









































  ARESTY  RUTGERS UNDERGRADUATE RESEARCH JOURNAL, VOLUME I, ISSUE III 
 
 
 

 
 

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. 

THE ROLE OF  
AUTOPHAGY  

IN PHOSPHATIDYL- 
GLYCEROL FACILITATED 

CHOLESTEROL  
CLEARANCE FROM  

THE ENDOLYSOSOMAL  
SYSTEM OF NPC-1  
DEFICIENT CELLS 

TAMARA ALLADA, OLGA ILNYTSKA PHD, 
JUDITH STORCH (FACULTY ADVISOR) 

 
 
 

✵ ABSTRACT 
Niemann Pick Type C (NPC) Disease is a rare 

lysosomal storage disorder in which one of the 
genes that codes for either the NPC-1 or NPC-2 pro-
tein is mutated, causing cell lysosomes to accumu-
late cholesterol and lipids. Previous studies discov-
ered that a unique late endosomal/lysosomal phos-
pholipid, lysobisphosphatidic acid (LPBA), is in-
volved in cholesterol clearance from late endo-
somes. It has also been shown that exogenous treat-
ment of the NPC-1 deficient cells with LBPA’s precur-
sor, phosphatidylglycerol (PG), leads to LBPA enrich-
ment and subsequent endolysosomal cholesterol 
clearance. Autophagy is a mechanism of cellular 
clearance in the endolysomal system and we are in-
terested to see if it is a partial route in cholesterol 
clearance during PG treatment of NPC-1 deficient 
cells. To do so, we silenced the gene that codes for 
an essential protein in the autophagy pathway, mak-
ing the cells autophagy deficient. We then treated 

the cells with PG, measured the amount of choles-
terol clearance in those cells, and compared it to 
cells with normal autophagy. We found significantly 
less cholesterol clearance by PG in cells with defec-
tive autophagy, confirming that autophagy is in-
volved as a partial route in cholesterol clearance dur-
ing PG treatment, but not enough of a difference to 
conclude that it is a major underlying mechanism.  

 

1 INTRODUCTION 
Niemann Pick Type C (NPC) Disease results 

in cholesterol and lipids becoming trapped in cell ly-
sosomes and unable to be trafficked through the cell 
to where they are needed.[19,26]  Cholesterol accumu-
lates in the lysosome and exits via lysosomal mem-
brane proteins, such as NPC-1 and NPC-2, in unaf-
fected cells. The NPC proteins are essential for trans-
porting cholesterol through the endolysosomal sys-
tem; therefore, nonfunctional NPC proteins result in 
an accumulation of cholesterol and secondary lipids 
in the late endosomal and lysosomal compartments. 
An NPC patient suffers from severe motor and neu-
rological symptoms that worsen with time.[14]   

The exact method of how cholesterol is 
transported out of the endolysosomal system is un-
known,[14] but our preliminary data suggests that au-
tophagy may be involved. Autophagy is a mecha-
nism of cellular clearance in which damaged pro-
teins, organelles, and membranes are transported to 
the endolysosomal system where they can be bro-
ken down into metabolites used by the cell.[28] It is 
essentially a cellular degradation and recycling pro-
cess.  In order for cells to perform essential biosyn-
thetic and energy production pathways, they need 
basic monomers of larger molecules. Cells can ob-
tain these monomers through the break-down and 
recycling of damaged organelles, proteins, and cel-
lular membranes. These molecular degradations oc-
cur in lysosomes, which are acidic vesicles contain-
ing numerous hydrolases and found within the cell. 
Hydrolases are a class of proteins that break down 
large molecules into their monomers. Macroautoph-
agy involves sequestering the molecules that need 
to be degraded into vesicles called autophago-  



  ARESTY  RUTGERS UNDERGRADUATE RESEARCH JOURNAL, VOLUME I, ISSUE III 
 
 
 

somes and delivering them to lysosomes for degra-
dation,[28] as shown in FIGURE 1.   

The process of autophagy begins with the 
process shown in FIGURE 2. Several molecules come 
together to form the ULK1/2-ATG13-RB1CC1 induc-
tion complex, which can develop at multiple sites 
throughout the cytoplasm.[5,10] Once formed, the 
complex can either be activated or inactivated via a 
molecule called the Mechanistic Target of Rapamy-
cin Complex 1 (MTORC1). When MTORC1 is associ-
ated with the induction complex, the complex is in-
active and the process of autophagy stops. When 
MTORC1 dissociates from the induction complex, 
the complex activates, resuming autophagy.[9] To 
summarize, the process of autophagy is inhibited 
when MTORC1 is associated with the ULK1/2-
ATG13-RB1CC1 induction complex and resumes 
when MTORC1 disassociates from the induction 
complex.  

