NRSF regulates age-dependently cognitive ability and its conditional knockout in APP/PS1 mice moderately alters AD-like pathology.

NRSF/REST (neuron-restrictive silencer element, also known as repressor element 1-silencing transcription factor), plays a key role in neuronal homeostasis as a transcriptional repressor of neuronal genes. NRSF/REST relates to cognitive preservation and longevity of humans, but its specific functions in age-dependent and Alzheimer's disease (AD)-related memory deficits remain unclear. Here, we show that conditional NRSF/REST knockout either in the dorsal telencephalon or specially in neurons induced an age-dependently diminished retrieval performance in spatial or fear conditioning memory tasks and altered hippocampal synaptic transmission and activity-dependent synaptic plasticity. The NRSF/REST deficient mice were also characterized by an increase of activated glial cells, complement C3 protein and the transcription factor C/EBPß in the cortex and hippocampus. Reduction of NRSF/REST by conditional depletion upregulated the activation of astrocytes in APP/PS1 mice, and increased the C3-positive glial cells, but did not alter the Aß loads and memory retrieval performances of 6- and 12-month-old APP/PS1 mice. Simultaneously, overexpression of NRSF/REST improved cognitive abilities of aged wild type, but not in AD mice. These findings demonstrated that NRSF/REST is essential for the preservation of memory performance and activity-dependent synaptic plasticity during aging and takes potential roles in the onset of age-related memory impairments. However, while altering the glial activation, NRSF/REST deficiency does not interfere with the Aß deposits and the electrophysiological and cognitive AD-like pathologies.

Genetic advancements in obesity management and CRISPR-Cas9-based gene editing system.

Human genome research has reached new heights in the recent decade thanks to a major advance in genome editing. Genome editing enables scientists to understand better the functions of a single gene and its impact on a wide range of diseases. In brief, genome editing is a technique for introducing alterations into specific DNA sequences, such as insertions, deletions, or base substitutions. Several methods are adopted to perform genome editing and clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated nuclease 9 (Cas9) systems. Unfortunately, despite substantial progress in understanding the molecular pathways behind obesity, anti-obesity medications are now ineffective. If you are obese, a 10% weight decrease would be preferable to healthy body weight for most people. CRISPR-Cas9, on the other hand, has been shown to reduce body weight by an astonishing 20%. Hence, this updated review elaborates on the molecular basis of obesity, risk factors, types of gene therapy, possible mechanisms, and advantages of the CRISPR-Cas9 system over other methods.

VGLL4 plays a critical role in heart valve development and homeostasis.

Heart valve disease is a major clinical problem worldwide. Cardiac valve development and homeostasis need to be precisely controlled. Hippo signaling is essential for organ development and tissue homeostasis, while its role in valve formation and morphology maintenance remains unknown. VGLL4 is a transcription cofactor in vertebrates and we found it was mainly expressed in valve interstitial cells at the post-EMT stage and was maintained till the adult stage. Tissue specific knockout of VGLL4 in different cell lineages revealed that only loss of VGLL4 in endothelial cell lineage led to valve malformation with expanded expression of YAP targets. We further semi-knockout YAP in VGLL4 ablated hearts, and found hyper proliferation of arterial valve interstitial cells was significantly constrained. These findings suggest that VGLL4 is important for valve development and manipulation of Hippo components would be a potential therapy for preventing the progression of congenital valve disease.

Calcification of lower extremity arteries is related to the presence of osteoporosis in postmenopausal women with type 2 diabetes mellitus: a cross-sectional observational study.

