Publications by authors named "Jun-Yi Zhu"

36 Publications

Inactivating histone deacetylase HDA promotes longevity by mobilizing trehalose metabolism.

Nat Commun 2021 03 31;12(1):1981. Epub 2021 Mar 31.

Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.

Histone acetylations are important epigenetic markers for transcriptional activation in response to metabolic changes and various stresses. Using the high-throughput SEquencing-Based Yeast replicative Lifespan screen method and the yeast knockout collection, we demonstrate that the HDA complex, a class-II histone deacetylase (HDAC), regulates aging through its target of acetylated H3K18 at storage carbohydrate genes. We find that, in addition to longer lifespan, disruption of HDA results in resistance to DNA damage and osmotic stresses. We show that these effects are due to increased promoter H3K18 acetylation and transcriptional activation in the trehalose metabolic pathway in the absence of HDA. Furthermore, we determine that the longevity effect of HDA is independent of the Cyc8-Tup1 repressor complex known to interact with HDA and coordinate transcriptional repression. Silencing the HDA homologs in C. elegans and Drosophila increases their lifespan and delays aging-associated physical declines in adult flies. Hence, we demonstrate that this HDAC controls an evolutionarily conserved longevity pathway.
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http://dx.doi.org/10.1038/s41467-021-22257-2DOI Listing
March 2021

Functional analysis of SARS-CoV-2 proteins in Drosophila identifies Orf6-induced pathogenic effects with Selinexor as an effective treatment.

Cell Biosci 2021 Mar 25;11(1):59. Epub 2021 Mar 25.

Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.

Background: SARS-CoV-2 causes COVID-19 with a widely diverse disease profile that affects many different tissues. The mechanisms underlying its pathogenicity in host organisms remain unclear. Animal models for studying the pathogenicity of SARS-CoV-2 proteins are lacking.

Methods: Using bioinformatic analysis, we found that 90% of the virus-host interactions involve human proteins conserved in Drosophila. Therefore, we generated a series of transgenic fly lines for individual SARS-CoV-2 genes, and used the Gal4-UAS system to express these viral genes in Drosophila to study their pathogenicity.

Results: We found that the ubiquitous expression of Orf6, Nsp6 or Orf7a in Drosophila led to reduced viability and tissue defects, including reduced trachea branching as well as muscle deficits resulting in a "held-up" wing phenotype and poor climbing ability. Furthermore, muscles in these flies showed dramatically reduced mitochondria. Since Orf6 was found to interact with nucleopore proteins XPO1, we tested Selinexor, a drug that inhibits XPO1, and found that it could attenuate the Orf6-induced lethality and tissue-specific phenotypes observed in flies.

Conclusions: Our study established Drosophila as a model for studying the function of SARS-CoV2 genes, identified Orf6 as a highly pathogenic protein in various tissues, and demonstrated the potential of Selinexor for inhibiting Orf6 toxicity using an in vivo animal model system.
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http://dx.doi.org/10.1186/s13578-021-00567-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7992514PMC
March 2021

Diversity and composition of the Panax ginseng rhizosphere microbiome in various cultivation modesand ages.

BMC Microbiol 2021 Jan 8;21(1):18. Epub 2021 Jan 8.

School of Life Science, Tonghua Normal University, No.950 Yu Cai Road, Dongchang District, Tonghua, 134002, China.

Background: Continuous cropping of ginseng (Panax ginseng Meyer) cultivated in farmland for an extended period gives rise to soil-borne disease. The change in soil microbial composition is a major cause of soil-borne diseases and an obstacle to continuous cropping. The impact of cultivation modes and ages on the diversity and composition of the P. ginseng rhizosphere microbial community and technology suitable for cropping P. ginseng in farmland are still being explored.

Methods: Amplicon sequencing of bacterial 16S rRNA genes and fungal ITS regions were analyzed for microbial community composition and diversity.

Results: The obtained sequencing data were reasonable for estimating soil microbial diversity. We observed significant variations in richness, diversity, and relative abundances of microbial taxa between farmland, deforestation field, and different cultivation years. The bacterial communities of LCK (forest soil where P. ginseng was not grown) had a much higher richness and diversity than those in NCK (farmland soil where P. ginseng was not grown). The increase in cultivation years of P. ginseng in farmland and deforestation field significantly changed the diversity of soil microbial communities. In addition, the accumulation of P. ginseng soil-borne pathogens (Monographella cucumerina, Ilyonectria mors-panacis, I. robusta, Fusarium solani, and Nectria ramulariae) varied with the cropping age of P. ginseng.

Conclusion: Soil microbial diversity and function were significantly poorer in farmland than in the deforestation field and were affected by P. ginseng planting years. The abundance of common soil-borne pathogens of P. ginseng increased with the cultivation age and led to an imbalance in the microbial community.
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http://dx.doi.org/10.1186/s12866-020-02081-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7792351PMC
January 2021

Autophagy inhibition rescues structural and functional defects caused by the loss of mitochondrial chaperone in .

Autophagy 2021 Jan 25:1-15. Epub 2021 Jan 25.

Research Group Synaptic Plasticity, Hertie Institute for Clinical Brain Research, University of Tübingen , Tübingen, Germany.

We investigated in larval and adult models whether loss of the mitochondrial chaperone is sufficient to cause pathological alterations commonly observed in Parkinson disease. At affected larval neuromuscular junctions, no effects on terminal size, bouton size or number, synapse size, or number were observed, suggesting that we studied an early stage of pathogenesis. At this stage, we noted a loss of synaptic vesicle proteins and active zone components, delayed synapse maturation, reduced evoked and spontaneous excitatory junctional potentials, increased synaptic fatigue, and cytoskeleton rearrangements. The adult model displayed ATP depletion, altered body posture, and susceptibility to heat-induced paralysis. Adult phenotypes could be suppressed by knockdown of , and . The knockdown of components of the macroautophagy/autophagy machinery or overexpression of human broadly rescued larval and adult phenotypes, while disease-associated variants did not. Overexpression of or promotion of autophagy exacerbated defects. AEL: after egg laying; AZ: active zone; brp: bruchpilot; Csp: cysteine string protein; dlg: discs large; eEJPs: evoked excitatory junctional potentials; GluR: glutamate receptor; HO: hydrogen peroxide; mEJP: miniature excitatory junctional potentials; MT: microtubule; NMJ: neuromuscular junction; PD: Parkinson disease; : PTEN-induced putative kinase 1; PSD: postsynaptic density; SSR: subsynaptic reticulum; SV: synaptic vesicle; VGlut: vesicular glutamate transporter.
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http://dx.doi.org/10.1080/15548627.2020.1871211DOI Listing
January 2021

Exocyst Genes Are Essential for Recycling Membrane Proteins and Maintaining Slit Diaphragm in Nephrocytes.

