Case report: Gitelman syndrome with diabetes: Confirmed by both hydrochlorothiazide test and genetic testing.

RATIONALE: Gitelman syndrome (GS) is an autosomal recessive tubulopathy caused by mutations of the SLC12A3 gene. It is characterized by hypokalemic metabolic alkalosis, hypomagnesemia and hypocalciuria. Hypokalemia, hypomagnesemia, and increased renin-angiotensin-aldosterone system (RAAS) activity can cause glucose metabolism dysfunction. The diagnosis of GS includes clinical diagnosis, genetic diagnosis and functional diagnosis. The gene diagnosis is the golden criterion while as functional diagnosis is of great value in differential diagnosis. The hydrochlorothiazide (HCT) test is helpful to distinguish GS from batter syndrome, but few cases have been reported to have HCT testing. PATIENT CONCERNS: A 51-year-old Chinese woman presented to emergency department because of intermittent fatigue for more than 10 years. DIAGNOSES: Laboratory test results showed hypokalemia, hypomagnesemia, hypocalciuria and metabolic alkalosis. The HCT test showed no response. Using next-generation and Sanger sequencing, we identified 2 heterozygous missense variants (c.533C > T:p.S178L and c.2582G > A:p.R861H) in the SLC12A3 gene. In addition, the patient was diagnosed with type 2 diabetes mellitus 7 years ago. Based on these findings, the patient was diagnosed with GS with type 2 diabetic mellitus (T2DM). INTERVENTIONS: She was given potassium and magnesium supplements, and dapagliflozin was used to control her blood glucose. OUTCOMES: After treatments, her fatigue symptoms were reduced, blood potassium and magnesium levels were increased, and blood glucose levels were well controlled. LESSONS: When GS is considered in patients with unexplained hypokalemia, the HCT test can be used for differential diagnosis, and genetic testing can be continued to confirm the diagnosis when conditions are available. GS patients often have abnormal glucose metabolism, which is mainly caused by hypokalemia, hypomagnesemia, and secondary activation of RAAS. When a patient is diagnosed with GS and type 2 diabetes, sodium-glucose cotransporter 2 inhibitors (SGLT2i) can be used to control the blood glucose level and assist in raising blood magnesium.

Chemoselective Cleavage of Acylsulfonamides and Sulfonamides by Aluminum Halides.

The chemoselective cleavage of C-N bonds of amides, sulfonamides, and acylsulfonamides by aluminum halides is described. AlCl3 and AlI3 display complementary reactivities toward N-alkyl and N-acyl moieties. N-Alkylacylsulfonamides, secondary N-(tert-butyl)sulfonamides, and tertiary N-(tert-butyl)amides undergo N-dealkylation upon treatments with AlI3 generated in situ from aluminum and iodine in acetonitrile. In contrast, AlCl3 preferentially cleaves N-acyl groups of tertiary and secondary sulfonamides.

Alternative splicing of DSP1 enhances snRNA accumulation by promoting transcription termination and recycle of the processing complex.

Small nuclear RNAs (snRNAs) are the basal components of the spliceosome and play crucial roles in splicing. Their biogenesis is spatiotemporally regulated. However, related mechanisms are still poorly understood. Defective in snRNA processing (DSP1) is an essential component of the DSP1 complex that catalyzes plant snRNA 3'-end maturation by cotranscriptional endonucleolytic cleavage of the primary snRNA transcripts (presnRNAs). Here, we show that DSP1 is subjected to alternative splicing in pollens and embryos, resulting in two splicing variants, DSP1α and DSP1ß. Unlike DSP1α, DSP1ß is not required for presnRNA 3'-end cleavage. Rather, it competes with DSP1α for the interaction with CPSF73-I, the catalytic subunit of the DSP1 complex, which promotes efficient release of CPSF73-I and the DNA-dependent RNA polymerease II (Pol II) from the 3' end of snRNA loci thereby facilitates snRNA transcription termination, resulting in increased snRNA levels in pollens. Taken together, this study uncovers a mechanism that spatially regulates snRNA accumulation.

DSP1 and DSP4 Act Synergistically in Small Nuclear RNA 3' End Maturation and Pollen Growth.

Small nuclear RNAs (snRNAs) play essential roles in spliceosome assembly and splicing. Most snRNAs are transcribed by the DNA-dependent RNA polymerase II (Pol II) and require 3'-end endonucleolytic cleavage. We have previously shown that the Arabidopsis (Arabidopsis thaliana) Defective in snRNA Processing 1 (DSP1) complex, composed of at least five subunits, is responsible for snRNA 3' maturation and is essential for plant development. Yet it remains unclear how DSP1 complex subunits act together to process snRNAs. Here, we show that DSP4, a member of the metallo-ß-lactamase family, physically interacts with DSP1 through its ß-Casp domain. Null dsp4-1 mutants have pleiotropic developmental defects, including impaired pollen development and reduced pre-snRNA transcription and 3' maturation, resembling the phenotype of the dsp1-1 mutant. Interestingly, dsp1-1 dsp4-1 double mutants exhibit complete male sterility and reduced pre-snRNA transcription and 3'-end maturation, unlike dsp1-1 or dsp4-1 In addition, Pol II occupancy at snRNA loci is lower in dsp1-1 dsp4-1 than in either single mutant. We also detected miscleaved pre-snRNAs in dsp1-1 dsp4-1, but not in dsp1-1 or dsp4-1 Taken together, these data reveal that DSP1 and DSP4 function is essential for pollen development, and that the two cooperatively promote pre-snRNA transcription and 3'-end processing efficiency and accuracy.

