Multiplex gene editing reduces oxalate production in primary hyperoxaluria type 1.

Targeting key enzymes that generate oxalate precursors or substrates is an alternative strategy to eliminate primary hyperoxaluria type I (PH1), the most common and life-threatening type of primary hyperoxaluria. The compact Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) from the Prevotella and Francisella 1 (Cpf1) protein simplifies multiplex gene editing and allows for all-in-one adeno-associated virus (AAV) delivery. We hypothesized that the multiplex capabilities of the Cpf1 system could help minimize oxalate formation in PH1 by simultaneously targeting the hepatic hydroxyacid oxidase 1 ( Hao1) and lactate dehydrogenase A ( Ldha) genes. Study cohorts included treated PH1 rats ( Agxt Q84X rats injected with AAV-AsCpf1 at 7 days of age), phosphate-buffered saline (PBS)-injected PH1 rats, untreated PH1 rats, and age-matched wild-type (WT) rats. The most efficient and specific CRISPR RNA (crRNA) pairs targeting the rat Hao1 and Ldha genes were initially screened ex vivo. In vivo experiments demonstrated efficient genome editing of the Hao1 and Ldha genes, primarily resulting in small deletions. This resulted in decreased transcription and translational expression of Hao1 and Ldha. Treatment significantly reduced urine oxalate levels, reduced kidney damage, and alleviated nephrocalcinosis in rats with PH1. No liver toxicity, ex-liver genome editing, or obvious off-target effects were detected. We demonstrated the AAV-AsCpf1 system can target multiple genes and rescue the pathogenic phenotype in PH1, serving as a proof-of-concept for the development of multiplex genome editing-based gene therapy.

Generation of genetically modified rat models via the CRISPR/Cas9 technology.

The RNA-guided CRISPR/Cas9 genomic editing system consists of a single guide RNA (sgRNA) and a Cas9 nuclease. The two components form a complex in cells and target the genomic loci complementary to the sgRNA. The Cas9 nuclease cleaves the target site creating a double stranded DNA break (DSB). In mammalian cells, DSBs are often repaired via error prone non-homologous end joining (NHEJ) or via homology directed repair (HDR) with the presence of donor DNA templates. Micro-injection of the CRISPR/Cas9 system into the rat embryos enables generation of genetically modified rat models. Here, we describe a detailed protocol for creating gene knockout or knockin rat models via the CRISPR/Cas9 technology.

A method for constructing GLP-1 overexpression intestinal organoids.

As a potent insulinotrophic hormone, glucagon-like peptide 1 (GLP-1) is mainly secreted by intestinal L cells, which can effectively promote the release of insulin and thus reduce blood glucose. Therefore, GLP-1 and its analogs have a good prospect in the treatment of type 2 diabetes. In this study, we constructed mouse intestinal organoids that overexpress GLP-1 by optimizing the GLP-1 lentivirus infection method. We found that supernatants secreted by the GLP-1 overexpression organoids effectively enhanced glucose tolerance in wild-type and diabetic mouse. Thus, the GLP-1 overexpression organoids built in this study may provide a novel strategy for the treatment of type 2 diabetes.

Effect of Uhrf1 on intestinal development.

As a best-characterized epigenetic modification, DNA methylation plays an important role in mammalian development. Uhrf1 is a critical epigenetic regulator that can bind to hemimethylated DNA and recruit DNA methyltransferase 1 to maintain DNA methylation. So far, the role of Uhrf1-mediated DNA methylation in intestinal development is still unknown. In order to investigate the impact of Uhrf1 deletion in intestinal development, we have successfully constructed the epithelial-specific Uhrf1 knockout mouse model. After Uhrf1 ablation, we found the mutant mice exhibited abnormal epithlial structure with less and shorter villi and shrinked crypts compared with wild type mice via hematoxylin-eosin staining. Further analysis showed that Uhrf1 deletion in the intestinal epithelium significantly decreased the cell proliferation and induced cell apoptosis. In addition, Uhrf1 deletion inhibited the normal epithelial differentiation and the expression of intestinal stem cell marker genes. Preliminary mechanism study revealed that loss of Uhrf1 caused global DNA hypomethylation which induced DNA damage in crypt cells. Taken together, our data suggested that DNA methylation mediated by Uhrf1 is vital for the normal intestinal development. Our results enriched the in vivo role of Uhrf1 and laid the foundation for further epigenetic regulatory mechanism exploration.

