[Survival analysis of long-term HIV/AIDS cases aged 15 years and over under antiretroviral treatment in Henan Province from 2002 to 2020].

Objective: To analyze the survival and influencing factors of HIV infections and AIDS cases (HIV/AIDS) aged 15 years and over who had received antiretroviral treatment (ART) for more than 10 years in Henan Province. Methods: In this retrospective cohort study, data of HIV infections and AIDS cases in Henan province were collected from the AIDS Prevention and Control System between January 1, 2002 and December 31, 2020. This study included 20 256 participants alive after 10-year ART with complete baseline and follow-up information, such as demographic characteristics, CD4+T lymphocyte count and viral load. Cox proportional risk regression model was used to analyze influencing factors of HIV/AIDS survival. Results: A total of 20 256 participants were followed up for 82 738.2 person-years, with an average follow-up of 4.1 person-years, of which most cases were blood transmission (85.5%) and married (71.2%). The male to female ratio was 1∶1.06 and the age at 10 years of ART was (51.2±8.7) years old. About 88.5% of HIV/AIDS patients received ART in village/township treatment institutions. Overall, there were 2 030 deaths during this period, among which 1 897 were due to AIDS-related diseases (93.5%) and the case fatality rate was 9.4% (1 897/20 256). Cox proportional risk regression model showed that participants aged 40-54, 55-69, and ≥70 years had a higher risk of death compared to those aged 25-39, with adjusted HRs (95%CI) of 1.57 (1.19-2.08), 3.78 (2.86-4.99), and 6.17 (4.33-8.79), respectively. Participants with the initial CD4+T lymphocyte count about 200-349/µl and<200/µl had a higher risk of death compared to those with initial CD4+T lymphocyte count ≥350/µl, with adjusted HRs (95%CI) of 1.81 (1.61-2.04) and 3.64 (3.20-4.15), respectively. Participants with the initial viral load outcome ≥1 000 copies/ml had a higher risk of death compared to those with the initial viral load outcome<1 000 copies/ml, with adjusted HRs (95%CI) of 1.73 (1.52-1.97). Participants receiving the second-line ART had a lower risk of death compared to those receiving the first-line ART, with adjusted HRs (95%CI) of 0.12 (0.11-0.14). Conclusion: From 2002 to 2020, the survival rate of HIV/AIDS treated with ART for more than 10 years is high in Henan Province. Age, CD4+T lymphocyte count and viral load are influencing factors of HIV/AIDS survival.

[AGT rs5051 gene polymorphism increases the risk of coronary heart disease in patients with non-alcoholic fatty liver disease in the Han Chinese population].

Objective: To investigate the relationship between the angiotensinogen (AGT) rs5051 single nucleotide polymorphism (SNP) and the onset risk of coronary heart disease (CHD) in patients with non-alcoholic fatty liver disease (NAFLD) in the Han Chinese population. Methods: A total of 454 subjects were enrolled in this study. Among them, 140 cases were with NAFLD, 112 cases with NAFLD combined with CHD, and 202 healthy controls. Blood samples of all subjects were examined for biochemical indexes. Genotype at AGT rs5051 locus was detected by polymerase chain reaction. SPSS 21.0 statistical software was used for data statistical analysis. Results: The differences in distribution of AGT rs5051 genotypes and alleles between the NAFLD and the control group were not statistically significant (P > 0.05). The differences in the distribution of AGT rs5051 genotypes and alleles between the NAFLD combined with CHD and the NAFLD group were statistically significant (χ(2) = 10.32, P = 0.001; χ(2) = 11.72, P < 0.001). Binary logistic regression analysis results showed that TC + CC genotype had increased the occurrence risk of CHD in NAFLD patients (OR = 2.203, 95% CI: 1.322 ~ 3.670, P = 0.02) than AGT rs5051 TT genotype carriers. After adjusting for gender, age, and body mass index, the TC + CC genotype still significantly increased the occurrence risk of CHD in NAFLD patients (OR = 2.378, 95% CI: 1.384 ~ 4.087, P = 0.02). In addition, AGT rs5051 C allele mutations had significantly increased the occurrence risk of CHD in patients with NAFLD (OR = 2.018 before adjustment, 95% CI: 1.345 ~ 3.027, P = 0.001; OR = 2.161, 95% CI: 1.406 ~ 3.322 after adjustment. P < 0.001). Conclusion: This study is the first to report the correlation between AGT rs5051 polymorphism and the occurrence risk of CHD in patients with NAFLD in Han Chinese population. AGT rs5051 polymorphism can significantly increase the risk of CHD in patients with NAFLD.

