RESUMEN
Heritable symbionts are common among animals in nature, but the molecular mechanisms underpinning symbiont invasions of host populations have been elusive. In this study, we demonstrate the spread of Rickettsia in an invasive agricultural pest, the whitefly Bemisia tabaci Mediterranean (MED), across northeastern China from 2018 to 2023. Here, we show that the beneficial symbiont Rickettsia spreads by manipulating host hormone signals. Our analyses suggest that Rickettsia have been horizontally acquired by B. tabaci MED from another invasive whitefly B. tabaci Middle East-Asia Minor 1 during periods of coexistence. Rickettsia is transmitted maternally and horizontally from female B. tabaci MED individuals. Rickettsia infection enhances fecundity and results in female bias among whiteflies. Our findings reveal that Rickettsia infection stimulates juvenile hormone (JH) synthesis, in turn enhancing fecundity, copulation events, and the female ratio of the offspring. Consequently, Rickettsia infection results in increased whitefly fecundity and female bias by modulating the JH pathway. More female progeny facilitates the transmission of Rickettsia. This study illustrates that the spread of Rickettsia among invasive whiteflies in northeastern China is propelled by host hormone regulation. Such symbiont invasions lead to rapid physiological and molecular evolution in the host, influencing the biology and ecology of an invasive species.
Asunto(s)
Fertilidad , Hemípteros , Rickettsia , Razón de Masculinidad , Simbiosis , Animales , Rickettsia/fisiología , Hemípteros/microbiología , Hemípteros/fisiología , Femenino , Masculino , Hormonas Juveniles/metabolismo , ChinaRESUMEN
Bacteriocytes are host cells specialized to harbor symbionts in certain insect taxa. The adaptation, development, and evolution of bacteriocytes underlie insect symbiosis maintenance. Bacteriocytes carry enriched host genes of insect and bacterial origin whose transcription can be regulated by microRNAs, which are involved in host-symbiont metabolic interactions. Recognition proteins of peptidoglycan, the bacterial cell wall component, and autophagy regulate symbiont abundance in bacteriocytes. Horizontally transferred genes expressed in bacteriocytes influence the metabolism of symbiont peptidoglycan, which may affect the bacteriocyte immune response against symbionts. Bacteriocytes release or transport symbionts into ovaries for symbiont vertical transmission. Bacteriocyte development and death, regulated by transcriptional factors, are variable in different insect species. The evolutionary origin of insect bacteriocytes remains unclear. Future research should elucidate bacteriocyte cell biology, the molecular interplay between bacteriocyte metabolic and immune functions, the genetic basis of bacteriocyte origin, and the coordination between bacteriocyte function and host biology in diverse symbioses.
Asunto(s)
Hemípteros , Peptidoglicano , Animales , Hemípteros/genética , Hemípteros/microbiología , Insectos , Bacterias/genética , Simbiosis/fisiologíaRESUMEN
Horizontal gene transfer is widespread in insects bearing intracellular symbionts. Horizontally transferred genes (HTGs) are presumably involved in amino acid synthesis in sternorrhynchan insects. However, their role in insect-symbiont interactions remains largely unknown. We found symbionts Portiera, Hamiltonella and Rickettsia possess most genes involved in lysine synthesis in the whitefly Bemisia tabaci MEAM1 although their genomes are reduced. Hamiltonella maintains a nearly complete lysine synthesis pathway. In contrast, Portiera and Rickettsia require the complementation of whitefly HTGs for lysine synthesis and have lysE, encoding a lysine exporter. Furthermore, each horizontally transferred lysine gene of ten B. tabaci cryptic species shares an evolutionary origin. We demonstrated that Hamiltonella did not alter the titers of Portiera and Rickettsia or lysine gene expression of Portiera, Rickettsia and whiteflies. Hamiltonella also did not impact on lysine levels or protein localization in bacteriocytes harboring Portiera and ovaries infected with Rickettsia. Complementation with whitefly lysine synthesis HTGs rescued E. coli lysine gene knockout mutants. Silencing whitefly lysA in whiteflies harboring Hamiltonella reduced lysine levels, adult fecundity and titers of Portiera and Rickettsia without influencing the expression of Hamiltonella lysA. Furthermore, silencing whitefly lysA in whiteflies lacking Hamiltonella reduced lysine levels, adult fecundity and titers of Portiera and Rickettsia in ovarioles. Therefore, we, for the first time, demonstrated an essential amino acid lysine synthesized through HTGs is important for whitefly reproduction and fitness of both obligate and facultative symbionts, and it illustrates the mutual dependence between whitefly and its two symbionts. Collectively, this study reveals that acquisition of horizontally transferred lysine genes contributes to coadaptation and coevolution between B. tabaci and its symbionts.