[Gene editing technology and its recent progress in disease therapy].

Gene editing is a genetic manipulation technology which utilizes bacterial nucleases to accurately and efficiently modify DNA or RNA. Gene editing has broad applications in basic research, breeding, and drug screening, and it is gaining validity and applicability to the therapy of many diseases especially genetic-based disease. In this review, we summarize the development of gene editing technology, its different strategies and applications in the treatment of disease, and the research of gene editing therapy for genetic diseases (including base editor and epigenetic regulation) in the treatment of disorders and diseases of the blood system, liver, muscle and nervous system. Finally, we discuss the future development prospects of gene editing therapy.

Uhrf2 deletion impairs the formation of hippocampus-dependent memory by changing the structure of the dentate gyrus.

Ubiquitin-like with PHD and ring finger domains 2 (Uhrf2) is distributed in many brain regions, including the cortex and hippocampus. Decreased Uhrf2 expression is involved in neurodegenerative disease. A recent study showed Uhrf2 deletion impaired spatial memory; however, the mechanism remains elusive. In our study, we determined that Uhrf2+/- and Uhrf2-/- mice had significant learning and memory deficiencies in contextual fear conditioning (CFC) and the novel place recognition test but not in the novel object recognition test. Interestingly, there were no changes in the Uhrf2 protein levels in the hippocampus of C57BL6 mice after CFC training, which suggests Uhrf2 in adult mice may not be related to the formation of CFC long-term memory. Based on Nissl staining, Uhrf2 deletion caused neuropathological changes specifically in the crest of the dentate gyrus (DG), such as cell swelling, a vague outline and confused boundary; however, no changes were identified in the medial prefrontal cortex (mPFC). Transmission electron microscope assay further indicated a series of abnormal ultrastructure changes in neurons and glia in the DG crest. These results suggested that Uhrf2 deletion selectively blocked the development of the DG crest and impaired hippocampus-dependent learning and memory. Our study will facilitate a better understanding of the role of Uhrf2 protein in the central nervous system.

The "new favorite" of gene editing technology-single base editors.

Programmable nucleases are cutting edge genetic technology which edits targeted DNA sequences through generation of site-specific double-strand DNA breaks (DSBs). To improve the efficiency and precision of genetic modification, scientists have developed a single-base editing system (base editor) through combining of CRISPR/Cas9 system with cytosine deaminase. Compared with Cas9 system, this base editor can convert cytosine to thymine (C > T) at specific site more efficiently without inducing DSBs to avoid generation of indels. However, the base editor can only generate transition of pyrimidine but could not modify purines. Recently, Nature published a novel base editing system to convert adenine to guanine (ABEs, adenine base editors) through fusion of Cas9 nickase to a modified deaminase which is evolved through screening of random library based on tRNA adenine deaminase from E. coli. Here, we summarize the development of single-base editing tools and the latest research progress, especially the optimization process of ABEs, as well as the potential directions of the base editors.

Generation of site-specific mutant mice using the CRISPR/Cas9 system.

The CRISPR/Cas9 system is a recently developed important technology for genome editing in cellular and animal models. Here we established a CRISPR/Cas9-based system of generating site-specific mutant mice using DNA double-strand breaks (DSBs) induced homologous recombination (HR)-dependent or independent repair mechanism. Through co-microinjection of Cas9 mRNA and single-guide RNA (sgRNA) targeting genomic DNA sequence corresponding to enzyme activity of lysine (K)-specific demethylase 2b (Kdm2b), both a frame-shifted Kdm2b null mutant and a Kdm2b enzyme activity disrupted mouse strain were obtained simultaneously. Moreover, sgRNA targeting flavin containing monooxygenases3 (Fmo3) gene and the corresponding single strand oligonucleotides (ssODN) donor template with point mutation were co-injected into the male pronucleus of one-cell mouse embryos stimulated HR-mediated repair mechanism. Genomic sequence analysis of F0 mice showed that frame-shifted Fmo3 knockout mouse and site-specific Fmo3 knock-in mouse with single base substitution were successfully generated, and these mutations could be stably transmitted to the next generation. Therefore, we successfully generated mouse strains containing site-specific mutations through HR-dependent and -independent DSB repair using the CRISPR/Cas9 system.

