Zika Virus (ZIKV) was
first isolated in 1947 from a sentinel monkey in Uganda and associated with
human infection in 1954 when neutralizing antibodies were detected in the sera
of residents in India, with antibodies also being found in residents from
various African countries. ZIKV is mosquitoe-borne Flavivirus that is
predominantly transmitted via Aedes
Agypti, although sexual transmission (female to male, male to female, male
to male) and transmission via blood transfusion has also been reported.
Clinically most cases are
asymptomatic and symptomatic cases only present themselves with relative benign
symptoms in adults, the exception being Guillain Barre Syndrome. During in the
current outbreak in the Americas and –albeit only retroactively identified- in
the 2013/2014 outbreak in French Polynesia, ZIKV has been identified to a
causative agent of abnormal foetal brain development, leading to congenital
defects, namely microcephaly, anomalies of the CNS, miscarriages and in rare
cases foetal and/or neonatal death. Studies in both wt and immunodeficient mice
confirmed that the infection of pregnant mice with various strains of ZIKV
including strains from Asia (SZ01, FSS1305), Oceania (H/PF/2013), Brazil
(Paraiba 2015), Puerto Rico
(PRVABC59) and Mexico (MEX_1_7) indeed can cause abnormal development of
the (foetal) brain by apoptosis of neural progenitor cells similar to
representatives of the African strain, ZIKV MR766 (Uganda, 1947) and ZIKV IbH30656
(Nigeria, 1968), tested. In addition, the infection of brain organoids, neurospheres,
human (foetal) Neural Progenitor Cells (h (f) NPC) and human Neural Stem Cells
(NSC) with various ZIKV strains including a primary isolate from Africa, ZIKV
ArB41644, demonstrated that ZIKV can indeed induce apoptosis of proliferating
but probably not of mature neurons. Recently the infection of cranial neural
crest cells (CNCC) with either ZIKV MR766 or ZIKV H/PF/2013 has been reported
to induce high levels of cytokines that are detrimental for neurogenesis,
causing bystander apoptosis of uninfected neuronal cells. Infected CNCC do not
undergo apoptosis at 24 hrs p.i. but apoptosis is increased at 72 hrs p.i.
confirming that both ZIKV MR766 and ZIKV H/PF/2013 can induce apoptosis of CNCC
although only approx. 8% of ZIKV infected CNCC undergo apoptosis compared to 4%
of mock or DENV infected CNCC, indicating that CNCC support viral infection
whilst being protected against apoptosis probably by VEGF as indicated by increased
secretion of VEGF which has been shown to inhibit apoptosis of human
microvascular endothelial cells (HUMEC).
In brains of wt C57BL/6
mice intracranial infected with ZIKV MR766 day 7 postnatal and analysed day 4
p.i. brain mass is reduced compared to mock infected mice by 25%, as well as
showing an increase of NeuN+ and
CTIP+ cells that also positive for active Caspase-3, indicating that
ZIKV MR766 does not or rarely induces apoptosis in corticospinal cells,
neuronal progenitor cells and astrocytes but in mature neurons in postnatal
mice. These results are in contrast with
previously discussed results that indicate that in foetal mice, mature neurons
are ZIKV negative and do not undergo apoptosis upon ZIKV infection. In contrast
to mice infected at day 7 postnatal, mice infected at three weeks postnatal do
show less severe apoptosis as measured by the presence of active Caspase-3
although similar to day 7 postnatal infected mice, widespread apoptosis of NeuN+
cells is detected by the presence active Caspase-3. When interpreting
these experiments however, one has to bear in mind that ZIKV MR766 is a
neurotrophic strain adapted to mice brain due to repeated intracranial passage.
Autophagy
and viral infection
Autophagy is a cellular
degradation pathway that involves the sequestration of cytoplasmic component
such as organelles, protein aggregates or pathogens with (transient) double
membrane most commonly derived from the ER, forming a phagosome that ultimately
matures into the autophagosome and is degraded by lysosomal enzymes such as
acidic hydrolases upon fusion with the lysosome. In general, basal autophagy is
part of the turnover of RNA, proteins and organelles but can be induced in
cells undergoing various forms of stress, including starvation. Both genome
wide screens and large scale proteomic basic screens identified a substantial
number of autophagy related regulators, including but not limited to autophagy
related genes (ATG) that initiate the formation and the maturation of
autophagosomes, aided by improved imaging, as well as degrading substrates such
as RNA in lysosomes.
