Methods to Investigate the Regulatory Role of Small RNAs and Ribosomal Occupancy of <em>Plasmodium falciparum</em>

The genetic variation responsible for the sickle cell allele (HbS) enables erythrocytes to resist infection by the malaria parasite, P. falciparum. The ...

Duke University School of Medicine

Peripheral arterial disease (PAD) caused by occlusive atherosclerosis of the lower extremity has 2 major clinical manifestations. Critical limb ischemia is characterized by rest pain and/or tissue loss and has a > or = 40% risk of death and major amputation. Intermittent claudication causes pain on walking, has no tissue loss, and has amputation plus mortality rates of 2% to 4% per year. Progression from claudication to limb ischemia is infrequent. Risk factors in most PAD patients overlap. Thus, we hypothesized that genetic variations may be linked to presence or absence of tissue loss in PAD.

A quantitative trait locus (LSq-1) on mouse chromosome 7 is linked to the absence of tissue loss after surgical hindlimb ischemia.

Human mature erythrocytes are terminally differentiated cells that have lost their nuclei and organelles during development. Even though mature erythrocytes lack ribosomal and other large-sized RNAs, they still retain small-sized RNAs. We have recently shown that there are abundant and diverse species of microRNAs in mature erythrocytes through the use of several different techniques, including northern blot, miRNA microarray, and real-time PCR. Furthermore, fractionation and genomic analysis has revealed that erythrocyte microRNA expression is different from that of reticulocytes or leukocytes and that mature erythrocytes contribute the majority of microRNA expression in whole blood. Therefore, global analysis of microRNA expression in circulating erythrocytes has the potential to provide mechanistic insights into erythrocyte biology and erythrocyte-related disorders. Here, we have provided the detailed methods for isolating and characterizing the microRNAs from human mature erythrocytes to enable such researches into human diseases involving erythrocytes.

Isolation and characterization of microRNAs of human mature erythrocytes.

In the malaria parasite Plasmodium falciparum, global studies of translational regulation have been hampered by the inability to isolate malaria polysomes. We describe here a novel method for polysome profiling in P. falciparum, a powerful approach which allows both a global view of translation and the measurement of ribosomal loading and density for specific mRNAs. Simultaneous lysis of infected erythrocytes and parasites releases stable, intact malaria polysomes, which are then purified by centrifugation through a sucrose cushion. The polysomes are resuspended, separated by velocity sedimentation and then fractionated, yielding a characteristic polysome profile reflecting the global level of translational activity in the parasite. RNA isolated from specific fractions can be used to determine the density of ribosomes loaded onto a particular transcript of interest, and is free of host ribosome contamination. Thus, our approach opens translational regulation in malaria to genome-wide analysis.

Polysome profiling of the malaria parasite Plasmodium falciparum.

Within solid tumor microenvironments, lactic acidosis, and hypoxia each have powerful effects on cancer pathophysiology. However, the influence that these processes exert on each other is unknown. Here, we report that a significant portion of the transcriptional response to hypoxia elicited in cancer cells is abolished by simultaneous exposure to lactic acidosis. In particular, lactic acidosis abolished stabilization of HIF-1α protein which occurs normally under hypoxic conditions. In contrast, lactic acidosis strongly synergized with hypoxia to activate the unfolded protein response (UPR) and an inflammatory response, displaying a strong similarity to ATF4-driven amino acid deprivation responses (AAR). In certain breast tumors and breast tumor cells examined, an integrative analysis of gene expression and array CGH data revealed DNA copy number alterations at the ATF4 locus, an important activator of the UPR/AAR pathway. In this setting, varying ATF4 levels influenced the survival of cells after exposure to hypoxia and lactic acidosis. Our findings reveal that the condition of lactic acidosis present in solid tumors inhibits canonical hypoxia responses and activates UPR and inflammation responses. Furthermore, these data suggest that ATF4 status may be a critical determinant of the ability of cancer cells to adapt to oxygen and acidity fluctuations in the tumor microenvironment, perhaps linking short-term transcriptional responses to long-term selection for copy number alterations in cancer cells.