Bioinspired polydopamine as the scaffold for the active AuNPs anchoring and the chemical simultaneously reduced graphene oxide: characterization and the enhanced biosensing application.

We report here an efficient approach to enhance the performance of biosensing platform based on graphene or graphene derivate. Initially, graphene oxides (GO) nanosheets were reduced and surface functionalized by one-step oxidative polymerization of dopamine in basic solution at environment friendly condition to obtain the polydopamine (Pdop) modified reduced graphene oxides (PDRGO). The bioinspired surface was further used as a support to anchor active gold nanoparticles (AuNPs). The morphology and structure of the as-prepared AuNPs/PDRGO nanocomposite were investigated by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform-infrared spectroscopy (FT-IR). Electrochemical studies demonstrate that the as-prepared AuNPs/PDRGO hybrid materials possess excellent electrochemical properties and electrocatalytic activity toward the oxidation of NADH at low potential (0.1 V vs. SCE) with the fast response (15s) and the broad linear range (5.0 × 10(-8)-4.2 × 10(-5)M). Thus, this AuNPs/PDRGO nanocomposite can be further used to fabricate a sensitive alcohol biosensor using alcohol dehydrogenase (ADH), by simply incorporating the specific enzyme within the composite matrix with the aid of chitosan (Chit).

Oxidative decarboxylation of mandelic acid derivative by recombinant Escherichia coli: a novel method of ethyl vanillin synthesis.

The benzoylformate decarboxylase gene (mdlC) from Pseudomonas putida was expressed in Escherichia coli BL21(DE3). The recombinant strain together with E. coli/pET30a-mdlB converted (S)-3-ethoxy-4-hydroxymandelic acid (S-EMA) into ethyl vanillin without ethyl vanillin degradation. 4 g ethyl vanillin/l was obtained from 10 g EMA/l within 12 h at 30 °C. This is the first report on the biotransformation of (S)-EMA to ethyl vanillin.

Rhabdomyosarcoma of the breast: a clinicopathologic study and review of the literature.

BACKGROUND: Rhabdomyosarcoma (RMS) is an uncommon malignancy of the breast. The aim of this study was to summarize its clinicopathologic features and biological behavior. METHODS: Five primary or secondary breast RMSs were collected. Their clinicopathological characteristics and all published literature about breast RMS were reviewed. Immunohistochemical study of desmin, myogenic differentiation 1 (MyoD1), myogenin, leukocyte common antigen (LCA), vimentin, cytokeratin (AE1/AE3), E-cadherin, neuron specific enolase (NSE), CD99, chorioallantoic membrane 5.2 (CAM5.2) and epithelial membrane antigen (EMA) expression were performed. RESULTS: The five patients were all female with ages ranging from 16 to 46 years old (mean, 30 years). Three were metastatic breast RMSs, two embryonal and one solid variant alveolar, with the primary tumor sites the right labium majus, left nasal meatus and nasopharynx, respectively. The other two, one embryonal and one alveolar, were primaries. Grossly, the surgical specimens revealed round or oval, well-demarcated but nonencapsulated masses. Their cut surfaces consisted of homogeneous grayish yellow or white tissue. Microscopically, most tumor cells were poorly differentiated small round, oval or small polygons with eosinophilic cytoplasm. All cases were positive for vimentin, desmin, MyoD1 and myogenin. One embryonal RMS also had a few cells with perinuclear staining of AE1/AE3. The other markers were negative. CONCLUSIONS: Although primary or metastatic RMS in breast was almost confined to young adolescent females, our cases suggested that it can also happen to the middle-aged women. Embryonal RMS has a certain metastatic potential. MyoD1 and myogenin are two useful markers when making differential diagnosis. Axillary lymph node status and age may play a role in the prognosis of primary breast RMS patients.

PI3K expression and PIK3CA mutations are related to colorectal cancer metastases.