In addition, FIGURE 2 displays how the nutrient 
status of the cell is involved in autophagy regulation. 
During nutrient starvation, there is low energy in the 
cell. The nutrition status therefore determines the 
status of autophagy, as the cell needs the monomers 
produced by autophagy for the energy production 
pathways.[9] During nutrient enrichment, there is 
enough energy in the cell and autophagy is not 
needed.  

The next step of autophagy is nucleation, or 
formation of the membrane, which is an essential 
step in macroautophagy.[18] Once the membrane be-
gins to expand, it is called a phagophore. This struc-
ture is double membranous and expands to eventu-
ally create a closed, circular vesicle.[8] The process of 
phagophore elongation is composed of 2 conju-
gated systems. The first system results in the for-
mation of the ATG12-ATG5-ATG16L1 complex, as 
shown in FIGURE 3, which is needed for the second sys-
tem. Once formed, the complex associates with the 
phagophore membrane.[15,16] The second system is 
shown in FIGURE 4 and ultimately allows the phago-
phore membrane to elongate and move locations 
within the cell.[18] One step in this process is facili-
tated by the ATG12-ATG5-ATG16L1 complex 
formed in the first system. As the phagophore mem-
brane expands, it curves around its target molecules, 

FIGURE 1: Overview of macroautophagy in mammalian cells. 
Figure obtained from [18]. 

FIGURE 2: Activation of the induction complex during a nu-
trient starved cellular state. Figure obtained from [18]. 

FIGURE 3: (LEFT) ATG12–ATG5-ATG16L1 conjugation 
complex. Figure obtained from [18]. 

FIGURE 4: (RIGHT) ATG8/LC3 conjugation system.  
Figure obtained from [18]. 

 



  ARESTY  RUTGERS UNDERGRADUATE RESEARCH JOURNAL, VOLUME I, ISSUE III 
 
 
 

known as cargo, and keeps adjusting to wrap around 
the cargo.[18] When it has fully wrapped around the 
cargo, the ends connect, forming a closed double 
membranous vesicle known as an autophago-
some.[18]  

The autophagosome will move toward the 
lysosome via the cell’s microtubules.[17] Once at the 
lysosome, the autophagosome’s outer membrane 
will fuse with the lysosomal membrane, creating an 
autolysosome. The autophagosome may also fuse 
with endosomes, in both early and late stages, be-
fore fusing with the lysosome.[2,25] The last step of au-
tophagy is referred to as autophagic flux where deg-
radation within the autolysosome begins when the 
inner membrane is disrupted by ATG15.[7,24] Once 
the inner membrane is disrupted, the cargo that the 
autophagosome carried is exposed to the lyso-
some’s acidic environment and hydrolases that de-
grade molecules into their basic monomers. These 
metabolites are then exported from the lysosome 
into the cell via transporter proteins on the lysosomal 
membrane.[29] Different metabolites are transported 
out by different receptors. NPC-1 and NPC-2 pro-
teins are examples of these receptors used in the 
transport of cholesterol out of the lysosome.[20,27]  

Niemann Pick C (NPC) Disease is a type of 
lysosomal storage disorder, which is a category of 
disorders usually caused by a mutation in a gene that 
codes for a lysosomal transport protein.[21] Several 
studies have shown that autophagy is blocked or 
dysfunctional in most lysosomal storage disorders 
because of impaired fusion between the autophago-
some and the lysosome.[13,22,23] This block is thought 
to be caused by abnormal cholesterol accumulation 
in the lysosome.[1] Therefore, in NPC disease, since 
one of the NPC proteins is nonfunctional, cholesterol 
will be trapped in the lysosomes and autophagy will 
be blocked due to an inability of the autophago-
some to fuse with cholesterol-filled lysosomes.  