It is unknown whether there is any relationship between extremity arterial macroangiopathy and osteoporosis in type 2 diabetic mellitus (T2DM) patients. We provide evidence to show the association between lower extremity arterial calcification and the presence of osteoporosis in postmenopausal T2DM women, but not in T2DM men of similar age. PURPOSE: To investigate the relationship between lower extremity arterial calcification and the presence of osteoporosis in type 2 diabetic mellitus (T2DM) patients. METHODS: We performed a retrospective cross-sectional study in patients with T2DM. They were assigned into two groups (patients with or without vascular calcification) in both sexes. Clinical characteristics, presence of osteoporosis, and bone metabolic markers were compared. Arterial calcification was determined by ultrasonography examination. Osteoporosis was defined based on the measurements from dual-energy X-ray absorptiometry. The relationship between the lower extremity arterial calcification and the presence of osteoporosis was analyzed. Statistical analysis was performed in SPSS 26.0. RESULTS: A total of 933 T2DM patients (535 men ≥ 50 years old, and 398 postmenopausal women) were identified and analyzed. A significant association between arterial calcification and osteoporosis was only observed in women, with a higher prevalence of osteoporosis observed in women with calcification (40.8%) than in women without calcification (26.9%) (P = 0.004). Compared to women without calcification, women with calcification had lower bone mineral densities in the hip (P < 0.001) and femoral neck (P < 0.001). Ordinal logistic regression analysis showed that women with calcification had a nearly 2-fold increased risk for osteoporosis, even after adjusting for age, duration of T2DM, body mass index, pulse pressure, clearance of creatinine, glycosylated hemoglobin, and fasting C-peptide. Similar differences were not identified between men with and without calcification. CONCLUSION: Calcification of lower extremity arteries is related with the presence of osteoporosis in postmenopausal T2DM women.

The TEA domain family transcription factor TEAD4 represses murine adipogenesis by recruiting the cofactors VGLL4 and CtBP2 into a transcriptional complex.

The Hippo signaling pathway is known to play an important role in multiple physiological processes, including adipogenesis. However, whether the downstream components of the Hippo pathway are involved in adipogenesis remains unknown. Here we demonstrate that the TEA domain family (TEAD) transcription factors are essential for adipogenesis in murine 3T3-L1 preadipocytes. Knockdown of TEAD1-4 stimulated adipogenesis and increased the expression of adipocyte markers in these cells. Interestingly, we found that the TEAD4 knockdown-mediated adipogenesis proceeded in a Yes-associated protein (YAP)/TAZ (Wwtr1)-independent manner and that adipogenesis suppression in WT cells involved formation of a ternary complex comprising TEAD4 and the transcriptional cofactors C-terminal binding protein 2 (CtBP2) and vestigial-like family member 4 (VGLL4). VGLL4 acted as an adaptor protein that enhanced the interaction between TEAD4 and CtBP2, and this TEAD4-VGLL4-CtBP2 ternary complex dynamically existed at the early stage of adipogenesis. Finally, we verified that TEAD4 directly targets the promoters of major adipogenesis transcription factors such as peroxisome proliferator-activated receptor γ (PPARγ) and adiponectin, C1Q, and collagen domain-containing (Adipoq) during adipogenesis. These findings reveal critical insights into the role of the TEAD4-VGLL4-CtBP2 transcriptional repressor complex in suppression of adipogenesis in murine preadipocytes.

Involvement of the Hippo pathway in regeneration and fibrogenesis after ischaemic acute kidney injury: YAP is the key effector.

Renal tubule cells can recover after they undergo AKI (acute kidney injury). An incomplete repair of renal tubules can result in progressive fibrotic CKD (chronic kidney disease). Studies have revealed the relationship between tubular epithelial cells and kidney fibrogenesis. However, the underlying mechanism remains unclear. Hippo pathway components were evaluated in complete/incomplete repair of I/R (ischaemia/reperfusion) AKI rat models, HK-2 cells and AKI human renal biopsy samples. We found that the expression levels of the Hippo pathway components changed dynamically during kidney regeneration and fibrogenesis in rat models of I/R-induced AKI and human renal biopsy samples. The transcription cofactor YAP (Yes-associated protein) might be a key effector of renal regeneration and fibrogenesis. Our results showed further that YAP might elicit both beneficial and detrimental effects on I/R AKI. After I/R injury occurred, YAP could promote the repair of the injured epithelia. The constant YAP increase and activation might be related to interstitial fibrosis and abnormal renal tubule differentiation. These results indicate that the proper modulation of the Hippo pathway, specifically the transcription cofactor YAP, during repair might be a potent therapeutic target in AKI-CKD transition after I/R injury.

Soluble interleukin 2 receptor is risk for sarcopenia in Men with high fracture risk.