AIM: To assess the significance of phosphatidylinositol 3-kinase (PI3K) in colorectal cancer (CRC) and toxicity of LY294002 in CRC cells with different metastatic abilities. METHODS: Sixty formalin-fixed and paraffin-embedded CRC tumor specimens were investigated. Adjacent normal colonic mucosa specimens from 10 of these cases were selected as controls. PI3K protein was detected by immunohistochemistry and PIK3CA mutations were investigated by gene sequencing analysis. A flow-cytometry-based apoptosis detection kit was used to determine PI3K inhibitor-induced apoptosis in CRC cell lines SW480 and SW620. Expression of phosphorylated protein kinase B in CRC cell lines was detected by Western blotting. RESULTS: There was a significant difference in the proportion of primary lesions (30%, 18/60) vs metastatic lesions (46.7%, 28/60) that were positive for PI3K (P < 0.05). Mutations were detected in exon 9 (13.3%) and exon 20 (8.3%). Out of 60 cases, seven mutations were identified: two hotspot mutations, C.1633G>A resulting in E545A, and C.3140A>G resulting in H1047R; two novel missense mutations C.1624G>A and C.3079G>A; and three synonymous mutations (C.1641G>A, C.1581C>T and C.3027T>A). Exposure of SW480 cells to PI3K inhibitor for 48 h resulted in a significant increase of apoptotic cells in a dose-dependent manner [3.2% apoptotic cells in 0 µmol/L, 4.3% in 5 µmol/L, 6.3% in 10 µmol/L (P < 0.05), and 6.7% in 20 µmol/L (P < 0.05)]. Moreover, PI3K inhibitor induced a similar significant increase of apoptotic cells in the SW620 cell line for 48 h [3.3% apoptotic cells in 0 µmol/L, 13.3% in 5 µmol/L (P < 0.01), 19.2% in 10 µmol/L (P < 0.01), and 21.3% in 20 µmol/L (P < 0.01)]. CONCLUSION: High PI3K expression is associated with CRC metastasis. PI3K inhibitor induced apoptosis in CRC cells and displayed strong cytotoxicity for highly metastatic cells. PI3K inhibition may be an effective treatment for CRC.

Orphan G protein-coupled receptors (GPCRs): biological functions and potential drug targets.

The superfamily of G protein-coupled receptors (GPCRs) includes at least 800 seven-transmembrane receptors that participate in diverse physiological and pathological functions. GPCRs are the most successful targets of modern medicine, and approximately 36% of marketed pharmaceuticals target human GPCRs. However, the endogenous ligands of more than 140 GPCRs remain unidentified, leaving the natural functions of those GPCRs in doubt. These are the so-called orphan GPCRs, a great source of drug targets. This review focuses on the signaling transduction pathways of the adhesion GPCR family, the LGR subfamily, and the PSGR subfamily, and their potential functions in immunology, development, and cancers. In this review, we present the current approaches and difficulties of orphan GPCR deorphanization and characterization.

A prospective comparison of molecular assay and touch imprint cytology for intraoperative evaluation of sentinel lymph nodes.

BACKGROUND: Accurate intraoperative diagnosis of sentinel lymph node (SLN) metastases enables the selection of patients for axillary lymph node dissections during the same operation, reducing the need for a second operation. The present study aimed to prospectively compare the GeneSearch(TM) Breast Lymph Node (BLN) Assay with touch imprint cytology (TIC) for intraoperative evaluation of SLNs. METHODS: SLNs were sectioned in 1.5 - 3.0 mm pieces. TIC was performed on all pieces and the BLN Assay and postoperative histology evaluations were performed on different alternating node pieces. Overall performance of the BLN Assay was compared with that of TIC relative to the postoperative histology results. RESULTS: A total of 90 patients enrolled in the study. Complete intraoperative data for both the BLN Assay and TIC were collected in 86 patients. The sensitivity, specificity, and overall accuracy of the BLN Assay were 82%, 97%, and 92%, respectively on a per patient basis compared with those of TIC which were 67%, 100%, and 90%. CONCLUSIONS: Performance of the BLN Assay was superior to that of TIC and the additional application of TIC did not help improve the total sensitivity and accuracy of the intraoperative assessment. The existence of ectopic breast tissue might be a possible cause of false positive for the BLN assay. In addition, the BLN Assay complements histopathology assessment and can minimize sampling error without increasing pathologists' workload.

[Evaluation of intraoperative molecular assay in sentinel lymph node biopsy from breast cancer patients].