[Construction of transmembrane 6 superfamily member 2 E167K gene knock-in mouse model by using CRISPR/Cas9 technology].

Objective: To construct a transmembrane 6 superfamily member 2 (Tm6sf2) E167K gene knock-in mouse model. Methods: The plasmid was constructed to simultaneously express the single-stranded guide RNA Cas9 at a specific site of the mouse Tm6sf2 gene in the donor plasmid carrying the Tm6sf2 E167K fragment. The above two plasmids were injected into the mouse fertilized eggs together. The positive F0 generation mice were validated by PCR detection and sequencing. The number of F2 generation surviving mice in three genotypes of wild (Wt), heterozygous and knock-in (KI) were calculated. Wt and KI male mice (8 mice/ group) of F2 generation littermates were selected and given a normal diet for 8 weeks. The body weight of the mice was recorded every week, and the glucose metabolism and lipid metabolism indexes of the two mice were detected. The comparison between groups was performed with an independent sample t-test. Results: Genotype detection and sequencing results showed that the Tm6sf2 E167K gene knock-in mouse model was successfully established. KI mice had absence of homozygous lethal embryo phenotype. The body weight of KI mice was higher than that of Wt mice during lactation, and the difference between the two groups was statistically significant (P < 0.05).The fasting blood glucose of KI mice (9.50 ± 0.33)mmol/L was higher than that of Wt mice (7.80 ± 0.30)mmol/L, and the difference between the two groups was statistically significant (P < 0.05). During the oral glucose tolerance test, the 2-hour blood glucose level of KI mice (9.20 ± 0.51)mmol/L was higher than that of Wt mice (7.60 ± 0.18)mmol/L, and the difference between the two groups was statistically significant (P < 0.05). The liver triglyceride content of KI mice (8.40 ± 0.55)mg/g was higher than that of Wt mice (7.30 ± 0.63)mg/g, but the difference was not statistically significant (P > 0.05). There was no significant difference in plasma triglyceride levels between the two mice (P > 0.05). The Oil red O staining results showed that KI mice had more lipid accumulation in the centrilobular region of ​​liver than Wt mice. Conclusion: Tm6sf2 E167K gene knock-in mice were successfully constructed. Tm6sf2 E167K gene knock-in can cause abnormal glucose metabolism in mice and promote the occurrence of hepatic steatosis.

[Research progress of single-nucleotide polymorphism in theTM6SF2 rs58542926].

Transmembrane 6 superfamily member 2 (TM6SF2) is a recently discovered gene, which is located on the chromosome 19 (19p12) and encodes a protein consisting of 351 amino acids. Presently, many studies have reported that the single-nucleotide polymorphism of TM6SF2 rs58542926 and plasma lipids are closely related to the incidence and development of diseases, such as non-alcoholic fatty liver disease (NAFLD), cardiovascular disease (CVD), liver cancer, and hepatitis C. This review will summarize the research progress conducted in these areas.

[A 2-year cohort study on the caries risk assessment of 3-year-old caries-free children using Cariostat caries activity test].

Objective: To evaluate the caries status of a cohort of 3-year-old caries-free children from 2 kindergartens in Beijing in a period of 2 years by using Cariostat caries activity test and to assess the sensitivity and specificity of Cariostat score as a caries risk indicator for caries-free children. Methods: Totally 426 3-year-old caries-free children from 2 kindergartens in Beijing were recruited in the present study. Informed consents were obtained from the children's parents. Dental plaque samples of the children were collected and the Cariostat caries activity tests were conducted at baseline and once a year for 2 years. After two years, the caries status of the cohort children were re-evaluated and the caries incidences amongst children with high (2.0, 2.5, 3.0), medium (1.5) and low (1.0, 0.5, 0.0) levels of Cariostat scores were compared and analyzed. Results: Totally 864 3-year-old children from 2 kindergartens were screened before the study startedand 426 (49.3%) children were caries free. After 2-year follow-up, 312 out of 426 (73.2%) remained in the study. The overall caries incident rate was 46.5% (145/312). The caries incident rate of children with high level of Cariostat scores was 88.9% (88/99), while the caries incident rates of children with medium and low levels of Cariostat scores was 38.7% (36/93) and 17.5% (21/120), respectively. The sensitivity and specificity of the Cariostat test in assessing the caries risk of 3-year-old caries-free children in a period of 2 years were 60.7% and 93.4%, respectively. Conclusions: Cariostat caries activity test can be used as an indicator to predict the caries risk of 3-year-old caries-free children. Comprehensive caries management could be conducted for children in kindergartens based on the caries risk assessment results of caries experience and the Cariostat score.