Background & aims: Sarcopenia is an age-related disease that increases the risk of falls and fractures in older adults. However, there is no blood biochemical marker to help to predict or diagnose sarcopenia in clinical practice. Soluble interleukin 2 receptor (sIL-2R) was reported to be associated with muscle satellite cell dysfunction which played an important role in the pathogenesis of sarcopenia. Thereby, we aimed to explore the association between serum sIL-2R and sarcopenia in older adults at high risk of fractures. Methods: A total of 429 hospitalized older adults (age ≥55 years) were enrolled in this cross-sectional study (mean age â€‹= â€‹66.62 â€‹± â€‹6.59 years; 62.7% female). Logistic regression analysis was performed to assess the association of sIL-2R with sarcopenia, muscle mass, muscle strength, and physical performance, respectively. The optimal models for the diagnosis of sarcopenia and low hand grip strength (HGS) were established by multivariable binary logistic regression analysis with backward selection, and further were evaluated for the diagnostic values by receiver operating characteristic (ROC) curve. Results: Higher sIL-2R levels were found in sarcopenia than no-sarcopenia group in male (median 421 U/mL (interquartile range [IQR] 217 U/mL) vs median 362 U/mL (IQR 157 U/mL); n â€‹= â€‹77 vs 83; p â€‹< â€‹0.01). Compared to the lowest sIL-2R tertile, the highest tertile of sIL-2R was independently associated with the risk of low HGS (odds ratio [OR] 4.608, 95% confidence interval [CI] 1.673-12.695) and the risk of sarcopenia (OR 3.306, 95% CI 1.496-7.302) in men. ROC curves revealed that the Area Under the Curve (AUC) of the optimal models for diagnosing sarcopenia and low HGS was 0.752 and 0.846. Conclusion: Our results suggest that serum sIL-2R is the independent risk factor for sarcopenia and low muscle strength only in men. sIL-2R may be developed to be a biochemical marker for sarcopenia and low muscle strength diagnoses in older men at high risk of fractures, but more prospective studies are needed to prove it. The translational potential of this article: Our results showed that the highest tertile of sIL-2R was independent of low risk of HGS and sarcopenia in men, compared to the lowest tertile. As the population ages, sIL-2R may become a potential diagnostic tool for predicting low HGS and sarcopenia among men at high risk of fractures.

Ankrd26 gene disruption enhances adipogenesis of mouse embryonic fibroblasts.

We previously reported that partial disruption of the Ankrd26 gene in mice leads to hyperphagia and leptin-resistant obesity. To determine whether the Ankrd26 mutation can affect the development of adipocytes, we studied mouse embryo fibroblasts (MEFs) from the mutant mice. We found that Ankrd26(-/-) MEFs have a higher rate of spontaneous adipogenesis than normal MEFs and that adipocyte formation is greatly increased when the cells are induced with troglitazone alone or with a mixture of troglitazone, insulin, dexamethasone, and methylisobutylxanthine. Increased adipogenesis was detected as an increase in lipid droplet formation and in the expression of several markers of adipogenesis. There was an increase in expression of early stage adipogenesis genes such as Krox20, KLF5, C/EBPß, C/EBPδ, and late stage adipogenesis regulators KLF15, C/EBPα, PPARγ, and aP2. There was also an increase in adipocyte stem cell markers CD34 and Sca-1 and preadipocyte markers Gata2 and Pref-1, indicating an increase in both stem cells and progenitor cells in the mutant MEFs. Furthermore, ERK was found constitutively activated in Anrd26(-/-) MEFs, and the addition of MEK inhibitors to mutant cells blocked ERK activation, decreased adipogenesis induction, and significantly reduced expression of C/EBPδ, KLF15, PPARγ2, CD34, and Pref-1 genes. We conclude that Ankrd26 gene disruption promotes adipocyte differentiation at both the progenitor commitment and differentiation steps and that ERK activation plays a role in this process.

A New Index Based on Serum Creatinine and Cystatin C Can Predict the Risks of Sarcopenia, Falls and Fractures in Old Patients with Low Bone Mineral Density.

