Analysis of DNA sequences of six chloroplast and nuclear genes suggests incongruence, introgression, and incomplete lineage sorting in the evolution of Lespedeza (Fabaceae)

The genus Lespedeza (Fabaceae) consists of 40 species disjunctively distributed in East Asia and eastern North America. Phylogenetic relationships of all Lespedeza species and closely related genera were reconstructed using maximum parsimony, maximum likelihood, and Bayesian analyses of sequence data from five chloroplast (rpl16, rpl32-trnL, rps16-trnQ, trnL-F, and trnK/matK) and one nuclear (ITS) DNA regions. All analyses yielded consistent relationships among major lineages. Our results suggested that Campylotropis, Kummerowia, and Lespedeza are monophyletic, respectively. Lespedeza is resolved as sister to Kummerowia and these two together are further sister to Campylotropis. Neither of the two subgenera, subgen. Lespedeza and subgen. Macrolespedeza, in Lespedeza based on morphological characters, is recovered as monophyletic. Within Lespedeza, the North American clade is retrieved as sister to the Asian clade. The nuclear and chloroplast markers showed incongruent phylogenetic signals at shallow-level phylogeny, which may point to either introgression or incomplete lineage sorting in Lespedeza. The divergence times within Lespedeza and among related genera were estimated using Bayesian approach with BEAST. It is assumed that following the divergence between Kummerowia and Lespedeza in Asia in the late Miocene, the ancestor of Lespedeza diverged into the North American and the Asian lineages. The North American ancestor quickly migrated to North America through the Bering land bridge in the late Miocene. The North American and Asian lineages started to diversify almost simultaneously in the late Miocene but resulted in biased numbers of species in two continents.     

FIT2 organizes lipid droplet biogenesis with ER tubule-forming proteins and septins

Lipid droplets (LDs) are critical for lipid storage and energy metabolism. LDs form in the endoplasmic reticulum (ER). However, the molecular basis for LD biogenesis remains elusive. Here, we show that fat storage–inducing transmembrane protein 2 (FIT2) interacts with ER tubule-forming proteins Rtn4 and REEP5. The association is mainly transmembrane domain based and stimulated by oleic acid. Depletion of ER tubule-forming proteins decreases the number and size of LDs in cells and Caenorhabditis elegans, mimicking loss of FIT2. Through cytosolic loops, FIT2 binds to cytoskeletal protein septin 7, an interaction that is also required for normal LD biogenesis. Depletion of ER tubule-forming proteins or septins delays nascent LD formation. In addition, FIT2-interacting proteins are up-regulated during adipocyte differentiation, and ER tubule-forming proteins, septin 7, and FIT2 are transiently enriched at LD formation sites. Thus, FIT2-mediated nascent LD biogenesis is facilitated by ER tubule-forming proteins and septins.     

Functional expression of α7 nicotinic acetylcholine receptors in human periodontal ligament fibroblasts and rat periodontal tissues

Tobacco smoking is the main risk factor associated with chronic periodontitis, but the mechanisms that underlie this relationship are largely unknown. Recent reports proposed that nicotine plays an important role in tobacco-related morbidity by acting through the nicotinic acetylcholine receptors (nAChRs) expressed by non-neuronal cells. The aim of this study was to investigate whether α7 nAChR was expressed in periodontal tissues and whether it functions by regulating IL-1β in the process of periodontitis. In vitro, human periodontal ligament (PDL) cells were cultured with 10⁻¹² M of nicotine and/or 10⁻⁹ M of alpha-bungarotoxin (α-Btx), a α7 nAChR antagonist. The expression of α7 nAChR and IL-1β in PDL cells and the effects of nicotine/α-Btx administration on their expression were explored. In vivo, an experimental periodontitis rat model was established, and the effects of nicotine/α-Btx administration on expression of α7 nAChR and development of periodontitis were evaluated. We found that α7 nAChR was present in human PDL cells and rat periodontal tissues. The expressions of α7 nAChR and IL-1β were significantly increased by nicotine administration, whereas α-Btx treatment partially suppressed these effects. This study was the first to demonstrate the functional expression of α7 nAChR in human PDL cells and rat periodontal tissues. Our results may be pertinent to a better understanding of the relationships among smoking, nicotine, and periodontitis.     

