Vascular endothelial growth factor-A (VEGF-A) is a critical angiogenic factor which is mainly secreted from podocytes and epithelial cells in kidney and plays an important role in renal pathophysiology. In recent years, functions of different isoforms of VEGF-A and the new secretion approach via extracellular vesicles (EVs) have been identified. Thus, further understanding are needed for the role of VEGF-A and its isoforms in renal injury and repair. In this review, we summarized the expression, secretion and regulation of VEGF-A, its biological function, and the role of different isoforms of VEGF-A in the development of different renal diseases. Meanwhile, the research progress of VEGF-A as diagnostic marker and therapeutic target for renal diseases were discussed.
Humans ; Kidney/metabolism* ; Kidney Diseases ; Protein Isoforms/metabolism* ; Vascular Endothelial Growth Factor A/physiology*

Metallothioneins (MTs) are a group of intracellular proteins of low molecular weight and rich cysteine, encoded by a family of genes containing at least 10 functional isoforms in human. MTs widely exist in the male reproductive system and are involved in many pathophysiological processes such as metal ion homeostasis and detoxification, protection against oxidative damage, cell proliferation and apoptosis, chemoresistance and radiotherapy resistance. This review describes the location and effects of MTs in the male reproductive system.
Gene Expression Profiling ; Genitalia, Male ; metabolism ; physiopathology ; Humans ; Male ; Metallothionein ; genetics ; metabolism ; physiology ; Protein Isoforms ; genetics ; metabolism ; physiology

Inhibin, which is important for normal gonadal function, acts on the pituitary gonadotropins to suppress folliclestimulating hormone (FSH) secretion. The level and cellular localization of the inhibin isotypes, alpha, beta(A) and beta(B), in the testis of mice were examined during postnatal development in order to determine if inhibin expression is related to testicular maturation. Mouse testes were sampled on postnatal days (PNDs) 1, 3, 6, 18, 48 and 120, and analyzed by Western blotting and immunofluorescence. Western blot analysis showed very low levels of inhibin alpha, beta(A) and beta(B) expression in the testes at days 1 to 6 after birth. The levels then increased gradually from PND 18 to 48-120, and there were significant peaks at PND 48. Inhibin alpha, beta(A) and beta(B) were detected in testicular cells during postnatal development using immunohistochemistry. The immunoreactivity of inhibin alpha was rarely observed in testicular cells during PND 1 to 6, or in the cytoplasmic process of Sertoli cells surrounding the germ cells and interstitial cells during PND 18 to 120. Inhibin beta(A) and beta(B) immunoreactivity was rarely observed in the testis from PND 1 to 6. On the other hand, it was observed in some spermatogonial cells, as well as in the interstitial space between PND 48 and PND 120. We conclude that the expression of inhibin isotypes increases progressively in the testis of mice with increasing postnatal age, suggesting that inhibin is associated with a negative feedback signal for FSH in testicular maturation.
Aging/*physiology ; Animals ; Gene Expression Regulation/*physiology ; Inhibin-beta Subunits/genetics/*metabolism ; Inhibins/genetics/*metabolism ; Male ; Mice ; Mice, Inbred ICR ; Protein Isoforms/metabolism ; Protein Transport/*physiology ; Testis/*metabolism

Na(+)-H(+) exchangers (NHE) are major membrane proteins that have been identified as signal transduction mediators in the regulation of cell differentiation and important membrane ion transporters in the regulation of the intercellular pH and the cell volume. NHE are composed of at least six isoforms and activated in growth factor-regulated cell differentiation. However, little is known about the differential regulation of NHE expression in the development. In the present study, we studied developmental regulation of the expression of NHE isoforms in human fetal tissues by comparing the expression of various isoforms between two developmental stages, i.e., week 11 (11 W) and week 16 (16 W). The results demonstrated that NHE1 transcripts were expressed ubiquitously. In comparison to the expression at 16 W, the level of NHE1 transcripts was low and varied significantly in a tissue-specific pattern at 11 W, suggesting that the house-keeping function of MHE1 occurs at 11 W or earlier and becomes well established at least as early as at 16 W. The tissue-specifically restricted expression of NHE2 and NHE3 was regulated at 11 W and 16 W in an opposite tendency, supporting the overlapping relationship between NHE2 and NHE3 in the tissue distribution as reported in adults. NHE5 expression was relatively ubiquitous at 11 W and became restricted in the cerebellum at 16 W, suggesting that the restrictive expression of NHE5 in the brain occurs later than that of other isoforms. The present study demonstrates a space time-dependent regulation of the tissue-specific expression pattern of NHE isoforms during human development between 11 W and 16 W. The results also suggest that at 16 W or earlier the expression pattern of developing tissues becomes similar to that of adult tissues. The observed developmental regulation of NHE expression provides a molecular basis for further study of the function and regulation of NHE gene during development.
Fetus ; embryology ; metabolism ; Gene Expression Regulation, Developmental ; physiology ; Humans ; Organ Specificity ; Protein Isoforms ; metabolism ; physiology ; RNA, Messenger ; metabolism ; physiology ; Sodium-Hydrogen Exchangers ; metabolism ; physiology ; Tissue Distribution

OBJECTIVETo investigate the effects of estrogen on the expression of phosphofructokinase muscle-specific isoform (PFK-M) in genioglossus of chronic intermittent hypoxia (CIH) rats.