Functional interaction between responses to lactic acidosis and hypoxia regulates genomic transcriptional outputs.

Eritrociti che trasportano un allele variante di emoglobina (HbS), che causa la malattia di cellule di falce e resiste all&#39;infezione con il parassita Plasmodium falciparum malaria. Le basi molecolari di questa resistenza, che &egrave; stata a lungo riconosciuta come multifattoriale, rimane non completamente capita. Qui vi mostriamo che la composizione microRNA (miRNA), HBA eterozigoti o omozigoti HbSS eritrociti, contribuisce alla resistenza contro p. falciparum. Durante il ciclo di vita di intraerythrocytic di p. falciparum, un sottoinsieme di eritrociti miRNAs traslocano in parassita. Due miRNAs, miR-451 e let-7i, erano altamente arricchito negli eritrociti HBA e HbSS, e questi miRNAs, insieme a miR-223, regolato negativamente la crescita del parassita. Sorprendentemente, abbiamo trovato che miR-451 e let-7i integrato nel parassita essenziale Messaggero RNAs e, tramite caricamento ribosomiale compromessa, ha provocato l&#39;inibizione traslazionale. Quindi, gli eritrociti cellule falciformi esibiscono cella-intrinseca resistenza alla malaria in parte attraverso un&#39;attivit&agrave; di miRNA atipico, che pu&ograve; rappresentare una strategia di difesa ospite unico contro agenti patogeni eucarioti complessi.

Traslocazione di falciforme degli eritrociti microRNA in Plasmodium falciparum inibisce la traduzione di parassita e contribuisce alla resistenza della malaria.