Asunto(s)
Evolución Molecular , Transferencia de Gen Horizontal , Halomonadaceae/fisiología , Hemípteros/microbiología , Lisina/metabolismo , Rickettsia/fisiología , Simbiosis , Animales , Hemípteros/genética , Hemípteros/crecimiento & desarrollo , Lisina/genéticaRESUMEN
A/J mouse is a typical animal model of age-related deafness. Previous studies have shown that the mice suffer from progressive hearing loss and degeneration of cochlear cells, and a variation of H55 N in citrate synthase (CS) causes about 40% the hearing loss. CS is a key enzyme in the tricarboxylic acid cycle, which is transported from cytoplasm to mitochondria after synthesis, sorted by the mitochondrial targeting sequence (MTS). To explore the mechanism of CS (H55 N) variation in affecting its function, HEI-OC1 cells were infected with lentivirus particles to express CS-Flag or CS(H55 N)-Flag. The results showed that H55 N variation in CS, as purified by co-immunoprecipitation, decreased the enzyme activity by about 50%. Confocal microscope co-localization indicated that the CS (H55 N) variation led to a decrement in its mitochondrial content. Western blot also showed the amount of CS(H55 N)-Flag was more than that of CS(WT)-Flag in the cytosol. The results suggest H55 N variation in CS lead to decrement of its enzyme activity and targeting transport to mitochondria. We therefore conclude that decrement in CS activity and mitochondrial delivery contributes to the degeneration of cochlear cells and thus the hearing loss in A/J mice.
Asunto(s)
Pérdida Auditiva , Mitocondrias , Animales , Citrato (si)-Sintasa , Cóclea , RatonesRESUMEN
Nutritional symbionts are restricted to specialized host cells called bacteriocytes in various insect orders. These symbionts can provide essential nutrients to the host. However, the cellular mechanisms underlying the regulation of these insect-symbiont metabolic associations remain largely unclear. The whitefly Bemisia tabaci MEAM1 hosts "Candidatus Portiera aleyrodidarum" (here, "Ca. Portiera") and "Candidatus Hamiltonella defensa" (here, "Ca. Hamiltonella") bacteria in the same bacteriocyte. In this study, the induction of autophagy by chemical treatment and gene silencing decreased symbiont titers and essential amino acid (EAA) and B vitamin contents. In contrast, the repression of autophagy in bacteriocytes via Atg8 silencing increased symbiont titers, and amino acid and B vitamin contents. Furthermore, dietary supplementation with non-EAAs or B vitamins alleviated autophagy in whitefly bacteriocytes, elevated TOR (target of rapamycin) expression, and increased symbiont titers. TOR silencing restored symbiont titers in whiteflies after dietary supplementation with B vitamins. These data suggest that "Ca. Portiera" and "Ca. Hamiltonella" evade autophagy of the whitefly bacteriocytes by activating the TOR pathway via providing essential nutrients. Taken together, we demonstrate that autophagy plays a critical role in regulating the metabolic interactions between the whitefly and two intracellular symbionts. Therefore, this study reveals that autophagy is an important cellular basis for bacteriocyte evolution and symbiosis persistence in whiteflies. The whitefly symbiosis unravels the interactions between cellular and metabolic functions of bacteriocytes. IMPORTANCE Nutritional symbionts, which are restricted to specialized host cells called bacteriocytes, can provide essential nutrients for many hosts. However, the cellular mechanisms of regulation of animal-symbiont metabolic associations have been largely unexplored. Here, using the whitefly-"Ca. Portiera"/"Ca. Hamiltonella" endosymbiosis, we demonstrate autophagy regulates the symbiont titers and thereby alters the essential amino acid and B vitamin contents. For persistence in the whitefly bacteriocytes, "Ca. Portiera" and "Ca. Hamiltonella" alleviate autophagy by activating the TOR (target of rapamycin) pathway through providing essential nutrients. Therefore, we demonstrate that autophagy plays a critical role in regulating the metabolic interactions between the whitefly and two intracellular symbionts. This study also provides insight into the cellular basis of bacteriocyte evolution and symbiosis persistence in the whitefly. The mechanisms underlying the role of autophagy in whitefly symbiosis could be widespread in many insect nutritional symbioses. These findings provide a new avenue for whitefly control via regulating autophagy in the future.
