Proteins are the most versatile macromolecules and responsible for almost all cellular functions .Protein homeostasis (or proteostasis) is state of a balanced proteome, , depends on an extensive network of different types molecular chaperones, proteolytic systems (e.g. proteosome, autophagy) and their regulators. The dysfunction in proteostasis, leading to formation of misfolded proteins or the accumulation of protein aggregates which leads to many diseases e.g. sickle cell anaemia ; neurodegenerative diseases. Also The chaperon dysfunction leads to diseases called chaperonopathy e.g. Neurodegenerative diseases, cancers. .The pharmacological intervention to treat proteostasis dysfunction diseases are pharmacological chaperones, chemical chaperon, Heat shock transcription factor-1 activator; chaperon inhibitors,proteosome inhibitors and autophagy enhancers (activators).

1. The chaperon modulators
Proteostasis between diseases and drugs
Mohie-Aldien A Sherif
Professor of Pharmacology, Faculty of Medicine, Benha University, Benha, Egypt.

2. ;
) dependent
ch
domain of
-
(N
TriPhosphate
Adenosine
; ATP =
Alzheimer's disease
; AD=
? = unknown
Abbreviation:
Ch.=Chaperon; Co-Ch=Co chaperon; CMT=Charcot-Marie Tooth disease C=Cytoplasm ;CM = Cell membrane, CC =
Cancer cells, C=Constitutive ; CCT = chaperonin containing CJD= Creuzfeld‐Jacob diease; CF =cystic fibrosis TCP-1;
CNX =calnexin , CRT= calreticulin ; DRM= desmin-related myopathy ; D = Disagregase; EC=Extracellular,
ER=Endoplasmic reticulum ; F=foldase ; FALCA= FK506 associated with Leber congenital amaurosis ; GrpE= Nucleotide
exchange factor
Grp = glucose regulated protein ;GP = glycoprotein; GD =Gaucher's disease ; H=Holdase; Hb = hemoglobin ; HSP=, Heat
Shock Protein are chaperon induced by stress (through HSF1=Heat shock transcription factor-1) and can translocate from the
cytosol to the cell surface, particularly during ER stress ;HD =Huntington's disease ; HMN= hereditary motor neuropathies
;HSF1=Heat shock factor-1 ( a master transcriptional regulator that modulates the expression of chaperones in response to
stresses); IR= immunogenic response ;M=Mitochondria ; LIF= leukemia inhibitory factor NEFs =Nucleotide exchange
factor, ; MS=Multiple sclerosis; MJD = Machado ‐Joseph disease; MCD= mixed connective tissue disease ;MKBBS =
McKusick-Kaufman and Bardet-Biedl syndromes; MHC= major histocompatibility ;N =nucleus; NDI= nephrogenic
diabetes insipidus ;OIS = Oncogene-induced senescence (important defensive anti-cancer response involves, p53, p21,
HDM2 and P13/AKT pathways ; PD =Parkinson's disease ; PDIase= protein disulphide isomerase; PPIases =peptidyl-
prolyl cis/trans isomerases ;PhLPs= phosducin-like proteins ; PPMR =preterm premature membrane rupture ;
RA=rheumatoid arthritis S = Stress induced e.g., drugs, UV irradiation, and microbial stimulation ; SHR= steroid hormone
receptors ; TFs =Transcription factors; TLR =Toll Like Receptor ;TRiC =TCP-1 Ring Complex ; TCP-1=T complex
polypeptide-1;; WS=Williams syndrome Sch=Schizophrenia; , SLE= systemic lupus erythemoatosus, sHSP = small HSP ;
SS = Sjögren’s syndrome; TRiC/ TCP-1=TCP-1 Ring Complex, also called CCT for chaperonin containing TCP-1); SLE
=Systemic Lupus Erythmatosis; sHSP = small heat shock protein; ZG= zymogen granules

3. Function at specific
cell localization
Active protein
complex
●
Disaggregation:
Refolding
Delivered to proteasome
Degraded protein
(-)
Proteasome inhibitor
Nonselective
Chemical
chaperones
(+)
(+)
Selective Pharmacological
chaperons
Refolding
Unfolded/ Mis-folded / mutant
monomer
Stress;
mutations
Protect from aggregation:
Protein aggregation:
e.g. Neurodegenerative
diseases
(+)
inhibitors.
mTOR
*
:
enhancers
Autophagy
*AMPK/ SIRT1 activators
Ribosome attached chaperons
mRNA
Polypeptide emerging
from ribosome
Native proteins
Spontaneous folding.
Chaperon mediated Autophagy/ lysosomal degradation:
- Disaggregate and Delivered to proteasome
Summary of chaperon mediated protein homeostasis (doted outlines white boxes), associated abnormality diseases
(white boxes) and treatment strategies’ (grey doted outline boxes). Also, Misfolding protein degraded by proteasome

4. Summary of chaperon mediated protein homeostasis (doted outlines white boxes), associated
abnormality diseases (white boxes) and treatment strategies’ (grey doted outline boxes).Also; Misfolding
protein degraded by proteasome.