J Am Soc Nephrol 2020 05 1;31(5):1024-1034. Epub 2020 Apr 1.

Center for Precision Disease Modeling, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland

Background: Studies have linked mutations in genes encoding the eight-protein exocyst protein complex to kidney disease, but the underlying mechanism is unclear. Because nephrocytes share molecular and structural features with mammalian podocytes, they provide an efficient model for studying this issue.

Methods: We silenced genes encoding exocyst complex proteins specifically in nephrocytes and studied the effects on protein reabsorption by lacuna channels and filtration by the slit diaphragm. We performed nephrocyte functional assays, carried out super-resolution confocal microscopy of slit diaphragm proteins, and used transmission electron microscopy to analyze ultrastructural changes. We also examined the colocalization of slit diaphragm proteins with exocyst protein Sec15 and with endocytosis and recycling regulators Rab5, Rab7, and Rab11.

Results: Silencing exocyst genes in nephrocytes led to profound changes in structure and function. Abolition of cellular accumulation of hemolymph proteins with dramatically reduced lacuna channel membrane invaginations offered a strong indication of reabsorption defects. Moreover, the slit diaphragm's highly organized surface structure-essential for filtration-was disrupted, and key proteins were mislocalized. Ultrastructural analysis revealed that exocyst gene silencing led to the striking appearance of novel electron-dense structures that we named "exocyst rods," which likely represent accumulated membrane proteins following defective exocytosis or recycling. The slit diaphragm proteins partially colocalized with Sec15, Rab5, and Rab11.

Conclusions: Our findings suggest that the slit diaphragm of nephrocytes requires balanced endocytosis and recycling to maintain its structural integrity and that impairment of the exocyst complex leads to disruption of the slit diaphragm and nephrocyte malfunction. This model may help identify therapeutic targets for treating kidney diseases featuring molecular defects in vesicle endocytosis, exocytosis, and recycling.
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http://dx.doi.org/10.1681/ASN.2019060591DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7217423PMC
May 2020

Mutations in Are Implicated in Steroid-Resistant Nephrotic Syndrome.

J Am Soc Nephrol 2019 05 25;30(5):840-853. Epub 2019 Mar 25.

Center for Genetic Medicine Research, Children's National Health System, Washington, DC;

Background: Studies have identified mutations in >50 genes that can lead to monogenic steroid-resistant nephrotic syndrome (SRNS). The gene, which encodes one of the protein components of the nuclear pore complex nucleoporin 160 kD (Nup160), is expressed in both human and mouse kidney cells. Knockdown of impairs mouse podocytes in cell culture. Recently, siblings with SRNS and proteinuria in a nonconsanguineous family were found to carry compound-heterozygous mutations in .

Methods: We identified mutations by whole-exome and Sanger sequencing of genomic DNA from a young girl with familial SRNS and FSGS who did not carry mutations in other genes known to be associated with SRNS. We performed functional validation studies on the mutations using a model.

Results: We identified two compound-heterozygous mutations, and . We showed that silencing of specifically in nephrocytes (fly renal cells) led to functional abnormalities, reduced cell size and nuclear volume, and disorganized nuclear membrane structure. These defects were completely rescued by expression of the wild-type human gene in nephrocytes. By contrast, expression of the mutant allele completely failed to rescue nephrocyte phenotypes, and mutant allele rescued only nuclear pore complex and nuclear lamin localization defects.

Conclusions: Mutations in are implicated in SRNS. Our findings indicate that should be included in the SRNS diagnostic gene panel to identify additional patients with SRNS and homozygous or compound-heterozygous mutations and further strengthen the evidence that mutations can cause SRNS.
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http://dx.doi.org/10.1681/ASN.2018080786DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6493979PMC
May 2019

[MIPPO and ORIF for the treatment of elderly proximal humerus fractures of type Neer II:a case control study].

Zhongguo Gu Shang 2018 Feb;31(2):160-164

Department of Orthopaedics, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang, China;

Objective: To compare the clinical efficacy of minimally invasive percutaneous plate osteosynthesis(MIPPO)and open reduction and internal fixation (ORIF) in treating senile NEER IIproximal humerus fractures.

Methods: From March 2014 to March 2016, 46 elderly patients with Neer II proximal humerus fractures were retrospectively reviewed. Among them, 20 patients in MIPPO group included 9 males and 11 females with an average age of (70.4±4.4) years old; while 26 patients in ORIF group included 11 males and 15 females with an average age of (70.9±4.0) years old. The length of hospital stay, times of fluoroscopy, beginning time of function rehabilitation, healing time of fracture, Constant Murley score of the shoulder joint at 3, 6, 12 months after operation and complications were observed and compared.

Results: All patients were followed up for 12 to 24 months with an average of 16.8±3.7. The healing time of fracture, beginning time of function rehabilitation in MIPPO group were(13.0±0.8) weeks, (3.0±0.9) days respectively and shorter than those in ORIF group which were (13.8±1.4) weeks and(6.8±1.3) days. The times of fluoroscopy in MIPPO group was 19.2±3.7 and more than that in ORIF group which was 12.1±3.4. At 3 and 6 months after operation, Constant Murley score in MIPPO group were 81.3±3.9, 86.6±5.4 and more than that in ORIF group which were 69.5±6.6, 80.5±6.7. There were no differences between two groups in the length of hospital stay, Constant Murley score at 12 months after operation and grading at the final follow-up. There was one fracture redisplacement in each group. And 1 case of axillary nerve injury in MIPPO group, 2 cases of delayed union in ORIF group. No incision infection, screw loosening or plate break was found.

Conclusions: MIPPO and ORIF are both effective in treating Neer II proximal humeral fractures. MIPPO technique has the advantages of faster recovery, earlier rehabilitative exercise and better shoulder function. The disadvantages are more exposure to radiationd and the possibility of axillary nerve injure.
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http://dx.doi.org/10.3969/j.issn.1003-0034.2018.02.013DOI Listing
February 2018

NMDA receptor-gated visual responses in hippocampal CA1 neurons.