&#x643A;&#x5E26;&#x53D8;&#x5F02;&#x8840;&#x7EA2;&#x86CB;&#x767D;&#x57FA;&#x56E0; (HbS)&#xFF0C;&#x800C;&#x5BFC;&#x81F4;&#x9570;&#x72B6;&#x7EC6;&#x80DE;&#x75C5;&#x548C;&#x6297;&#x62D2;&#x7684;&#x6076;&#x6027;&#x759F;&#x75BE;&#x5BC4;&#x751F;&#x866B;&#x759F;&#x539F;&#x866B;&#x611F;&#x67D3;&#x7684;&#x7EA2;&#x7EC6;&#x80DE;&#x3002;&#x8FD9;&#x79CD;&#x963B;&#x529B;&#xFF0C;&#x957F;&#x671F;&#x4EE5;&#x6765;&#x88AB;&#x516C;&#x8BA4;&#x4E3A;&#x7EFC;&#x5408;&#x8BC4;&#x5224;&#xFF0C;&#x5176;&#x4E2D;&#x7684;&#x5206;&#x5B50;&#x57FA;&#x7840;&#x4ECD;&#x7136;&#x662F;&#x672A;&#x5B8C;&#x5168;&#x7406;&#x89E3;&#x7684;&#x3002;&#x5728;&#x8FD9;&#x91CC;&#x6211;&#x4EEC;&#x663E;&#x793A;&#x7684;&#x6C34;&#x5E73;&#x53CA; microRNA (&#x7C73;&#x5C14;) &#x7EC4;&#x6210;&#xFF0C;Hba &#x6742;&#x5408;&#x6027;&#x6216;&#x7EAF;&#x5408; HbSS &#x7EA2;&#x7EC6;&#x80DE;&#xFF0C;&#x6709;&#x52A9;&#x4E8E;&#x62B5;&#x6297;&#x759F;&#x539F;&#x866B;&#x3002;&#x671F;&#x95F4;&#x5E76;&#x759F;&#x539F;&#x866B;&#x7684;&#x751F;&#x547D;&#x5468;&#x671F;&#xFF0C;&#x7EA2;&#x7EC6;&#x80DE; Mirna &#x7684;&#x5B50;&#x96C6;&#x8F6C;&#x79FB;&#x5230;&#x8FD9;&#x79CD;&#x5BC4;&#x751F;&#x866B;&#x3002;&#x4E24;&#x4E2A; Mirna&#xFF0C;&#x548C;&#x5E73;&#x53F7;&#x7A7A;&#x95F4;&#x7AD9; 451 &#x548C;&#x8BA9;-7i &#x9AD8;&#x6D53;&#x7F29; Hba &#x548C; HbSS &#x7EA2;&#x7EC6;&#x80DE;&#x53CA;&#x8FD9;&#x4E9B; Mirna &#x4E0E;&#x548C;&#x5E73;&#x53F7;&#x7A7A;&#x95F4;&#x7AD9;-223&#xFF0C;&#x4E0D;&#x5229;&#x76D1;&#x7BA1;&#x759F;&#x539F;&#x866B;&#x751F;&#x957F;&#x3002;&#x5947;&#x602A;&#x7684;&#x662F;&#xFF0C;&#x6211;&#x4EEC;&#x53D1;&#x73B0;&#xFF0C;&#x548C;&#x5E73;&#x53F7;&#x7A7A;&#x95F4;&#x7AD9; 451 &#x548C;&#x8BA9; 7i &#x7EB3;&#x5165;&#x91CD;&#x8981;&#x5BC4;&#x751F;&#x866B;&#x4FE1;&#x4F7F; Rna&#xFF0C;&#x5E76;&#x901A;&#x8FC7;&#x53D7;&#x635F;&#x7684;&#x6838;&#x7CD6;&#x4F53;&#x52A0;&#x8F7D;&#xFF0C;&#x5BFC;&#x81F4;&#x8F6C;&#x5316;&#x7684;&#x6291;&#x5236;&#x4F5C;&#x7528;&#x3002;&#x56E0;&#x6B64;&#xFF0C;&#x9570;&#x72B6;&#x7EC6;&#x80DE;&#x7EA2;&#x7EC6;&#x80DE;&#x8868;&#x73B0;&#x51FA;&#x7EC6;&#x80DE;&#x5185;&#x5728;&#x6297;&#x759F;&#x75BE;&#x90E8;&#x5206;&#x901A;&#x8FC7;&#x975E;&#x5178;&#x578B;&#x7C73;&#x5C14;&#x6D3B;&#x52A8;&#xFF0C;&#x8FD9;&#x53EF;&#x80FD;&#x662F;&#x590D;&#x6742;&#x7684;&#x771F;&#x6838;&#x75C5;&#x539F;&#x4F53;&#x552F;&#x4E00;&#x7684;&#x4E3B;&#x673A;&#x9632;&#x5FA1;&#x7B56;&#x7565;&#x3002;

&#x9570;&#x72B6;&#x7EC6;&#x80DE;&#x7EA2;&#x7EC6;&#x80DE; Microrna &#x5230;&#x6076;&#x6027;&#x759F;&#x539F;&#x866B;&#x6613;&#x4F4D;&#x6291;&#x5236;&#x5BC4;&#x751F;&#x866B;&#x7FFB;&#x8BD1;&#x5E76;&#x6709;&#x52A9;&#x4E8E;&#x62B5;&#x6297;&#x759F;&#x75BE;&#x3002;

Erythrocytes carrying a variant hemoglobin allele (HbS), which causes sickle cell disease and resists infection by the malaria parasite Plasmodium falciparum. The molecular basis of this resistance, which has long been recognized as multifactorial, remains incompletely understood. Here we show that the dysregulated microRNA (miRNA) composition, of either heterozygous HbAS or homozygous HbSS erythrocytes, contributes to resistance against P. falciparum. During the intraerythrocytic life cycle of P. falciparum, a subset of erythrocyte miRNAs translocate into the parasite. Two miRNAs, miR-451 and let-7i, were highly enriched in HbAS and HbSS erythrocytes, and these miRNAs, along with miR-223, negatively regulated parasite growth. Surprisingly, we found that miR-451 and let-7i integrated into essential parasite messenger RNAs and, via impaired ribosomal loading, resulted in translational inhibition. Hence, sickle cell erythrocytes exhibit cell-intrinsic resistance to malaria in part through an atypical miRNA activity, which may represent a unique host defense strategy against complex eukaryotic pathogens.