5. Ch.(KD) Co -Ch. ATP site function Chaperonpathy)
S Hsps (>30) /
(HSPB1,5,8) &
(HSPB2,3,4,6,7,
9,10)C
(Called
dustmen of
cells)
No No C • F : protect against cellular stress , proper
cytoskeletal organization, anti-apoptotic, thermo-
tolerance ; Anti-inflammatory, antithrombotic,
immune-modulator.
•prevent aggregation in the lens (cataract)
*act as a Co-Ch of Hsp60 ,70,100
* ↓PTEN (tumor suppressor), OIS
-Neurodegenerative diseases e.g. AD, PD,
polyglutamine disorders, and amyotrophic
lateral sclerosis. Childhood cataracts,
- Mutations → linked to inherited peripheral
neuropathies and familial myopathies. Distal
hereditary motor neuropathy and charcot-
marie-tooth disease
Clusterin C/S
(>30)
No No EC inhibits stress-induced protein aggregation and
regulation of complement , apoptosis , protease
inhibition and lipid transport
up regulated in tissue injury ,aging ,AD ,
atherosclerosis , diabetes and cancer
Haptoglobin
(>30)
No No EC Hb. binding protein, Regulate cathepsin B activity,
angiogenesis, immune system ,as an acute-phase
reactant. (↑by inflammatory mediators’ )
Not determined
Caseins s(>30) No No EC H /inhibits protein aggregation; Not determined
PDIase S (55) no no ER Catalysts of folding, elimination of folding interme-
diates with inappropriate disulfide cross-links
cancer ,Diabetes, neurodegenerative,
cardiovascular disease
Hsp-DS (60)
Chaperonin C
/ prefoldin
(oligomeric )
HSP(10)C yes mt mtHSP60→F of newly imported mitochondrial
proteins; mt. homeostasis ;Prevent Mad Cow Disease
lactic acidemia , hereditary spastic paraplegia,
Tuberculosis,
C TRiC / CCT →F 10% of C polypeptide; ↓HSP 70,
cell growth, proliferation, survival & TOR signal.
M KBBS
EC UnF/F:↑ immunogenicity of tumor cells;
macrophage activator through Toll-like
receptors, & ↑cytokines
autosomal-recessive neurodegenerative
disorder ,Auto immune disease ; ;↑in cancers (
breast, ovary, colon, prostate, lung, brain)
Chaperones types, function and related Chaperonpathy (Chaperon related diseases

6. Ch.(KD) Co -Ch. ATP site function Chaperonpathy
CNX C (67 ) No No CC Glycoprotein Folding, ↑ macrophages against cancer Charcot-Marie-Tooth (CMT) disease
HSP(70) HSP(40);
Dna J
yes C,N,m,
Ec
F, prevent aggregation of unfolded peptides; membrane
transport of proteins ;Auto regulation in heat shock response
(HSF1 activity), anti apoptotic
Dilated cardiomyopathy ; distal hereditary
motor neuropathy; Pancreatic
adenocarcinoma ; cardiomyocyte
hypertrophy
HSP-CS/c (90)
or GP96
HIP,HOP,
p23
Wea-k C * F / H/D: •binding and stabilization/regulation of steroid
receptors, protein kinases ; Stabilize TFs
•Buffer for genetic variation?, *Inhibit HSF-1
Cancer ; Immunophilin, FA LCA ;AD , PD,
and HD,,Bipolar disorder, SLE
ER TLR and integrin chaperone controls T regulatory cell
function and the process of antigen presentation
advanced stage and poor survival
of cancer patients
HSP-HS
(>100/110)
Hsc70 Yes C,E
R,N
D/un-F.; •thermotolerance, proteolysis,(
Hsp104 restores proteasome activity in aging
cells)
•clathrinun-coating; embryogenesis, ↓ cancer
and transcription regulation; Antigen
presentation; radio-resistance .
PD , prion, Listeria, Leishmania
virulence & pathogenicity ,
CRTC No No ER Folding of glycoproteins, ↑ peptide loading to
the class I MHC; ↓translocation unfolded
proteins & binds/ inactive Ca2+ ion .
Myelo-proliferative neoplasm
Grp S
(78, 170, 94)
No No ER,
mt
Controlling signaling, proliferation, invasion,
apoptosis, inflammation and immunity.
cancer
α2Macroglo
bulin
No No EC inhibits protein aggregation protease inhibitor Up regulated in AD
Chaperones types, function and related Chaperonpathy