J Physiol 2018 05 31;596(10):1965-1979. Epub 2018 Mar 31.

Institute and Key Laboratory of Brain Functional Genomics of Chinese Ministry of Education, Shanghai Key Laboratory of Brain Functional Genomics, School of Life Sciences, East China Normal University, Shanghai, 200062, China.

Key Points: Sensory information processing in hippocampal circuits is critical for numerous hippocampus-dependent functions, but the underlying synaptic mechanism remains elusive. We performed whole-cell recording in vivo to examine visually evoked synaptic activity in hippocampal CA1 pyramidal cells (PCs). We first found that at resting potentials, ∼30% of CA1 PCs showed synaptic responses to a flash of visual stimulation. Interestingly, at depolarizing potentials, nearly all CA1 PCs were found to exhibit NMDA receptor-dependent responses, indicating the presence of NMDA receptor-mediated gating of CA1 responses. The NMDA receptor-gated CA1 responses may play important roles in the hippocampal function that depends on sensory information processing.

Abstract: Hippocampal processing of environmental information is critical for hippocampus-dependent brain functions that result from experience-induced hippocampal plasticity, such as memory acquisition and storage. Hippocampal responses to sensory stimulation have been extensively investigated, particularly with respect to spike activity. However, the synaptic mechanism for hippocampal processing of sensory stimulation has been much less understood. Here, we performed in vivo whole-cell recording on hippocampal CA1 pyramidal cells (PCs) from adult rodents to examine CA1 responses to a flash of visual stimulation. We first found in recordings obtained at resting potentials that ∼30% of CA1 PCs exhibited significant excitatory/inhibitory membrane-potential (MP) or membrane-current (MC) responses to the flash stimulus. Remarkably, in the other (∼70%) CA1 PCs, although no responses could be detected at resting potentials, clear excitatory MP or MC responses to the same flash stimulus were observed at depolarizing potentials, and these responses were further found to depend on NMDA receptors. Our findings demonstrate the presence of NMDA receptor-mediated gating of visual responses in hippocampal CA1 neurons, a synaptic mechanism for hippocampal processing of sensory information that may play important roles in hippocampus-dependent functions such as learning and memory.
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http://dx.doi.org/10.1113/JP275094DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5978316PMC
May 2018

Validating Candidate Congenital Heart Disease Genes in .

Bio Protoc 2017 Jun;7(12)

Center for Cancer and Immunology Research, Children's National Medical Center, 111 Michigan Ave. NW, Washington, DC, USA.

Genomic sequencing efforts can implicate large numbers of genes and mutations as potential disease risk factors. A high throughput model system to validate candidate gene association with pathology is therefore useful. We present such a system employing to validate candidate congenital heart disease (CHD) genes. The protocols exploit comprehensive libraries of UAS-GeneX-RNAi fly strains that when crossed into a 4×Hand-Gal4 genetic background afford highly efficient cardiac-specific knockdown of endogenous fly orthologs of human genes. A panel of quantitative assays evaluates phenotypic severity across multiple cardiac parameters. These include developmental lethality, larva and adult heart morphology, and adult longevity. These protocols were recently used to evaluate more than 100 candidate CHD genes implicated by patient whole-exome sequencing (Zhu ., 2017).
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http://dx.doi.org/10.21769/BioProtoc.2350DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5739056PMC
June 2017

Epigenetic mechanisms underlying maternal diabetes-associated risk of congenital heart disease.

JCI Insight 2017 10 19;2(20). Epub 2017 Oct 19.

Center for Cardiovascular Research and Heart Center, Nationwide Children's Hospital, Columbus, Ohio, USA.

Birth defects are the leading cause of infant mortality, and they are caused by a combination of genetic and environmental factors. Environmental risk factors may contribute to birth defects in genetically susceptible infants by altering critical molecular pathways during embryogenesis, but experimental evidence for gene-environment interactions is limited. Fetal hyperglycemia associated with maternal diabetes results in a 5-fold increased risk of congenital heart disease (CHD), but the molecular basis for this correlation is unknown. Here, we show that the effects of maternal hyperglycemia on cardiac development are sensitized by haploinsufficiency of Notch1, a key transcriptional regulator known to cause CHD. Using ATAC-seq, we found that hyperglycemia decreased chromatin accessibility at the endothelial NO synthase (Nos3) locus, resulting in reduced NO synthesis. Transcription of Jarid2, a regulator of histone methyltransferase complexes, was increased in response to reduced NO, and this upregulation directly resulted in inhibition of Notch1 expression to levels below a threshold necessary for normal heart development. We extended these findings using a Drosophila maternal diabetic model that revealed the evolutionary conservation of this interaction and the Jarid2-mediated mechanism. These findings identify a gene-environment interaction between maternal hyperglycemia and Notch signaling and support a model in which environmental factors cause birth defects in genetically susceptible infants.
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http://dx.doi.org/10.1172/jci.insight.95085DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5846898PMC
October 2017

Condyle Head Reimplantation Combined With Vascularized Free Flap for Mandibular Reconstruction.

J Craniofac Surg 2017 Sep;28(6):1559-1562

*The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory for Oral Biomedicine Ministry of Education, Wuhan University†Department of Oral Maxillofacial and Head Neck Oncology, School and Hospital of Stomatology, Wuhan University, Wuhan, China.

Due to the anatomic and functional complexity, reconstruction of the condylar process after mandibular tumor extirpation remains a surgical challenge. The aim of this study was to present the results and experience of condyle head reimplantation combined with vascularized free flap for mandibular reconstruction in our institution. In the current study, the authors evaluated the clinical features of condyle head reimplantation combined with vascularized free flap for mandibular reconstruction in 5 patients with benign mandibular intraosseous lesions from December 2013 to March 2015 in our institution. All patients showed nearly normal mouth opening, with minimal mandibular deviation and joint symptoms. The radiograph data showed that 4 patients had no obvious bone resorption of condyles while only 1 patient had prominent condyle resorption. All the condyles were cut above the condylar neck, with the biggest remaining condyle height being 2.8 cm and the smallest one being 1.1 cm. Moreover, the original vertical height of mandibular ramus was decreased by 2 to 3 mm during the surgery. In conclusion, this study revealed that combining the condyle reimplantation with vascularized free flap constitutes a reliable method in condylar reconstruction and a slight reduction of the vertical height of condyles may help to diminish unfavorable outcomes.
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http://dx.doi.org/10.1097/SCS.0000000000003930DOI Listing
September 2017

Down-regulation of polycystin in lymphatic malformations: possible role in the proliferation of lymphatic endothelial cells.

