1. |
- Chen, Liangliang, et al.
(författare)
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User-Friendly Genetic Conditional Knockout Strategies by CRISPR/Cas9
- 2018
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Ingår i: STEM CELLS INTERNATIONAL. - : HINDAWI LTD. - 1687-966X .- 1687-9678.
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Tidskriftsartikel (refereegranskat)abstract
- Loss-of-function studies are critically important in gene functional analysis of model organisms and cells. However, conditional gene inactivation in diploid cells is difficult to achieve, as it involves laborious vector construction, multifold electroporation, and complicated genotyping. Here, a strategy is presented for generating biallelic conditional gene and DNA regulatory region knockouts in mouse embryonic stem cells by codelivery of CRISPR-Cas9 and short-homology-arm targeting vectors sequentially or simultaneously. Collectively, a simple and rapid method was presented to knock out any DNA element conditionally. This approach will facilitate the functional studies of essential genes and regulatory regions during development.
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2. |
- Hu, Min, et al.
(författare)
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Hyperandrogenism and insulin resistance induce gravid uterine defects in association with mitochondrial dysfunction and aberrant ROS production.
- 2019
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Ingår i: American journal of physiology. Endocrinology and metabolism. - : American Physiological Society. - 1522-1555 .- 0193-1849. ; 316:5
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Tidskriftsartikel (refereegranskat)abstract
- Women with polycystic ovary syndrome (PCOS) are at increased risk of miscarriage, which often accompanies the hyperandrogenism and insulin resistance seen in these patients. However, neither the combinatorial interaction between these two PCOS-related etiological factors nor the mechanisms of their actions in the uterus during pregnancy are well understood. We hypothesised that hyperandrogensim and insulin resistance exert a causative role in miscarriage by inducing defects in uterine function that are accompanied by mitochondrial-mediated oxidative stress, inflammation and perturbed gene expression. Here we tested this hypothesis by studying the metabolic, endocrine and uterine abnormalities in pregnant rats after exposure to daily injection of 5α-dihydrotestosterone (DHT, 1.66 mg/kg body weight/day) and/or insulin (6.0 IU/day) from gestational day 7.5 to 13.5. We showed that while DHT-exposed and insulin-exposed pregnant rats presented impaired insulin sensitivity, DHT+insulin-exposed pregnant rats exhibited hyperandrogenism and peripheral insulin resistance, which mirrors pregnant PCOS patients. Compared to controls, hyperandrogenism and insulin resistance in the dam was associated with alterations in uterine morphology and aberrant expression of genes responsible for decidualization, placentation, angiogenesis and insulin signaling. Moreover, we observed changes in uterine mitochondrial function and homeostasis and suppression of both oxidative and antioxidative defenses in response to the hyperandrogenism and insulin resistance. These findings demonstrate that hyperandrogenism and insulin resistance induce mitochondria-mediated damage and a resulting imbalance between oxidative and antioxidative stress responses in the gravid uterus.
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3. |
- Hu, Min, et al.
(författare)
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Perturbed ovarian and uterine glucocorticoid receptor signaling accompanies the balanced regulation of mitochondrial function and NFκB-mediated inflammation under conditions of hyperandrogenism and insulin resistance.
- 2019
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Ingår i: Life sciences. - : Elsevier BV. - 1879-0631 .- 0024-3205. ; 232
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to determine whether glucocorticoid receptor (GR) signaling, mitochondrial function, and local inflammation in the ovary and uterus are intrinsically different in rats with hyperandrogenism and insulin resistance compared to controls.Female Sprague Dawley rats were exposed to daily injections of human chorionic gonadotropin and/or insulin.In both the ovary and the uterus, decreased expression of the two GR isoforms was concurrent with increased expression of Fkbp51 but not Fkbp52 mRNA in hCG+insulin-treated rats. However, these rats exhibited contrasting regulation of Hsd11b1 and Hsd11b2 mRNAs in the two tissues. Further, the expression of several oxidative phosphorylation-related proteins decreased in the ovary and uterus following hCG and insulin stimulation, in contrast to increased expression of many genes involved in mitochondrial function and homeostasis. Additionally, hCG+insulin-treated rats showed increased expression of ovarian and uterine NFκB signaling proteins and Tnfaip3 mRNA. The mRNA expression of Il1b, Il6, and Mmp2 was decreased in both tissues, while the mRNA expression of Tnfa, Ccl2, Ccl5, and Mmp3 was increased in the uterus. Ovaries and uteri from animals co-treated with hCG and insulin showed increased collagen deposition compared to controls.Our observations suggest that hyperandrogenism and insulin resistance disrupt ovarian and uterine GR activation and trigger compensatory or adaptive effects for mitochondrial homeostasis, allowing tissue-level maintenance of mitochondrial function in order to limit ovarian and uterine dysfunction. Our study also suggests that hyperandrogenism and insulin resistance activate NFκB signaling resulting in aberrant regulation of inflammation-related gene expression.