7. Potential Transmissible Proteins and candidate associated disease
Protein (site) Diseases Transmission Chaperon
(effect)
Experimentally Natural
PrPSc
(IC,EC, SP, RD,)
Prion diseases ; Creutzfeld -Jacob
disease; Gerstmann - Sträussler -
Schneiker syndrome; Fatal familial
insomnia; Kuru; Bovine spongi-form
encephalo-pathy; Scrapie Chronic
wasting disease
Yes in diverse animal species by various routes) Trazodone hydrochloride
dibenzoylmethane (Prevents neurodege-
neration in mouse models of prion
disease and fronto-temporal dementia)
Aβ
(EC,SP,
RD )
AD, Dutch hereditary cerebral
hemorrhage with amyloidosis;
Congophilic angiopathy
induction of pathology in trans-
genic mice by ICer/ IP
inoculation; aggregates are taken
up by cells.
ND Salubrinal (Suppress Aβ-induced
neuroinf-lammatory responses and
ameliorates function in AD)
Tau
(SP,RD, EC)
Tauopathies●; AD Corticobasal degener-
ation, Pick’s disease, Progressive
supranuclear palsy
cell-to-cell in culture &
transmission in transgenic mice
by ICer inoculation; transfer of
IC aggregates.
ND ND
α-synuclein / (GBA1)
(SP,RD,)
PD; Synucleinopathies ; Lewy body
variant of AD; Diffuse Lewy body disease
Dementia with Lewy bodies Multiple
system atrophy ; neuro-degeneration with
brain iron accumulation type I.
cell-to-cell and host-to-graft
spreading in animal models & by
ICer inoculation
Possibly (in humans,
transplanted cells develop
Lewy bodies).
Ambroxol / Isofagomine (Improves
phenotype of GBA1-associated PD
models)
Huntingtin (SP,RD,N) Huntington's disease cell-to-cell spreading in culture ND ND
A-A (EC) 2nd amyloidosis Accelerate pathology in mice by
various administration routes.
possible ND
Apolipo-protein A
(EC)
Mouse senile amyloidosis accelerate pathology in mice by
various routes of administration
to mice in the same cage
by feces consumption
ND
SOD1(SP,RD IC ,EC) ALS Cell to cell in culture ND ND
TDP-43 (SP,RD ,IC) No
Poly Q♣ (SP,RD,
intracellular)
Spinocerebelar ataxia Aggregates are taken up by
cultured cells and trigger
misfolding of wild-type protein;
aggregates can move between
cells.
Not ND ND

8. Chaperon homeostasis and drugs (gray box) affects it .
Abbreviations: HSF1=Heat ahock transcription factor-1

9. Heat shock transcription factor-1(HSF-1) activator = N-terminal-ATPase pan Hsp90 inhibitors
(which bind & inactivate HSF-1) inhibitors → ↑ HSR (especially HSP70 expression
Chaperone therapies Effect / Current clinical trials (CTs)
Celastrol CTs for rheumatoid arthritis /, GD & and Tay-Sachs disease
(high toxicity)
Carbenoxolone Phase II CTs in UK for psoriasis ;neurodegenerative diseases
Geldanamycin Analogues
e.g. 17-AAG
CTs for cancer treatment, discontinued due to in vivo
toxicity / poor solubility / poor BBB penetration, potential
antiviral
Luminespib Phase II CT in cancers
Ganetespib Phase I-3 clinical trials Anti- cancer e.g. lung; lipophilic ,
Triptolide anti-tumor, anti-inflammatory and immunosuppressive
Cardenolide CL-43 Anticancer
Ecg . Phase 2/3 in cognitive impairment and cancer

10. (PC) for targeting enzymes:
harmacological Chaperones
P
Chaperone therapies Enzyme Effect / Current clinical trials (CTs)
Competitive PC (reversibly bind
to enzyme active site via
hydrogen bond / van der Waal's
interactions → stabilize enzyme
but in high concentration; inhibit
enzyme;)
Ambroxol, GCase GD (phaseII -NCT01463215); high
doses needed in PD.
Isofagomine GD (phaseII-NCT00875160)
Pyrimethamine AHS SD and TSD late-onset form of GM2
Gangliosidosis
valienamine β Gase 1 Assists folding of misfolded for GM1
gangliosidosis
Galactose α-GALA Pompe (phaseII)
Migalastat α-GALA Approved in Fabry Disease & Niemann-
Pick disease type C
Eliglustat Pompe disease (phase-I ,NCT 02185651)
Phenanthridin
derivatives
NPCL-1 Removes folding defects of Nieamnn-
Pick type C1 protein
Cysteamine transmembrane conductance regulator in
CF
Cystine Cystinosis
Allosteric PC (small AA
sequences inserted into a scaffold
protein → bind to specific
proteins → regulate the activity
of cellular proteins e.g.
oncogenes, TF, cell cycle
regulators.
N-acetyl cysteine Acid α-glucosidase ↑ stability of recombinant GAA in ERT
in Pompe disease (In vitro studies in
patients’cell lines)
Tafamidis transthyretin approved for transthyretin-related
hereditary amyloidosis