Hum Pathol 2017 07 26;65:231-238. Epub 2017 May 26.

The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan 430079, China; Department of Oral and Maxillofacial Surgery, School & Hospital of Stomatology, Wuhan University, Wuhan 430079, China.

Lymphatic malformations (LMs) are composed of aberrant lymphatic vessels and regarded as benign growths of the lymphatic system. Recent studies have demonstrated that the mutant embryos of PKD1 and PKD2, encoding polycystin-1 (PC-1) and polycystin-2 (PC-2), respectively, result in aberrant lymphatic vessels similar to those observed in LMs. In this study, for the first time, we investigated PC-1 and PC-2 expression and assessed their roles in the development of LMs. Our results demonstrated that PC-1 and PC-2 gene and protein expressions were obviously decreased in LMs compared with normal skin tissues. In addition, the expression of phosphorylated ERK but not total ERK was up-regulated in LMs and negatively correlated with the expression of PC-1 and PC-2. Moreover, up-regulation of Ki67 was detected in LMs and positively correlated with ERK phosphorylation levels. Furthermore, cluster analysis better reflected close correlation between these signals. All of the above results provided strong evidence suggesting that the hyperactivation of the ERK pathway may be caused by down-regulation of PC-1 and PC-2 in LMs, contributing to increased proliferation of lymphatic endothelial cells in LMs. Our present study sheds light on novel potential mechanisms involved in LMs and may help to explore novel treatments for LMs.
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http://dx.doi.org/10.1016/j.humpath.2017.05.016DOI Listing
July 2017

Association of ATF4 Expression With Tissue Hypoxia and M2 Macrophage Infiltration in Infantile Hemangioma.

J Histochem Cytochem 2017 05 1;65(5):285-294. Epub 2017 Feb 1.

The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education (H-FX, J-YZ, J-NW, J-GR, YC, F-QW, WZ, GC, Y-FZ, J-HZ), School and Hospital of Stomatology, Wuhan University, Wuhan, China.

Accumulating studies have revealed the hypoxic condition and its crucial role in the distinctive progression of infantile hemangioma (IH), the most common benign tumor in infancy. Activating transcription factor 4 (ATF4), an important gene mediating cellular adaptation to various stress signals, could confer a survival advantage for tumor cells under hypoxia and regulate tumor progression. However, the potential role of ATF4 in IH was still unknown. In this study, the expression of hypoxia inducible factor (HIF)-1α, ATF4, and macrophage colony-stimulating factor (M-CSF) in 27 specimens of IH was measured by immunochemistry and double-labeling immunofluorescence, followed by the Spearman rank correlation test. Our results showed that the expression of HIF-1α, ATF4, and M-CSF was significantly upregulated in proliferating IH compared with involuting IH. Meanwhile, HIF-1α and ATF4, in parallel with ATF4 and M-CSF, exhibited positive correlation and synchronous expression. In addition, our in vitro studies demonstrated that hypoxia obviously upregulated the expression of HIF-1α, ATF4, and M-CSF in hemangioma stem cells. Most importantly, their expression was uniformly correlated with the percentage of M2-polarized macrophages in IH. All those results and established evidence indicated that hypoxia-induced ATF4 expression may promote progression of proliferating IH through M-CSF-induced M2-polarized macrophages infiltration.
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http://dx.doi.org/10.1369/0022155417694872DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5407535PMC
May 2017

A Personalized Model of Nephropathy Rescued by the Wild-Type Allele or Dietary Coenzyme Q Supplementation.

J Am Soc Nephrol 2017 Sep 20;28(9):2607-2617. Epub 2017 Apr 20.

Centers for Cancer and Immunology Research and

Clinical studies have identified patients with nephrotic syndrome caused by mutations in genes involved in the biosynthesis of coenzyme Q (CoQ), a lipid component of the mitochondrial electron transport chain and an important antioxidant. However, the cellular mechanisms through which these mutations induce podocyte injury remain obscure. Here, we exploited the striking similarities between nephrocytes and human podocytes to develop a model of these renal diseases, and performed a systematic analysis assessing the role of CoQ pathway genes in renal function. Nephrocyte-specific silencing of , , and , which are genes involved in the CoQ pathway that have been associated with genetic nephrotic syndrome in humans, induced dramatic adverse changes in these cells. In particular, silencing of led to an abnormal localization of slit diaphragms, collapse of lacunar channels, and more dysmorphic mitochondria. In addition, -deficient nephrocytes showed elevated levels of autophagy and mitophagy, increased levels of reactive oxygen species, and increased sensitivity to oxidative stress. Dietary supplementation with CoQ at least partially rescued these defects. Furthermore, expressing the wild-type human gene specifically in nephrocytes rescued the defective protein uptake, but expressing the mutant allele derived from a patient with nephropathy did not. We conclude that transgenic lines carrying mutations in the CoQ pathway genes are clinically relevant models with which to explore the pathogenesis of podocyte injury and could serve as a new platform to test novel therapeutic approaches.
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http://dx.doi.org/10.1681/ASN.2016060626DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5576924PMC
September 2017

The E3 ubiquitin ligase Nedd4/Nedd4L is directly regulated by microRNA 1.

Development 2017 03;144(5):866-875

Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA

is a small noncoding RNA molecule that modulates gene expression in heart and skeletal muscle. Loss of produces defects in somatic muscle and embryonic heart development, which have been partly attributed to directly targeting Delta to decrease Notch signaling. Here, we show that overexpression of in the fly wing can paradoxically increase Notch activity independently of its effects on Delta. Analyses of potential targets revealed that directly regulates the 3'UTR of the E3 ubiquitin ligase Analysis of embryonic and adult fly heart revealed that the Nedd4 protein regulates heart development in Larval fly hearts overexpressing have profound defects in actin filament organization that are partially rescued by concurrent overexpression of Nedd4. These results indicate that and Nedd4 act together in the formation and actin-dependent patterning of the fly heart. Importantly, we have found that the biochemical and genetic relationship between and the mammalian ortholog Nedd4-like () is evolutionarily conserved in the mammalian heart, potentially indicating a role for Nedd4L in mammalian postnatal maturation. Thus, -mediated regulation of Nedd4/Nedd4L expression may serve to broadly modulate the trafficking or degradation of Nedd4/Nedd4L substrates in the heart.
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http://dx.doi.org/10.1242/dev.140368DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5374346PMC
March 2017

Comprehensive functional analysis of Rab GTPases in Drosophila nephrocytes.