   It was found that cholesterol clearance de-
pends on the interaction of a region of the NPC-2  
protein with a lipid called lysobisphosphatidic acid, 
or LPBA.[6] In patients with NPC-1 disease, meaning 
their NPC-1 protein is dysfunctional, cholesterol 
clearance is still affected. This is because the limiting 
membrane of a lysosome is covered in a sugar coat 

called glycocalyx and it is believed that the luminal 
domains of the NPC-1 protein are required for cho-
lesterol to be able to penetrate through the gly-
cocalyx and exit the lysosome.[11,12] Increasing the 
LBPA levels in NPC-1 deficient cells have been found 
to result in a significant amount of cholesterol clear-
ance because the LBPA can still interact with the 
NPC-2 protein.[6] Exogenous treatment of LBPA’s 
precursor phosphatidylglycerol, or PG, also results in 
cholesterol clearance because the PG can go 
through its biosynthetic pathway to make LBPA.[13]  

Our preliminary data shows that PG treat-
ment of NPC-1 deficient cells facilitates autophago-
some fusion with the lysosome and subsequent au-
tophagic flux. Since NPC-1 deficient cells block au-
tophagy and PG helps it resume, we are interested 
in seeing if autolysosome formation and autophagic 
flux are involved in cholesterol clearance from late 
endosomes when these cells are treated with PG. To 
determine whether PG/LBPA-induced autophagic 
flux and cholesterol clearance are directly linked, we 
blocked autophagy by silencing the gene that codes 
for the ATG12 protein. ATG12 is essential to autoph-
agy because it is part of the ATG12-ATG5-ATG16L1 
complex that binds ATG8/LC3 to the membrane, an 
essential process in phagophore elongation. Au-
tophagy can be blocked by silencing the genes of a 
number of essential proteins to the process, but we 
will only focus on the gene that codes for ATG12. Af-
ter making the autophagy knockdown cell line and 
the control cell line, we treated the cells with PG and 
measured the subsequent cholesterol accumulation 
to see if the cells with blocked autophagy still 
cleared cholesterol to the same extent. If autophagy 
is involved in cholesterol clearance during PG treat-
ment, the cells that received the PG treatment but 
had autophagy blocked would have less cholesterol 
clearance than cells that received the PG treatment 
and had functional autophagy.  

 

2 METHODOLOGY  

 NPC-1 deficient cells were seeded in 12-well 
plates on coverslips with antibiotic-free growth me-
dium supplemented with FBS (fetal bovine serum), 
which contains nutrients that help the cells grow and 
divide. The cells were NPC-1 deficient either be- 



  ARESTY  RUTGERS UNDERGRADUATE RESEARCH JOURNAL, VOLUME I, ISSUE III 
 
 
 

cause they were fibroblast cells taken from patients 
with NPC-1 disease or because they were NPC-1 
knocked out HeLa cells, meaning the gene that 
codes for the NPC-1 protein was silenced. These 
HeLa cells are true NPC-1 -/-, meaning NPC-1 will be 
100% knocked-out.  

After 24 hours, the cells were at confluency, 
or 0.5 x 106 cells per plate, and we washed the cells 
with shRNA Transfection Medium. We then made 2 
cell lines: an autophagy knockout line and a control 
line. The cells for the autophagy knockout line were 
transduced with ATG12 shRNA lentiviral particles 
and the cells for the control line were transduced 
with scrambled control shRNA lentiviral particles. 
The cells of both lines were transduced with shRNA 
lentiviral particles in concentrations of 1x105 infec-
tious units of virus (IFU). The ATG12 shRNA encoded 
for a sequence that degraded mRNA in the cell that 
coded for the ATG12 protein. Autophagy was 
blocked because these cells could not make the 
ATG12 protein. The scrambled control shRNA en-
coded for a sequence that did not degrade any 
known cellular mRNA. Since these cells could ex-
press all of their normal proteins except NPC-1, au-
tophagy was not blocked. Knockdown shRNA did 
not get rid of 100% of the target mRNA, and prelim-
inary experiments showed that autophagy would be 
reduced but not completely blocked.  

After 48 hours of incubation, the old me-
dium was removed and 2 µg/mL antibiotic puromy-
cin medium was added to all well. Cells transfected 
with the virus particles would have a gene that make 
the cells resistant to puromycin, while cells that were 
not transfected would be killed by the antibiotic. 
Cells were then incubated for 3 days, after which all 
stable cells that remained alive were known to be the 
ones that were transfected.  
 Each cell line had a control group and a 
treatment group, with a total of 48 wells. We treated 
both treatment groups with 100μM PG and let the 
cells incubate. After 48 hours we washed all cells us-
ing phosphate buffer saline (PBS) and fixed them to 
the coverslips using a 4% paraformaldehyde solu-
tion. We then stained the cells on the coverslips with 
cholesterol-binding polyene antibiotic filipin III and 
a nuclear dye (sytox green). Each of the 48 coverslips 

contained about 50-100 fibroblast cells. Images 
were taken with the epifluorescent Revolve Micro-
scope at 40x magnification. Fluorescent intensities 
of the subcellular structures stained with filipin were 
analyzed using Image J software as described by.[11]  
 