Asunto(s)
Halomonadaceae , Hemípteros , Complejo Vitamínico B , Animales , Autofagia , Halomonadaceae/genética , Hemípteros/microbiología , Simbiosis/genética , Complejo Vitamínico B/metabolismoRESUMEN
Horizontally transferred genes (HTGs) play a key role in animal symbiosis, and some horizontally transferred genes or proteins are highly expressed in specialized host cells (bacteriocytes). However, it is not clear how HTGs are regulated, but microRNAs (miRNAs) are prime candidates given their previously demonstrated roles in symbiosis and impacts on the expression of host genes. A horizontally acquired PanBC that is highly expressed in whitefly bacteriocytes can cooperate with an obligate symbiont Portiera for pantothenate production, facilitating whitefly performance and Portiera titre. Here, we found that a whitefly miRNA, novel-m0780-5p, was up-regulated and its target panBC was down-regulated in Portiera-eliminated whiteflies. This miRNA was located in the cytoplasmic region of whitefly bacteriocytes. Injection of novel-m0780-5p agomir reduced the expression of PanBC in whitefly bacteriocytes, while injection of novel-m0780-5p antagomir enhanced PanBC expression. Agomir injection also reduced the pantothenate level, Portiera titre and whitefly performance. Supplementation with pantothenate restored Portiera titre and the fitness of agomir-injected whiteflies. Thus, we demonstrate that a whitefly miRNA regulates panBC-mediated host-symbiont collaboration required for pantothenate synthesis, benefiting the whitefly-Portiera symbiosis. Both panBC and novel-m0780-5p are present in the genomes of six Bemisia tabaci species. The expression of a novel miRNA in multiple B. tabaci species suggests that the miRNA evolved after panBC acquisition, and allowed this gene to be more tightly regulated. Our discovery provides the first account of a HTG being regulated by a miRNA from the host genome, and suggests key roles for interactions between miRNAs and HTGs in the functioning of symbiosis.
Asunto(s)
Halomonadaceae , Hemípteros , MicroARNs , Animales , Halomonadaceae/genética , Hemípteros/genética , MicroARNs/genética , Simbiosis/genéticaRESUMEN
BACKGROUND: Citrate Synthase (Cs) gene mutation (locus ahL4) has been found to play an important role in progressive hearing loss of A/J mice. HEI-OC1 cells have been widely used as an in vitro system to study cellular and molecular mechanisms related to hearing lose. We previously reported the increased apoptosis and the accumulation of reactive oxygen species in shRNACs-1429 cells, a Cs low-expressed cell model from HEI-OCI. The details of the mechanism of ROS production and apoptosis mediated by the abnormal expression of Cs needed to research furtherly. METHODS: iTRAQ proteomics was utilized to detect the differentially expressed proteins (DEPs) caused by low expression of Cs. The GO and KEGG pathways analysis were performed for annotation of the differentially expressed proteins. Protein-protein interaction network was constructed by STRING online database. Immunoblotting was utilized to confirm the protein levels of the the differentially expressed proteins. RESULTS: The differentially expressed proteins were significantly enriched in various signaling pathways mainly related to mitochondrial dysfunction diseases including Parkinson's disease, Alzheimer's disease, Huntington's disease, et al. Most noteworthy, the oxidative phosphorylation pathway was most significantly suppressed in the shRNACs-1429 cells,, in which a total of 10 differentially expressed proteins were enriched and were all downregulated by the abnormal expression of Cs. The downregulations of Ndufb5, Ndufv1 and Uqcrb were confirmed by immunoblotting. Meanwhile, the ATP levels of shRNACs-1429 cells were also reduced. CONCLUSIONS: These results suggest that low level expression of Cs induces the inhibition of oxidative phosphorylation pathway, which is responsible for the high level production of reactive oxygen species and low level of ATP, leading to the apoptosis of cochlear cells. This study may provide new theories for understanding and therapy of progressive hearing loss.