Cell Tissue Res 2017 06 8;368(3):615-627. Epub 2017 Feb 8.

Center for Cancer and Immunology Research, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA.

The Drosophila nephrocyte is a critical component of the fly renal system and bears structural and functional homology to podocytes and proximal tubule cells of the mammalian kidney. Investigations of nephrocyte cell biological processes are fundamental to understanding the insect renal system. Nephrocytes are highly active in endocytosis and vesicle trafficking. Rab GTPases regulate endocytosis and trafficking but specific functions of nephrocyte Rabs remain undefined. We analyzed Rab GTPase expression and function in Drosophila nephrocytes and found that 11 out of 27 Drosophila Rabs were required for normal activity. Rabs 1, 5, 7, 11 and 35 were most important. Gene silencing of the nephrocyte-specific Rab5 eliminated all intracellular vesicles and the specialized plasma membrane structures essential for nephrocyte function. Rab7 silencing dramatically increased clear vacuoles and reduced lysosomes. Rab11 silencing increased lysosomes and reduced clear vacuoles. Our results suggest that Rab5 mediates endocytosis that is essential for the maintenance of functionally critical nephrocyte plasma membrane structures and that Rabs 7 and 11 mediate alternative downstream vesicle trafficking pathways leading to protein degradation and membrane recycling, respectively. Elucidating molecular pathways underlying nephrocyte function has the potential to yield important insights into human kidney cell physiology and mechanisms of cell injury that lead to disease. The Drosophila nephrocyte is emerging as a useful in vivo model system for molecular target identification and initial testing of therapeutic approaches in humans.
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http://dx.doi.org/10.1007/s00441-017-2575-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5429992PMC
June 2017

A Drosophila model system to assess the function of human monogenic podocyte mutations that cause nephrotic syndrome.

Hum Mol Genet 2017 02;26(4):768-780

Center for Cancer and Immunology Research, Children's National Health Systems, 111 Michigan Ave. NW, Washington, DC, USA.

Many genetic mutations have been identified as monogenic causes of nephrotic syndrome (NS), but important knowledge gaps exist in the roles of these genes in kidney cell biology and renal diseases. More animal models are needed to assess the functions of these genes in vivo, and to determine how they cause NS in a timely manner. Drosophila nephrocytes and human podocytes share striking similarities, but to what degree these known NS genes play conserved roles in nephrocytes remains unknown. Here we systematically studied 40 genes associated with NS, including 7 that have not previously been analysed for renal function in an animal model. We found that 85% of these genes are required for nephrocyte functions, suggesting that a majority of human genes known to be associated with NS play conserved roles in renal function from flies to humans. To investigate functional conservation in more detail, we focused on Cindr, the fly homolog of the human NS gene CD2AP. Silencing Cindr in nephrocytes led to dramatic nephrocyte functional impairment and shortened life span, as well as collapse of nephrocyte lacunar channels and effacement of nephrocyte slit diaphragms. These phenotypes could be rescued by expression of a wild-type human CD2AP gene, but not a mutant allele derived from a patient with CD2AP-associated NS. We conclude that the Drosophila nephrocyte can be used to elucidate clinically relevant molecular mechanisms underlying the pathogenesis of most monogenic forms of NS, and to efficiently generate personalized in vivo models of genetic renal diseases bearing patient-specific mutations.
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http://dx.doi.org/10.1093/hmg/ddw428DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6074792PMC
February 2017

Downregulation of miR-145 in venous malformations: Its association with disorganized vessels and sclerotherapy.

Eur J Pharm Sci 2017 Mar 16;100:126-131. Epub 2017 Jan 16.

The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China; Department of Oral and Maxillofacial Surgery, School & Hospital of Stomatology, Wuhan University, Wuhan, China. Electronic address:

Venous malformations (VMs) are characterized by ectatic and tortuous venous channels with decreased perivascular cell coverage. Recent studies have discovered that miR-145 plays a critical role in amounts of vascular diseases through regulating the differentiation and phenotype of vascular smooth muscle cells (VSMCs). However, the potential roles of miR-145 in VMs remain unknown. In this study, 21 samples of VMs without treatment history, and 10 samples of healthy donor skin, were collected to evaluate the expression level of TGF-β, miR-145, and α-SMA by immunohistochemistry, in situ hybridization, and real-time polymerase chain reaction (PCR). Subsequently, their correlations were analyzed using the Spearman rank correlation test. In vitro studies were performed using human umbilical vein endothelial cells (HUVECs). The results showed that miR-145 was significantly downregulated in VMs compared with normal skin tissues, accompanied by a synchronously decreased TGF-β expression level and perivascular α-SMA cell coverage. Correlation analysis revealed that miR-145 expression was positively correlated with TGF-β expression and perivascular α-SMA cell coverage in VMs. In addition, TGF-β, miR-145, and α-SMA were concurrently increased in the tissues of VMs treated with bleomycin A5. More importantly, in vitro studies revealed that both recombinant human TGF-β and bleomycin A5 could significantly upregulate TGF-β and miR-145 expression in HUVECs with the similar increasing tendency. In summary, our present study unmasked the downregulation of miR-145 in VMs, possibly induced by TGF-β depression and closely correlated with disorganized vessels. Moreover, miR-145 may be involved in the sclerotherapy of VMs and possess the target potential.
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http://dx.doi.org/10.1016/j.ejps.2017.01.019DOI Listing
March 2017

High throughput in vivo functional validation of candidate congenital heart disease genes in .

Elife 2017 01 20;6. Epub 2017 Jan 20.

Center for Cancer and Immunology Research, Children's National Medical Center, Washington, United States.

Genomic sequencing has implicated large numbers of genes and de novo mutations as potential disease risk factors. A high throughput in vivo model system is needed to validate gene associations with pathology. We developed a -based functional system to screen candidate disease genes identified from Congenital Heart Disease (CHD) patients. 134 genes were tested in the heart using RNAi-based gene silencing. Quantitative analyses of multiple cardiac phenotypes demonstrated essential structural, functional, and developmental roles for more than 70 genes, including a subgroup encoding histone H3K4 modifying proteins. We also demonstrated the use of to evaluate cardiac phenotypes resulting from specific, patient-derived alleles of candidate disease genes. We describe the first high throughput in vivo validation system to screen candidate disease genes identified from patients. This approach has the potential to facilitate development of precision medicine approaches for CHD and other diseases associated with genetic factors.
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http://dx.doi.org/10.7554/eLife.22617DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5300701PMC
January 2017

Magnetic and Folate Functionalization Enables Rapid Isolation and Enhanced Tumor-Targeting of Cell-Derived Microvesicles.