3 RESULTS 
Fluorescent microscopy detects the intensity 

of filipin from the coverslips on which the cells were 
fixed (FIGURE 5). Filipin binds to cholesterol; the higher 
the filipin intensity, the higher the cholesterol levels 
in the cells. The results of the fluorescent microscopy 
are shown in FIGURE 6.   

Scr Control is a control group that is NPC-1 
deficient only. Scr+PG is a PG-treated group that is 
NPC-1 deficient only. Both of these groups came 
from the control cell line that received the scrambled 
control shRNA. ATG12 KD Control is a control group 
that is both NPC-1 deficient and has autophagy 
blocked. ATG12 KD + PG is a PG-treated group that 
is NPC-1 deficient and has autophagy blocked. Both 
of these groups have autophagy blocked because 
they came from the autophagy knockout cell line 
that received the ATG12 shRNA. The untreated con-
trol groups provide the baseline filipin intensity for 
each cell line. 

FIGURE 6 shows that there is a statistically sig-
nificant difference in cholesterol content between 
the Scr control and Scr+PG groups, with Scr+PG 
having less cholesterol. This is in agreement with the 
previous finding that PG supplementation increases 
LBPA levels and thus decreases cholesterol con-
tent.[14] The red bracket in FIGURE 6 shows that ATG12 
KD+PG has significantly more cholesterol than 
Scr+PG. This shows that autophagy is a partial route 
in cholesterol clearance during PG treatment, since 
the PG treatment was less effective when autophagy 
was blocked. Lastly, FIGURE 6 shows that ATG12 
KD+PG has significantly less cholesterol than ATG 
KD Control. This indicates that autophagy is not the 
major underlying mechanism for PG/LBPA-induced 
cholesterol efflux since PG treatment had an effect 
even when autophagy was blocked. This is also sug-
gested by the fact that there is only 15% more cho-
lesterol in ATG12 KD+PG than in Scr+PG; there 
would be closer to 100% more cholesterol in ATG12 



  ARESTY  RUTGERS UNDERGRADUATE RESEARCH JOURNAL, VOLUME I, ISSUE III 
 
 
 

KD+PG if autophagy was a major route in cholesterol 
clearance. The statistical tests were t-tests using a 
significance level of 0.01 and all three tests pro-
duced a p value of less than 0.001, as indicated by 
the asterisks.  

 

4 DISCUSSION 
The statistically significant results between 

Scr+PG and ATG12 KD+PG indicate that autophagy 
is blocked in NPC disease due to an inability of the 
autophagosome to fuse with the lysosome and this 
impaired ability is restored by PG/LBPA enrichment 
in NPC-1 cells, ince the inner-lysosomal portion of 
the NPC-1 protein is thought to be required for cho-
lesterol to penetrate through the glycocalyx that 
coats the limiting lysosomal membrane, enhanced 
autolysosome formation during PG/LBPA enrich-
ment could potentially provide a route for choles-
terol egress that bypasses the glycocalyx.[11,12,13,22,23] 
We hypothesize that the glycocalyx of the lysosome 
may become weakened when the autophagosome 
fuses with the lysosome, allowing cholesterol to 
more readily reach the limiting membrane of the ly-
sosome, and therefore more readily exit the com-
partment. 

 NPC-1 disease shares many similarities with 
Alzheimer’s disease.[3] Increased endogenous LBPA 
has been reported in both NPC-1[6] and Alzheimer’s 
disease,[4] where such an increase might be a com-
pensatory homeostatic cellular response to elimi-
nate toxic deposits. Therefore, PG/LBPA enrichment 
has great potential for the treatment of NPC-1 dis-
ease and potentially other lysosomal storage disor-
ders and neurological diseases with autophagy de-
fects, such as Parkinson’s or Alzheimer’s disease. It is 
important to understand all processes involved in 
cholesterol clearance during the treatment, includ-
ing autophagy. In future work, to understand the ex-
tent of autophagy’s role in cholesterol clearance dur-
ing PG treatment, we will block autophagy by silenc-
ing other molecules, such as ATG5. There are many 
ways that autophagy can be blocked because there 
are many essential proteins to the process that can 
be silenced. Silencing some genes for autophagy 
proteins may result in a more complete knockdown  
than silencing other genes.  