In the case of viral
infections, the interactions between positive sense RNA viruses is of
particular interest since autophagosomes might contribute to the decay of
(viral) RNA in lysosomes by RNase T2, RNASE1 and RNASE6/RNase K6. Although it
has not been determined experimentally, viral RNA might be targeted to
lysosomes directly (similar to LINE 1 via processing bodies/stress granules
that interact with NDP52/CALCOCO2 or p62/SQSTM-1) or as part of a complex with
viral and/or cellular proteins that form a RNA-Protein Binding complex (RBP).
 |
| Figure: General outline of the autophagy pathway |
More importantly however,
RNA viruses such as Chikungunya Virus (CHIKV), Coronaviruses’ (CoV), Polio
Virus, Measles Virus, DENV, Hepatitis C Virus (HCV) or Classical Swine Fever
Virus (CSFV) can utilize autophagosomes and/or double membrane vesicles (DMV)
to increase viral replication. As discussed in previous posts, in the case of
CHIKV or CoV, the formation of viral replication centers (RC) is dependent on
the autophagy machinery, including ATG5 and Beclin-1, whilst in others –such as
HCV- autophagy is also required for exit of the mature virions as exosomes. To
prevent degradation of assembled viral particles, viral proteins that inhibit
the fusion of the autophagosome with the lysosome by binding Beclin-1 for
instance are expressed late in the replication cycle.
 |
| Figure: Regulation of the autophagy pathway by CoV proteins as an example for the regulation of autophagy by viral proteins |
Autophagy itself can be
activated via the inhibition of the Phosphatidylinositol-3 Kinase
(PI3-K)-Akt-mTOR pathway, thereby inducing the phosphorylation of the ULK-1
complex and subsequently inducing the formation of the phagosome and
autophagosome. This pathway is activated by the binding of growth factors such
as Insulin to their respective cell surface receptor followed by the conversion
of membrane bound Phosphatidylinositol-4’,5’-bisphosphate (PIP2) to
Phosphatidylinositol-3’,4’,5’-trisphosphate (PIP3) thus recruiting
Akt to the plasma membrane and phosphorylating Akt. Phosphorylated Akt activates
the TSC1/2 complex, the GTPase activating protein (GAP) of Rheb. Activated Rheb
binds and activates the mTOR-Raptor complex, inhibiting the formation of
autophagosomes and thus autophagy.
Indeed, preventing the
phosphorylation of Akt both at Thr 308 and Ser473 reduces the phosphorylation of
mTOR at Ser2448 thus promoting autophagy whereas the ectopic expression of a constitutively
active myristoylated mutant of Akt (Akt3 E17K) inhibits autophagy.
 |
| Figure: Akt inhibits the formation of autophagosomes via mTORC-1 |
The inhibition of autophagy in neuronal cells can induce
neurodegeneration and autophagy defects –including lysosomal defects- have been
implicated in Huntington Disease and ALS as well as in microcephaly and
megalencephaly-polydactyly-polymicrogyria-hydrocephalus.
CSFV and Autophagy: where
autophagy meets viral persistence
Before discussing recent
results concerning ZIKV and autophagy, it is worth examining the role of
autophagy in cells persistently infected with CSFV and how autophagy
contributes to the survival of viral infected cells.
Classical Swine Fever
Virus (CSFV) is positive strand RNA virus which is classified as a Pestivirus
within the Flaviviridae, causing
highly virulent disease in swine characterized by a high fever, leukopenia and
hemorrhages with a mortality. In infected PK-15 and 3D4/2 cells, CSFV inhibits
the type I Interferon response, leading to persistent infection in the absence
of apoptosis. In a recently published study, CSFV has been shown to induce the
formation of LC3-II positive (mature) autophagosomes as early as 48 hrs p.i.
and both the viral E2 and NS5A proteins have been shown to localise in LC3
positive vesicles as early as 24 hrs p.i. which can be inhibited by
3-Methyladenine (3-MA) as well as by downregulating the expression of either
Beclin-1 or LC3-B suggesting that CSFV does induce the formation of
autophagosomes as well as autophagic flux as evidenced by decreased levels of
p62/SQSTM-1 in CSFV infected PK-5 and 3D4/2 cells.