METHODSFifty male SD rats were randomly divided into five groups: the normal control group (NC), the chronic intermittent hypoxia group (CIH), and three doses of estrogen plus hypoxia groups (LE, ME, HE). Rats in the latter four groups were used to build CIH models (8 h/d, 5 weeks). In the mean time, rats in the latter three groups were injected with three dose levels of estrogen (0.1, 0.2, 0.3 mg/kg), and rats in NC and CIH groups were injected with sterile olive oil as control. At the end of the treatment, the genioglossus was isolated and quickly removed. The mRNA levels of PFK-M were determined by real-time RT-PCR and the protein content of PFK-M was detected by Western blotting analysis.

RESULTSPFK-M mRNA and protein in CIH group (2.144 ± 0.260, 0.875 ± 0.025) were both higher than those (1.000 ± 0.259, 0.413 ± 0.013) in NC group (P < 0.05). The expression of PFK-M mRNA in LE, ME and HE groups were 1.424 ± 0.193, 1.395 ± 0.251 and 1.310 ± 0.094, respectively. The expression of protein in LE, ME and HE groups were 0.638 ± 0.015, 0.576 ± 0.017 and 0.505 ± 0.021, respectively. Compared with CIH group, the expression of PFK-M mRNA and protein in LE, ME and HE groups were all inhibited significantly (P < 0.05). Among the three treatment groups, decreased protein content of PFK-M was observed only in HE group when compared with LE group (P < 0.05), but no significant difference was detected in the expression of PFK-M mRNA.

CONCLUSIONSCIH exposure could increase the expression of PFK-M mRNA and protein in rat genioglossus, while estrogen administration could dose dependently inhibit the overexpression.

Animals ; Estrogens ; physiology ; Hypoxia ; Male ; Muscle, Skeletal ; metabolism ; Phosphofructokinases ; biosynthesis ; Protein Isoforms ; RNA, Messenger ; Rats ; Tongue ; metabolism

Thyroid hormone plays pivotal roles in growth, differentiation, development and metabolic homeostasis via thyroid hormone receptors (TRs) by controlling the expression of TR target genes. The transcriptional activity of TRs is modulated by multiple factors including various TR isoforms, diverse thyroid hormone response elements, different heterodimeric partners, coregulators, and the cellular location of TRs. In the present review, we summarize recent advance in understanding the molecular mechanisms of thyroid hormone action obtained from human subject research, thyroid hormone mimetics application, TR isoform-specific knock-in mouse models, and mitochondrion study with highlights in metabolic regulations. Finally, as future perspectives, we share our thoughts about current challenges and possible approaches to promote our knowledge of thyroid hormone action in metabolism.
Animals ; Gene Knockout Techniques ; Humans ; Mice ; Mitochondria ; metabolism ; Protein Isoforms ; genetics ; metabolism ; physiology ; Receptors, Thyroid Hormone ; metabolism ; Thyroid Diseases ; metabolism ; pathology ; Thyroid Hormones ; genetics ; metabolism ; physiology

Synaptotagmin is a Ca2+ sensing protein, which triggers a fusion of synaptic vesicles in neuronal transmission. Little is known regarding the expression of Ca2+ - dependent synaptotagmin isoforms and their contribution to the release of secretory vesicles in mouse and rat parotid acinar cells. We investigated a type of Ca2+ - dependent synaptotagmin and Ca2+ signaling in both rat and mouse parotid acinar cells using RT-PCR, microfluorometry, and amylase assay. Mouse parotid acinar cells exhibited much more sensitive amylase release in response to muscarinic stimulation than did rat parotid acinar cells. However, transient [Ca2+]i increases and Ca2+ influx in response to muscarinic stimulation in both cells were identical, suggesting that the expression or activity of the Ca2+ sensing proteins is different. Seven Ca2+ - dependent synaptotagmins, from 1 to 7, were expressed in the mouse parotid acinar cells. However, in the rat parotid acinar cells, only synaptotagmins 1, 3, 4 and 7 were expressed. These results indicate that the expression of Ca2+ - dependent synaptotagmins may contribute to the release of secretory vesicles in parotid acinar cells.
Synaptotagmins/*metabolism ; Signal Transduction ; Rats ; Protein Isoforms/metabolism ; Parotid Gland/cytology/*metabolism ; Muscarinic Agonists/pharmacology ; Mice ; Exocytosis/drug effects/physiology ; Carbachol/pharmacology ; Calcium/metabolism/*physiology ; Animals ; Amylases/secretion