Translocation of sickle cell erythrocyte microRNAs into Plasmodium falciparum inhibits parasite translation and contributes to malaria resistance.

&Eacute;rythrocytes portant un all&egrave;le variant de l&#39;h&eacute;moglobine (HbS), qui provoque la dr&eacute;panocytose et r&eacute;siste &agrave; l&#39;infection par le parasite Plasmodium falciparum de paludisme. La base mol&eacute;culaire de cette r&eacute;sistance, qui est reconnue depuis longtemps comme multifactorielle, reste incompl&egrave;tement comprise. Ici, nous montrons que la composition de microARN (miARN) dysr&eacute;gulation, HBA h&eacute;t&eacute;rozygotes ou homozygotes HbSS &eacute;rythrocytes, contribue &agrave; la r&eacute;sistance contre P. falciparum. Pendant la dur&eacute;e de vie d&#39;intra-&eacute;rythrocytaire de P. falciparum, un sous-ensemble des &eacute;rythrocytes miARN translocation dans le parasite. Deux miARN, miR-451 et laissez-7i, &eacute;tait hautement enrichi dans les &eacute;rythrocytes de HBA et HbSS, et ces miARN, avec miR-223, r&eacute;gul&eacute; n&eacute;gativement la croissance du parasite. &Eacute;tonnamment, nous avons constat&eacute; que miR-451 et let-7i int&eacute;gr&eacute;s dans les ARN messagers parasite essentiel et, par l&#39;interm&eacute;diaire de chargement ribosomique avec facult&eacute;s affaiblies, a provoqu&eacute; une inhibition translationnelle. Par cons&eacute;quent, dr&eacute;panocytose &eacute;rythrocytes pi&egrave;ce r&eacute;sistance cellulaire intrins&egrave;que au paludisme en partie gr&acirc;ce &agrave; une activit&eacute; atypique miRNA, qui peut repr&eacute;senter une strat&eacute;gie de d&eacute;fense du h&ocirc;te unique contre les complexes pathog&egrave;nes eucaryotes.

Translocation de dr&eacute;panocytose &eacute;rythrocytaire microARN dans Plasmodium falciparum inhibe la traduction de parasite et contribue &agrave; la r&eacute;sistance du paludisme.

Erythrozyten mit einem variant H&auml;moglobin Allel (HbS), Sichelzellan&auml;mie und str&auml;ubt sich gegen Infektion durch die Malaria Parasit Plasmodium Falciparum. Die molekulare Basis dieser Widerstand, der seit langem als multifaktorielle anerkannt hat, bleibt unvollst&auml;ndig verstanden. Hier zeigen wir, dass die defekten MicroRNA (MiRNA) Zusammensetzung, heterozygote HbAS oder Homozygote HbSS Erythrozyten, zum Widerstand gegen p. Falciparum beitr&auml;gt. W&auml;hrend des Lebenszyklus f&uuml;r die Intraerythrocytic von p. Falciparum eine Teilmenge der Erythrozyten MiRNAs akkumulieren in den Parasiten. Zwei MiRNAs, MiR-451 und lassen-7i, waren hoch angereichertes HbAS und HbSS Erythrozyten, und diese MiRNAs, zusammen mit MiR-223, negativ reguliert Parasit Wachstum. &Uuml;berraschend, wir gefunden, die MiR-451 und lassen-7i in wesentlichen Parasit Messenger-RNAs integriert und &uuml;ber gest&ouml;rte ribosomal laden, f&uuml;hrte translational Hemmung. Daher weisen Sichelzelle Erythrozyten Zelle-intrinsische Resistenz gegen Malaria Teil durch eine atypische MiRNA-Aktivit&auml;t, die eine einzigartige Host-Verteidigungsstrategie gegen komplexe eukaryotischen Krankheitserreger darstellen kann.