ACS Nano 2017 01 3;11(1):277-290. Epub 2017 Jan 3.

The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine of Ministry of Education, School and Hospital of Stomatology, Wuhan University , Wuhan 430079, P. R. China.

Cell-derived microvesicles (MVs), which are biogenic nanosized membrane-bound vesicles that convey bioactive molecules between cells, have recently received attention for use as natural therapeutic platforms. However, the medical applications of MV-based delivery platforms are limited by the lack of effective methods for the efficient isolation of MVs and the convenient tuning of their targeting properties. Herein, we report the development of magnetic and folate (FA)-modified MVs based on a donor cell-assisted membrane modification strategy. MVs inherit the membrane properties of their donor cells, which allows them to be modified with the biotin and FA on their own membrane. By conjugating with streptavidin-modified iron oxide nanoparticles (SA-IONPs), the MVs can be conveniently, efficiently, and rapidly isolated from the supernatant of their donor cells using magnetic activated sorting. Moreover, the conjugated magnetic nanoparticles and FA confer magnetic and ligand targeting activities on the MVs. Then, the MVs were transformed into antitumor delivery platforms by directly loading doxorubicin via electroporation. The modified MVs exhibited significantly enhanced antitumor efficacy both in vitro and in vivo. Taken together, this study provides an efficient and convenient strategy for the simultaneous isolation of cell-derived MVs and transformation into targeted drug delivery nanovectors, thus facilitating the development of natural therapeutic nanoplatforms.
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http://dx.doi.org/10.1021/acsnano.6b05630DOI Listing
January 2017

APOL1-G1 in Nephrocytes Induces Hypertrophy and Accelerates Cell Death.

J Am Soc Nephrol 2017 Apr 18;28(4):1106-1116. Epub 2016 Nov 18.

Center for Cancer and Immunology Research, Washington, DC;

People of African ancestry carrying certain APOL1 mutant alleles are at elevated risk of developing renal diseases. However, the mechanisms underlying -associated renal diseases are unknown. Because the gene is unique to humans and some primates, new animal models are needed to understand the function of APOL1 We generated transgenic fly lines expressing the human wild type allele (G0) or the predominant risk allele (G1) in different tissues. Ubiquitous expression of G0 or G1 in induced lethal phenotypes, and G1 was more toxic than was G0. Selective expression of the G0 or G1 transgene in nephrocytes, fly cells homologous to mammalian podocytes, induced increased endocytic activity and accumulation of hemolymph proteins, dextran particles, and silver nitrate. As transgenic flies with either allele aged, nephrocyte function declined, cell size increased, and nephrocytes died prematurely. Compared with G0-expressing cells, however, G1-expressing cells showed more dramatic phenotypes, resembling those observed in cultured mammalian podocytes overexpressing APOL1-G1. Expressing the G0 or G1 transgene in nephrocytes also impaired the acidification of organelles. We conclude that expression of an transgene initially enhances nephrocyte function, causing hypertrophy and subsequent cell death. This new model uncovers a novel mechanism by which upregulated expression of APOL1-G1 could precipitate renal disease in humans. Furthermore, this model may facilitate the identification of APOL1-interacting molecules that could serve as new drug targets to treat -associated renal diseases.
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http://dx.doi.org/10.1681/ASN.2016050550DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5373456PMC
April 2017

Analysis of the association of single nucleotide polymorphisms of interleukin-23 receptor (IL-23R) and inflammatory bowel disease in a Chinese Han cohort.

Oncotarget 2016 10;7(42):67851-67856

Department of Gastroenterology, Suzhou Municipal Hospital (Eastern), Suzhou Hospital Affiliated to Nanjing Medical University, Suzhou, China.

Inflammatory bowel disease (IBD) is a chronic, complex genetic disease with rapidly increasing prevalence in China. The interactions of genetic, environmental, and microbial factors contribute to the development of IBD, however, the precise etiologies of IBD are not well understood yet. Interleukin-23 receptor (IL-23R) encodes a subunit of receptor for IL-23, which is an important proinflammatory cytokine. In this study, we investigated the relationship between the single nucleotide polymorphism (SNP) of IL-23R gene and IBD in Chinese Han population. We genotyped three nonsynonymous IL-23R SNPs with amino acid changes (rs11209026, p.Arg381Gln; rs41313262 p.Val362Ile and rs11465797 p.Thr175Asn) in 198 patients with IBD (124 UC and 74 CD) and 100 healthy controls. The prevalence of the A allele in IL-23R Arg381Gln of CD appeared less than controls, but it was not statistically significant (2.70% vs. 6.00%, p > 0.05). There was no statistical difference between UC and controls (5.65% vs. 6.00%, p = 0.91). The p.Val362Ile variant was present in 2.42% of UC patients, in 2.70% of CD patients, which was similar in the control (2.00%). There was no statistical difference among these three groups. We did not detect Thr175Asn (rs11465797 c.524 C>A) in all the three groups. In conclusion, our study demonstrated that the p.Val362Ile and Arg381Gln were not associated with susceptibility to IBD in Chinese Han population.
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http://dx.doi.org/10.18632/oncotarget.12296DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5356524PMC
October 2016

Gia/Mthl5 is an aorta specific GPCR required for Drosophila heart tube morphology and normal pericardial cell positioning.

Dev Biol 2016 06 16;414(1):100-7. Epub 2016 Mar 16.