Protective Effect of Selenium on Aflatoxin B1-Induced Testicular Toxicity in Mice.

Aflatoxins have been considered as one of the major risk factors of male infertility, and aflatoxin B1 (AFB1) is the most highly toxic and prevalent member of the aflatoxins family. Selenium (Se), an essential nutritional trace mineral for normal testicular development and male fertility, has received extensive intensive on protective effects of male reproductive system due to its potential antioxidant and activating testosterone synthesis. To investigate the protective effect of Se on AFB1-induced testicular toxicity, the mice were orally administered with AFB1 (0.75 mg/kg) and Se (0.2 mg/kg or 0.4 mg/kg) for 45 days. We found that that Se elevated testes index, sperm functional parameters (concentration, malformation, and motility), and the level of serum testosterone in AFB1-exposed mice. Moreover, our results showed that Se attenuated the AFB1-induced oxidative stress and the reduction of testicular testosterone synthesis enzyme protein expression such as steroidogenic acute regulatory protein (StAR), P450 side-chain cleavage (P450scc), and 17ß-hydroxysteroid dehydrogenase (17ß-HSD) in AFB1-exposed mice. These results demonstrated that Se conferred protection against AFB1-induced testicular toxicity and can be attributed to its antioxidant and increased testosterone level by stimulating protein expression of StAR and testosterone synthetic enzymes.

[Comparison of Therapeutic Efficacy for Neonatal ABO Hemolytic Disease Treated with Intravenous Immunoglobin G by Different Modes of Administration].

OBJECTIVE: To compare the therapeutic efficacy of patients with neonatal ABO hemolytic disease treated with introvenous immunoglobin G (IVIG) by different modes of administration. METHODS: Ninety-three in patients with neonatal ABO hemolytic disease treated in our hospital were divided into group A (31 cases), B(31 cases) and C (31 cases). Based on basic treatment, the patients in group A were treated by a single high dose of IVIG (1 g/kg), patients in group B were treated by multiple low-dose of IVIG (0.5 g/kg), and the patients in group C treated by placebo without IVIG used as controls. The phototherapy time, jaundice time in 3 groups were observed; the total bilirubin levels in 3 groups were compared before and after treatment; the incidence of anemia, the rate of blood transfusion and the occurrence of bilirubin encephalopathy were compared after treatment between 3 groups. RESULTS: The phototherapy time, jaundice time in group A were statistically significantly shorter than those in the group B and C (P<0.05), but there was not statistical significantly difference between group B and C(P>0.05). Before treatment, serum TBIL level in 3 groups was not significantly different (P>0.05); and after treatment for 24 h and 48 h, the serum TBIL levels in group A were significantly lower than that in group B and C (P<0.05); after treatment for 72 h, the serum TBIL level in group A was all lower than 34.2 µmol/L; before treatment, Hb levels in 3 groups were not significantly different (P>0.05); Hb level in group A was significantly higher than that in group B and C after treatment for 24 h, 48 h and 72 h (P<0.05). The incidence of anemia in group A after treatment was significantly lower than that in group B and C, and that in group B significantly lower than that in group C(P<0.05). The rate of blood transfusion in group A was significantly lower than that in the group B and C (P<0.05); the rate of blood transfusion was not statistically significantly different between group B and C(P>0.05). CONCLUSION: The single high dose of IVIG infusion can effectively reduce the serum TBIL level, shorten treatment time and reduce the incidence of anemia and blood transfusion, so the therapeutic efficacy is significantly improved.

snRNA 3' End Processing by a CPSF73-Containing Complex Essential for Development in Arabidopsis.