Autophagy induction by
CSFV however not only increases viral replication –presumably by forming viral
RC- but also decreases viral induced apoptosis and decreasing mRNA levels of
genes related to the type I Interferon response and IFN stimulated genes
(ISG).
CSFV induces apoptosis
via activation of the intrinsic apoptotic pathway, i.e. via activation of
Caspase-9 and Caspase-3, by inducing the accumulation of mitochondrial reactive
oxygen species (ROS) if autophagy is inhibited in infected PK-5 and 3D4/2 cells
by shBeclin1 or shLC3 which can be inhibited by either Z-VAD (a pan caspase
inhibitor) or Necrostatin-1 (Nec-1/ROS scavenger). In addition to the intrinsic
pathway, the extrinsic –Caspase-8 dependent- is also triggered in CSFV infected
autophagy deficient cells.
CSFV induction of
mitochondrial ROS not only induces the activation of apoptosis but also induces
autophagy and thus promotes the clearance of damaged mitochondria via
mitophagy, which is indirectly indicated by the increase of copy numbers of
mitochondrial DNA in autophagy deficient PK-5 and 3D4/2 CSFV infected cells
(flow cytometry using JC-1, NAO or TMRE was not performed) and/or promotes
autophagy in a Nrf-2 dependent manner.
The accumulation of ROS
in CFSV infected cells also induces antiviral signalling via RIG-1 and MDA-5,
including increased expression of TNF/TNF-α, IFN-β/IFNB1 and FAS/TNFRSF6 in
autophagy deficient CSFV infected cells, thus inducing the extrinsic pathway in
an autocrine manner, which is inhibited in shDDX58, shIFIH1 and shMAVS CSFV
infected autophagy deficient cells. The induction of autophagy by CSFV
therefore might not only promote the clearance of damaged mitochondria but also
the decreasing transcripts of ISG via RNautophagy.
 |
| Figure: CSFV inhibitors apoptosis and induces autophagy via multiple pathways |
Also, so far it has not been demonstrated if CSFV induced formation of ROS also induces the induction of TLR-9 by mitochondrial DNA. In this scenario, a complex of mtDNA and TLR-9 might be degraded via autophagy and thus abrogate antiviral signalling.
ZIKV and autophagy: impairment of autophagic
flux linked to ZIKV induced apoptosis ?
In the case of ZIKV, the
formation of autophagosome like vesicles has been observed in ZIKV MR766
infected human primary fibroblasts and keratinocytes and in the cytoplasm of
C6/36 cells infected with a ZIKV isolate from a patient in Brazil although in
A549 cells infected with ZIKV H/PF/2013 no LC3 positive structures have been detected.
Following the infection
human foetal neural stem cells (fNSC) infected with either ZIKV MR766, ZIKV
H/PF/2013 or ZIKV IbH30656 the formation of neurospheres is significantly
impaired at day 7 p.i., as indicated by fewer neurospheres present which are
also smaller in size, due to the induction of apoptosis as measured by TUNEL
staining. Ina accordance with previously published results, ZIKV infected fNSC
derived neurospheres also exhibit a reduction of cell proliferation measured by
both BrdU incorporation, suggesting that ZIKV indeed does affect the
proliferation of foetal neuronal precursor cells.
Similar to ZIKV MR766 infected human keratinocytes, the infection of
fNSC with ZIKV MR766 or ZIKV IbH30656 induces the formation of LC3-II positive
autophagosomes, without affecting autophagic flux, indicating that ZIKV
infection of fNSC induces the formation of autophagosomes without affecting the
formation of autolysosomes as measured by the degradation of p62/SQSTM-1. It
should be noted that the infection of HeLa cells transiently transfected with a
GFP/RFP-LC3 tandem plasmid with ZIKV MR766 increases GFP+/RFP+ punctae,
indicating that the formation of the autolysosome might be inhibited. The
discrepancy can either be due to the use of HeLa cells or it might be possible
that ZIKV infection leads to the proteasomal degradation of p62/SQSTM-1 in fNSC similar to DENV-2 infected Huh-7 cells.