As new screening tools for sarcopenia, the serum sarcopenia index (SI) and creatinine/cystatin C ratio (CCR) had not been confirmd in a population with a high fragility fracture risk. This study aimed to evaluate whether SI and CCR indicators are useful for diagnosing sarcopenia and to determine their prediction values for future falls and fractures. A total of 404 hospitalized older adults were enrolled in this longitudinal follow-up study (mean age = 66.43 ± 6.80 years). The receiver operating curve (ROC) was used to assess the diagnostic accuracy of SI and CCR. Backward-selection binary logistic regression was applied to develop the optimal models for the diagnosis of new falls and fractures. SI had a significantly higher area under the curve (AUC) than CCR for predicting sarcopenia. The optimal models had acceptable discriminative powers for predicting new falls and fractures. Lower SI and CCR are the independent risks for sarcopenia, new falls, and fractures in the low-BMD population. SI and CCR, as easily accessible biochemical markers, may be useful in the detection of sarcopenia and in predicting the occurrence of new falls and fractures in patients with low BMD who have not previously experienced falls or fractures. However, further external validations are required.

Anemia is related to osteoporosis in Chinese type 2 diabetic patients.

Both anemia and osteoporosis are common in type 2 diabetes mellitus (T2DM). However, the relationship between them remains to be determined. This study showed that anemia was related to osteoporosis in male and female T2DM patients. Diabetes patients with anemia should also be wary of osteoporosis. INTRODUCTION: Anemia and osteoporosis are considered complications of type 2 diabetes mellitus (T2DM). However, the relationship between anemia and osteoporosis in the T2DM population remains to be determined. Thus, we planned the present study to verify their relationship. METHODS: A retrospective cross-sectional study was performed. The patients were divided into groups according to sex and hemoglobin levels (Q1: ≤ 120, Q2: 120 to ≤ 140, Q3: > 140 in men; Q1: ≤ 110, Q2: 110 to ≤ 130, Q3: > 130 in women). Clinical characteristics and bone mineral density (BMD) were compared. The relationship between anemia and osteoporosis was determined after adjusting for age, diabetic duration, body mass index, alanine aminotransferase, creatinine, HbA1c, and fasting C-peptide. Statistical analysis was performed using SPSS 26.0. RESULTS: This study included 2336 patients (1150 men and 1186 postmenopausal women). The percentage of osteoporosis differed by hemoglobin status in both men (Q1: 20.2%, Q2: 15.5%, Q3: 12.4%, P = 0.031) and women (Q1: 51.4%, Q2: 38.0%, Q3: 34.5%, P < 0.001). Q1, with the lowest hemoglobin level, has higher percentage of osteoporosis in men (20.2%) and in women (51.4%). Hip BMD (men: r = 0.168, P < 0.001, women: r = 0.126, P < 0.001) and femur neck BMD (men: r = 0.150, P < 0.001, women: r = 0.134, P < 0.001) were correlated with hemoglobin levels in both sexes. The odds of osteoporosis increased 1.4-fold in men and 2.0-fold in women in the Q1 groups compared with Q3 groups. CONCLUSION: Anemia was related to osteoporosis in T2DM patients regardless of sex. Diabetic patients with anemia (men with hemoglobin below 120 g/L and women with hemoglobin below 110 g/L) should also be wary of osteoporosis.

Serum superoxide dismutase activity: a sensitive, convenient, and economical indicator associated with the prevalence of chronic type 2 diabetic complications, especially in men.

To investigate the relationship between serum superoxide dismutase (SOD) activity and the presence of chronic complications in patients with type 2 diabetes mellitus (T2DM). We conducted a retrospective cross-sectional study in patients with T2DM. They were assigned to three groups (Q1, Q2, and Q3) by SOD levels in both sexes. Clinical characteristics, cardiovascular disease, diabetic retinopathy, nephropathy, and peripheral neuropathy were compared. The relationship between the SOD and the prevalence of chronic complications was analyzed by binary logistic regression. Statistical analysis was performed in SPSS 26.0 (SPSS Inc., Chicago, IL). A total of 645 T2DM patients (401 men and 244 women) with complete data for SOD and medical records of complications were included. In men, patients in the Q1 group (lowest serum SOD activity) had the highest prevalence of diabetes with atherosclerosis (AS) (p<.001), DN (p=.029), and DPN (p=.001). In comparison, only DN was found to have the highest prevalence in the Q1 group in women (p=.010). In the multivariate analysis, patients in the Q1 group had a 3.0-, 1.6-, 1.9-, and 2.4-fold risk for the prevalence of AS, DR, DN, and DPN, respectively, compared with the Q3 group. In women, a 7.0-fold risk for the prevalence of DN in the Q1 group was found compared with the Q3 group. After adjusting for the age, duration of T2DM, body mass index, pulse pressure, alanine transaminase, clearance of creatinine, triglyceride, glycosylated hemoglobin, and fasting C-peptide in the models, the differences found in both men and women persisted. SOD activity is related to cardiovascular and microvascular diseases in men and the prevalence of diabetic nephropathy in women in T2DM.