Translokation der Sichelzelle Erythrozyten MicroRNAs in Plasmodium Falciparum Parasit &Uuml;bersetzung hemmt und tr&auml;gt zur Malaria-Resistenz.

&#x8D64;&#x8840;&#x7403;&#x306F;&#x3001;&#x938C;&#x72B6;&#x8D64;&#x8840;&#x7403;&#x75C5;&#x306E;&#x539F;&#x56E0;&#x3057;&#x3001;&#x30DE;&#x30E9;&#x30EA;&#x30A2;&#x539F;&#x866B;&#x306B;&#x3088;&#x308B;&#x611F;&#x67D3;&#x306B;&#x62B5;&#x6297;&#x3059;&#x308B;&#x30D0;&#x30EA;&#x30A2;&#x30F3;&#x30C8; &#x30D8;&#x30E2;&#x30B0;&#x30ED;&#x30D3;&#x30F3;&#x907A;&#x4F1D;&#x5B50; (HbS)&#x3002;&#x9577;&#x3044;&#x591A;&#x56E0;&#x5B50;&#x3068;&#x3057;&#x3066;&#x8A8D;&#x8B58;&#x3055;&#x308C;&#x3066;&#x3044;&#x308B;&#x3001;&#x3053;&#x306E;&#x62B5;&#x6297;&#x6027;&#x306E;&#x5206;&#x5B50;&#x57FA;&#x76E4;&#x306E;&#x4E0D;&#x5B8C;&#x5168;&#x306A;&#x7406;&#x89E3;&#x307E;&#x307E;&#x3067;&#x3059;&#x3002;&#x3053;&#x3053;&#x3067;&#x6765;&#x3059;&#x30DE;&#x30A4;&#x30AF;&#x30ED; Rna &#xFF08;miRNA&#xFF09; &#x7D44;&#x6210;&#x306E;&#x30D8;&#x30C6;&#x30ED;&#x63A5;&#x5408;&#x4F53;&#x306E; Hba &#x307E;&#x305F;&#x306F;&#x30DB;&#x30E2; hbss &#x306E;&#x4EE3;&#x308A;&#x306E;&#x8D64;&#x8840;&#x7403;&#x306E;&#x30DE;&#x30E9;&#x30EA;&#x30A2;&#x306B;&#x5BFE;&#x3059;&#x308B;&#x62B5;&#x6297;&#x6027;&#x306B;&#x5BC4;&#x4E0E;&#x3059;&#x308B;&#x3053;&#x3068;&#x3092;&#x793A;&#x3057;&#x307E;&#x3059;&#x3002;&#x30DE;&#x30E9;&#x30EA;&#x30A2;&#x306E;&#x8D64;&#x8840;&#x7403;&#x5BFF;&#x547D;&#x30B5;&#x30A4;&#x30AF;&#x30EB;&#x4E2D;&#x306B;&#x8D64;&#x8840;&#x7403; miRNAs &#x306E;&#x30B5;&#x30D6;&#x30BB;&#x30C3;&#x30C8;&#x306B;&#x5BC4;&#x751F;&#x866B;&#x3092;&#x5909;&#x3048;&#x307E;&#x3059;&#x3002;2 &#x3064;&#x306E; Mirna&#x3001;&#x30DF;&#x30FC;&#x30EB; 