miR-326 Targets Antiapoptotic Bcl-xL and Mediates Apoptosis in Human Platelets

Platelets play crucial roles in hemostasis, thrombosis, wound healing, inflammation, angiogenesis, and tumor metastases. Because they are anucleated blood cells, platelets lack nuclear DNA, but they do contain mitochondrial DNA, which plays a key role in regulating apoptosis. Recent evidence has suggested that miRNAs are also involved in regulating gene expression and apoptosis in platelets. Our previous study showed that the expression of miR-326 increased visibly when apheresis platelets were stored in vitro. The antiapoptotic Bcl-2 family regulator Bcl-xL has been identified as a putative target of miR-326. In the present study, dual reporter luciferase assays were used to characterize the function of miR-326 in the regulation of the apoptosis of platelet cells. These assays demonstrated that miR-326 bound to the 3′-translated region of Bcl-xL. To directly assess the functional effects of miR-326 expression, levels of Bcl-xL and the apoptotic status of stored apheresis platelets were measured after transfection of miR-326 mimic or inhibitor. Results indicated that miR-326 inhibited Bcl-xL expression and induced apoptosis in stored platelets. Additionally, miR-326 inhibited Bcl-2 protein expression and enhanced Bak expression, possibly through an indirect mechanism, though there was no effect on the expression of Bax. The effect of miR-326 appeared to be limited to apoptosis, with no significant effect on platelet activation. These results provide new insight into the molecular mechanisms affecting differential platelet gene regulation, which may increase understanding of the role of platelet apoptosis in multiple diseases.     

Identification of Outer Membrane and Exoproteins of Carbapenem-Resistant Multilocus Sequence Type 258 Klebsiella pneumoniae

Carbapenem-resistant Klebsiella pneumoniae strains have emerged as a cause of life-threatening infections in susceptible individuals (e.g., transplant recipients and critically ill patients). Strains classified as multilocus sequence type (ST) 258 are among the most prominent causes of carbapenem-resistant K. pneumoniae infections worldwide, but the basis for the success of this lineage remains incompletely determined. To gain a more comprehensive view of the molecules potentially involved in the success of ST258, we used a proteomics approach to identify surface-associated and culture supernatant proteins produced by ST258. Protein samples were prepared from varied culture conditions in vitro, and were analyzed by a combination of two-dimensional electrophoresis and liquid chromatography followed by tandem mass spectrometry (LC-MS/MS). We identified a total of 193 proteins in outer membrane preparations from bacteria cultured in Luria-Bertani broth (LB) or RPMI 1640 tissue culture media (RPMI). Compared with LB, several iron-acquisition proteins, including IutA, HmuR, HmuS, CirA, FepA, FitA, FoxA, FhuD, and YfeX, were more highly expressed in RPMI. Of the 177 proteins identified in spent media, only the fimbrial subunit, MrkA, was predicted to be extracellular, a finding that suggests few proteins (or a limited quantity) are freely secreted by ST258. Notably, we discovered 203 proteins not reported in previous K. pneumoniae proteome studies. In silico modeling of proteins with unknown function revealed several proteins with beta-barrel transmembrane structures typical of porins, as well as possible host-interacting proteins. Taken together, these findings contribute several new targets for the mechanistic study of drug-resistance and pathogenesis by ST258 K. pneumoniae isolates.     

Exercise‐induced α‐ketoglutaric acid stimulates muscle hypertrophy and fat loss through OXGR1‐dependent adrenal activation

The authors approached the journal to correct a mistake in the data presented in Appendix␣Fig S3D. The authors state that the mouse images in Appendix␣Fig S3D mistakenly displayed images from Fig 2F and Appendix␣Fig S1F. The images in Appendix␣Fig S3D are herewith corrected. The authors state that this change does not affect the conclusions or the statistics. The source data for these panels have been added to the original publication.The authors note that the following sentence needs to be corrected from: Appendix Figure S3D. Original. Appendix Figure S3D. Corrected. “Interestingly, several well‐established accumulation signatures of succinate, malate, hypoxanthine, and xanthine induced by endurance exercise (Lewis et␣al, 2010) were found to be decreased by endurance exercise (Figs 1D and EV1A–D)”.to“Interestingly, several well‐established accumulation signatures of succinate, malate, hypoxanthine, and xanthine induced by endurance exercise (Lewis et␣al, 2010) were found to be decreased by resistance exercise (Figs 1D and EV1A–D)”.Further, the authors requested to amend the legend of Appendix␣Fig S3R to indicate that the same sample for the iWAT group, “WT+2%AKG” treatment, is shown in Fig 3P. The corrected legend reads: “(R‐S). Representative images (R) and quantification (S) of p‐HSL DAB staining from male OXGR1OE^AG mice treated with AKG for 12 weeks (n = 6 per group). The same sample is shown as in Fig 3P ”.The authors regret these errors and any confusion they may have caused. All authors approve of this correction.     