RESUMEN
In many intracellular symbioses, the microbial symbionts provide nutrients advantageous to the host. However, the function of Hamiltonella defensa, a symbiotic bacterium localized in specialized host cells (bacteriocytes) of a whitefly Bemisia tabaci, is uncertain. We eliminate this bacterium from its whitefly host by two alternative methods: heat treatment and antibiotics. The sex ratio of the host progeny and subsequent generations of Hamiltonella-free females was skewed from 1 : 1 (male : female) to an excess of males, often exceeding a ratio of 20 : 1. B. tabaci is haplodiploid, with diploid females derived from fertilized eggs and haploid males from unfertilized eggs. The Hamiltonella status of the insect did not affect copulation frequency or sperm reserve in the spermathecae, indicating that the male-biased sex ratio is unlikely due to the limitation of sperm but likely to be associated with events subsequent to sperm transfer to the female insects, such as failure in fertilization. The host reproductive response to Hamiltonella elimination is consistent with two alternative processes: adaptive shift in sex allocation by females and a constitutive compensatory response of the insect to Hamiltonella-mediated manipulation. Our findings suggest that a bacteriocyte symbiont influences the reproductive output of female progeny in a haplodiploid insect.
Asunto(s)
Enterobacteriaceae/fisiología , Hemípteros/microbiología , Hemípteros/fisiología , Razón de Masculinidad , Simbiosis , Animales , Femenino , Masculino , ReproducciónRESUMEN
OBJECTIVE: The objective of this study is to determine the role and underlying mechanisms of RGC-32 (response gene to complement 32 protein) in atherogenesis. APPROACH AND RESULTS: RGC-32 was mainly expressed in endothelial cells of atherosclerotic lesions in both ApoE-/- (apolipoprotein E deficient) mice and human patients. Rgc-32 deficiency (Rgc32-/-) attenuated the high-fat diet-induced and spontaneously developed atherosclerotic lesions in ApoE-/- mice without affecting serum cholesterol concentration. Rgc32-/- seemed to decrease the macrophage content without altering collagen and smooth muscle contents or lesional macrophage proliferation in the lesions. Transplantation of WT (wild type) mouse bone marrow to lethally irradiated Rgc32-/- mice did not alter Rgc32-/--caused reduction of lesion formation and macrophage accumulation, suggesting that RGC-32 in resident vascular cells, but not the macrophages, plays a critical role in the atherogenesis. Of importance, Rgc32-/- decreased the expression of ICAM-1 (intercellular adhesion molecule-1) and VCAM-1 (vascular cell adhesion molecule-1) in endothelial cells both in vivo and in vitro, resulting in a decrease in TNF-α (tumor necrosis factor-α)-induced monocyte-endothelial cell interaction. Mechanistically, RGC-32 mediated the ICAM-1 and VCAM-1 expression, at least partially, through NF (nuclear factor)-κB signaling pathway. RGC-32 directly interacted with NF-κB and facilitated its nuclear translocation and enhanced TNF-α-induced NF-κB binding to ICAM-1 and VCAM-1 promoters. CONCLUSIONS: RGC-32 mediates atherogenesis by facilitating monocyte-endothelial cell interaction via the induction of endothelial ICAM-1 and VCAM-1 expression, at least partially, through NF-κB signaling pathway.