In any case, treatment of ZIKV infected fNSC with Chloroquine decreases viral RNA/viral titres whilst Rapamycin treatment increases levels of both viral RNA and titers as
early as 10 hrs p.i. suggesting that autophagic flux is necessary for
viral replication. Based on the results described for CSFV above, autophagic
flux might be necessary to prevent viral induced apoptosis and/or antiviral
signalling; therefore, treatment with Chloroquine might prevent the degradation
of viral RNA-TLR complexes and thus induce antiviral signalling whereas in
untreated cells residual autophagy might be sufficient for inducing a partial
antiviral response. Treatment of fNSC
with 3-MA inhibits viral replication, suggesting that autophagosome formation
is required for viral replication, probably for the formation of viral RC.
The ability to initiate the formation of the autophagosome is further
highlighted by results that the replication of ZIKV MR766 in Atg3 -/- MEF and
Atg5 -/-/MEF as well as in MEF transfected with siATG13 or siATG3 is lower when
compared to wt MEF.
In DENV and HCV infected cells, the localisation of viral proteins
induces the formation of viral replication complexes by utilizing the autophagy
machinery; in a similar way, CoV nsp-3 and -4 have been shown to induce the
formation of LC3-II positive vesicles that are derived from the ER.
In the case of ZIKV, the expression of NS4A and NS4B induces the
formation of GFP-LC3 positive punctae in HeLa-GFP-LC3 cells which is more
pronounced if both NS4A and NS4B are co-expressed. Similar to ZIKV MR766
infected cells, the co-expression of NS4A and NS4B increases the percentage of
GFP+/RFP+ positive punctae, indicating that autophagic flux might be inhibited,
although p62/SQSTM-1 levels are decreased which is probably due to proteasomal degradation of p62/SQSTM-1 (as described above).
Based on immunofluorescence data and on data obtained from DENV NS4A and
DENV NS4B, both ZIKV NS4A and NS4B are localised at the ER, suggesting that
autophagy might be induced by the ER stress response.
 |
| Figure: Topology of DENV NS4A and NS4B |
As described before, the ER stress response can initiate autophagy by
negatively regulating the PI-3-K/Akt pathway. Indeed, ZIKV NS4A and NS4B reduce
the phosphorylation of Akt at both Thr308 and Ser473 as well as of mTOR at
Ser2448 which can be reversed by the expression of a constitutively active form
of Akt, Myr-HA-Akt3 E17K, in ZIKV MR766 infected fNSC or HeLa cells, suggesting that NS4A and NS4B induce the ER stress response, although it has not proven experimentally yet.
 |
| Figure:ZIKV NS4A and NS4B inhibits PI3-K and therefore activates the formation of autophagosomes |
In addition, the expression of ZIKV NS4A and NS4B decreases the
proliferation of fNSC as measured by Ki67, which is more pronounced if both
NS4A and NS4B are co-expressed. Since prolonged ER stress induces not only
autophagy but also apoptosis, the (co-) expression of NS4A and NS4B might
induce both autophagy and apoptosis although the percentage of apoptotic cells
following the transfection of fNSC with ZIKV NS4A/B has not been determined.
 |
| Figure: ZIKV NS4A and NS4B decrease the expression of Ki-67 and the proliferation of fNSC |
In conclusion, the infection of fNSC with ZIKV MR766, ZIKV IbH30656 and ZIKV
H/PF/2013 induces apoptosis, decreased cell proliferation, smaller neurospheres
and the formation of autophagosomes with impaired autophagic flux, the latter
probably induced by both NS4A and NS4B protein. The notion that ZIKV MR766 inhibits
the fusion of the autophagosome with the lysosome -or lysosomal maturation- and
thus induces neurodegeneration by impairing the degradation of autophagic
substrates is supported by findings in ZIKV MR766 infected hNPC, the expression
of LAMP-2 is downregulated.
 |
| Figure: ZIKV and autophagy |
If the impairment of
autophagic flux however is linked to the induction of apoptosis in ZIKV
infected primary neuronal cells has not been demonstrated. It might be possible
that similar to CSFV infected cells, autophagy is required for abrogating
antiviral signalling.
It should be noted that the infection of hNPC with ZIKV MR766 downregulates the expression of key proteins involved in the onset and progression of stress induced autophagy. Therefore, ZIKV infection of neuronal and non-neuronal cells might inhibit stress induced and selective autophagy whilst promoting the formation of viral RC. It is therefore important to analyse if the formation of viral RC is totally or only partially dependent on the ability to induce the formation of autophagosomes since viral proteins might be able to induce some of the processes required for the formation of RC independent of the autophagy machinery.
