the treatment of NPC.


Pathogens ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 246
Author(s):  
Fanzhi Kong ◽  
Yaru Xu ◽  
Wei Ran ◽  
Baishuang Yin ◽  
Li Feng ◽  
...  

Porcine epidemic diarrhea (PED) is a highly contagious, intestinal infectious disease caused by porcine epidemic diarrhea virus (PEDV). PEDV as an emerging and re-emerging epizootic virus of swine causes substantial economic losses to the pig industry in China and other countries. In China, the occurrence of PED shows significant seasonal variations, usually outbreak during the winter season. The epidemic characteristics of PED may be highly correlated with the changes of ambient temperature. However, molecular mechanism on the seasonal occurrence of PED still remains unclear. It has been widely observed that low ambient temperature up-regulates the expression of host heat shock protein 70 (Hsp70). Here, we showed that nucleotide and protein levels of Hsp70 were up-regulated in the intestinal of cold exposed pig and cold exposed Vero E6 cells. We found that overexpression of Hsp70 could increase PEDV mRNA synthesis and protein expression in Vero E6 and IPEC-J2 cells, while the siRNAs mediated knockdown of Hsp70 and VER155008 mediated inhibition of Hsp70 resulted in inhibition of viral mRNA synthesis and protein expression in Vero E6 cells. These data suggested that Hsp70 positively regulated PEDV mRNA synthesis and protein expression, which being helpful for understanding the seasonality of PED epidemics and development of novel antiviral therapies in the future.


Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1989 ◽  
Author(s):  
Kashi Bhattarai ◽  
Hwa-Young Lee ◽  
Seung-Hyun Kim ◽  
Jong-Sug Park ◽  
Hyung-Ryong Kim ◽  
...  

Dry mouth is a common complaint among the elderly population. The aim of this study was to investigate the effect of Ixeris dentata (IXD) extract on aging-induced dry mouth. We used young (two months) and aged (20 months) SD rats in our study. Using water as the vehicle, IXD extract (25, 50, and 100 mg/kg) was given via oral gavage to the young and aged rats for eight weeks. We found that the salivary flow rate relative to the submandibular gland weight was differently influenced by IXD extract treatment. IXD extract augmented the submandibular gland acinar cells, which are depleted during aging. In addition, the decreased salivary alpha-amylase, inositol triphosphate receptor, and aquaporin-5 in the aging rats were upregulated by IXD treatment. Free radical-induced oxidative stress in the aging rats was also alleviated in the IXD-treated group. The formation of high molecular weight complexes of protein disulfide isomerase, decreased expression of an ER chaperone (GRP78), and increased ER stress response (ATF-4, CHOP and p-JNK) in aging rats was regulated with IXD treatment, and eventually increased salivary secretions from the aging submandibular glands. These are the first data to suggest that IXD extract might ameliorate aging-associated oral dryness by regulating the ER environment.


Author(s):  
L.S. Cutler

Many studies previously have shown that the B-adrenergic agonist isoproterenol and the a-adrenergic agonist norepinephrine will stimulate secretion by the adult rat submandibular (SMG) and parotid glands. Recent data from several laboratories indicates that adrenergic agonists bind to specific receptors on the secretory cell surface and stimulate membrane associated adenylate cyclase activity which generates cyclic AMP. The production of cyclic AMP apparently initiates a cascade of events which culminates in exocytosis. During recent studies in our laboratory it was observed that the adenylate cyclase activity in plasma membrane fractions derived from the prenatal and early neonatal rat submandibular gland was retractile to stimulation by isoproterenol but was stimulated by norepinephrine. In addition, in vitro secretion studies indicated that these prenatal and neonatal glands would not secrete peroxidase in response to isoproterenol but would secrete in response to norepinephrine. In contrast to these in vitro observations, it has been shown that the injection of isoproterenol into the living newborn rat results in secretion of peroxidase by the SMG (1).


2020 ◽  
Vol 27 (12) ◽  
pp. 699-710
Author(s):  
Irasema Mendieta ◽  
Gabriel Rodríguez-Gómez ◽  
Bertha Rueda-Zarazúa ◽  
Julia Rodríguez-Castelán ◽  
Winniberg Álvarez-León ◽  
...  