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4. |
- Hu, Min, et al.
(författare)
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Suppression of uterine and placental ferroptosis by N-acetylcysteine in a rat model of polycystic ovary syndrome. : Ferroptosis and N-acetylcysteine
- 2021
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Ingår i: Molecular human reproduction. - : Oxford University Press (OUP). - 1460-2407 .- 1360-9947. ; 27:12
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Tidskriftsartikel (refereegranskat)abstract
- The mechanisms that link hyperandrogenism and insulin resistance to the increased miscarriage rate in women with polycystic ovary syndrome (PCOS) remain elusive. Previous studies demonstrate that increased uterine and placental ferroptosis is associated with oxidative stress-induced fetal loss in a pre-clinical PCOS-like rat model. Here, we investigated the efficacy and molecular mechanism of action of the antioxidant N-acetylcysteine (NAC) in reversing gravid uterine and placental ferroptosis in pregnant rats exposed to 5α-dihydrotestosterone (DHT) and insulin. Molecular and histological analyses showed that NAC attenuated DHT and insulin-induced uterine ferroptosis, including dose-dependent increases in anti-ferroptosis gene content. Changes in other molecular factors after NAC treatment were also observed in the placenta exposed to DHT and insulin, such as increased glutathione peroxidase 4 protein level. Further, increased apoptosis inducing factor mitochondria associated 2 mRNA expression was seen in the placenta but not in the uterus. Additionally, NAC was not sufficient to rescue DHT+insulin-induced mitochondria-morphological abnormalities in the uterus, whereas the same treatment partially reversed such abnormalities in the placenta. Finally, we demonstrated that NAC selectively normalized uterine leukemia inhibitory factor, osteopontin/secreted phosphoprotein 1, progesterone receptor, and homeobox A11 mRNA expression and placental estrogen related receptor beta and trophoblast specific protein alpha mRNA expression. Collectively, our data provide insight into how NAC exerts beneficial effects on differentially attenuating gravid uterine and placental ferroptosis in a PCOS-like rat model with fetal loss. These results indicate that exogenous administration of NAC represents a potential therapeutic strategy in the treatment of hyperandrogenism and insulin resistance-induced uterine and placental dysfunction.
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5. |
- Li, Hongxia, et al.
(författare)
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Microscopic insights of phase-transition-induced vapor transport enhancement in porous media
- 2024
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Ingår i: International Journal of Multiphase Flow. - 0301-9322. ; 177
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Tidskriftsartikel (refereegranskat)abstract
- Vapor transport in porous media, often associated with liquid-vapor phase change, is an fundamental process in many emerging underground energy storage and extraction processes (i.e., seasonal solar thermal aquifer storage, geothermal extraction, extraterrestrial in-situ water extraction). By jointly using experimental imaging and numerical modeling at the micro-scale, we conduct mechanistic pore scale investigation of capillarity-dominated phase change dynamics and its influence on vapor transport in partially saturated porous rock micromodel. Strongly linked to surface roughness and wettability condition, the capillarity hinders water vaporization from rock surface micro/nano-structures as observed under the environmental scanning electron microscope. By varying the contact angle of 0°, 60°, and 120°, the lattice Boltzmann simulation shows the wettability-dependent vaporization process of capillary-hold water, where pores with hydrophilic surfaces contains significantly more liquid water than that of the hydrophobic ones under the same temperature. When saturated vapor flows through rock porous patterns, capillarity further induces water condensation on the strongly water-wet surfaces. Water condensation, yet forming water bridges/islands and causing the blockage of vapor diffusion, enhances the vapor diffusion ability counterintuitively. The reduction of diffusion path is revealed as the main reason by assessing the local vapor pressure distribution before and after the pore filling by condensate. The findings support the debatable enhancement mechanisms postulated by Philip and de Vries. This work offers the insightful interfacial hydrodynamics of vapor transport in porous media and potentially provides operational guidance for geothermal applications and beyond.
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6. |
- Yang, Chengkun, et al.