Licoricidin, an isoflavonoid isolated from Glycyrrhiza uralensis Fisher, prevents UVA-induced photoaging of human dermal fibroblasts.

OBJECTIVE: Licoricidin is an isoflavonoid isolated from Glycyrrhiza uralensis Fisher. In this study, we investigated the effects of licoricidin on photoaging of UVA-irradiated human dermal fibroblasts (HDFs). METHODS: In vitro reactive oxygen species (ROS) scavenging activity, cellular protective effect and inhibition of elastase activity was determined by Fe3+ -EDTA/H2 O2 systems, photohaemolysis and elastase activity assay, respectively. Anti-oxidative capacity of the compound was evaluated by fluorescent ELISA and 2', 7'-dichlorofluorescin-diacetate (DCF-DA) assay. The expression of protein and phosphorylation was examined using Western blot. RESULTS: The ROS scavenging activity (OSC50 ) of licoricidin was 2.77 µM. It was 3.1-fold higher than that of L-ascorbic acid. Its protective effects were confirmed in a study of 1 O2 -induced cellular damage to human erythrocytes. The τ50 value of 10 µM of licoricidin was 71.0 min; this was markedly higher than that obtained with α-tocopherol (37.0 min). The elastase inhibitory activity of licoricidin (IC50 of 61.2 µM) was 2.1-fold more potent than that of oleanolic acid. Licoricidin markedly reduced the UVA-induced intracellular ROS in a concentration-dependent manner. Western blot revealed that licoricidin attenuated the UVA-dependent induction of MMP-1 protein. Mechanistically, this appeared to be due to licoricidin-dependent inhibition of mitogen-activated protein kinases (MAPK) phosphorylation, which resulted in decreased c-Jun activation and reduced c-Jun and c-Fos expression. CONCLUSION: Licoricidin blocks UVA-induced photoaging via ROS scavenging. This activity converges to limit the activity of MMP-1. These data suggest that licoricidin may be considered as an active ingredient in new topically applied anti-ageing formulations.

[Influence of leptin receptor gene K109R polymorphism on the risk of nonalcoholic fatty liver disease and its interaction with PNPLA3 I148M polymorphism].

OBJECTIVE: To investigate the influence of leptin receptor (LEPR) gene K109R polymorphism on the risk of nonalcoholic fatty liver disease (NAFLD) and its interaction with PNPLA3 I148M polymorphism in the Han Chinese population in Qingdao, China. METHODS: Blood samples were collected from 296 NAFLD patients and 321 healthy controls, and the genotypes of these patients were determined by PCR and genotyping. Related statistical analyses were performed to compare genotypes, alleles, and clinical data between the two groups. Generalized multifactor dimensionality reduction (GMDR) was used to investigate the interaction between LEPR K109R and PNPLA3 I148M genes. RESULTS: The distribution of LEPR K109R genotypes and alleles showed no significant differences between the NAFLD group and the control group (P > 0.05). PNPLA3 I148M gene polymorphisms were closely associated with the risk of NAFLD, and the risk of NAFLD in G mutant gene carriers was 2.07 times that in patients who did not carry this gene (OR = 2.07, 95% CI 1.423-3.013, P < 0.001). The joint action of LEPR K109R and PNPLA3 I148M significantly increased the risk of NAFL (OR = 3.393, 95% CI 1.856-6.201, P < 0.001). CONCLUSION: In the Han Chinese population in Qingdao, LEPR K109R gene polymorphism is not associated with the risk of NAFLD, but its interaction with PNPLA3 I148M polymorphism can significantly increase the risk of NAFLD.