Asunto(s)
Aterosclerosis/prevención & control , Células Endoteliales/metabolismo , Inflamación/prevención & control , Proteínas Nucleares/deficiencia , Animales , Aterosclerosis/genética , Aterosclerosis/metabolismo , Aterosclerosis/patología , Adhesión Celular , Proteínas de Ciclo Celular/metabolismo , Técnicas de Cocultivo , Modelos Animales de Enfermedad , Células Endoteliales/patología , Predisposición Genética a la Enfermedad , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Células Endoteliales de la Vena Umbilical Humana/patología , Humanos , Inflamación/genética , Inflamación/metabolismo , Inflamación/patología , Mediadores de Inflamación/metabolismo , Molécula 1 de Adhesión Intercelular/metabolismo , Macrófagos/metabolismo , Macrófagos/patología , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados para ApoE , Monocitos/metabolismo , Monocitos/patología , Proteínas Musculares/metabolismo , FN-kappa B/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Proteínas Nucleares/genética , Fenotipo , Placa Aterosclerótica , Transducción de Señal , Células THP-1 , Molécula 1 de Adhesión Celular Vascular/metabolismoRESUMEN
Hepatic steatosis is associated with insulin resistance and metabolic syndrome because of increased hepatic triglyceride content. We have reported previously that deficiency of response gene to complement 32 (RGC-32) prevents high-fat diet (HFD)-induced obesity and insulin resistance in mice. This study was conducted to determine the role of RGC-32 in the regulation of hepatic steatosis. We observed that hepatic RGC-32 was induced dramatically by both HFD challenge and ethanol administration. RGC-32 knockout (RGC32(-/-)) mice were resistant to HFD- and ethanol-induced hepatic steatosis. The hepatic triglyceride content of RGC32(-/-) mice was decreased significantly compared with WT controls even under normal chow conditions. Moreover, RGC-32 deficiency decreased the expression of lipogenesis-related genes, sterol regulatory element binding protein 1c (SREBP-1c), fatty acid synthase, and stearoyl-CoA desaturase 1 (SCD1). RGC-32 deficiency also decreased SCD1 activity, as indicated by decreased desaturase indices of the liver and serum. Mechanistically, insulin and ethanol induced RGC-32 expression through the NF-κB signaling pathway, which, in turn, increased SCD1 expression in a SREBP-1c-dependent manner. RGC-32 also promoted SREBP-1c expression through activating liver X receptor. These results demonstrate that RGC-32 contributes to the development of hepatic steatosis by facilitating de novo lipogenesis through activating liver X receptor, leading to the induction of SREBP-1c and its target genes. Therefore, RGC-32 may be a potential novel drug target for the treatment of hepatic steatosis and its related diseases.
Asunto(s)
Hígado Graso/prevención & control , Lipogénesis/genética , Proteínas Nucleares/fisiología , Animales , Dieta Alta en Grasa , Etanol/toxicidad , Hígado Graso/inducido químicamente , Hígado Graso/genética , Receptores X del Hígado , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , FN-kappa B/metabolismo , Proteínas Nucleares/genética , Receptores Nucleares Huérfanos/metabolismo , Transducción de Señal , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismoRESUMEN
Various insects require intracellular bacteria that are restricted to specialized cells (bacteriocytes) and are transmitted vertically via the female ovary, but the transmission mechanisms are obscure. We hypothesized that, in the whitefly Bemisia tabaci, where intact bacteriocytes (and not isolated bacteria) are transferred to oocytes, the transmission mechanism would be evident as cellular and molecular differences between the nymph (pre-adult) and adult bacteriocytes. We demonstrate dramatic remodelling of bacteriocytes at the developmental transition from nymph to adulthood. This transition involves the loss of cell-cell adhesion, high division rates to constant cell size and onset of cell mobility, enabling the bacteriocytes to crawl to the ovaries. These changes are accompanied by cytoskeleton reorganization and changes in gene expression: genes functioning in cell-cell adhesion display reduced expression and genes involved in cell division, cell motility and endocytosis/exocytosis have elevated expression in adult bacteriocytes, relative to nymph bacteriocytes. This study demonstrates, for the first time, how developmentally orchestrated remodelling of gene expression and correlated changes in cell behaviour underpin the capacity of bacteriocytes to mediate the vertical transmission and persistence of the symbiotic bacteria on which the insect host depends.