An improved lentiviral system for efficient expression and purification of ß-defensins in mammalian cells.

ß-Defensins are a family of conserved small cationic antimicrobial peptides with different significant biological functions. The majority of mammalian ß-defensins are expressed in epididymis, and many of them are predicted to have post-translational modifications. However, only a few of its members have been well studied due to the limitations of expressing and purifying bioactive proteins with correct post-translational modifications efficiently. Here we developed a novel Fc tagged lentiviral system and Fc tagged prokaryotic expression systems provided new options for ß-defensins expression and purification. The novel lentiviral system contains a secretive signal peptide, an N-terminal IgG Fc tag, a green fluorescent protein (GFP), and a puromycin selection marker to facilitate efficient expression and fast purification of ß-defensins by protein A magnetic or agarose beads. It also enables stable and large-scale expression of ß-defensins with regular biological activities and post-translational modification. Purified ß-defensins such as Bin1b and a novel human ß-defensin hBD129 showed antimicrobial activity, immuno-regulatory activity, and expected post-translational phosphorylation, which were not found in Escherichia coli (E. coli) in expressed form. Furthermore, we successfully applied the novel system to identify mBin1b interacting proteins, explaining Bin1b in a better way. These results suggest that the novel lentiviral system is a powerful approach to produce correct post-translational processed ß-defensins with bioactivities and is useful to identify their interacting proteins. This study has laid the foundation for future studies to characterize function and mechanism of novel ß-defensins.

Identification of Potential BRAF Inhibitor Joint Therapy Targets in PTC based on WGCAN and DCGA.

As the most common mutation in papillary thyroid cancer (PTC), B-type Raf kinase V600E mutation (BRAFV600E ) has become an important target for the clinical treatment of PTC. However, the clinical application still faces the problem of resistance to BRAF inhibitors (BRAFi). Therefore, exploring BRAFV600E-associated prognostic factors to providing potential joint targets is important for combined targeted therapy with BRAFi. In this study, we combined transcript data and clinical information from 199 BRAF wild-type (BRAFWT ) patients and 283 BRAFV600E mutant patients collected from The Cancer Genome Atlas (TCGA), and screened 455 BRAFV600E- associated genes through differential analysis and weighted gene co-expression network analysis. Based on these BRAFV600E -associated genes, we performed functional enrichment analysis and co-expression differential analysis and constructed a core co-expression network. Next, genes in the differential co-expression network were used to predict drugs for therapy in the crowd extracted expression of differential signatures (CREEDS) database, and the key genes were selected based on the hub co-expression network through survival analyses and receiver operating characteristic (ROC) curve analyses. Finally, we obtained eight BRAFV600E -associated biomarkers with both prognostic and diagnostic values as potential BRAFi joint targets, including FN1, MET, SLC34A2, NGEF, TBC1D2, PLCD3, PROS1, and NECTIN4. Among these genes, FN1, MET, PROS1, and TBC1D2 were validated through GEO database. Two novel biomarkers, PROS1 and TBC1D2, were further validated by qRT-PCR experiment. Besides, we obtained four potential targeted drugs that could be used in combination with BRAFi to treat PTC, including MET inhibitor, ERBB3 inhibitor, anti-NaPi2b antibody-drug conjugate, and carboplatin through literature review. The study provided potential drug targets for combination therapy with BRAFi for PTC to overcome the drug resistance for BRAFi.

Knockout of glutathione peroxidase 5 down-regulates the piRNAs in the caput epididymidis of aged mice.

