Pyridostigmine attenuates hypertension by inhibiting activation of the renin-angiotensin system in the hypothalamic paraventricular nucleus.

Activation of the renin-angiotensin system (RAS) triggers oxidative stress and an inflammatory response in the hypothalamic paraventricular nucleus (PVN), in turn increasing the sympathetic hyperactivity that is a major cause of hypertension. Pyridostigmine has cardioprotective effects by suppressing the RAS of myocardial tissue. However, whether pyridostigmine attenuates hypertension by inhibiting the RAS of the PVN remains unclear. We thus investigated the effect and mechanism of pyridostigmine on two-kidney one-clip (2K1C)-induced hypertension. 2K1C rats received pyridostigmine, or not, for 8 weeks. Cardiovascular function, hemodynamic parameters, and autonomic activity were measured. The PVN levels of pro-/anti-inflammatory cytokines, oxidative stress, and RAS signaling molecules were evaluated. Our results showed that hypertension was accompanied by cardiovascular dysfunction and an autonomic imbalance characterized by enhanced sympathetic but diminished vagal activity. The PVN levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), reactive oxygen species (ROS), NOX-2, and malondialdehyde (MDA) increased; those of IL-10 and superoxide dismutase (SOD) decreased. Moreover, the RAS signaling pathway was activated, as evidenced by increased levels of the angiotensin-converting enzyme (ACE), angiotensin II (Ang II), and the Ang II type 1 receptor (AT1R) and a decreased AT2R level. Pyridostigmine lowered blood pressure and improved cardiovascular function, associated with restoration of the autonomic balance. Meanwhile, pyridostigmine decreased PVN IL-6, TNF-α, ROS, NOX-2, and MDA levels and increased IL-10 and SOD levels. Additionally, pyridostigmine suppressed PVN ACE, Ang II, and AT1R levels and increased AT2R expression. Pyridostigmine attenuated hypertension by inhibiting PVN oxidative stress and inflammation induced by the RAS.

[Effects of Land Use Types on Water Quality at Different Buffer Scales: Tianjin Section of the Haihe River Basin as an Example].

It is important to explore the relationship between land use types and water quality to improve the surface water environment. Based on monthly water quality monitoring data from 16 nationally controlled surface water quality monitoring stations in Tianjin and land use data in 2021, GIS spatial analysis and mathematical and statistical methods were used to study the influence of land use types on surface water quality in buffer zones at different scales. The results showed that:① the land use types in the study area were mainly construction land, farmland, and water areas, which had significant effects on river water quality. Except for water temperature (WT) and pH, the farmland, construction land, and water areas were negatively correlated with each water quality indicator; forest land and grassland were positively correlated with dissolved oxygen (DO) and total nitrogen (TN) and negatively correlated with other water quality indicators. ② The water quality indicators showed obvious spatial differences in different seasons. The pH, DO and TN concentrations were higher in the dry season, whereas the permanganate index, ammonia nitrogen (NH4+-N), and total phosphorus (TP) concentrations were higher in the rainy season. ③ The results of the RDA analysis showed that the 800 m buffer zone land use had the greatest explanatory power for water quality changes in the dry season (50.4%), whereas the 3 000 m buffer zone land use could explain the water quality changes in the rainy season to the greatest extent (49.6%); from the average explanation rate of the dry and rainy seasons, the 3 000 m buffer zone was the best impact scale (50.0%) on water quality indicators in Tianjin. ④ The partial least squares regression (PLSR) analysis showed that the most important variables affecting surface water quality changes were construction land, farmland, and water areas. The predictive ability of the PLSR model of most water quality indicators was stronger in the dry season than that in the rainy season. In the dry season, all water quality indicators, except WT and pH, were most influenced by farmland. In the rainy season, construction land had the greatest influence on WT and NH4+-N concentrations, and the most important influencing factor for the remaining water quality indicators was still farmland. This study showed that the rational planning of land use types within 3 000 m of rivers or lakes was beneficial to improving the water quality of surface water.