[Effect of chitooligosaccharide on hepatic triglyceride metabolism and related mechanisms].

OBJECTIVE: To investigate the effect of chitooligosaccharide (COS) on hepatic triglyceride (TG) metabolism and related mechanisms. METHODS: The LO2 cells treated by 1 mmol/L fatty acid were used as model group, the cells treated by 1 mmol/L fatty acid and 0.5 mg/ml COS were used as COS group, and the untreated cells were used as control group. The TG content in cells was measured. RT-PCR and Western blot were used to measure the mRNA and protein expression of sterol regulatory element binding protein-1c (SREBP-1c), fatty acid synthase (FAS), and carnitine palmityl transferase 1A (CPT1A) in each group. Male C57BL/6J mice were randomized into control group, high-fat group, and COS group to receive different treatments. Sixteen weeks later, the liver was harvested for HE and oil red O staining to measure the content of TG in the liver. The t-test or one-way analysis of variance was used for comparison of data between groups, and the SNK method was used for comparison of data between any two groups. RESULTS: The LO2 cells in the model group had an increased number of lipid droplets and an increased TG content, and after COS treatment, the TG content was low. The COS group had significantly lower relative mRNA expression of SREBP-1c and FAS compared with the model group (1.135 ± 0.177 vs 2.322 ± 0.198,F= 60.457,P< 0.01; 1.226 ± 0.150 vs 1.801 ± 0.159,F= 24.753,P< 0.01), while compared with the control group, the COS group had significantly higher mRNA expression of CPT1A (1.254 ± 0.156 vs 1.908 ± 0.087,F= 31.734,P< 0.01). The COS group had significantly lower protein expression of SREBP-1c and FAS than the model group (0.161 ± 0.081 vs 0.351±0.016,F= 188.920,P< 0.01; 0.332 ± 0.023 vs 1.238 ± 0.051,F= 624.069,P< 0.01), and significantly higher protein expression of CPT1A than the model group (1.014 ± 0.033 vs 0.561 ± 0.046,F= 193.793,P< 0.01). COS reduced the TG content in the liver in rats on high-fat diet. CONCLUSION: COS can reduce the accumulation of TG in the hepatocyte model of nonalcoholic fatty liver disease and in the liver in rats on high-fat diet, and the possible mechanism may be related to inhibiting the expression of SREBP-1c and downstream FAS, reducing the synthesis of TG, increasing the expression of CPT1A, and accelerating the breakdown of TG.

ZnO nanorods with low intrinsic defects and high optical performance grown by facile microwave-assisted solution method.

Vertically aligned ZnO nanorods were grown at 90 °C by both microwave synthesis and traditional heated water bath method on Si (100) substrate with a precoated ZnO nanoparticle seed layer. A detailed comparison in the morphology, defects, and optical properties of the ZnO nanorods grown by the two methods across the pH range of 10.07-10.9 for microwave synthesis and conventional heated water bath method was performed using scanning electron microscopy, photoluminescence, and X-ray photoelectron spectroscopy. The results show that the microwave route leads to more uniformly distributed nanorods with a lower density of native defects of oxygen interstitials and zinc vacancies. The microwave synthesis presents a promising new approach of fabricating metal oxide nanostructures and devices toward green applications.

Computational models on quantitative prediction of bioactivity of HIV-1 integrase 3' processing inhibitors.

In this study, four computational quantitative structure-activity relationship (QSAR) models were built to predict the bioactivity of 3' processing (3'P) inhibitors of HIV-1 integrase. Some 453 inhibitors whose bioactivity values were detected by the radiolabelling method were collected. The molecular structures were represented with MOE descriptors. In total, 21 descriptors were selected for modelling. All inhibitors were divided into a training set and a test set with two methods: (1) by a Kohonen's self-organizing map (SOM); (2) by a random selection. For every training set and test set, a multilinear regression (MLR) analysis and a support vector machine (SVM) were used to establish models, respectively. For the training/test set divided by SOM, the correlation coefficients (r) were over 0.84, and for the training/test set split randomly, the r values were over 0.86. Some molecular properties such as hydrogen bond donor capacity, atomic partial charge properties, molecular refractivity, the number of aromatic bonds and molecular surface area, volume and shape properties played important roles for inhibiting 3' processing step of HIV-1 integrase.