OBJECTIVE: to evaluate the application of GeneSearch(TM) breast lymph node assay in intraoperative detection of metastases in sentinel lymph node (SLN) from breast cancer patients. METHODS: a total of 225 SLN from 88 patients was prospectively studied. Each SLN was cut into 2 mm slabs which were examined by intraoperative imprint cytology (IIC) first, followed by GeneSearch assay and post-operative serial sectioning. GeneSearch used real-time fluorescence quantitative RT-PCR technology to detect the expression of CK19 and mammaglobin in SLN. The results of GeneSearch assay were correlated with those of IIC and post-operative serial sectioning. RESULTS: amongst the 88 cases studied, 225 SLNs were found, and obvious metastatic carcinoma cells were identified in 27 SLNs and micrometastasis in 9 SLNs. One hundred and eight-nine SLNs were considered as "negative" (with "isolated tumor cells" present in 5 SLNs). The turn-around time of intraoperative GeneSearch assay ranged from 35 to 45 minutes (mean = 40 minutes). The concordance rate between GeneSearch assay and post-operative serial sectioning was 95.6% (215/225), with a sensitivity of 86.1% (31/36), compared with 94.7% (213/225) and 72.2% (26/36) respectively for IIC. The size of metastatic foci correlated with the Ct value of CK19 and mammaglobin (P < 0.01). CONCLUSIONS: GeneSearch assay for intraoperative detection of metastase in SLN has a satisfactory performance and demonstrates a relatively higher sensitivity than IIC. The potential clinical application still requires further evaluation of larger number of cases.

G protein-coupled receptor 48 upregulates estrogen receptor alpha expression via cAMP/PKA signaling in the male reproductive tract.

The epididymis and efferent ducts play major roles in sperm maturation, transport, concentration and storage by reabsorbing water, ions and proteins produced from seminiferous tubules. Gpr48-null male mice demonstrate reproductive tract defects and infertility. In the present study, we found that estrogen receptor alpha (ERalpha) was dramatically reduced in the epididymis and efferent ducts in Gpr48-null male mice. We further revealed that ERalpha could be upregulated by Gpr48 activation via the cAMP/PKA signaling pathway. Moreover, we identified a cAMP responsive element (Cre) motif located at -1307 to -1300 bp in the ERalpha promoter that is able to interact with Cre binding protein (Creb). In conclusion, Gpr48 participates in the development of the male epididymis and efferent ducts through regulation of ERalpha expression via the cAMP/PKA signaling pathway.

Hemolytic disease of neonates due to anti-M: report of one case and review of reports of 21 cases / 中华儿科杂志

<p><b>OBJECTIVE</b>To analyze and summarize clinical manifestation of hemolytic disease of the newborn (HDN) due to anti-M.</p><p><b>METHODS</b>Data of one case of HDN due to anti-M and the reports of 21 cases seen in the past 20 years at the home country were reviewed and analyzed.</p><p><b>RESULTS</b>There was an increasing number of reports of cases with HDN due to anti-M. Among the 22 cases, four were the first fetus. Of 18 infants, ten were male, and eight were female. The blood group was MN in 19/21 infants, and was M in 2/21 infants. The blood group was N in 10/21 mothers, and was NN in 11/21 mothers. Among the 18 infants, the direct antiglobulin test of 7 infants were positive, of 4 infants were dubiously positive, and of 7 infants was negative. Among the 16 infants, the antibody release test of 13 infants was positive, and of 3 infants were negative. Among 17 infants, the free antibody test of all was positive. Among the 21 mothers, the anti-M of IgG were positive in all mothers, and along with IgM in 11 mothers. The anti-M of IgG was positive in all infants. Mild or severe anemia and icterus were found in all cases. Among the 15 cases, jaundice was evident on the 1st day of life in 11 cases. Among 13 cases, marked elevation of both indirect- and direct-reacting bilirubin levels was reported in 4 cases. Phototherapy was applied when jaundice became evident. High-dose intravenous immunoglobulin was given to 4/15 cases. Exchange transfusion were performed in 8 of 22 cases. Three cases died, and 19 cases were cured.</p><p><b>CONCLUSION</b>HDN of varying degrees of severity has been reported in association with anti-M and can even lead to intrauterine deaths or requiring treatment with exchange transfusion. If the mother has a history of prior intrauterine deaths, abortion, hydrops fetalis, severe fetal anemia or infertile, MN blood group and anti-M antibodies should be tested after excluding the possibility of other causes and HDN due to ABO or Rh blood group incompatibility. As the efficacy of phototherapy increases, the role of exchange transfusion in acute management is rapidly decreasing. High-dose intravenous immunoglobulin and/or intramuscular metalloporphyrins may further reduce the need for exchange transfusion. The exchange transfusion may be performed through peripheral arterial (drawn out) and venous (infused in) lines.</p>