It should be noted that the infection of hNPC with ZIKV MR766 downregulates the expression of key proteins involved in the onset and progression of stress induced autophagy. Therefore, ZIKV infection of neuronal and non-neuronal cells might inhibit stress induced and selective autophagy whilst promoting the formation of viral RC. It is therefore important to analyse if the formation of viral RC is totally or only partially dependent on the ability to induce the formation of autophagosomes since viral proteins might be able to induce some of the processes required for the formation of RC independent of the autophagy machinery.
 |
| Table: Genes that are up- or downregulated in ZIKV MR766 infected hNPC |
A screen of FDA approved
revealed that both Bortezomib and Ivermectin inhibit the replication of ZIKV Mex_1_7 in infected Huh-7, HeLa
and/or Human Amnion Epithelial Cells. Both Bortezomib and Ivermectin
induce apoptosis of cancer cells by inhibiting autophagy, indicating that in
ZIKV infected (neuronal) cells autophagy might not only support viral
replication by forming viral RC but also by inhibiting apoptosis at least in
the early stages of viral replication. If the induction of autophagy has also
consequences for the establishment of persistently infected cells, however
remains to be seen.
Further reading
Pei J, Zhao M, Ye Z, Gou H, Wang J, Yi L, Dong X, Liu W, Luo Y, Liao M, & Chen J (2014). Autophagy enhances the replication of classical swine fever virus in vitro. Autophagy, 10 (1), 93-110 PMID: 24262968
Pei J, Deng J, Ye Z, Wang J, Gou H, Liu W, Zhao M, Liao M, Yi L, & Chen J (2016). Absence of autophagy promotes apoptosis by modulating the ROS-dependent RLR signaling pathway in classical swine fever virus-infected cells. Autophagy, 12 (10), 1738-1758 PMID: 27463126
Summerfield A, Knötig SM, & McCullough KC (1998). Lymphocyte apoptosis during classical swine fever: implication of activation-induced cell death. Journal of virology, 72 (3), 1853-61 PMID: 9499036
Frankel LB, Lubas M, & Lund AH (2016). Emerging connections between RNA and autophagy. Autophagy, 1-21 PMID: 27715443
He L, Zhang YM, Lin Z, Li WW, Wang J, & Li HL (2012). Classical swine fever virus NS5A protein localizes to endoplasmic reticulum and induces oxidative stress in vascular endothelial cells. Virus genes, 45 (2), 274-82 PMID: 22718084
He L, Zhang Y, Fang Y, Liang W, Lin J, & Cheng M (2014). Classical swine fever virus induces oxidative stress in swine umbilical vein endothelial cells. BMC veterinary research, 10 PMID: 25439655
Zhang F, Hammack C, Ogden SC, Cheng Y, Lee EM, Wen Z, Qian X, Nguyen HN, Li Y, Yao B, Xu M, Xu T, Chen L, Wang Z, Feng H, Huang WK, Yoon KJ, Shan C, Huang L, Qin Z, Christian KM, Shi PY, Xu M, Xia M, Zheng W, Wu H, Song H, Tang H, Ming GL, & Jin P (2016). Molecular signatures associated with ZIKV exposure in human cortical neural progenitors. Nucleic acids research, 44 (18), 8610-8620 PMID: 27580721
Calvet, G., Aguiar, R., Melo, A., Sampaio, S., de Filippis, I., Fabri, A., Araujo, E., de Sequeira, P., de Mendonça, M., de Oliveira, L., Tschoeke, D., Schrago, C., Thompson, F., Brasil, P., dos Santos, F., Nogueira, R., Tanuri, A., & de Filippis, A. (2016). Detection and sequencing of Zika virus from amniotic fluid of fetuses with microcephaly in Brazil: a case study The Lancet Infectious Diseases, 16 (6), 653-660 DOI: 10.1016/S1473-3099(16)00095-5