The three mammalian isoforms of transforming growth factor-beta (TGF-beta1, beta2, beta3) are potent regulators of cell growth, differentiation, and extracellular matrix deposition. To study their role in skin differentiation, we investigated the expression of TGF-beta isoforms on cell growth and differentiation induction of the human keratinocyte cell line, HaCaT by elevating the Ca2+ concentration. An ELISA and RT-PCR assay revealed secreted TGF-beta 1 protein and TGF-beta1 mRNA were increased during calci-um-induced differentiation. In contrast, major differences were seen for TGF-beta 2 and TGF-beta 3 mRNA which were decreased during differentiation, but TGF-beta 2 and TGF-3beta protein were not evident on an ELISA. These results suggest different functions for each TGF-beta isoforms in epidermal differentiation, such that TGF-beta 1 is associ-ated with the more differentiated state, and TGF-beta 2 and TGF-beta 3 may be associ-ated the more proliferated state.
Cell Differentiation/physiology ; Cell Line ; Gene Expression Regulation, Developmental/*physiology ; Humans ; Keratinocytes/*cytology/*physiology ; Protein Isoforms/metabolism ; Transforming Growth Factor beta/*metabolism

OBJECTIVE: In order to supply an effective reference of early injury time estimation and explore the time limit of detection of EDA\EDB mRNA in human skin samples, the expression of alternative splicing segment of fibronectin--EDA\EDB in incised wound of human skin were studied. METHODS: Using in situ hybridization with DIG-labeled anti-sense RNA probe, the expression of FN EDA\EDB domain was detected in human skin incised wound at the early stage of injury (from 30 min to 3 h). RESULTS: The positive expression rates of FN-EDA\EDB immediately after injury and area far away from wound were same as the control group. The expression of FN-EDA\EDB in human skin incised wound showed a gradually increased tendency in early injury time (within 3 h). The positive expression cells were mainly distributed in basement cells of epidermis and the expression of EDA is much higher than EDB. It's difficult to detect EDA\EDB mRNA when the samples were deposited in air for 4 hour. CONCLUSION FN-EDA\EDB may be used as a sensitive mark for the estimation of early injury time. The in-situ hybridization technique is not applicable in the application.
Fibronectins/genetics* ; Forensic Medicine ; Humans ; In Situ Hybridization ; Protein Isoforms/genetics* ; RNA, Messenger/genetics* ; Skin/metabolism* ; Time Factors ; Wound Healing/physiology*

BACKGROUND/AIMS: Peroxiredoxin (Prx) belongs to a ubiquitous family of antioxidant enzymes that regulates many cellular processes through intracellular oxidative signal transduction pathways. Silica-induced lung damage involves reactive oxygen species (ROS) that trigger subsequent toxic effects and inflammatory responses in alveolar epithelial cells resulting in fibrosis. Therefore, we investigated the role of Prx in the development of lung oxidant injury caused by silicosis, and determined the implication of ROS in that process. METHODS: Lung epithelial cell lines A549 and WI26 were treated with 1% silica for 0, 24, or 48 hours, following pretreatment of the A549 cells with N-acetyl-L-cysteine and diphenylene iodonium and no pretreatment of the WI26 cells. We transfected an HA-ubiquitin construct into the A549 cell line and then analyzed the cells via Western blotting and co-immunoprecipitation. RESULTS: Silica treatment induced cell death in the A549 lung epithelial cell line and selectively degraded Prx I without impairing protein synthesis in the A549 cells, even when the ROS effect was blocked chemically by N-acetyl-L-cysteine. A co-immunoprecipitation study revealed that Prx I did not undergo ubiquitination. CONCLUSIONS: Silica treatment induces a decrease of Prx I expression in lung epithelial cell lines regardless of the presence of ROS. The silica-induced degradation of Prx does not involve the ubiquitin-proteasomal pathway.
Cell Line ; Epithelial Cells/drug effects/metabolism ; Humans ; Lung/chemistry/*drug effects/metabolism ; Peroxiredoxins/analysis/*physiology ; Protein Isoforms ; Reactive Oxygen Species/metabolism ; Silicon Dioxide/*toxicity ; Ubiquitin/metabolism