Cholesterol oxidase from Bordetella species promotes irreversible cell apoptosis in lung adenocarcinoma by cholesterol oxidation.

Cholesterol oxidase (COD), an enzyme catalyzing the oxidation of cholesterol, has been applied to track the distribution of membrane cholesterol. Little investigations about the effect of COD on tumor cells have been performed. In the present study, we provided evidence that COD from Bordetella species (COD-B), induced apoptosis of lung cancer cells in vitro and in vivo. COD-B treatment inhibited Akt and ERK1/2 phosphorylation in dose- and time-dependent manner, which was not reversed and was even aggravated by cholesterol addition. Further investigation indicated that COD-B treatment promoted the generation of reactive oxygen species (ROS) and that cholesterol addition further elevated ROS levels. Moreover, COD-B treatment resulted in JNK and p38 phosphorylation, downregulation of Bcl-2, upregulation of Bax, activated caspase-3 and cytochrome C release, which likely responded to freshly produced hydrogen peroxide that accompanied cholesterol oxidation. Catalase pretreatment could only partially prevent COD-B-induced events, suggesting that catalase inhibited H2O2-induced signal transduction but had little effect on signal pathways involved in cholesterol depletion. Our results demonstrated that COD-B led to irreversible cell apoptosis by decreasing cholesterol content and increasing ROS level. In addition, COD-B may be a promising candidate for a novel anti-tumor therapy.

Molecular basis for the regulation of islet beta cell mass in mice: the role of E-cadherin.

AIMS/HYPOTHESIS: In rodents and humans, the rate of beta cell proliferation declines rapidly after birth; formation of the islets of Langerhans begins perinatally and continues after birth. Here, we tested the hypothesis that increasing levels of E-cadherin during islet formation mediate the decline in beta cell proliferation rate by contributing to a reduction of nuclear ß-catenin and D-cyclins. METHODS: We examined E-cadherin, nuclear ß-catenin, and D-cyclin levels, as well as cell proliferation during in vitro and in vivo formation of islet cell aggregates, using ß-TC6 cells and transgenic mice with green fluorescent protein (GFP)-labelled beta cells, respectively. We tested the role of E-cadherin using antisense-mediated reductions of E-cadherin in ß-TC6 cells, and mice segregating for a beta cell-specific E-cadherin knockout (Ecad [also known as Cdh1] ßKO). RESULTS: In vitro, pseudo-islets of ß-TC6 cells displayed increased E-cadherin but decreased nuclear ß-catenin and cyclin D2, and reduced rates of cell proliferation, compared with monolayers. Antisense knockdown of E-cadherin increased cell proliferation and levels of cyclins D1 and D2. After birth, beta cells showed increased levels of E-cadherin, but decreased levels of D-cyclin, whereas islets of Ecad ßKO mice showed increased levels of D-cyclins and nuclear ß-catenin, as well as increased beta cell proliferation. These islets were significantly larger than those of control mice and displayed reduced levels of connexin 36. These changes correlated with reduced insulin response to ambient glucose, both in vitro and in vivo. CONCLUSIONS/INTERPRETATION: The findings support our hypothesis by indicating an important role of E-cadherin in the control of beta cell mass and function.

Polymorphic microsatellite loci for the genetic analysis of Lycoris radiata (Amaryllidaceae) and cross-amplification in other congeneric species.

Lycoris radiata is a perennial herb that has been used in traditional Chinese medicine for a long time and has two main medicinal components in its bulb, lycorine and galanthamine. However, the original microsatellite loci have not been developed for any species of Lycoris. Total genomic DNA was extracted from fresh bulbs using a modified CTAB protocol. We isolated 10 microsatellite loci from 21 L. radiata individuals of a natural population from Yellow Mountain in Anhui Province, China. The number of alleles ranged from two to nine. The observed and expected heterozygosities ranged from 0.238 to 0.952 and from 0.455 to 0.784, respectively. One locus significantly deviated from Hardy-Weinberg equilibrium and no significant linkage disequilibrium was found between pairs of loci. Cross-species amplification of these microsatellite loci was characterized in additional five species (L. sprengeri, L. anhuiensis, L. albiflora, L. longituba, and L. chinensis) of Lycoris. The results suggest that these microsatellite markers would contribute to the population genetic studies of L. radiata and other related species.