451 &#x3068;&#x805E;&#x304B;&#x305B;&#x3066; 7i &#x975E;&#x5E38;&#x306B; Hba &#x3068; hbss &#x306E;&#x4EE3;&#x308A;&#x306E;&#x8D64;&#x8840;&#x7403;&#x3067;&#x6FC3;&#x7E2E;&#x3055;&#x308C;&#x3001;&#x30DF;&#x30FC;&#x30EB;-223 &#x3068;&#x4E00;&#x7DD2;&#x306B;&#x3053;&#x308C;&#x3089;&#x306E; miRNAs &#x306F;&#x5426;&#x5B9A;&#x7684;&#x306B;&#x5BC4;&#x751F;&#x866B;&#x6210;&#x9577;&#x3092;&#x898F;&#x5236;&#x3055;&#x308C;&#x3066;&#x3044;&#x307E;&#x3059;&#x3002;&#x9A5A;&#x3044;&#x305F;&#x3053;&#x3068;&#x306B;&#x3001;&#x6211;&#x3005; &#x306F;&#x30DF;&#x30FC;&#x30EB; 451 &#x3092;&#x767A;&#x898B;&#x3057;&#x305F;&#x3068; let 7i &#x4E0D;&#x53EF;&#x6B20;&#x5BC4;&#x751F;&#x866B;&#x30E1;&#x30C3;&#x30BB;&#x30F3;&#x30B8;&#x30E3;&#x30FC; Rna &#x306B;&#x7D71;&#x5408;&#x3057;&#x3001;&#x969C;&#x5BB3;&#x306E;&#x30EA;&#x30DC;&#x30BD;&#x30FC;&#x30E0;&#x306E;&#x8AAD;&#x307F;&#x8FBC;&#x307F;&#x306B;&#x3088;&#x3063;&#x3066;&#x4E26;&#x9032;&#x963B;&#x5BB3;&#x306B;&#x8D77;&#x56E0;&#x3057;&#x307E;&#x3057;&#x305F;&#x3002;&#x305D;&#x308C;&#x6545;&#x306B;&#x3001;&#x938C;&#x72B6;&#x8D64;&#x8840;&#x7403;&#x8D64;&#x8840;&#x7403;&#x7D30;&#x80DE;&#x56FA;&#x6709;&#x306E;&#x62B5;&#x6297;&#x3092;&#x4ECB;&#x3057;&#x3066;&#x8907;&#x96D1;&#x306A;&#x771F;&#x6838;&#x751F;&#x7269;&#x306E;&#x75C5;&#x539F;&#x4F53;&#x306B;&#x5BFE;&#x3059;&#x308B;&#x4E00;&#x610F;&#x306E;&#x30DB;&#x30B9;&#x30C8;&#x9632;&#x885B;&#x6226;&#x7565;&#x3092;&#x8868;&#x3059;&#x53EF;&#x80FD;&#x6027;&#x304C;&#x3042;&#x308A;&#x307E;&#x3059;&#x975E;&#x5B9A;&#x578B; miRNA &#x6D3B;&#x52D5;&#x306E;&#x4E00;&#x90E8;&#x306F;&#x30DE;&#x30E9;&#x30EA;&#x30A2;&#x306B;&#x5C55;&#x793A;&#x3057;&#x307E;&#x3059;&#x3002;