Nogo-B mediates endothelial oxidative stress and inflammation to promote coronary atherosclerosis in pressure-overloaded mouse hearts.

AIMS: Endothelial dysfunction plays a pivotal role in atherosclerosis, but the detailed mechanism remains incomplete understood. Nogo-B is an endoplasmic reticulum (ER)-localized protein mediating ER-mitochondrial morphology. We previously showed endothelial Nogo-B as a key regulator of endothelial function in the setting of hypertension. Here, we aim to further assess the role of Nogo-B in coronary atherosclerosis in ApoE-/- mice with pressure overload. METHODS AND RESULTS: We generated double knockout (DKO) mouse models of systemically or endothelium-specifically excising Nogo-A/B gene on an ApoE-/- background. After 7 weeks of transverse aortic constriction (TAC) surgery, compared to ApoE-/- mice DKO mice were resistant to the development of coronary atherosclerotic lesions and plaque rapture. Sustained elevation of Nogo-B and adhesion molecules (VCAM-1/ICAM-1), early markers of atherosclerosis, was identified in heart tissues and endothelial cells (ECs) isolated from TAC ApoE-/- mice, changes that were significantly repressed by Nogo-B deficiency. In cultured human umbilical vein endothelial cells (HUVECs) exposure to inflammatory cytokines (TNF-α, IL-1ß), Nogo-B was upregulated and activated reactive oxide species (ROS)-p38-p65 signaling axis. Mitofusin 2 (Mfn2) is a key protein tethering ER to mitochondria in ECs, and we showed that Nogo-B expression positively correlated with Mfn2 protein level. And Nogo-B deletion in ECs or in ApoE-/- mice reduced Mfn2 protein content and increased ER-mitochondria distance, reduced ER-mitochondrial Ca2+ transport and mitochondrial ROS generation, and prevented VCAM-1/ICAM-1 upregulation and EC dysfunction, eventually restrained atherosclerotic lesions development. CONCLUSION: Our study revealed that Nogo-B is a critical modulator in promoting endothelial dysfunction and consequent pathogenesis of coronary atherosclerosis in pressure overloaded hearts of ApoE-/- mice. Nogo-B may hold the promise to be a common therapeutic target in the setting of hypertension.

Association between urinary polycyclic aromatic hydrocarbons metabolites and high-normal blood pressure in coke oven workers / 中国职业医学

@#Objective （ ） To investigate the association between urinary polycyclic aromatic hydrocarbons PAHs metabolites - Methods and high normal blood pressure in coke oven workers. A total of 433 coke oven workers were selected as the study - subjects using convenient sampling method. They were divided into normal blood pressure group and high normal blood pressure group according to their blood pressure level. The levels of ten kinds of urinary hydroxylated PAHs metabolites were measured by - Results - high performance liquid chromatography mass spectrometry. Among the subjects,57.5% had high normal blood - ， - ， - pressure. The levels of 1 hydroxynathalene 2 hydroxyphenanthrene 1 hydroxyphenanthrene and the metabolite of total PAHs - （ P ） in the high normal blood pressure group were higher than those in the normal blood pressure group all <0.05 . The results of - ， - ， - ， the multivariate logistic regression analysis showed that urinary 1 hydroxynathalene 2 hydroxyfluorene 3 hydroxychrysene - （ P ）， and metabolite of total PAHs were all risk factors for high normal blood pressure in coke oven workers all <0.05 after ， ， ， ， ， adjusting for confounding factors such as gender length of service body mass index smoking index alcohol consumption tea ， ， ， Conclusion consumption night shift exercise frequency and other PAHs metabolites. Exposure to PAHs in coke oven plants may increase the risk of elevated blood pressure within the normal range among coke oven workers.

Terahertz non-label subwavelength imaging with composite photonics-plasmonics structured illumination.