Cauchemez S, Besnard M, Bompard P, Dub T, Guillemette-Artur P, Eyrolle-Guignot D, Salje H, Van Kerkhove MD, Abadie V, Garel C, Fontanet A, & Mallet HP (2016). Association between Zika virus and microcephaly in French Polynesia, 2013-15: a retrospective study. Lancet (London, England), 387 (10033), 2125-32 PMID: 26993883
Cloëtta D, Thomanetz V, Baranek C, Lustenberger RM, Lin S, Oliveri F, Atanasoski S, & Rüegg MA (2013). Inactivation of mTORC1 in the developing brain causes microcephaly and affects gliogenesis. The Journal of neuroscience : the official journal of the Society for Neuroscience, 33 (18), 7799-810 PMID: 23637172
Cugola FR, Fernandes IR, Russo FB, Freitas BC, Dias JL, Guimarães KP, Benazzato C, Almeida N, Pignatari GC, Romero S, Polonio CM, Cunha I, Freitas CL, Brandão WN, Rossato C, Andrade DG, Faria Dde P, Garcez AT, Buchpigel CA, Braconi CT, Mendes E, Sall AA, Zanotto PM, Peron JP, Muotri AR, & Beltrão-Braga PC (2016). The Brazilian Zika virus strain causes birth defects in experimental models. Nature, 534 (7606), 267-71 PMID: 27279226
De Carvalho NS, De Carvalho BF, Fugaça CA, Dóris B, & Biscaia ES (2016). Zika virus infection during pregnancy and microcephaly occurrence: a review of literature and Brazilian data. The Brazilian journal of infectious diseases : an official publication of the Brazilian Society of Infectious Diseases, 20 (3), 282-9 PMID: 27102780
Arroba AI, Rodríguez-de la Rosa L, Murillo-Cuesta S, Vaquero-Villanueva L, Hurlé JM, Varela-Nieto I, & Valverde ÁM (2016). Autophagy resolves early retinal inflammation in Igf1-deficient mice. Disease models & mechanisms, 9 (9), 965-74 PMID: 27483352
Paul P, & Münz C (2016). Autophagy and Mammalian Viruses: Roles in Immune Response, Viral Replication, and Beyond. Advances in virus research, 95, 149-95 PMID: 27112282
McLean JE, Wudzinska A, Datan E, Quaglino D, & Zakeri Z (2011). Flavivirus NS4A-induced autophagy protects cells against death and enhances virus replication. The Journal of biological chemistry, 286 (25), 22147-59 PMID: 21511946
Liang Q, Luo Z, Zeng J, Chen W, Foo SS, Lee SA, Ge J, Wang S, Goldman SA, Zlokovic BV, Zhao Z, & Jung JU (2016). Zika Virus NS4A and NS4B Proteins Deregulate Akt-mTOR Signaling in Human Fetal Neural Stem Cells to Inhibit Neurogenesis and Induce Autophagy. Cell stem cell PMID: 27524440
Barrows NJ, Campos RK, Powell ST, Prasanth KR, Schott-Lerner G, Soto-Acosta R, Galarza-Muñoz G, McGrath EL, Urrabaz-Garza R, Gao J, Wu P, Menon R, Saade G, Fernandez-Salas I, Rossi SL, Vasilakis N, Routh A, Bradrick SS, & Garcia-Blanco MA (2016). A Screen of FDA-Approved Drugs for Inhibitors of Zika Virus Infection. Cell host & microbe, 20 (2), 259-70 PMID: 27476412
Tang, H., Hammack, C., Ogden, S., Wen, Z., Qian, X., Li, Y., Yao, B., Shin, J., Zhang, F., Lee, E., Christian, K., Didier, R., Jin, P., Song, H., & Ming, G. (2016). Zika Virus Infects Human Cortical Neural Progenitors and Attenuates Their Growth Cell Stem Cell, 18 (5), 587-590 DOI: 10.1016/j.stem.2016.02.016
Goodfellow FT, Tesla B, Simchick G, Zhao Q, Hodge T, Brindley MA, & Stice SL (2016). Zika Virus Induced Mortality and Microcephaly in Chicken Embryos. Stem cells and development PMID: 27627457
Sir D, Kuo CF, Tian Y, Liu HM, Huang EJ, Jung JU, Machida K, & Ou JH (2012). Replication of hepatitis C virus RNA on autophagosomal membranes. The Journal of biological chemistry, 287 (22), 18036-43 PMID: 22496373