Center for Cancer and Immunology Research, Children's Research Institute, Children's National Medical Center, 111 Michigan Ave. NW, Washington, DC 20010, USA. Electronic address:

G-protein signaling is known to be required for cell-cell contacts during the development of the Drosophila dorsal vessel. However, the identity of the G protein-coupled receptor (GPCR) that regulates this signaling pathway activity is unknown. Here we describe the identification of a novel cardiac specific GPCR, called Gia, for "GPCR in aorta". Gia is the only heart-specific GPCR identified in Drosophila to date and it is specifically expressed in cardioblasts that fuse at the dorsal midline to become the aorta. Gia is the only Drosophila gene so far identified for which expression is entirely restricted to cells of the aorta. Deletion of Gia led to a broken-hearted phenotype, characterized by pericardial cells dissociated from cardioblasts and abnormal distribution of cell junction proteins. Both phenotypes were similar to those observed in mutants of the heterotrimeric cardiac G proteins. Lack of Gia also led to defects in the alignment and fusion of cardioblasts in the aorta. Gia forms a protein complex with G-αo47A, the alpha subunit of the heterotrimeric cardiac G proteins and interacts genetically with G-αo47A during cardiac morphogenesis. Our study identified Gia as an essential aorta-specific GPCR that functions upstream of cardiac heterotrimeric G proteins and is required for morphological integrity of the aorta during heart tube formation. These studies lead to a redefinition of the bro phenotype, to encompass morphological integrity of the heart tube as well as cardioblast-pericardial cell spatial interactions.
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http://dx.doi.org/10.1016/j.ydbio.2016.03.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4875858PMC
June 2016

Wnt4 is required for ostia development in the Drosophila heart.

Dev Biol 2016 05 16;413(2):188-98. Epub 2016 Mar 16.

Center for Cancer and Immunology Research, Children's Research Institute, Children's National Medical Center, 111 Michigan Ave. NW, Washington, DC 20010, USA; Department of Pediatrics, George Washington University School of Medicine and Health Sciences, Washington, DC 20010, USA. Electronic address:

The Drosophila ostia are valve-like structures in the heart with functional similarity to vertebrate cardiac valves. The Wnt/β-catenin signaling pathway is critical for valve development in zebrafish and mouse, but the key ligand(s) for valve induction remains unclear. We observed high levels of Wnt4 gene expression in Drosophila ostia progenitor cells, immediately prior to morphological differentiation of these cells associated with ostia formation. This differentiation was blocked in Wnt4 mutants and in flies expressing canonical Wnt signaling pathway inhibitors but not inhibitors of the planar cell polarity pathway. High levels of Wnt4 dependent activation of a canonical Wnt signaling reporter was observed specifically in ostia progenitor cells. In vertebrate valve formation Wnt signaling is active in cells undergoing early endothelial-mesenchymal transition (EMT) and the Wnt9 homolog of Drosophila Wnt4 is expressed in valve progenitors. In demonstrating an essential role for Wnt4 in ostia development we have identified similarities between molecular and cellular events associated with early EMT during vertebrate valve development and the differentiation and partial delamination of ostia progenitor cells in the process of ostia formation.
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http://dx.doi.org/10.1016/j.ydbio.2016.03.008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4857614PMC
May 2016

Characterization of Endothelial Microparticles Induced by Different Therapeutic Drugs for Infantile Hemangioma.

J Cardiovasc Pharmacol 2015 Sep;66(3):261-9

*The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China; and †Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, Wuhan, China.

Endothelial microparticles (EMPs) are complex vesicular structures with great significance in vascular pathophysiology. Here, we aimed to determine the impact of therapeutic drugs for infantile hemangioma, a common vascular tumor of infancy, on the biochemical features of EMPs. We exposed human umbilical vein endothelial cells to propranolol (Pro), dexamethasone (Dex), or rapamycin (Rap). Compared with controls, Pro and Rap dramatically augmented EMP release, whereas Dex significantly suppressed EMP generation. Drug-stimulated EMPs could inherit but tended to lose specific endothelial surface antigens from their parental cells. On the one hand, markedly distinct messenger RNA expression patterns were observed within and between drug-stimulated endothelial cells and derived EMPs. On the other hand, Rap-treated endothelial cells and Pro-induced EMPs displayed downregulation of multiple angiogenesis-related molecules at messenger RNA level compared with corresponding controls. Meanwhile, among tested angiogenesis-associated microRNAs, twelve microRNAs were downregulated in drug-induced EMPs, whereas only let-7b and miR-133a were markedly upregulated. Collectively, these data may indicate selective and distinctive package of biomolecules into EMPs depending on specific drugs. Our findings may provide novel insights into the underlying mechanisms of pharmacological therapy for infantile hemangioma.
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http://dx.doi.org/10.1097/FJC.0000000000000273DOI Listing
September 2015

Macrophages Contribute to the Progression of Infantile Hemangioma by Regulating the Proliferation and Differentiation of Hemangioma Stem Cells.

J Invest Dermatol 2015 Dec 19;135(12):3163-3172. Epub 2015 Aug 19.

The State Key Laboratory Breeding Base of Basic Science of Stomatology, Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China; Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, Wuhan, China. Electronic address:

Macrophage infiltration has been implicated in infantile hemangioma (IH), the most common tumor of infancy. However, the exact role of macrophages in IH remains unknown. This study aims to clarify the functional significance of macrophages in the progression of IH. The distribution of macrophages in human IH was analyzed, and our results revealed that polarized macrophages were more prevalent in proliferating IHs than in involuting IHs, which was consistent with the increased macrophage-related cytokines in proliferating IHs. In vitro results further demonstrated that polarized macrophages effectively promoted the proliferation of hemangioma stem cells (HemSCs) and suppressed their adipogenesis in an Akt- and extracellular signal-regulated kinase 1/2 (Erk1/2)-dependent manner. Moreover, M2- but not M1-polarized macrophages promoted the endothelial differentiation of HemSCs. Furthermore, mixing macrophages in a murine hemangioma model elevated microvessel density and postponed fat tissue formation, which was concomitant with the activation of Akt and Erk1/2 signals. Cluster analysis revealed a close correlation among the macrophage markers, Ki67, vascular endothelial growth factor (VEGF), p-Akt, and p-Erk1/2 in human IH tissues. Collectively, our results suggest that macrophages in IH contribute to tumor progression by promoting the proliferation and endothelial differentiation while suppressing the adipogenesis of HemSCs. These findings indicate that targeting the infiltrating macrophages in IH is a promising therapeutic approach to accelerate IH regression.
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http://dx.doi.org/10.1038/jid.2015.321DOI Listing
December 2015

Hyperbranched-hyperbranched polymeric nanoassembly to mediate controllable co-delivery of siRNA and drug for synergistic tumor therapy.

J Control Release 2015 Oct 10;216:9-17. Epub 2015 Aug 10.

Key Laboratory of Biomedical Polymers of Ministry of Education & Department of Chemistry, Wuhan University, Wuhan 430072, China.