Inspired by the capability of structured illumination microscopy (SIM) in subwavelength imaging, many researchers devoted themselves to investigating this methodology. However, due to the free-propagating feature of the traditional structured illumination fields, the resolution can be only improved up to two-fold of the diffraction-limited microscopy. Besides, most of the previous studies, relying on incoherent illumination sources, are restricted to fluorescent samples. In this work, a subwavelength non-fluorescent imaging method is proposed based on the illumination of terahertz traveling waves and plasmonics. Excited along with a metal grating, the spoof surface plasmons (SSPs) are employed as one of the illuminating sources. When the scattering waves with the SSPs illumination are captured, the sample's high-order spatial frequencies (SF) components are already encoded into the obtainable low-order ones. Then, a modified post-processing algorithm is exploited to shift the modulated SF components to their actual positions in the SF domain. In this manner, the fine information of samples is introduced to reconstruct the desired imaging, leading to an enhancement of the resolution up to 0.12λ0. Encouragingly, the resolution can be further enhanced by attaching extra illumination of SSPs with an elaborately selected frequency. This method holds promise for some important applications in terahertz non-fluorescent microscopy and sample detection with weak scattering.

Design of Double-Layer Electrically Extremely Small-Size Displacement Sensor.

In this paper, a displacement sensor with an electrically extremely small size and high sensitivity is proposed based on an elaborately designed metamaterial element, i.e., coupled split-ring resonators (SRRs). The sensor consists of a feeding structure with a rectangular opening loop and a sensing structure with double-layer coupled SRRs. The movable double-layer structures can be used to measure the relative displacement. The size of microwave displacement sensors can be significantly reduced due to the compact feeding and sensing structures. By adjusting the position of the split gap within the resonator, the detection directions of the displacement sensing can be further expanded accordingly (along with the x- or y-axis) without increasing its physical size. Compared with previous works, the extremely compact size of 0.05λ0 × 0.05λ0 (λ0 denotes the free-space wavelength), a high sensitivity, and a high quality factor (Q-factor) can be achieved by the proposed sensor. From the perspective of the advantages above, the proposed sensor holds promise for being applied in many high-precision industrial measurement scenarios.

Bifunctional Luneburg-fish-eye lens based on the manipulation of spoof surface plasmons.

Manipulation of spoof surface plasmons (SSPs) has recently intrigued enormous interest due to the capability of guiding waves with subwavelength footsteps. However, most of the previous studies, manifested for a single functionality, are not suitable for multifunctional integrated devices. Herein, a bifunctional Luneburg-fish-eye lens is proposed based on a 2D metal pillar array. First, by tuning the dimension of the metal pillars in the array, its ability to precisely manipulate the SSPs along one direction is confirmed, achieving subwavelength focusing and imaging with a resolution up to 0.14λ. Then, separately controlling the propagation of the SSPs along the orthotropic directions is further implemented, and the bifunctional Luneburg-fish-eye lens is realized. It is experimentally characterized as a Luneburg lens along the x axis, whereas in the y axis, it presents the properties of a Maxwell fish-eye lens. This bifunctional lens can reduce the system complexity and exert flexibility in multifunctional applications, while the proposed metal pillar-based design method broadens the application range of the gradient refractive-index lens in microwave, terahertz, and even optical ranges.

Pharmacological Therapy of Abdominal Aortic Aneurysm: An Update.

BACKGROUND: Abdominal aortic aneurysm (AAA), a progressive segmental abdominal aortic dilation, is associated with high mortality. AAA is characterized by inflammation, smooth muscle cell (SMC) depletion and extracellular matrix (ECM) degradation. Surgical intervention and endovascular therapy are recommended to prevent rupture of large AAAs. Unfortunately, there is no reliable pharmacological agent available to limit AAA expansion. In the past decades, extensive investigations and a body of ongoing clinical trials aimed at defining potent treatments to inhibit and even regress AAA growth. CONCLUSION: In this review, we summarized recent progress of potential strategies, particularly macrolides, tetracyclines, statins, angiotensin converting enzyme inhibitors, angiotensin receptor blocker, corticosteroid, anti-platelet drugs and mast cell stabilizers. We also consider recently identified novel molecular targets, which have potential to be translated into clinical practice in the future.