Adams Waldorf, K., Stencel-Baerenwald, J., Kapur, R., Studholme, C., Boldenow, E., Vornhagen, J., Baldessari, A., Dighe, M., Thiel, J., Merillat, S., Armistead, B., Tisoncik-Go, J., Green, R., Davis, M., Dewey, E., Fairgrieve, M., Gatenby, J., Richards, T., Garden, G., Diamond, M., Juul, S., Grant, R., Kuller, L., Shaw, D., Ogle, J., Gough, G., Lee, W., English, C., Hevner, R., Dobyns, W., Gale, M., & Rajagopal, L. (2016). Fetal brain lesions after subcutaneous inoculation of Zika virus in a pregnant nonhuman primate Nature Medicine DOI: 10.1038/nm.4193
Metz P, Chiramel A, Chatel-Chaix L, Alvisi G, Bankhead P, Mora-Rodriguez R, Long G, Hamacher-Brady A, Brady NR, & Bartenschlager R (2015). Dengue Virus Inhibition of Autophagic Flux and Dependency of Viral Replication on Proteasomal Degradation of the Autophagy Receptor p62. Journal of virology, 89 (15), 8026-41 PMID: 26018155
Huang J, Li Y, Qi Y, Zhang Y, Zhang L, Wang Z, Zhang X, & Gui L (2014). Coordinated regulation of autophagy and apoptosis determines endothelial cell fate during Dengue virus type 2 infection. Molecular and cellular biochemistry, 397 (1-2), 157-65 PMID: 25138703
Ho HK, White CC, Fernandez C, Fausto N, Kavanagh TJ, Nelson SD, & Bruschi SA (2005). Nrf2 activation involves an oxidative-stress independent pathway in tetrafluoroethylcysteine-induced cytotoxicity. Toxicological sciences : an official journal of the Society of Toxicology, 86 (2), 354-64 PMID: 15901913
Ravikumar, B., Sarkar, S., Davies, J., Futter, M., Garcia-Arencibia, M., Green-Thompson, Z., Jimenez-Sanchez, M., Korolchuk, V., Lichtenberg, M., Luo, S., Massey, D., Menzies, F., Moreau, K., Narayanan, U., Renna, M., Siddiqi, F., Underwood, B., Winslow, A., & Rubinsztein, D. (2010). Regulation of Mammalian Autophagy in Physiology and Pathophysiology Physiological Reviews, 90 (4), 1383-1435 DOI: 10.1152/physrev.00030.2009
Menzies FM, Fleming A, & Rubinsztein DC (2015). Compromised autophagy and neurodegenerative diseases. Nature reviews. Neuroscience, 16 (6), 345-57 PMID: 25991442
Li, Y., Chen, B., Zou, W., Wang, X., Wu, Y., Zhao, D., Sun, Y., Liu, Y., Chen, L., Miao, L., Yang, C., & Wang, X. (2016). The lysosomal membrane protein SCAV-3 maintains lysosome integrity and adult longevity The Journal of Cell Biology DOI: 10.1083/jcb.201602090
De Leo MG, Staiano L, Vicinanza M, Luciani A, Carissimo A, Mutarelli M, Di Campli A, Polishchuk E, Di Tullio G, Morra V, Levtchenko E, Oltrabella F, Starborg T, Santoro M, di Bernardo D, Devuyst O, Lowe M, Medina DL, Ballabio A, & De Matteis MA (2016). Autophagosome-lysosome fusion triggers a lysosomal response mediated by TLR9 and controlled by OCRL. Nature cell biology, 18 (8), 839-50 PMID: 27398910
Draganov D, Gopalakrishna-Pillai S, Chen YR, Zuckerman N, Moeller S, Wang C, Ann D, & Lee PP (2015). Modulation of P2X4/P2X7/Pannexin-1 sensitivity to extracellular ATP via Ivermectin induces a non-apoptotic and inflammatory form of cancer cell death. Scientific reports, 5 PMID: 26552848
Selimovic D, Porzig BB, El-Khattouti A, Badura HE, Ahmad M, Ghanjati F, Santourlidis S, Haikel Y, & Hassan M (2015). Corrigendum to "Bortezomib/proteasome inhibitor triggers both apoptosis and autophagy-dependent pathways in melanoma cells". [Cell Signal. 25(1)Jan 2013 308-18]. Cellular signalling PMID: 25666930