Simulation study on the trembling shear behavior of eletrorheological fluid.

The trembling shear behavior of electrorheological (ER) fluids has been investigated by using a computer simulation method, and a shear-slide boundary model is proposed to understand this phenomenon. A thiourea-doped Ba-Ti-O ER fluid which shows a trembling shear behavior was first prepared and then systematically studied by both theoretical and experimental methods. The shear curves of ER fluids in the dynamic state were simulated with shear rates from 0.1 to 1000 s(-1) under different electric fields. The simulation results of the flow curves match the experimental results very well. The trembling shear curves are divided into four regions and each region can be explained by the proposed model.

The oncometabolite 2-hydroxyglutarate inhibits histone lysine demethylases.

Mutations in isocitrate dehydrogenases (IDHs) have a gain-of-function effect leading to R(-)-2-hydroxyglutarate (R-2HG) accumulation. By using biochemical, structural and cellular assays, we show that either or both R- and S-2HG inhibit 2-oxoglutarate (2OG)-dependent oxygenases with varying potencies. Half-maximal inhibitory concentration (IC(50)) values for the R-form of 2HG varied from approximately 25 µM for the histone N(ɛ)-lysine demethylase JMJD2A to more than 5 mM for the hypoxia-inducible factor (HIF) prolyl hydroxylase. The results indicate that candidate oncogenic pathways in IDH-associated malignancy should include those that are regulated by other 2OG oxygenases than HIF hydroxylases, in particular those involving the regulation of histone methylation.

Boundary effect in electrorheological fluids.

The effect of the boundary friction coefficient on the rheological properties of the electrorheological (ER) fluids in quasistatic and dynamic states is investigated by computer simulation. The relation between the shear stress and the boundary friction coefficient in quasistatic and dynamic states is discussed qualitatively and quantitatively, and the trend matches the previously reported experimental results well. The flow curves of ER fluids, under different friction coefficients, are calculated, and it is found that the friction coefficient affects the flow curves. In two dimensions, the transitions in structure corresponding to the shear stress variations are presented to understand the mechanism of ER fluids.

Growth performance, meat quality, and gut microflora of broiler chickens fed with cranberry extract.

Cranberry fruit components have been reported to have antimicrobial activities against a variety of pathogenic bacteria and to be beneficial for human health. Studies on their effects are very limited in animals and especially in chickens. This study investigated the effect of feed supplementation with a commercial cranberry fruit extract (CFE) on the performance, breast meat quality, and intestinal integrity of broiler chickens. Twelve hundred male 1-d-old broiler chicks were allocated randomly to CFE treatments at 0, 40, 80, or 160 mg/kg of feed from d 0 to 35. Cloacal and cecal samples were collected weekly to evaluate the influence of treatments on the intestinal population of generic Escherichia coli, Clostridium perfringens, Enterococcus spp., and Lactobacillus spp. At d 35, BW were 1.62, 1.60, 1.61, and 1.64 kg for the control birds and birds fed 40, 80, and 160 mg of CFE/kg of feed, respectively. Feed intake ranged from 2.7 to 2.8 kg and feed efficiency from 1.8 to 1.9 g of feed/g of BW. However, the treatment effects on bird performance were not statistically significant (P > 0.05). The mortality rate tended to be lower (P = 0.09) in birds fed 40 mg of CFE/kg of feed. Feed supplementation with CFE did not significantly alter any broiler meat properties evaluated when compared with the control diet (P > 0.05). At d 28, the populations of Enterococcus spp. in cecal and cloacal samples were significantly lower (P < 0.05) in birds receiving CFE at 160 mg/kg of feed than the other groups. No significant differences were noted between the control and the treatment groups for general health and intestinal integrity (P > 0.05). These findings suggest that more studies are needed to investigate potential beneficial effects of CFE or its derivatives in broiler production.

Insulin receptor and IGF1R are not required for oocyte growth, differentiation, and maturation in mice.