SIRT3 in cardiovascular diseases: Emerging roles and therapeutic implications.

SIRT3 belongs to a highly conserved protein family of histone deacetylases and it is rich in mitochondria. As acetyl-modification is one of the important post-translational modifications that prevail in the mitochondria, it is not surprising that SIRT3 plays a key regulatory role in this organelle. SIRT3 has a wide range of substrates that are involved in the physiological and pathological processes of oxidative stress, ischemia-reperfusion injury, mitochondrial metabolism homeostasis and cellular death. These pathophysiological processes are considered as the underlying mechanisms of diseases like cardiac hypertrophy, myocardial infarction and heart failure, indicating the potential roles of SIRT3 in cardiovascular diseases. In this review, we will summarize the emerging roles and therapeutic implications of SIRT3 in cardiovascular diseases by providing an update on the latest understanding of its functions.

Regulatory T lymphocytes in myocardial infarction: A promising new therapeutic target.

Myocardial infarction (MI) is one of the leading causes of death especially in developed countries. Although the advent of early myocardial reperfusion therapy contributes to decreasing the mortality of patients with MI, cardiac ischemia-reperfusion injury and adverse remodeling during the repair process still remain the major factors impairing cardiac function and resulting in unsatisfactory prognosis. Excessive inflammation and immune responses play a crucial role during the whole process of MI. Regulatory T lymphocytes, characterized by immunosuppressive capacity, are associated with many immune-related diseases. Recent studies have proven a protective role of regulatory T cells in MI, which is mainly achieved by modulating inflammation and immune responses. In this review, we will summarize current knowledge of regulatory T lymphocytes, and highlight their roles in the onset of MI, ischemia-reperfusion injury, as well as post-infarct cardiac healing and remodeling.

Identification of potential biomarkers for artificial cold exposure-induced hypertensive stroke by proteomic analysis.

BACKGROUND: The effect of changing temperature on an individual's cerebrovascular risk is both biologically plausible and supported by epidemiologic evidence. We used a global proteomic-based approach to analyze the expression alterations of proteins in artificial cold exposure (ACE)-induced hypertensive stroke in renovascular hypertensive rats (RHR) and to identify the biomarker of ACE-induced hypertensive stroke. METHODS: The RHR models were established by 2 kidney 2 clip methods. ACE treatment was achieved using an intelligent artificial climate cabinet. Blood pressure and neurologic symptoms were observed before and after ACE treatment. Hemorrhagic condition and infarction survey were examined using 2,3,5-triphenyltetrazolium chloride staining. The total number of proteins derived from the cerebral tissue of the RHR models were analyzed with 2-dimensional gel electrophoresis (2-DE), ImageMaster 2D Platinum software, and mass spectrometry. Significantly regulated proteins selected for further functional studies using the Search Tool for the Retrieval of Interacting Genes/Proteins system were verified by Western blot. RESULTS: ACE-induced stroke in the RHR group (31.25%, 25 of 80 vs. 16.25%, 13 of 80; P < .05) but not in the sham-operated group. Following ACE treatment, we identified 37 differentially expressed proteins and 28 were unique. Two of the upregulated proteins, Syt1 and Idh3a, were obtained by bioinformatics analysis and verified by Western blot. CONCLUSIONS: The rate of morbidity as a result of stroke in RHR was obviously elevated after ACE treatment. ACE might affect protein expression profile in cerebral tissues of RHR. Syt1 and Idh3a may play a vital role in ACE-induced hypertensive stroke.

Inhibition of hepatocellular carcinoma growth by adenovirus-mediated expression of human telomerase reverse transcriptase COOH-27 terminal polypeptide in mice.