Neuroblastoma (NB) is the most common solid childhood tumor, and all-trans retinoic acid (ATRA) is used as a treatment to decrease minimal residual disease. Molecular iodine (I2) induces differentiation and/or apoptosis in several neoplastic cells through activation of PPARγ nuclear receptors. Here, we analyzed whether the coadministration of I2 and ATRA increases the efficacy of NB treatment. ATRA-sensitive (SH-SY5Y), partially-sensitive (SK-N-BE(2)), and non-sensitive (SK-N-AS) NB cells were used to analyze the effect of I2 and ATRA in vitro and in xenografts (Foxn1 nu/nu mice), exploring actions on cellular viability, differentiation, and molecular responses. In the SH-SY5Y cells, 200 μM I2 caused a 100-fold (0.01 µM) reduction in the antiproliferative dose of ATRA and promoted neurite extension and neural marker expression (tyrosine hydroxylase (TH) and tyrosine kinase receptor alpha (Trk-A)). In SK-N-AS, the I2 supplement sensitized these cells to 0.1 μM ATRA, increasing the ATRA-receptor (RARα) and PPARγ expression, and decreasing the Survivin expression. The I2 supplement increased the mitochondrial membrane potential in SK-N-AS suggesting the participation of mitochondrial-mediated mechanisms involved in the sensibilization to ATRA. In vivo, oral I2 supplementation (0.025%) synergized the antitumor effect of ATRA (1.5 mg/kg BW) and prevented side effects (body weight loss and diarrhea episodes). The immunohistochemical analysis showed that I2 supplementation decreased the intratumoral vasculature (CD34). We suggest that the I2 + ATRA combination should be studied in preclinical and clinical trials to evaluate its potential adjuvant effect in addition to conventional treatments.


2020 ◽  
Vol 27 (5) ◽  
pp. 432-446
Author(s):  
Akiko Yamamoto ◽  
Ken-ichiro Matsunaga ◽  
Toyoaki Anai ◽  
Hitoshi Kawano ◽  
Toshihisa Ueda ◽  
...  

Background: Intermediate Filaments (IFs) are major constituents of the cytoskeletal systems in animal cells. Objective: To gain insights into the structure-function relationship of invertebrate cytoplasmic IF proteins, we characterized an IF protein from the platyhelminth, Dugesia japonica, termed Dif-1. Method: cDNA cloning, in situ hybridization, immunohistochemical analysis, and IF assembly experiments in vitro using recombinant Dif-1, were performed for protein characterization. Results: The structure deduced from the cDNA sequence showed that Djf-1 comprises 568 amino acids and has a tripartite domain structure (N-terminal head, central rod, and C-terminal tail) that is characteristic of IF proteins. Similar to nuclear IF lamins, Djf-1 contains an extra 42 residues in the coil 1b subdomain of the rod domain that is absent from vertebrate cytoplasmic IF proteins and a nuclear lamin-homology segment of approximately 105 residues in the tail domain; however, it contains no nuclear localization signal. In situ hybridization analysis showed that Djf-1 mRNA is specifically expressed in cells located within the marginal region encircling the worm body. Immunohistochemical analysis showed that Djf-1 protein forms cytoplasmic IFs located close to the microvilli of the cells. In vitro IF assembly experiments using recombinant proteins showed that Djf-1 alone polymerizes into IFs. Deletion of the extra 42 residues in the coil 1b subdomain resulted in the failure of IF formation. Conclusions: Together with data from other histological studies, our results suggest that Djf- 1 is expressed specifically in anchor cells within the glandular adhesive organs of the worm and that Djf-1 IFs may play a role in protecting the cells from mechanical stress.


Author(s):  
Haiyun Sun ◽  
Chong Wang ◽  
Ying Zhou ◽  
Xingbo Cheng

Objective: Diabetic cardiomyopathy (DCM) is an important complication of diabetes. This study was attempted to discover the effects of long noncoding RNA OIP5-AS1 (OIP5-AS1) on the viability and oxidative stress of cardiomyocyte in DCM. Methods: The expression of OIP5-AS1 and microRNA-34a (miR-34a) in DCM was detected by qRT-PCR. In vitro, DCM was simulated by high glucose (HG, 30 mM) treatment in H9c2 cells. The viability of HG (30 mM)-treated H9c2 cells was examined by MTT assay. The reactive oxygen species (ROS), superoxide dismutase (SOD) and malondialdehyde (MDA) levels were used to evaluate the oxidative stress of HG (30 mM)-treated H9c2 cells. Dual-luciferase reporter assay was used to confirm the interactions among OIP5-AS1, miR-34a and SIRT1. Western blot was applied to analyze the protein expression of SIRT1. Results: The expression of OIP5-AS1 was down-regulated in DCM, but miR-34a was up-regulated. The functional experiment stated that OIP5-AS1 overexpression increased the viability and SOD level, while decreased the ROS and MDA levels in HG (30 mM)-treated H9c2 cells. The mechanical experiment confirmed that OIP5-AS1 and SIRT1 were both targeted by miR-34a with the complementary binding sites at 3′UTR. MiR-34a overexpression inhibited the protein expression of SIRT1. In the feedback experiments, miR-34a overexpression or SIRT1 inhibition weakened the promoting effect on viability, and mitigated the reduction effect on oxidative stress caused by OIP5-AS1 overexpression in HG (30 mM)-treated H9c2 cells. Conclusions: OIP5-AS1 overexpression enhanced viability and attenuated oxidative stress of cardiomyocyte via regulating miR-34a/SIRT1 axis in DCM, providing a new therapeutic target for DCM.