Asunto(s)
Bacterias , Hemípteros/microbiología , Oocitos/microbiología , Ovario/citología , Simbiosis , Animales , Adhesión Celular , Movimiento Celular , Citoesqueleto/fisiología , Femenino , Ovario/microbiologíaRESUMEN
Plant-mediated interactions between begomoviruses and whiteflies exert important influences on the population dynamics of vectors and the epidemiology of plant diseases. In this article, we synthesize the relevant literature to identify patterns to the interactions. We then review studies on the ecological, biochemical and molecular mechanisms underlying the interactions and finally elaborate on the most interesting issues for future research. The interactions between begomoviruses and the insect vector, the whitefly Bemisia tabaci, via their shared host plants can be mutualistic, neutral or negative. However, in contrast to a pattern of improved performance of vectors on virus-infected plants that has been observed with persistently transmitted RNA viruses, the number of cases exhibiting mutualistic, neutral or negative effects in the indirect interactions between begomoviruses and whiteflies appear evenly distributed. With regard to the mechanisms of plant-mediated positive effects on whiteflies, two case studies indicate that suppression of plant defence and/or alteration in plant nutrition as a result of virus infection can be important. Our review shows that we are only just beginning to understand the tripartite interactions between begomoviruses, whiteflies and plants. Future efforts in this area should try to expand the number and diversity of pathosystems for investigation to reveal the patterns of interactions, to investigate the molecular and biochemical mechanisms of the interactions using a multidisciplinary approach, and to examine the virus-plant-vector interactions in the field and in natural plant communities.
Asunto(s)
Begomovirus/fisiología , Hemípteros/fisiología , Hemípteros/virología , Magnoliopsida/virología , Enfermedades de las Plantas/virología , Animales , Magnoliopsida/crecimiento & desarrolloRESUMEN
The short-range order (SRO) structure in high-entropy alloys (HEAs) is closely associated with many properties, which can be studied through density functional theory (DFT) calculations. Atomic-scale modeling and calculations require substantial computational resources, and machine learning can provide rapid estimations of DFT results. To describe SRO information in HEAs, a new descriptor based on Voronoi Analysis and Shannon Entropy (VASE) is proposed. Based on Voronoi analysis, the Shannon entropy is introduced to directly characterize atomic spatial arrangement information except for composition and atomic interactions, which is necessary for describing the disorder atomic occupancy in HEAs. The new descriptor is used for predicting the formation energy of FeCoNiAlTiCu system based on machine learning model, which is more accurate than other descriptors (Coulomb matrices, partial radial distribution functions, and Voronoi analysis). Moreover, the model trained based on VASE descriptors exhibits the best predictive performance for unrelaxed structures (24.06 meV/atom). The introduction of Shannon entropy provides an effective representation of atomic arrangement information in HEAs, which is a powerful tool for investigating the SRO phenomena.
RESUMEN
Host reproduction can be manipulated by bacterial symbionts in various ways. Parthenogenesis induction is the most effective type of reproduction manipulation by symbionts for their transmission. Insect sex is determined by regulation of doublesex (dsx) splicing through transformer2 (tra2) and transformer (tra) interaction. Although parthenogenesis induction by symbionts has been studied since the 1970s, its underlying molecular mechanism is unknown. Here we identify a Wolbachia parthenogenesis-induction feminization factor gene (piff) that targets sex-determining genes and causes female-producing parthenogenesis in the haplodiploid parasitoid Encarsia formosa. We found that Wolbachia elimination repressed expression of female-specific dsx and enhanced expression of male-specific dsx, which led to the production of wasp haploid male offspring. Furthermore, we found that E. formosa tra is truncated and non-functional, and Wolbachia has a functional tra homolog, termed piff, with an insect origin. Wolbachia PIFF can colocalize and interact with wasp TRA2. Moreover, Wolbachia piff has coordinated expression with tra2 and dsx of E. formosa. Our results demonstrate the bacterial symbiont Wolbachia has acquired an insect gene to manipulate the host sex determination cascade and induce parthenogenesis in wasps. This study reveals insect-to-bacteria horizontal gene transfer drives the evolution of animal sex determination systems, elucidating a striking mechanism of insect-microbe symbiosis.