A 27-kDa C-terminal fragment of human telomerase reverse transcriptase, hTERTC27, has previously been reported to inhibit the growth and tumorigenicity of HeLa human cervical cancer cells and U87-MG human glioblastoma multiforme cells. However, the antitumor effects of hTERTC27 in hepatoma and its underlying mechanisms are unclear. In the current study, the therapeutic effect of hTERTC27, mediated by recombinant adenovirus, in hepatocellular carcinoma (HCC) was explored in vitro and in vivo to investigate the possible mechanisms. The results indicated that recombinant adenovirus carrying hTERTC27 (rAdv-hTERTC27) effectively inhibited the growth and induced apoptosis of the Hepa 1-6 HCC cells. Dendritic cells transduced with rAdv-hTERTC27 were highly effective at inducing antigen-specific T cell proliferation and increasing the activated cytotoxicity of T cells against Hepa 1-6 cells. HCC was inhibited significantly when a single dose of 5×107 pfu rAdv-hTERTC27 was administered intravenously. In summary, the results of this study demonstrated that rAdv-hTERTC27 may serve as a reagent for intravenous administration when combined with telomerase-based gene therapy and immunotherapy for cancer.

Regulation of paracellular permeability: factors and mechanisms.

Epithelial permeability is composed of transcellular permeability and paracellular permeability. Paracellular permeability is controlled by tight junctions (TJs). Claudins and occludin are two major transmembrane proteins in TJs, which directly determine the paracellular permeability to different ions or large molecules. Intracellular signaling pathways including Rho/Rho-associated protein kinase, protein kinase Cs, and mitogen-activated protein kinase, modulate the TJ proteins to affect paracellular permeability in response for diverse stimuli. Cytokines, growth factors and hormones in organism can regulate the paracellular permeability via signaling pathway. The transcellular transporters such as Na-K-ATPase, Na(+)-coupled transporters and chloride channels, can interact with paracellular transport and regulate the TJs. In this review, we summarized the factors affecting paracellular permeability and new progressions of the related mechanism in recent studies, and pointed out further research areas.

The microRNA-302-367 cluster suppresses the proliferation of cervical carcinoma cells through the novel target AKT1.

The miR-302-367 cluster is specifically expressed in human embryonic stem cells and has been shown to convert human somatic cells into induced pluripotent stem cells. Here, we investigated the role of the miR-302-367 cluster in cervical carcinoma. The cluster was not endogenously expressed in cervical cancer cells, and its ectopic expression did not reprogram the cervical cancer cells to an embryonic stem cell-like state. However, ectopic expression of the miR-302-367 cluster in HeLa and SiHa cervical cancer cells inhibited cell proliferation and tumor formation by blocking the G1/S cell cycle transition. We identified a new cell cycle regulatory pathway in which the miR-302-367 cluster directly down-regulated both cyclin D1 and AKT1 and indirectly up-regulated p27(Kip1) and p21(Cip1), leading to the suppression of cervical cancer cell proliferation. Our findings suggest that the miR-302-367 cluster may be used as a therapeutic reagent for the treatment of cervical carcinoma.

Effective antitumor immunity against murine gliomas using dendritic cells transduced with hTERTC27 recombinant adenovirus.

hTERTC27, a 27-kDa hTERT C-terminal polypeptide has been demonstrated to cause hTERT-positive HeLa cell apoptosis and inhibits the growth of mouse melanoma. hTERTC27 has been associated with telomere dysfunction, regulation of gene-regulated apoptosis, the cell cycle and activation of natural killer (NK) cells, but its mechanism of action is not fully understood. Here, we report that dendritic cells (DCs) transduced with hTERTC27 can increase T-cell proliferation, and augment the concentration of interleukin-2 (IL-2) and interferon-γ (IFN-γ) in the supernatants of T cells. It can also induce antigen-specific cytotoxic T lymphocytes (CTL) against glioma cells in vitro. Moreover, hTERTC27 gene-transduced DCs exhibit a very potent cytotoxicity to glioma cells in vivo. It could prolong the survival time and inhibit the growth of glioma-bearing mice. These data suggest that hTERTC27 gene-transduced DCs can efficiently enhance immunity against gliomas in vitro and in vivo.