The mammalian epididymis not only plays a fundamental role in the maturation of spermatozoa, but also provides protection against various stressors. The foremost among these is the threat posed by oxidative stress, which arises from an imbalance in reactive oxygen species and can elicit damage to cellular lipids, proteins, and nucleic acids. In mice, the risk of oxidative damage to spermatozoa is mitigated through the expression and secretion of glutathione peroxidase 5 (GPX5) as a major luminal scavenger in the proximal caput epididymidal segment. Accordingly, the loss of GPX5-mediated protection leads to impaired DNA integrity in the spermatozoa of aged Gpx5-/- mice. To explore the underlying mechanism, we have conducted transcriptomic analysis of caput epididymidal epithelial cells from aged (13 months old) Gpx5-/- mice. This analysis revealed the dysregulation of several thousand epididymal mRNA transcripts, including the downregulation of a subgroup of piRNA pathway genes, in aged Gpx5-/- mice. In agreement with these findings, we also observed the loss of piRNAs, which potentially bind to the P-element-induced wimpy testis (PIWI)-like proteins PIWIL1 and PIWIL2. The absence of these piRNAs was correlated with the elevated mRNA levels of their putative gene targets in the caput epididymidis of Gpx5-/- mice. Importantly, the oxidative stress response genes tend to have more targeting piRNAs, and many of them were among the top increased genes upon the loss of GPX5. Taken together, our findings suggest the existence of a previously uncharacterized somatic piRNA pathway in the mammalian epididymis and its possible involvement in the aging and oxidative stress-mediated responses.

Functional imaging of interleukin 1 beta expression in inflammatory process using bioluminescence imaging in transgenic mice.

BACKGROUND: Interleukin 1 beta (IL-1beta) plays an important role in a number of chronic and acute inflammatory diseases. To understand the role of IL-1beta in disease processes and develop an in vivo screening system for anti-inflammatory drugs, a transgenic mouse line was generated which incorporated the transgene firefly luciferase gene driven by a 4.5-kb fragment of the human IL-1beta gene promoter. Luciferase gene expression was monitored in live mice under anesthesia using bioluminescence imaging in a number of inflammatory disease models. RESULTS: In a LPS-induced sepsis model, dramatic increase in luciferase activity was observed in the mice. This transgene induction was time dependent and correlated with an increase of endogenous IL-1beta mRNA and pro-IL-1beta protein levels in the mice. In a zymosan-induced arthritis model and an oxazolone-induced skin hypersensitivity reaction model, luciferase expression was locally induced in the zymosan injected knee joint and in the ear with oxazolone application, respectively. Dexamethasone suppressed the expression of luciferase gene both in the acute sepsis model and in the acute arthritis model. CONCLUSION: Our data suggest that the transgenic mice model could be used to study transcriptional regulation of the IL-1beta gene expression in the inflammatory process and evaluation the effect of anti-inflammatory drug in vivo.

[Expression of human ß-defensin and its relationship with inflammatory factor in human dental pulp tissue].

PURPOSE: To investigate the expression of human ß-defensin(HBD) in human dental pulp tissue and to explore the regulation of HBD in pulp inflammation and the relationship among HBD family members. METHODS: The gene expression of HBD in human dental pulp tissue was assessed in NCBI GEO profiles and was verified by RT-PCR. Human dental pulp cells were stimulated with TNF-α, IL-1α, IL-1ß and IL-6 in different combinations and the expression of HBD2 was analyzed by qPCR. Human dental pulp cells were pretreated with HBD110 and then stimulated with LPS and the expression of TNF-α,IL-1α and HBD2 were analyzed by qPCR. GraphPad Prism 5.01 was used to analyze the results of the experimental and the control groups. RESULTS: 27 HBDs were found to express in human dental pulp tissue in NCBI GEO Profiles. The joint overexpression of TNF-α, IL-1α, IL-1ß and IL-6 increased the expression of HBD2; HBD110 increased the expression of HBD2 by increasing the expression of TNF-α and IL-1α. CONCLUSIONS: Many other HBDs have positive expression in human dental pulp issue besides of HBD1, HBD2, HBD3, HBD4 and the inflammation factors and other HBDs can regulate the expression of HBD2 in dental pulp.

[The establishment of conditional MT transgenic mice model].