Asunto(s)
Transferencia de Gen Horizontal , Simbiosis , Avispas , Wolbachia , Animales , Wolbachia/fisiología , Wolbachia/genética , Avispas/fisiología , Avispas/microbiología , Avispas/genética , Simbiosis/genética , Femenino , Masculino , Partenogénesis/genética , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Procesos de Determinación del Sexo/genéticaRESUMEN
The Fscn2 (Fascin2) gene encodes an actin cross-linking protein that is involved in the formation of hair cell stereocilia and retina structure. Mutations in Fscn2 gene have been linked to hearing impairment and retinal degeneration in humans and mice. To understand the function of the Fscn2 gene, we generated the Fscn2 knockout mice, which showed progressive loss of hearing and hair cells. Our goal of the present study was to investigate the mechanism underlying cochlear cell death in the Fscn2 knockout mice. Microarray analysis revealed upregulation of expression of PARVB, a local adhesion protein, in the inner ears of Fscn2 knockout mice at 8 weeks of age. Further studies showed increased levels of PARVB together with cleaved-Caspase9 and decreased levels of ILK, p-ILK, p-AKT, and Bcl-2 in the inner ears of Fscn2 knockout mice of the same age. Knockdown of Fscn2 in HEI-OCI cells led to decreased cell proliferation ability and migration rate, along with increased levels of PARVB and decreased levels of ILK, p-ILK, p-AKT, Bcl-2 and activated Rac1 and Cdc42. Overexpression of Fscn2 or inhibition of Parvb expression in HEI-OC1 cells promoted cell proliferation and migration, with increased levels of ILK, p-ILK, p-AKT, and Bcl-2. Finally, FSCN2 binds with PPAR-γ to reduce its nuclear translocation in HEI-OC1 cells, and inhibition of PPAR-γ by GW9662 decreased the level of PARVB and increased the levels of p-AKT, p-ILK, and Bcl-2. Our results suggest that FSCN2 negatively regulates PARVB expression by inhibiting the entry of PPAR-γ into the cell nucleus, resulting in inhibition of ILK-AKT related pathways and of cochlear cell survival in Fscn2 knockout mice. Our findings provide new insights and ideas for the prevention and treatment of genetic hearing loss.
RESUMEN
Vectors often perform better on plants infected with pathogens, and this promotes the spread of pathogens. However, few studies have examined how plant defensive compounds mediate such mutualistic relationships. Although tobacco plants are relatively poor host plants for the whitefly Bemisia tabaci, tobacco's suitability to the whitefly was substantially increased when infected by the begomovirus Tomato yellow leaf curl China virus. The change in suitability was associated with induced terpenoid synthesis in whitefly-infested plants and repressed terpenoid synthesis in virus-infected plants. Elevation of terpenoid levels via exogenous stem applications reduced the performance of whiteflies. In contrast, suppression of terpenoid synthesis via gene silencing improved whitefly fitness. By integrating genomics, transcriptomics and metabolomics, this study demonstrated that virus infection depleted the terpenoid-mediated plant defence against whiteflies, thereby favouring vector-virus mutualism. These data suggest that plant terpenoids play a key role in shaping vector-pathogen relationships.
Asunto(s)
Begomovirus/fisiología , Hemípteros/fisiología , Interacciones Huésped-Patógeno , Insectos Vectores/fisiología , Nicotiana/virología , Terpenos/metabolismo , Animales , Femenino , Regulación de la Expresión Génica de las Plantas , Masculino , Enfermedades de las Plantas , Crecimiento Demográfico , Simbiosis , Nicotiana/genética , Nicotiana/metabolismoRESUMEN
Background: Knee osteoarthritis (KOA) is a common degenerative disease among the older people that severely affects their daily life. Previous studies have confirmed that movement biomechanics are altered in patients with KOA during task performance. However, changes that occur in lower limb joints and muscles in the three planes during stand-to-sit (STS) tasks in patients with early-stage KOA are unclear. Method: Of the 36 participants recruited in this study, 24 (8 males and 16 females) and 12 (4 males and 8 females) were added to the KOA and control groups, respectively. The Nexus Vicon motion capture system along with Delsys wireless surface electromyography devices and plantar pressure measurement mat was used to record test data. A Visual 3D software was used to process the data and calculate the biomechanical and electromyographic parameters during STS tasks. Results: There was no significant difference in task duration between the two groups. Patients with KOA could perform a greater range of pelvic motion and smaller range of hip and knee joint motion with a lower maximum hip joint angular acceleration in the sagittal plane and greater knee and ankle joint motion in the coronal plane. There was no significant difference in the motion range in the horizontal plane. During the STS task, patients in the KOA group had a lower vertical ground reaction force (GRF) amplitude on the injured side but a higher integrated GRF on both sides than those in the control group. Moreover, patients with KOA demonstrated higher PERM and PABM of the lower limb joints and smaller knee PADM and ankle PEM. Additionally, maximum activation levels of GMed muscle, affected-side gluteus medius (GM), ST, rectus femoris (RF), and tibialis anterior (TA) muscles were lower in patients with KOA than in controls. Conversely, the activation level of biceps femoris (BF) was higher. Furthermore, the integral EMG values of GMed, GM, ST, VL, RF, vastus medialis VM, and TA muscles on the affected side were lower, except for the BF muscle, in patients with KOA. Conclusion: Compared with the participants in the control group, patients with early-stage KOA exhibited consistent changes in sEMG parameters and biomechanical alterations in the sagittal plane, as observed in previous studies. However, differences in parameters were observed in the coronal and transverse planes of these patients. The noninvasive analysis of the 3D parameters of the involved motion patterns may lead to the early detection of KOA.