Human tissue kallikrein promoted activation of the ipsilesional sensorimotor cortex after acute cerebral infarction.

BACKGROUND/AIMS: Kallikrein, a serine proteinase, has been reported to have many functions, such as selectively dilating arterioles in the ischemic area and enhancing angiogenesis and neurogenesis. Therefore, it may promote cerebral poststroke reorganization. We observed the effect of human tissue kallikrein on the brain motor activation of acute ischemic stroke patients and evaluated patient condition severity and prognosis. METHODS: Forty-four cases suffering from cerebral infarction between 6 and 72 h of onset were randomly assigned into the kallikrein group (n = 24) and the control group (n = 20). The control group was given conventional treatment, whereas the kallikrein group was given both conventional treatment and human tissue kallikrein over the course of 12-14 days. The activation of the sensorimotor cortex (SMC) and cerebellum, the affected forefinger strength and the NIHSS scores were evaluated before and after treatment. The MBI and MRS scores were assessed at 30 and 90 days after stroke onset. RESULTS: There were no differences between the two groups in activation volume, patient condition and scores before treatment. After treatment, the ipsilesional SMC activation volume was significantly larger and the increase in the volume was significantly greater in the kallikrein group than in the control group (p < 0.05 for both). The NIHSS score was significantly smaller and the improvement in the score was significantly greater in the kallikrein group after treatment (p < 0.05 for both). Moreover, the MBI scores at 30 days were significantly higher, whereas the MRS scores at 30 days were significantly lower in the kallikrein group than in the control group (p < 0.05 for both). CONCLUSIONS: Kallikrein improved neural function effectively and quickly after stroke, and promoting cerebral reorganization might be an important mechanism for kallikrein in the treatment of acute cerebral infarction.

Hypoxic tissues are associated with microvessel density following brain ischemia-reperfusion.

Hypoxic tissue has been observed in the surrounding areas of the ischemic core following cerebral infarction. The underlying mechanisms for this potentially reversible ischemic region remain to be determined. In this study, we generated permanent brain ischemia (PI) and reperfusion after inducing ischemia for 1.5 h (ischemia-reperfusion or IR) in a rat model of middle cerebral artery occlusion. Using immunofluorescence, we observed hypoxic tissue in ischemic brains and assessed microvessel density in and surrounding the hypoxic tissue. We found that the hypoxic tissues were observed at 1 and 3 days in PI rats and at 1, 3, 7, and 14 days in IR rats. The hypoxic tissue gradually decreased over time. The microvessel density increased in a time-dependent manner in focal brain ischemic tissue in PI and IR rats. Furthermore, IR induced a significant increase in microvessel density when compared with PI rats (P < 0.05). Microvessel density surrounding hypoxic tissue was significantly higher when compared with within the hypoxic tissue (P < 0.05). These data demonstrate that hypoxic tissue may exist for a long period (14 days) following brain IR and indicate that hypoxic tissue usually existed with low microvessel density. Furthermore, the duration of hypoxic tissue was partially dependent on the degree of microvessel proliferation.

The preventive effect of oral EGCG in a fetal alcohol spectrum disorder mouse model.