In mammals, insulin and insulin-like growth factors (IGFs: IGF1 and IGF2) act through 2 structurally related receptors, the insulin receptor (INSR) and the type 1 IGF receptor (IGF1R), both of which are expressed in developing oocytes. IGF1 plays an important role in female reproduction, and female Igf1 knockout mice fail to ovulate and are infertile. On the other hand, little is known about the in vivo role of the insulin signaling pathway in oocytes during follicular development, although exposure to insulin or IGF1 in vitro improves oocyte maturation. To further address the significance of insulin/IGF signaling, we used conditional mutant mice and ablated the function of the genes encoding INSR, IGF1R, or both receptors specifically in developing mouse oocytes. Our genetic evidence showed unexpectedly that the female reproductive functions are not affected when Insr, Igf1r or both Insr;Igf1r are ablated in oocytes, as the female mice are fertile and exhibit normal estrous cyclicity, oocyte development and maturation, parturition frequency, and litter size. In view of these novel observations indicating that the insulin/IGF signaling is not essential in oocytes, the IGF1-dependent female fertility is re-evaluated and discussed.

BF-1 interferes with transforming growth factor beta signaling by associating with Smad partners.

The winged-helix (WH) BF-1 gene, which encodes brain factor 1 (BF-1) (also known as foxg1), is essential for the proliferation of the progenitor cells of the cerebral cortex. Here we show that BF-1-deficient telencephalic progenitor cells are more apt to leave the cell cycle in response to transforming growth factor beta (TGF-beta) and activin. We found that ectopic expression of BF-1 in vitro inhibits TGF-beta mediated growth inhibition and transcriptional activation. Surprisingly, we found that the ability of BF-1 to function as a TGF-beta antagonist does not require its DNA binding activity. Therefore, we investigated whether BF-1 can inhibit Smad-dependent transcriptional responses by interacting with Smads or Smad binding partners. We found that BF-1 does not interact with Smads. Because the identities of the Smad partners mediating growth inhibition by TGF-beta are not clearly established, we examined a model reporter system which is known to be activated by activin and TGF-beta through Smads and the WH factor FAST-2. We demonstrate that BF-1 associates with FAST-2. This interaction is dependent on the same region of protein which mediates its ability to interfere with the antiproliferative activity of TGF-beta and with TGF-beta-dependent transcriptional activation. Furthermore, the interaction of FAST-2 with BF-1 is mediated by the same domain which is required for FAST-2 to interact with Smad2. We propose a model in which BF-1 interferes with transcriptional responses to TGF-beta by interacting with FAST-2 or with other DNA binding proteins which function as Smad2 partners and which have a common mode of interaction with Smad2.

Conditional mutagenesis in mice with heat shock promoter-driven cre transgenes.

To explore the potential of a simple and rapid approach for ubiquitous conditional gene disruption, we have generated Cre-producer mouse transgenic lines (Hs-cre1, 6 and 7) expressing a recombinase transgene (cre) from a heat shock gene promoter and tested their performance in Cre-mediated excision of target DNA in crosses with Cre-responder strains carrying loxP-modified alleles of the genes encoding the Huntington's disease gene homolog (Hdh), the epidermal growth factor receptor (Egfr), and the type 1 insulin-like growth factor receptor (Igf1r). Analyses of progeny possessing various transgene/reporter combinations showed that cre expression can occur without heat shock in early embryos, but this constitutive transcription is stochastic and transgene dependent. Thus, Hs-cre1 behaves predominantly as a "deleter" strain, since the majority of progeny (approximately 70-85%) exhibit complete recombination, regardless of reporter locus. Lines Hs-cre6 and Hs-cre7, however, function successfully as "mosaicking" strains because, in addition to two extreme classes of progeny with 0% or 100% recombination, they generate an intermediate class of mosaics exhibiting various degrees of partial DNA excision. Notably, the frequency of offspring in each class varies between reporters, but mosaic embryos are consistently obtained in adequate numbers (approximately 30-60%). The Hs-cre6 transgene is also inducible and can be used to introduce mosaicism into adult tissues at preselected developmental times by heat shock treatment of mice with 0% recombination in tail DNA. By bypassing the lethality resulting from some gene knockouts, mosaic embryos and mice make particular mutational analyses possible and are also very useful for the identification of cell lineage-specific gene functions.