Oncogene ◽  
2021 ◽  
Author(s):  
Jiuna Zhang ◽  
Xiaoyu Jiang ◽  
Jie Yin ◽  
Shiying Dou ◽  
Xiaoli Xie ◽  
...  

AbstractRING finger proteins (RNFs) play a critical role in cancer initiation and progression. RNF141 is a member of RNFs family; however, its clinical significance, roles, and mechanism in colorectal cancer (CRC) remain poorly understood. Here, we examined the expression of RNF141 in 64 pairs of CRC and adjacent normal tissues by real-time PCR, Western blot, and immunohistochemical analysis. We found that there was more expression of RNF141 in CRC tissue compared with its adjacent normal tissue and high RNF141 expression associated with T stage. In vivo and in vitro functional experiments were conducted and revealed the oncogenic role of RNF141 in CRC. RNF141 knockdown suppressed proliferation, arrested the cell cycle in the G1 phase, inhibited migration, invasion and HUVEC tube formation but promoted apoptosis, whereas RNF141 overexpression exerted the opposite effects in CRC cells. The subcutaneous xenograft models showed that RNF141 knockdown reduced tumor growth, but its overexpression promoted tumor growth. Mechanistically, liquid chromatography-tandem mass spectrometry indicated RNF141 interacted with KRAS, which was confirmed by Co-immunoprecipitation, Immunofluorescence assay. Further analysis with bimolecular fluorescence complementation (BiFC) and Glutathione-S-transferase (GST) pull-down assays showed that RNF141 could directly bind to KRAS. Importantly, the upregulation of RNF141 increased GTP-bound KRAS, but its knockdown resulted in a reduction accordingly. Next, we demonstrated that RNF141 induced KRAS activation via increasing its enrichment on the plasma membrane not altering total KRAS expression, which was facilitated by the interaction with LYPLA1. Moreover, KRAS silencing partially abolished the effect of RNF141 on cell proliferation and apoptosis. In addition, our findings presented that RNF141 functioned as an oncogene by upregulating KRAS activity in a manner of promoting KRAS enrichment on the plasma membrane in CRC.


2021 ◽  
Vol 49 (2) ◽  
pp. 030006052098635
Author(s):  
Qi Gao ◽  
Ningqing Chang ◽  
Donglian Liu

Objectives To investigate the mechanisms underlying the protective effect of sufentanil against acute lung injury (ALI). Material and Methods Rats were administered lipopolysaccharide (LPS) by endotracheal instillation to establish a model of ALI. LPS was used to stimulate BEAS-2B cells. The targets and promoter activities of IκB were assessed using a luciferase reporter assay. Apoptosis of BEAS-2B cells was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling. Results Sufentanil treatment markedly reduced pathological changes in lung tissue, pulmonary edema and secretion of inflammatory factors associated with ALI in vivo and in vitro. In addition, sufentanil suppressed apoptosis induced by LPS and activated NF-κB both in vivo and in vitro. Furthermore, upregulation of high mobility group box protein 1 (HMGB1) protein levels and downregulation of miR-129-5p levels were observed in vivo and in vitro following sufentanil treatment. miR-129-5p targeted the 3ʹ untranslated region and its inhibition decreased promoter activities of IκB-α. miR-129-5p inhibition significantly weakened the protective effect of sufentanil on LPS-treated BEAS-2B cells. Conclusion Sufentanil regulated the miR-129-5p/HMGB1 axis to enhance IκB-α expression, suggesting that sufentanil represents a candidate drug for ALI protection and providing avenues for clinical treatment.


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