Uridine-rich small nuclear RNAs (snRNAs) are the basal components of the spliceosome and play essential roles in splicing. The biogenesis of the majority of snRNAs involves 3' end endonucleolytic cleavage of the nascent transcript from the elongating DNA-dependent RNA ploymerase II. However, the protein factors responsible for this process remain elusive in plants. Here, we show that DEFECTIVE in snRNA PROCESSING 1 (DSP1) is an essential protein for snRNA 3' end maturation in Arabidopsis. A hypomorphic dsp1-1 mutation causes pleiotropic developmental defects, impairs the 3' end processing of snRNAs, increases the levels of snRNA primary transcripts (pre-snRNAs), and alters the occupancy of Pol II at snRNA loci. In addition, DSP1 binds snRNA loci and interacts with Pol-II in a DNA/RNA-dependent manner. We further show that DSP1 forms a conserved complex, which contains at least four additional proteins, to catalyze snRNA 3' end maturation in Arabidopsis. The catalytic component of this complex is likely the cleavage and polyadenylation specificity factor 73 kDa-I (CSPF73-I), which is the nuclease cleaving the pre-mRNA 3' end. However, the DSP1 complex does not affect pre-mRNA 3' end cleavage, suggesting that plants may use different CPSF73-I-containing complexes to process snRNAs and pre-mRNAs. This study identifies a complex responsible for the snRNA 3' end maturation in plants and uncovers a previously unknown function of CPSF73 in snRNA maturation.

Soybean GmbZIP123 gene enhances lipid content in the seeds of transgenic Arabidopsis plants.

Soybean is one of most important oil crops and a significant increase in lipid content in soybean seeds would facilitate vegetable oil production in the world. Although the pathways for lipid biosynthesis in higher plants have been uncovered, our understanding of regulatory mechanism controlling lipid accumulation is still limited. In this study, we identified 87 transcription factor genes with a higher abundance at the stage of lipid accumulation in soybean seeds. One of these genes, GmbZIP123, was selected to further study its function in regulation of lipid accumulation. Overexpression of GmbZIP123 enhanced lipid content in the seeds of transgenic Arabidopsis thaliana plants. The GmbZIP123 transgene promoted expression of two sucrose transporter genes (SUC1 and SUC5) and three cell-wall invertase genes (cwINV1, cwINV3, and cwINV6) by binding directly to the promoters of these genes. Consistently, the cell-wall invertase activity and sugar translocation were all enhanced in siliques of GmbZIP123 transgenic plants. Higher levels of glucose, fructose, and sucrose were also found in seeds of GmbZIP123 transgenic plants. These results suggest that GmbZIP123 may participate in regulation of lipid accumulation in soybean seeds by controlling sugar transport into seeds from photoautotrophic tissues. This study provides novel insights into the regulatory mechanism for lipid accumulation in seeds and may facilitate improvements in oil production in soybean and other oil crops through genetic manipulation of the GmbZIP123 gene.

A novel rice gene, NRR responds to macronutrient deficiency and regulates root growth.

To better understand the response of rice to nutrient stress, we have taken a systematic approach to identify rice genes that respond to deficiency of macronutrients and affect rice growth. We report here the expression and biological functions of a previously uncharacterized rice gene that we have named NRR (nutrition response and root growth). NRR is alternatively spliced, producing two 5'-coterminal transcripts, NRRa and NRRb, encoding two proteins of 308 and 223 aa, respectively. Compared to NRRb, NRRa possesses an additional CCT domain at the C-terminus. Expression of NRR in rice seedling roots was significantly influenced by deficiency of macronutrients. Knock-down of expression of NRRa or NRRb by RNA interference resulted in enhanced rice root growth. By contrast, overexpression of NRRa in rice exhibited significantly retarded root growth. These results revealed that both NRRa and NRRb played negative regulatory roles in rice root growth. Our findings suggest that NRRa and NRRb, acting as the key components, modulate the rice root architecture with the availability of macronutrients.

An R2R3-type transcription factor gene AtMYB59 regulates root growth and cell cycle progression in Arabidopsis.

MYB proteins play important roles in eukaryotic organisms. In plants, the R1R2R3-type MYB proteins function in cell cycle control. However, whether the R2R3-type MYB protein is also involved in the cell division process remains unknown. Here, we report that an R2R3-type transcription factor gene, AtMYB59, is involved in the regulation of cell cycle progression and root growth. The AtMYB59 protein is localized in the nuclei of onion epidermal cells and has transactivation activity. Expression of AtMYB59 in yeast cells suppresses cell proliferation, and the transformants have more nuclei and higher aneuploid DNA content with longer cells. Mutation in the conserved domain of AtMYB59 abolishes its effects on yeast cell growth. In synchronized Arabidopsis cell suspensions, the AtMYB59 gene is specifically expressed in the S phase during cell cycle progression. Expression and promoter-GUS analysis reveals that the AtMYB59 gene is abundantly expressed in roots. Transgenic plants overexpressing AtMYB59 have shorter roots compared with wild-type plants (Arabidopsis accession Col-0), and around half of the mitotic cells in root tips are at metaphase. Conversely, the null mutant myb59-1 has longer roots and fewer mitotic cells at metaphase than Col, suggesting that AtMYB59 may inhibit root growth by extending the metaphase of mitotic cells. AtMYB59 regulates many downstream genes, including the CYCB1;1 gene, probably through binding to MYB-responsive elements. These results support a role for AtMYB59 in cell cycle regulation and plant root growth.