De novo MECP2 duplication derived from paternal germ line result in dysmorphism and developmental delay

Xq28 duplications encompassing the methyl CpG binding protein 2 (MECP2) in males exhibit a distinct phenotype, including developmental delay, facial dysmorphism, muscular hypotonia, intellectual disability, poor or absent speech, recurrent infections and early death. The vast majority of affected males inherit the MECP2 duplication from their usually asymptomatic carrier mothers. Only a few cases with Xq28 duplication originating from de novo unbalanced X/Y translocation have been reported and the paternal origin of the aberration has only been validated in three males in the related literature. Here we present a karyotypically normal male with features characteristic of the MECP2 duplication syndrome. The genome-wide SNP genotyping shows a de novo 2.26-Mb duplication from Xq28 to the terminus. The genotypes of the SNPs within the duplicated region indicated a paternal origin. Furthermore, the results of fluorescence in situ hybridization (FISH) indicated a novel Xq:Yp translocation, characterized as der(Y)t(Y;X)(p11.32;q28), which suggests an aberrant that occurred during spermatogenesis. The phenotype is compared to the previously reported cases with Xq28 duplication originated from an unbalanced X/Y translocation, and there was no specific part of the phenotype that could be contributed to the origin of parental imbalances. This report further highlights the capacity of high-molecular cytogenetic methods, such as SNP array and FISH, in the identification of submicroscopic rearrangement, structural configuration and parental origin of aberrant while in the evaluation of children with idiopathic developmental delay and intellectual disability.     

Assessment of hepatoprotective potential of Radix Fici Hirtae on alcohol-induced liver injury in Kunming mice

ObjectiveThe objective of the present study was to investigate the hepatoprotective role of Radix Fici Hirtae on acute alcohol-induced liver injury in mice.MethodsThe component of Radix Fici Hirtae was extracted using petroleum ether, chloroform, ethyl acetate and n-butanol and divided into three dose groups of high, medium and low according to the clinical man's normal dose of the 50 g crude drug/d (0.83 g/kg body weight). Saline in concentration of 10 mg/mL, 5 mg/mL and 2.5 mg/mL and a dose of mouse lavage (0.2 mL/10 g mouse body weight) were added to the solution. Histopathlogical analysis of liver was performed. Finally, liver protection was validated by examining the effect of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AKP), and lactate dehydrogenase (LDH) on the hepatic function of mice in alcohol-induced liver injury model.ResultsExcept for group with saturated n-butyl alcohol, for the rest of the groups, pathological changes of hepatic lipid and inflammatory cells infiltration were alleviated and liver sinus was normal. As compared to model group, the concentrations of AST, ALT, AKP and LDH in chloroform groups and ethyl acetate groups were significantly decreased.ConclusionsExtracts of Radix Fici Hirtae are effective for the prevention of alcohol-induced hepatic damage in mice. The results revealed that extracts of Radix Fici Hirtae could be used as hepatoprotective agent.     

Aldosterone induction of hepatic stellate cell contraction through activation of RhoA/ROCK-2 signaling pathway

The RhoA/ROCK-2 signaling pathway is necessary for activated hepatic stellate cell (HSC) contraction. HSC contraction plays an important role in the pathogenesis of cirrhosis and portal hypertension. This study investigated whether aldosterone contributes to HSC contraction by activation of the RhoA/ROCK-2 signaling pathway. Primary HSCs were isolated from Sprague-Dawley rats via in situ pronase/collagenase perfusion. We found that aldosterone enhanced the contraction of a collagen lattice seeded with HSCs. This induced contraction was suppressed by the mineralcorticoid receptor (MR) inhibitor spironolactone, the ROCK-2 inhibitor Y27632, and the angiotensin II type 1 receptor (AT(1)R) inhibitor irbesartan. Moreover, actin fiber staining showed that aldosterone significantly increased actin fiber formation in HSCs. Pre-incubating with spironolactone, Y27632, or irbesartan inhibited the aldosterone-induced actin fiber reorganization. Molecularly, the effect of aldosterone on activation of HSC contraction was mediated by phosphorylated myosin light chain (P-MLC) through the RhoA/ROCK-2 signaling pathway. All these inhibitors had the ability to block aldosterone-induced protein expressions in the RhoA/ROCK-2/P-MLC cascade in HSCs. Taken together, our current study suggests that aldosterone induces contraction of activated HSCs through the activation of the RhoA/ROCK-2 signaling pathway. This finding may provide a potential therapeutic target for control of cirrhosis and portal hypertension.     

Expression of the large isoform of ribulose-1,5-bisphosphate carboxylase/oxygenase activase gene driven by rbcS promoter in Oryza sativa enhances the photosynthetic capacity

In order to investigate the effect of large isoform of ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) activase (RuBPCO-A) on photosynthesis, cDNA of the enzyme (rca) was transferred to rice cultivars (Oryza sativa f. japonica cv. Nipponbare) under the control of RuBPCO small subunit gene promoter (rbcS) via Agrobacterium tumefaciens-mediated transformation. Transgenic rice plants were identified by polymerase chain reaction (PCR) and Southern and Western blot analyses. Net photosynthetic rate (P _N) values of the T₁ transgenic lines 34 (T34) and 40 (T40) were 45.26 and 46.32 % higher than that of the control plants, respectively. At the same time, their carboxylation efficiency and RuBPCO initial activity, quantum yield of electron transport in photosystem 2 (Φ_PS2), and steady state photochemical fluorescence quenching (q_P) increased. In addition, heading time of the transgenic rice was advanced. Thus increasing the amount of large isoform of RuBPCO-A in the transgenic rice might have a stimulatory effect on both photosynthesis and plant growth.