一株产琼胶酶细菌的分离、鉴定及其琼胶酶基本性质

【目的】分离海洋来源的琼胶酶产生菌,对其进行分类鉴定,并研究其所产琼胶酶的基本酶学性质,为琼胶酶的应用研究及开发利用奠定基础。【方法】通过以琼脂为唯一碳源的选择培养基分离产琼胶酶的菌株;利用16S rRNA基因序列分析、表型和生理生化特征对菌株进行鉴定;通过DNS-还原糖法测定琼胶酶活性;利用显色底物法测定琼胶酶的类型;对菌株所产琼胶酶粗酶的酶学性质进行初步研究。【结果】分离到一株产琼胶酶的菌株NTa,16S rRNA基因序列分析显示该菌株属于寡养单胞菌属(Stenotrophomonas sp.);该菌株主要产胞外琼胶酶,可分泌α-琼胶酶和β-琼胶酶;琼胶酶粗酶的最适反应温度和pH分别为40℃和7.0,并且琼胶酶在温度低于30℃,pH为7.0-9.0时稳定;Ca2+对琼胶酶粗酶具有促进作用,Ag+、Fe2+、Ba2+、Mn2+、Cu2+、Zn2+和Fe3+均可不同程度地抑制酶的活性;EDTA对琼胶酶粗酶活性具有抑制作用;琼胶酶粗酶对检测的抑制剂、去垢剂及变性剂有较好的抗性。【结论】海洋细菌Stenotrophomonas sp.NTa是一种新型的产琼胶酶菌株,可同时分泌α-琼胶酶和β-琼胶酶,具有潜在开发利用价值。     

Functional implications of squamosal suture size in paranthropus boisei

It has been hypothesized that the extensively overlapping temporal and parietal bones of the squamosal sutures in Paranthropus boisei are adaptations for withstanding loads associated with feeding. Finite element analysis (FEA) was used to investigate the biomechanical effects of suture size (i.e., the area of overlap between the temporal and parietal bones) on stress, strain energy, and strain ratio in the squamosal sutures of Pan troglodytes and P. boisei (specimen OH 5) during biting. Finite element models (FEMs) of OH 5 and a P. troglodytes cranium were constructed from CT scans. These models contain sutures that approximate the actual suture sizes preserved in both crania. The FEM of Pan was then modified to create two additional FEMs with squamosal sutures that are 50% smaller and 25% larger than those in the original model. Comparisons among the models test the effect of suture size on the structural integrity of the squamosal suture as the temporal squama and parietal bone move relative to each other during simulated premolar biting. Results indicate that with increasing suture size there is a decreased risk of suture failure, and that maximum stress values in the OH 5 suture were favorable compared to values in the Pan model with the normal suture size. Strain ratios suggest that shear is an important strain regime in the squamosal suture. This study is consistent with the hypothesis that larger sutures help reduce the likelihood of suture failure under high biting loads. Am J Phys Anthropol 153:260–268, 2014. © 2013 Wiley Periodicals, Inc.     