&#x938C;&#x72B6;&#x8D64;&#x8840;&#x7403;&#x8D64;&#x8840;&#x7403; microRNAs &#x306E;&#x8EE2;&#x6D41;&#x30DE;&#x30E9;&#x30EA;&#x30A2;&#x539F;&#x866B;&#x306B;&#x306F;&#x5BC4;&#x751F;&#x866B;&#x306E;&#x7FFB;&#x8A33;&#x3092;&#x963B;&#x5BB3;&#x3057;&#x3066;&#x30DE;&#x30E9;&#x30EA;&#x30A2;&#x8010;&#x6027;&#x306B;&#x5BC4;&#x4E0E;&#x3057;&#x307E;&#x3059;&#x3002;

&#xC801;&#xD608;&#xAD6C; &#xBCC0;&#xD615; &#xD5E4;&#xBAA8;&#xAE00;&#xB85C;&#xBE48; &#xB300;&#xB9BD; (HbS), &#xB0AB; &#xC138;&#xD3EC; &#xC9C8;&#xBCD1;&#xC758; &#xC6D0;&#xC778;&#xACFC; &#xB9D0;&#xB77C;&#xB9AC;&#xC544; &#xAE30;&#xC0DD;&#xCDA9; Plasmodium falciparum&#xC5D0; &#xC758;&#xD574; &#xAC10;&#xC5FC;&#xC744; &#xC800;&#xD56D; &#xD558;&#xB294; &#xC6B4;&#xBC18;. &#xC624;&#xB798; multifactorial&#xB85C; &#xC778;&#xC815; &#xB418;&#xC5C8;&#xC2B5;&#xB2C8;&#xB2E4;,&#xC774; &#xC800;&#xD56D;&#xC758; &#xBD84;&#xC790; &#xB2E8;&#xC704;&#xB85C; &#xB0A8;&#xC544; &#xBD88;&#xC644;&#xC804; &#xD558; &#xAC8C; &#xC774;&#xD574;. &#xC5EC;&#xAE30; &#xC6B0;&#xB9AC;&#xAC00; dysregulated microRNA (&#xBBF8;&#xB974;) &#xC870;&#xC131; heterozygous Hba &#xB610;&#xB294; &#xC801;&#xD608;&#xAD6C;, HbSS homozygous P. falciparum&#xC5D0; &#xB300; &#xD55C; &#xC800;&#xD56D;&#xC5D0; &#xAE30;&#xC5EC;&#xB97C; &#xBCF4;&#xC5EC;&#xC90D;&#xB2C8;&#xB2E4;. P. falciparum intraerythrocytic &#xC218;&#xBA85; &#xC8FC;&#xAE30; &#xB3D9;&#xC548; &#xC801;&#xD608;&#xAD6C; Mirnas&#xC758; &#xD558;&#xC704; &#xC9D1;&#xD569; &#xAE30;&#xC0DD;&#xCDA9;&#xC73C;&#xB85C; &#xC774;&#xB3D9;. &#xB450; miRNAs, &#xBBF8;&#xB974;-451 &#xBC0F; &#xD558;&#xC790; 7i &#xD588;&#xB2E4; Hba &#xBC0F; HbSS &#xC801;&#xD608;&#xAD6C;&#xC5D0;&#xC11C; &#xB9E4;&#xC6B0; &#xD48D;&#xC131; &#xD558; &#xACE0; &#xBBF8;&#xB974;-223, &#xD568;&#xAED8; &#xC774;&#xB7EC;&#xD55C; Mirnas&#xB294; &#xBD80;&#xC815;&#xC801;&#xC778; &#xAE30;&#xC0DD;&#xCDA9; &#xC131;&#xC7A5; &#xADDC;&#xC81C;. &#xB180;&#xB78D;&#xAC8C;&#xB3C4;, &#xC6B0;&#xB9AC;&#xB294; &#xBBF8;&#xB974;-451&#xC744; &#xBC1C;&#xACAC; &#xD558; &#xACE0; &#xD558;&#xC790; 7i &#xD544;&#xC218; &#xAE30;&#xC0DD;&#xCDA9; &#xBA54;&#xC2E0;&#xC800; Rnas&#xC5D0; &#xD1B5;&#xD569; &#xD558; &#xACE0;, &#xC7A5;&#xC560;&#xC778;&#xB41C; ribosomal &#xB85C;&#xB4DC;&#xB97C; &#xD1B5;&#xD574; &#xBCC0;&#xD658; &#xC5B5;&#xC81C; &#xACB0;&#xACFC;. &#xB530;&#xB77C;&#xC11C;, &#xC801;&#xD608;&#xAD6C; &#xC801;&#xD608;&#xAD6C; &#xB9D0;&#xB77C;&#xB9AC;&#xC544; &#xBCF5;&#xC7A1; &#xD55C; &#xC9C4; &#xD575; &#xBCD1;&#xC6D0; &#xADE0;&#xC5D0; &#xB300; &#xD55C; &#xACE0;&#xC720;&#xD55C; &#xD638;&#xC2A4;&#xD2B8; &#xBC29;&#xC5B4; &#xC804;&#xB7B5;&#xC744; &#xB098;&#xD0C0;&#xB0B4;&#xB294; &#xBE44;&#xC815;&#xD615; miRNA &#xD65C;&#xB3D9;&#xC744; &#xD1B5;&#xD574; &#xC77C;&#xBD80; &#xC140; &#xB0B4;&#xC7A5; &#xC800;&#xD56D; &#xC804;&#xC2DC;.