BACKGROUND: Fetal alcohol spectrum disorder (FASD) is a challenging public health problem. Previous studies have found an association between FASD and oxidative stress. In the present study, we assessed the role of oxidative stress in ethanol-induced embryonic damage and the effect of (-)-epigallocatechin-3-gallate (EGCG), a powerful antioxidant extracted from green tea, on the development of FASD in a murine model. METHODS: Pregnant female mice were given intraperitoneal ethanol (25%, 0.005 to 0.02 ml/g) on gestational day 8 (G8) to establish the FASD model. On G10.25, mice were sacrificed and embryos were collected and photographed to determine head length (HL), head width (HW), and crown rump length (CRL). For mice given EGCG, administration was through a feeding tube on G7 and G8 (dose: 200, 300, or 400 mg/kg/d, the total amount for a day was divided into 2 equal portions). G10.25 embryos were evaluated morphologically. Brain tissues of G9.25 embryos were used for RT-PCR and western blotting of neural marker genes and proteins and detection of oxidative stress indicators. RESULTS: Administration of ethanol to pregnant mice on G8 led to the retardation of embryonic growth and down-regulation of neural marker genes. In addition, administration of ethanol (0.02 ml/g) led to the elevation of oxidative stress indicators [hydrogen peroxide (H2O2) and malondialdehyde (MDA)]. Administration of EGCG on G7 and G8 along with ethanol on G8 ameliorated the ethanol-induced growth retardation. Mice given EGCG (400 mg/kg/d) along with ethanol had embryo sizes and neural marker genes expression similar to the normal controls. Furthermore, EGCG (400 mg/kg on G7 and G8) inhibited the increase in H2O2 and MDA. CONCLUSIONS: In a murine model, oxidative stress appears to play an important role in ethanol-induced embryonic growth retardation. EGCG can prevent some of the embryonic injuries caused by ethanol.

MicroRNA-17 post-transcriptionally regulates polycystic kidney disease-2 gene and promotes cell proliferation.

To identify the possible microRNAs (miRNAs) which target the polycystic kidney disease-2 gene (PKD2), and clarify effects of the miRNAs on PKD2. We preliminarily used bioinformatics to analyze 3'UTR (3'untranslated regions) of PKD1 and PKD2 in order to predict the potential microRNAs targeted on them. Subsequently, the stable cell lines with overexpression of microRNA-17 (miR-17) were screened, and luciferase assay combined with the mutation 3'UTR of PKD2 were performed to verify PKD2 is the target of miR-17. Moreover, RT-PCR and Western Blotting were used to determine the post-transcriptionally regulation of PKD2 by miR-17. Finally, MTT cell assays allied with PKD2 rescued strategy were employed to evaluate cell proliferation effects. Our study firstly found that the 3'UTR of PKD2 was more conservation than that of PKD1, and microRNA-17 directly targets the 3'UTR of PKD2 and post-transcriptionally repress the expression of PKD2. Moreover, our findings also demonstrated that overexpression of miR-17 may promote cell proliferation via post-transcriptionally repression of PKD2 in HEK 293T. This suggested that microRNA might be a novel mechanism for cystogenesis as well as a potential therapeutic target for the cell proliferation of autosomal dominant polycystic kidney disease (ADPKD).

Down-regulation of Pkd2 by siRNAs suppresses cell-cell adhesion in the mouse melanoma cells.

The Pkd2 gene encodes an integral protein (~130 kDa), named polycystin-2 (PC-2). PC-2 is mainly involved in autosomal dominant polycystic kidney disease. Recently, polycystin-1/polycystin-2 complex has been shown to act as an adhesion complex mediating or regulating cell-cell or cell-matrix adhesion, suggesting that PC-2 may play a role in cell-cell/cell-matrix interactions. Here, we knocked down the expression of Pkd2 gene with small interfering RNAs (siRNAs) in the mouse melanoma cells (B16 cells), indicating that the cells transfected with the targeted siRNAs significantly suppressed cell-cell adhesion, but not cell-matrix adhesion, compared to the cells transfected with non-targeted control (NC) siRNA. This study provides the first directly functional evidence that PC-2 mediates cell-cell adhesion. Furthermore, we demonstrated that PC-2 modulated cell-cell adhesion may be, at least partially, associated with E-cadherin. Collectively, these findings for the first time showed that PC-2 may mediate cell-cell adhesion, at least partially, through E-cadherin.