This study reported a flexible nanoplatform constructed on the pH-dependent self-assembly of two kinds of hyperbranched polymers, and then validated its potency as the controllable siRNA/drug co-delivery vehicle for the combination of chemotherapy with RNA interfering (RNAi) therapy. By virtue of pH-reversible phenylboronate linking, phenylboronic acid-tethered hyperbranched oligoethylenimine (OEI600-PBA) and 1,3-diol-rich hyperbranched polyglycerol (HBPO) can be spontaneously interlinked together into a core-corona nanoconstruction. The special buildup of compactly clustering OEI600-PBA units around hydrophobic HBPO aggregate offered significant advantages over parent OEI600-PBA, including strengthened affinity to siRNA, ability of further loading anticancer drug, easier cellular transport, and acidity-responsive release of payloads. To evaluate the co-delivery capability, Beclin1 siRNA and antitumor DOX were used as the therapeutic models in order to suppress the post-chemotherapy survival of tumor cells caused by drug-induced autophagy. The nanoassembly-mediated single delivery of DOX displayed even better anticancer effects than free DOX, demonstrating the superiority of our pH-responsive nano-design. The nanoassembly-mediated co-delivery of siRNA together with DOX can effectively silence Beclin1 gene, suppress DOX-induced autophagy, and consequently provide strong synergism with a significant enhancement of cell-killing effects in cultured cancerous cells. The in vivo combinational treatment was shown to make the tumor more sensitive to DOX chemotherapy while displaying substantially improved safety as compared with the monochemotherapy.
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http://dx.doi.org/10.1016/j.jconrel.2015.08.006DOI Listing
October 2015

KANK deficiency leads to podocyte dysfunction and nephrotic syndrome.

J Clin Invest 2015 Jun 11;125(6):2375-84. Epub 2015 May 11.

Steroid-resistant nephrotic syndrome (SRNS) is a frequent cause of progressive renal function decline and affects millions of people. In a recent study, 30% of SRNS cases evaluated were the result of monogenic mutations in 1 of 27 different genes. Here, using homozygosity mapping and whole-exome sequencing, we identified recessive mutations in kidney ankyrin repeat-containing protein 1 (KANK1), KANK2, and KANK4 in individuals with nephrotic syndrome. In an independent functional genetic screen of Drosophila cardiac nephrocytes, which are equivalents of mammalian podocytes, we determined that the Drosophila KANK homolog (dKank) is essential for nephrocyte function. RNAi-mediated knockdown of dKank in nephrocytes disrupted slit diaphragm filtration structures and lacuna channel structures. In rats, KANK1, KANK2, and KANK4 all localized to podocytes in glomeruli, and KANK1 partially colocalized with synaptopodin. Knockdown of kank2 in zebrafish recapitulated a nephrotic syndrome phenotype, resulting in proteinuria and podocyte foot process effacement. In rat glomeruli and cultured human podocytes, KANK2 interacted with ARHGDIA, a known regulator of RHO GTPases in podocytes that is dysfunctional in some types of nephrotic syndrome. Knockdown of KANK2 in cultured podocytes increased active GTP-bound RHOA and decreased migration. Together, these data suggest that KANK family genes play evolutionarily conserved roles in podocyte function, likely through regulating RHO GTPase signaling.
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http://dx.doi.org/10.1172/JCI79504DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4497755PMC
June 2015

Transformation of cell-derived microparticles into quantum-dot-labeled nanovectors for antitumor siRNA delivery.

Angew Chem Int Ed Engl 2015 Jan 20;54(3):1036-40. Epub 2014 Nov 20.

Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, and the Institute for Advanced Studies, Wuhan University, 299 Bayi Road, Wuhan 430072 (China); Key Laboratory of Oral Biomedicine (Ministry of Education) and Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079 (China).

Cell-derived microparticles (MPs) have been recently recognized as critical intercellular information conveyors. However, further understanding of their biological behavior and potential application has been hampered by the limitations of current labeling techniques. Herein, a universal donor-cell-assisted membrane biotinylation strategy was proposed for labeling MPs by skillfully utilizing the natural membrane phospholipid exchange of their donor cells. This innovative strategy conveniently led to specific, efficient, reproducible, and biocompatible quantum dot (QD) labeling of MPs, thereby reliably conferring valuable traceability on MPs. By further loading with small interference RNA, QD-labeled MPs that had inherent cell-targeting and biomolecule-conveying ability were successfully employed for combined bioimaging and tumor-targeted therapy. This study provides the first reliable and biofriendly strategy for transforming biogenic MPs into functionalized nanovectors.
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http://dx.doi.org/10.1002/anie.201410223DOI Listing
January 2015

A boronate-linked linear-hyperbranched polymeric nanovehicle for pH-dependent tumor-targeted drug delivery.

Biomaterials 2014 Jun 31;35(19):5240-9. Epub 2014 Mar 31.

Key Laboratory of Biomedical Polymers of Ministry of Education & Department of Chemistry, Wuhan University, Wuhan 430072, China.

Advanced drug delivery systems, which possess post-functionalization feasibility to achieve targetability and traceability, favorable pharmacokinetics with dynamic but controllable stability, and preferable tumor accumulation with prolonged drug residence in disease sites, represent ideal nanomedicine paradigm for tumor therapy. To address this challenge, here we reported a dynamic module-assembly strategy based on reversible boronic acid/1,3-diol bioorthogonality. As a prototype, metastable hybrid nanoself-assembly between hydrophobic hyperbranched diol-enriched polycarbonate (HP-OH) and hydrophilic linear PEG terminated with phenylboronic acid (mPEG-PBA) is demonstrated in vitro and in vivo. The nanoconstruction maintained excellent stability with little leakage of loaded drugs under the simulated physiological conditions. Such a stable nanostructure enabled the effective in vivo tumor accumulation in tumor site as revealed by NIR imaging technique. More importantly, this nanoconstruction presented a pH-labile destruction profile in response to acidic microenvironment and simultaneously the fast liberation of loaded drugs. Accordingly at the cellular level, the intracellular structural dissociation was also proved in terms of the strong acidity in late endosome/lysosome, thus favoring the prolonged retention of remaining drug-loaded HP-OH aggregates within tumor cells. Hence, our delicate design open up a dynamical module-assembly path to develop site and time dual-controlled nanotherapeutics for tumor chemotherapy, allowing enhanced tumor selectivity through prolonged retention of delivery system in tumor cells followed by a timely drug release pattern.
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http://dx.doi.org/10.1016/j.biomaterials.2014.03.029DOI Listing
June 2014