(författare)
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Postharvest white light combined with different UV-B doses differently promotes anthocyanin accumulation and antioxidant capacity in mango peel
- 2024
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Ingår i: Lebensmittel-Wissenschaft + Technologie. - : Academic Press. - 0023-6438 .- 1096-1127. ; 203
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Tidskriftsartikel (refereegranskat)abstract
- Fruit peel color is an important index of mango fruit quality. Therefore, increasing the anthocyanin accumulation and improving coloration in red mango are crucial for mango industry. The anthocyanin accumulation in mango is light-regulated. However, the effect of white light combined with different doses of UV-B on anthocyanin biosynthesis has not been clarified. Also lacking is a comprehensive analysis of responses of mango fruit peel to UV-B/white light treatments. In this study, green mature ‘Guifei’ mango fruits were subjected to white light combined with low (WL+UV-BL) or high dose UV-B (WL+UV-BH). Anthocyanin concentration, anthocyanin-related gene expression, reactive oxygen species (ROS), antioxidant, and plant hormone concentrations, and antioxidant enzyme activity were measured. The results showed that especially a WL+UV-BH regimen promoted anthocyanin formation in mango peel. Anthocyaninand light signal-related gene expression, ROS content, antioxidant enzyme activity, antioxidant concentrations, and total antioxidant capacity were also increased by UVB/ white light. Such treatments led to higher concentrations of jasmonic acid and cytokines, but decreased content of 1-aminocyclopropane-1-carboxylic acid and salicylic acids. Commercially, our findings may contribute to improving the commercial quality of mango. Scientifically, the present data sheds light on the mango fruit peelspecific molecular and physiological response network under UV-B/white light treatments.
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7. |
- Yang, Shuo, et al.
(författare)
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Hydrodynamics of gas-liquid displacement in porous media: fingering pattern evolution at the breakthrough moment and the steady state
- 2022
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Ingår i: Advances in Water Resources. - : Elsevier BV. - 0309-1708. ; 170
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Tidskriftsartikel (refereegranskat)abstract
- Gas-liquid displacement in porous media widely exists in many terrestrial/extraterrestrial subsurface resource extraction and utilization applications. The typical fingering displacement during gas invading has been well identified through extensive research efforts. Yet, the evolution of fingering structures after invading breakthrough is rarely reported. Herein, through a joint approach of experimental flow imaging and digital image processing, we investigated the gas-liquid fingering displacement in a porous-patterned microfluidic chip from the breakthrough moment until reaching the steady state. With a wide range of capillary number Ca and viscosity ratio M, we visualized the evolution of finger morphologies in different flow regimes including capillary fingering (CF), viscous fingering (VF), and crossover zone (CZ). Interestingly, we found that finger structures of CF regime remain the same after the breakthrough, whereas fingers of VF regime keep expanding until almost all the pore space is invaded and eventually reaches to steady state. Followed with experimental observations, a comparative quantification of fingering patterns was also conducted in terms of invasion velocity, phase saturation and fractal dimension. A dramatic increase of gas saturation, from 0.15 to 0.60 at the case of Log10Ca=- 5.17 and Log10M=-2.78, is obtained in the VF regime when the steady state is reached, so is the fractal dimension (from 0.14 to 0.16, even higher than one of CF). The underlying mechanism of such fingering expansion in VF is further revealed from the time evolution of fingering after breakthrough. A previously unobserved fingering cycle, consisting of new finger forming, cap invading, breakthrough and finger vanishing, keeps repeating until the saturation reaches the maximum. We believe that these findings are of significance in evaluating extraction effectiveness, economic benefits and storage safety for subsurface applications.
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8. |
- Yeung, Leo W. Y., 1981-, et al.
(författare)
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Perfluorinated Compounds and Total and Extractable Organic Fluorine in Human Blood Samples from China
- 2008
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Ingår i: Environmental Science and Technology. - Washington, USA : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 42:21, s. 8140-8145
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Tidskriftsartikel (refereegranskat)abstract
- An improved extraction (ion pairing) and cleanup (ENVI-carb and solid phase extraction) method was developed for analysis of perfluorinated compounds (PFCs) in human whole blood samples from China. Ten PFCs including PFOS, PFHxS, PFOSA, PFDoDA, PFUnDA, PFDA, PFNA, PFOA, PFHpA, and PFHxA were detected in the blood samples (n = 30) from five cities (Jintan, Nanjing, Guiyang, Beijing, and Shenyang). PFOS was found to be the dominant PFC ranging from 0.446-83.1 ng/mL. Total fluorine (TF) and extractable organic fluorine (EOF) also were measured in the blood samples using combustion ion chromatography for fluorine. Analysis of known PFCs and extractable organic fluorine showed that known PFCs could account for >70% of EOF in samples from Beijing, Shenyang, and Guiyang, whereas known PFCs could only account for similar to 30% of EOF in samples from Jintan. Results of the present study indicated the presence of substantial amounts of unidentified organic fluorine in human blood samples from Jintan. Characterization and identification of these unidentified fluorinated compounds will be instructive.
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