Plasmodium falciparum&#xC5D0; &#xACB8; &#xC0C1; &#xC801;&#xD608;&#xAD6C; &#xC801;&#xD608;&#xAD6C; Micrornas&#xC758; &#xC804; &#xAE30;&#xC0DD;&#xCDA9; &#xBC88;&#xC5ED; &#xC5B5;&#xC81C; &#xBC0F; &#xB9D0;&#xB77C;&#xB9AC;&#xC544; &#xC800;&#xD56D;&#xC5D0; &#xAE30;&#xC5EC; &#xD55C;&#xB2E4;.

Eritrocitos con un alelo de la variante de la hemoglobina (HbS), que causa la enfermedad de c&eacute;lulas falciformes y resiste la infecci&oacute;n por el par&aacute;sito de la malaria Plasmodium falciparum. La base molecular de esta resistencia, que ha sido reconocida como multifactorial, sigue siendo incompleto entendida. Aqu&iacute; mostramos que la composici&oacute;n dysregulated de microARN (miARN), heterocigoto HBA o homocig&oacute;ticos HbSS eritrocitos, contribuye a la resistencia contra p. falciparum. Durante el ciclo de vida de intraerythrocytic de p. falciparum, un subconjunto de eritrocito miRNAs translocan en el par&aacute;sito. Dos miRNAs, miR-451 y dej&oacute;-7i, eran altamente enriquecidos en eritrocitos HbAS y HbSS, y estos miRNAs, junto con el miR-223, hab&iacute;an regulada negativamente el crecimiento del par&aacute;sito. Sorprendentemente, encontramos que miR-451 y dej&oacute;-7i integrado en par&aacute;sito esencial mensajero ARN y, v&iacute;a carga ribosomal deteriorada, dio lugar a la inhibici&oacute;n traduccional. Por lo tanto, los eritrocitos falciformes exhiben resistencia celular intr&iacute;nseca a la malaria en parte a trav&eacute;s de una actividad de miRNA anormal, que puede representar una estrategia de defensa &uacute;nico anfitri&oacute;n frente a pat&oacute;genos eucariotas complejos.

Desplazamiento de c&eacute;lulas falciformes eritrocito microRNAs en Plasmodium falciparum inhibe traducci&oacute;n del par&aacute;sito y contribuye a la resistencia de la malaria.

A variety of oncogenic and environmental factors alter tumor metabolism to serve the distinct cellular biosynthetic and bioenergetic needs present during oncogenesis. Extracellular acidosis is a common microenvironmental stress in solid tumors, but little is known about its metabolic influence, particularly when present in the absence of hypoxia. In order to characterize the extent of tumor cell metabolic adaptations to acidosis, we employed stable isotope tracers to examine how acidosis impacts glucose, glutamine, and palmitate metabolism in breast cancer cells exposed to extracellular acidosis.

Gregory LaMonte

Department of Molecular Genetics and Microbiology,
Center for Genomic and Computational Biology

Duke University School of Medicine

Methods to Investigate the Regulatory Role of Small RNAs and Ribosomal Occupancy of Plasmodium falciparum

Gregory LaMonte

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Molecular Genetics and Microbiology,Center for Genomic and Computational Biology

Duke University School of Medicine

Methods to Investigate the Regulatory Role of Small RNAs and Ribosomal Occupancy of Plasmodium falciparum

Department of Molecular Genetics and Microbiology,
Center for Genomic and Computational Biology