FIGURE 5: Sample of images of NPC-1 fibroblast cells in 
each condition, filipin stained. 

FIGURE 6: Quantification of filipin intensity in NPC1-deficient 
fibroblasts stably transduced with lentiviral non silencing 
control shRNA (Scr) or shRNA targeting Atg12 and selected 
for stable shRNA expression. 𝑁𝑁 > 500 cells/condition. Data 
from 2 independent experiments. ∗∗∗ signifies a 𝑝𝑝 value  
< 0.001. 



  ARESTY  RUTGERS UNDERGRADUATE RESEARCH JOURNAL, VOLUME I, ISSUE III 
 
 
 

Patients with NPC-1 disease develop detri-
mental neurological symptoms because their cells 
accumulate cholesterol in the endolysosomal com-
partment and are unable to clear the cholesterol 
from that compartment. LBPA clears cholesterol 
from the endolysosomal compartment, which indi-
cates that potential therapies to prevent the neuro-
logical symptoms may be found in interventions that 
increase LBPA, such as PG treatment. Uncovering 
the full process of PG-facilitated clearance of choles-
terol will aid in manipulating LBPA levels for poten-
tial therapeutic benefits in patients with NPC dis-
ease, other lysosomal storage disorders, and neuro-
logical diseases∎  

 

5 REFERENCES  
[1] Ballabio A, Bonifacino JS. Lysosomes as dynamic regulators 

of cell and organismal homeostasis. Nature reviews Molecu-
lar cell biology. 2020;21(2):101-118.  

[2]  Berg TO, Fengsrud M, Strømhaug PE, Berg T, Seglen PO. 
Isolation and characterization of rat liver amphisomes. Evi-
dence for fusion of autophagosomes with both early and late 
endosomes. The Journal of biological chemistry. 
1998;273(34):21883-. 

[3] Borbon IA, Erickson RP. Interactions of Npc1 and amyloid ac-
cumulation/deposition in the APP/PS1 mouse model of Alz-
heimer’s. Journal of applied genetics. 2011;52(2):213-218.  

[4] Chan RB, Oliveira TG, Cortes EP, et al. Comparative Lip-
idomic Analysis of Mouse and Human Brain with Alzheimer 
Disease. The Journal of biological chemistry. 
2012;287(4):2678-2688.  

[5] Chen Y, Klionsky DJ. The regulation of autophagy - unan-
swered questions. Journal of cell science. 2011;124(Pt 
2):161-170.  

[6] Chevallier J, Chamoun Z, Jiang G, et al. Lysobisphosphatidic 
Acid Controls Endosomal Cholesterol Levels. The Journal of 
biological chemistry. 2008;283(41):27871-27880.  

[7] Epple UD, Suriapranata I, Eskelinen EL, Thumm M. 
Aut5/Cvt17p, a Putative Lipase Essential for Disintegration of 
Autophagic Bodies inside the Vacuole. Journal of Bacteriol-
ogy. 2001;183(20):5942-5955.  

[8] He C, Klionsky DJ. Regulation mechanisms and signaling 
pathways of autophagy. Annual review of genetics. 
2009;43(1):67-93.  

[9] Hosokawa N, Hara T, Kaizuka T, et al. Nutrient-dependent 
mTORC1 association with the ULK1-Atg13-FIP200 complex 
required for autophagy. Molecular biology of the cell. 
2009;20(7):1981-1991.  

[10] Itakura E, Mizushima N. Characterization of autophagosome 
formation site by a hierarchical analysis of mammalian Atg 
proteins. Autophagy. 2010;6(6):764-776.  

[11] Kwon HJ, Abi-Mosleh L, Wang ML, et al. Structure of N-Ter-
minal Domain of NPC1 Reveals Distinct Subdomains for 
Binding and Transfer of Cholesterol. Cell. 2009;137(7):1213-
1224.  

[12] Li X, Saha P, Li J, Blobel G, Pfeffer SR. Clues to the mecha-
nism of cholesterol transfer from the structure of NPC1 mid-
dle lumenal domain bound to NPC2. Proceedings of the Na-
tional Academy of Sciences - PNAS. 2016;113(36):10079-
10084.  