OBJECTIVE: To construct the doxycycline-inducible MT transgenic mice model, and provide a basis for the study of hemangioma as well as MT molecular function in vivo. METHODS: Tetracycline-controlled expression systems were employed to this study. A conditional transgenic vector combining the two transcriptional units on a single plasmid was constructed, and the MT gene was subcloned into this vector. To minimize any potential interference, the two elements were spaced with a 1.2 kb cHS4 insulator. To shield the transgene from the affection of chromosomal position effect and improve its expression efficiency, another cHS4 insulator was inserted into the upstream of transgene cassette. After transient transfection of cells in vitro, and analyzing the relative quantification of MT transcripts (target) in mRNA samples by semi-quantitative RT-PCR method, the pronuclear microinjection technique was used to introduce the purified transgene into the chromosomes of fertilized mice eggs, in order to obtain transgenic positive animals. The MT expression in positive mouse was induced through adding deoxycycline in drinking water. Phenotype analysis was done by pathology, and MT expression was confirmed by RT-PCR. RESULTS: The conditional transgenic vector was constructed successfully, and the expression of MT in vitro was regulated by doxycycline. Five transgenic positive mice were obtained through pronuclear microinjection. After MT induction, one transgenic mice developed hemangiomas, and the expression of MT was confirmed by RT-PCR method. The others were active and in breeding. CONCLUSION: Conditional MT transgenic animal model was constructed successfully, and may provide platform for the experimental research of hemangioma as well as the MT molecular function in vivo.

ANKRD26 and its interacting partners TRIO, GPS2, HMMR and DIPA regulate adipogenesis in 3T3-L1 cells.

Partial inactivation of the Ankyrin repeat domain 26 (Ankrd26) gene causes obesity and diabetes in mice and increases spontaneous and induced adipogenesis in mouse embryonic fibroblasts. However, it is not yet known how the Ankrd26 protein carries out its biological functions. We identified by yeast two-hybrid and immunoprecipitation assays the triple functional domain protein (TRIO), the G protein pathway suppressor 2 (GPS2), the delta-interacting protein A (DIPA) and the hyaluronan-mediated motility receptor (HMMR) as ANKRD26 interacting partners. Adipogenesis of 3T3-L1 cells was increased by selective down-regulation of Ankrd26, Trio, Gps2, Hmmr and Dipa. Furthermore, GPS2 and DIPA, which are normally located in the nucleus, were translocated to the cytoplasm, when the C-terminus of ANKRD26 was introduced into these cells. These findings provide biochemical evidence that ANKRD26, TRIO, GPS2 and HMMR are novel and important regulators of adipogenesis and identify new targets for the modulation of adipogenesis.

Increased fat mass and insulin resistance in mice lacking pancreatic lipase-related protein 1.

Pancreatic triglyceride lipase (PTL) and its cofactor, colipase, are required for efficient dietary triglyceride digestion. In addition to PTL, pancreatic acinar cells synthesize two pancreatic lipase-related proteins (PLRP1 and PLRP2), which have a high degree of sequence and structural homology with PTL. The lipase activity of PLRP2 has been confirmed, whereas no known triglyceride lipase activity has been detected with PLRP1 up to now. To explore the biological functions of PLRP1 in vivo, we generated Plrp1 knockout (KO) mice in our laboratory. Here we show that the Plrp1 KO mice displayed mature-onset obesity with increased fat mass, impaired glucose clearance and the resultant insulin resistance. When fed on high-fat (HF) diet, the Plrp1 KO mice exhibited an increased weight gain, fat mass and severe insulin resistance compared with wild-type mice. Pancreatic juice extracted from Plrp1 KO mice had greater ability to hydrolyze triglyceride than that from the wild-type littermates. We propose that PLRP1 may function as a metabolic inhibitor in vivo of PLT-colipase-mediated dietary triglyceride digestion and provides potential anti-obesity targets for developing new drugs.

Conditional RNA interference achieved by Oct-1 POU/rtTA fusion protein activator and a modified TRE-mouse U6 promoter.

RNA interference (RNAi) is a powerful technique and is widely used to down-regulate expression of specific genes in cultured cells and in vivo. In this paper, we report our development of a new tetracycline-inducible RNAi expression using a modified TRE-mouse U6 promoter in which the distal sequence element (DSE) was replaced by the tetracycline-responsive element (TRE). The modified TRE-mouse U6 promoter can be activated by a Tet-on version tetracycline-regulated artificial activator rTetOct which was constructed by fusing the rtTA DNA binding domain with the Oct-1 POU activation domain. This rTetOct/TRE-U6 system was successfully applied to conditionally and reversibly down-regulate the expression of endogenous p53 gene in MCF7 cells, and the expression of beta-defensin gene (mBin1b) either transiently expressed in COS7 cells or stably expressed in CHO cells.