RESUMEN
Nicotinamide adenine dinucleotide (NAD+ ) level has been associated with various age-related diseases and its pharmacological modulation emerges as a potential approach for aging intervention. But human NAD+ landscape exhibits large heterogeneity. The lack of rapid, low-cost assays limits the establishment of whole-blood NAD+ baseline and the development of personalized therapies, especially for those with poor responses towards conventional NAD+ supplementations. Here, we developed an automated NAD+ analyzer for the rapid measurement of NAD+ with 5 µL of capillary blood using recombinant bioluminescent sensor protein and automated optical reader. The minimal invasiveness of the assay allowed a frequent and decentralized mapping of real-world NAD+ dynamics. We showed that aerobic sport and NMN supplementation increased whole-blood NAD+ and that male on average has higher NAD+ than female before the age of 50. We further revealed the long-term stability of human NAD+ baseline over 100 days and identified major real-world NAD+ -modulating behaviors.
Asunto(s)
NAD , Mononucleótido de Nicotinamida , Masculino , Femenino , Humanos , NAD/metabolismo , Mononucleótido de Nicotinamida/farmacología , Envejecimiento/fisiología , Compuestos de PiridinioRESUMEN
Integration between animal reproduction and symbiont inheritance is fundamental in symbiosis biology, but the underlying molecular mechanisms are largely unknown. Vitellogenin (Vg) is critical for oogenesis, and it is also a pathogen pattern recognition molecule in some animals. Previous studies have shown that Vg is involved in the regulation of symbiont abundance and transmission. However, the mechanisms by which an insect and its symbiont contribute to the function of Vg and how Vg impacts the persistence of insect-microbe symbiosis remain largely unclear. Symbionts are transovarially transmitted via maternal inheritance of the bacteriocytes in the whitefly Bemisia tabaci. Surprisingly, Vg is localized in bacteriocytes of whiteflies. Vg could be synthesized in whitefly bacteriocytes by the gene Vg expressed in these cells or exported into bacteriocytes from hemolymph via the Vg receptor. We further found that the juvenile hormone and "Candidatus Portiera aleyrodidarum" (here termed Portiera) control the level and localization of Vg in whiteflies. Immunocapture PCR revealed interactions between Vg and Portiera. Suppressing Vg expression reduced Portiera abundance as well as whitefly oogenesis and fecundity. Thus, we reveal that Vg facilitated the persistence of whitefly-bacteriocyte symbiont associations. This study will provide insight into the key role of Vg in the coevolution of insect reproduction and symbiont inheritance. IMPORTANCE Intracellular heritable symbionts have been incorporated into insect reproductive and developmental biology by various mechanisms. All Bemisia tabaci species harbor the obligate symbiont Portiera in specialized insect cells called bacteriocytes. We report that the whitefly juvenile hormone and Portiera determined vitellogenin (Vg) localization in bacteriocytes of whiteflies. In turn, Vg affected whitefly fecundity as well as fitness and transmission of the symbiont. Our findings show that Vg, a multifunctional protein, is indispensable for symbiont integration into the reproduction and development of insects. This reflects the outcome of long-term coevolution of the insect-microbe symbiosis.