[13] Lieberman AP, Puertollano R, Raben N, Slaugenhaupt S, 
Walkley SU, Ballabio A. Autophagy in lysosomal storage dis-
orders. Autophagy. 2012;8(5):719-730.  

[14] McCauliff LA, Langan A, Li R, et al. Intracellular cholesterol 
trafficking is dependent upon NPC2 interaction with 
lysobisphosphatidic acid. eLife. 2019;8.  

[15] Mizushima N, Kuma A, Kobayashi Y, et al. Mouse Apg16L, a 
novel WD-repeat protein, targets to the autophagic isolation 
membrane with the Apg12-Apg5 conjugate. Journal of cell 
science. 2003;116(Pt 9):1679-1688.  

  



  ARESTY  RUTGERS UNDERGRADUATE RESEARCH JOURNAL, VOLUME I, ISSUE III 
 
 
 

[16] Mizushima N, Yamamoto A, Hatano M, et al. Dissection of 
Autophagosome Formation Using Apg5-Deficient Mouse 
Embryonic Stem Cells. The Journal of cell biology. 
2001;152(4):657-667.  

[17] Monastyrska I, Rieter E, Klionsky DJ, Reggiori F. Multiple 
roles of the cytoskeleton in autophagy. Biological reviews of 
the Cambridge Philosophical Society. 2009;84(3):431-448.  

[18] Parzych KR, Klionsky DJ. An overview of autophagy: mor-
phology, mechanism, and regulation. Antioxid Redox Signal. 
2014;20(3):460-473.  

[19] Peake KB, Vance JE. Defective cholesterol trafficking in Nie-
mann-Pick C-deficient cells. FEBS letters. 
2010;584(13):2731-2739.  

[20] Pfeffer SR. NPC intracellular cholesterol transporter 1 
(NPC1)-mediated cholesterol export from lysosomes. The 
Journal of biological chemistry. 2019;294(5):1706-1709.  

[21] Saftig P, Klumperman J. Lysosome biogenesis and lysosomal 
membrane proteins: trafficking meets function. Nature re-
views Molecular cell biology. 2009;10(9):623-635.  

[22] Seranova E, Connolly KJ, Zatyka M, et al. Dysregulation of 
autophagy as a common mechanism in lysosomal storage 
diseases. Essays in biochemistry. 2017;61(6):733-749.  

 
 
 
 
 

[23] Settembre C, Fraldi A, Jahreiss L, et al. A block of autophagy 
in lysosomal storage disorders. Human molecular genetics. 
2008;17(1):119-129. 

[24] Teter SA, Eggerton KP, Scott SV, Kim J, Fischer AM, Klionsky 
DJ. Degradation of Lipid Vesicles in the Yeast Vacuole Re-
quires Function of Cvt17, a Putative Lipase. The Journal of 
biological chemistry. 2001;276(3):2083-2087.   

[25] Tooze J, Hollinshead M, Ludwig T, Howell K, Hoflack B, Kern 
H. In exocrine pancreas, the basolateral endocytic pathway 
converges with the autophagic pathway immediately after 
the early endosome. J Cell Biol. 1990 Aug;111(2):329-45. 

[26] Vanier M, Millat G. Niemann-Pick disease type C. Clinical ge-
netics. 2003;64(4):269-281.  

[27] Yim WW-Y, Mizushima N. Lysosome biology in autophagy. 
Cell discovery. 2020;6(1):6-6.  

[28] Yorimitsu T, Klionsky DJ. Autophagy: molecular machinery 
for self-eating. Cell death and differentiation. 
2005;12(S2):1542-1552.  

[29] Xu H, Ren D. Lysosomal Physiology. Annual review of physi-
ology. 2015;77(1):57-80. 

My name is Tamara Allada and I am a 2021 Rutgers graduate and the main author of this paper. I 
spent my final two years of college working with Dr. Judith Storch and Dr. Olga Ilnytska in the Rut-
gers Department of Nutritional Sciences. Our lab's main area of study is the method of intracellular 
cholesterol transport, as the exact pathway in which cholesterol is trafficked through a cell is cur-
rently unknown. There are many lysosomal storage disorders, such as Niemman Pick C Disease, 
that cause cholesterol to become trapped in a compartment of the cell and unable to be trafficked, 
resulting in severe neurological defects. Knowing the exact pathway of intracellular cholesterol 
transport would aid greatly in the search for a treatment to such disorders. 

 
 