Genetic diversity in Puerto Rico and its implications for the peopling of the Island and the West Indies

Puerto Rico and the surrounding islands rest on the eastern fringe of the Caribbean's Greater Antilles, located less than 100 miles northwest of the Lesser Antilles. Puerto Ricans are genetic descendants of pre‐Columbian peoples, as well as peoples of European and African descent through 500 years of migration to the island. To infer these patterns of pre‐Columbian and historic peopling of the Caribbean, we characterized genetic diversity in 326 individuals from the southeastern region of Puerto Rico and the island municipality of Vieques. We sequenced the mitochondrial DNA (mtDNA) control region of all of the samples and the complete mitogenomes of 12 of them to infer their putative place of origin. In addition, we genotyped 121 male samples for 25 Y‐chromosome single nucleotide polymorphism and 17 STR loci. Approximately 60% of the participants had indigenous mtDNA haplotypes (mostly from haplogroups A2 and C1), while 25% had African and 15% European haplotypes. Three A2 sublineages were unique to the Greater Antilles, one of which was similar to Mesoamerican types, while C1b haplogroups showed links to South America, suggesting that people reached the island from the two distinct continental source areas. However, none of the male participants had indigenous Y‐chromosomes, with 85% of them instead being European/Mediterranean and 15% sub‐Saharan African in origin. West Eurasian Y‐chromosome short tandem repeat haplotypes were quite diverse and showed similarities to those observed in southern Europe, North Africa and the Middle East. These results attest to the distinct, yet equally complex, pasts for the male and female ancestors of modern day Puerto Ricans. Am J Phys Anthropol 155:352–368, 2014. © 2014 Wiley Periodicals, Inc.     

Mapping bone cell distributions to assess ontogenetic origin of primate midfacial form

Midfacial reduction in primates has been explained as a byproduct of other growth patterns, especially the convergent orbits. This is at once an evolutionary and developmental explanation for relatively short snouts in most modern primates. Here, we use histological sections of perinatal nonhuman primates (tamarin, tarsier, loris) to investigate how orbital morphology emerges during ontogeny in selected primates compared to another euarchontan (Tupaia glis). We annotated serial histological sections for location of osteoclasts or osteoblasts, and used these to create three‐dimensional “modeling maps” showing perinatal growth patterns of the facial skeleton. In addition, in one specimen we transferred annotations from histological sections to CT slices, to create a rotatable 3D volume that shows orbital modeling. Our findings suggest that growth in the competing orbital and neurocranial functional matrices differs among species, influencing modeling patterns. Distinctions among species are observed in the frontal bone, at a shared interface between the endocranial fossa and the orbit. The medial orbital wall is extensively resorptive in primates, whereas the medial orbit is generally depositional in Tupaia. As hypothesized, the orbital soft tissues encroach on available interorbital space. However, eye size cannot, by itself, explain the extent of reduction of the olfactory recess. In Loris, the posterior portion of medial orbit differed from the other primates. It showed evidence of outward drift where the olfactory bulb increased in cross‐sectional area. We suggest the olfactory bulbs are significant to orbit position in strepsirrhines, influencing an expanded interorbital breadth at early stages of development. Am J Phys Anthropol 154:424–435, 2014. © 2014 Wiley Periodicals, Inc.     

Technical Note: Calcium and carbon stable isotope ratios as paleodietary indicators

Calcium stable isotope ratios are hypothesized to vary as a function of trophic level. This premise raises the possibility of using calcium stable isotope ratios to study the dietary behaviors of fossil taxa and to test competing hypotheses on the adaptive origins of euprimates. To explore this concept, we measured the stable isotope composition of contemporary mammals in northern Borneo and northwestern Costa Rica, two communities with functional or phylogenetic relevance to primate origins. We found that bone collagen δ¹³C and δ¹⁵N values could differentiate trophic levels in each assemblage, a result that justifies the use of these systems to test the predicted inverse relationship between bioapatite δ¹³C and δ⁴⁴Ca values. As expected, taxonomic carnivores (felids) showed a combination of high δ¹³C and low δ⁴⁴Ca values; however, the δ⁴⁴Ca values of other faunivores were indistinguishable from those of primary consumers. We suggest that the trophic insensitivity of most bioapatite δ⁴⁴Ca values is attributable to the negligible calcium content of arthropod prey. Although the present results are inconclusive, the tandem analysis of δ⁴⁴Ca and δ¹³C values in fossils continues to hold promise for informing paleodietary studies and we highlight this potential by drawing attention to the stable isotope composition of the Early Eocene primate Cantius. Am J Phys Anthropol 154:633–643, 2014. © 2014 Wiley Periodicals, Inc.