11. Chemical chaperones: nonspecifically creating a chemical environment that
encourages proteins to acquire the proper conformation /folding
Chaperone therapies Effect / Current clinical trials (CTs)
Osmolytes (i.e., 2% trehalose,
mannitol)
Mannitol is FDA-approved osmotic diuretic , high doses required
for benefits in PD
Hydrophobic compounds e.g.
4-Phenylbutyrate 4-(PBA)
FDA-approved, currently used for urea cycle disorders / high
doses near max tolerability for human benefits
Glycerol Enhances radiation induced apoptosis in Thyroid carcinoma
Trehalose Neuroprotection in Human, animal and in vitro
Galactose Intravenous for GM1 gangliosidosis / fabry disease

12. Heat shock transcription factor-1(HSF-1) activator = increase heat shock response.
members Effect / Current clinical trials (CTs) Adverse effect
Celastrol CTs for rheumatoid arthritis /, GD& and Tay-Sachs
disease (high toxicity)
Anti-fertility effects in men
Carbenoxolone Phase II CTs in UK for psoriasis ; neurodegenerative
diseases
fluid retention, raised blood pressure,
and hypokalaemia.
Geldanamycin
Analogues e.g. 17-AAG
CTs for cancer treatment, discontinued due to in vivo
toxicity .analogues 17-AAG (less toxic) (currently in
Phase I/IItrials)
Significant hepato-toxicity. poor
solubility / poor BBB penetration,
potential anti-viral
Arimoclomol Phase II/III clinical trials ALS
for ALS
Well tolerated
Riluzole Approved by the FDA for clinical use
in ALS.
mild gastrointestinal
toxicity
Luminespib Phase II CT in cancers Diarrhea, nausea, fatigue Neutropenia,
visual disturbances, and fever
Ganetespib Phase I-3 clinical trials Anti- cancer e.g. lung; lipophilic
,
diarrhea, fatigue, anemia, and rash
Triptolide anti-tumor, anti-inflammatory and immunosuppressive poor water solubility and has
several side effects such as diarrhea,
skin rashes, and pigmentation
Cardenolide CL-43 Anticancer vomiting, palpitation, epigastric pain, a
burning sensation in the
abdomen, shortness of breath, and
diarrhoea; sinus bradycardia,
Ecg . Phase 2/3 in cognitive impairment and cancer.generally
recognized as safe (GRAS) by FDA
Headache, nervousness, vomiting,
Diarrhea, Irritability, arrhythmia

13. )
HSPsIs
HSPs inhibitors (
HSP60 Is mizoribine immunosuppressive , used clinically after renal
transplantation
epolactaene Covalently binding to HSP60 Cys442
novobiocin ATP inhibitors
HSP-70 Is Apoptozole (↓ATPase) induced apoptosis in cancer cell lines.; Potential antiviral
Myricetin Inhibited tumor growth in pancreatic cancer.
HSP90 (C-
terminal ) Is
Novobiocin analogue Inhibit signaling pathways that are responsible for the
growth and proliferation of tumor cells.
Hsp27
Inhibitors
Apartorsen
( ASO)
phase II in lung cancer
*Grp inhibitors Versipelostatin Down-regulates GRP78 and MDR1 expression in gastric
cancer
GRP78BP A targeted protein to guide drugs to GC cells
Genistein/versipelostatin Inhibit transcription of Grp
*HSP(27)
/HSPB1
inhibitors
Querctin, Ivermectin
Apartorsen
*Anticancer:
-Stimulate apoptosis, sensitization to chemotherapy.
-inhibit migration, invasion, metastasis, growth ,
proliferation.
*attenuate radiation-induced pulmonary inflammation.

14. List of some small molecule autophagy activators
mechanism drugs Candidate disease
mTORC1 inhibitors Rapamycin and rapalogues AD, HD, PD, FTD, SCA Type III, Prion
disease ,
curcumin, generally recognized as safe (GRAS) by FDA :
A.D. (phase 2), Cancer (phase 2)
Temsirolimus HD; approved for the treatment of advanced
renal cell carcinoma
resveratrol Aging ;AD
latrepirdine● AD,P
IMPase Inhibitors lithium HD, PD
Valproic acid (HDI)+ AD ,Cancer
Carbamazepine+ AD
AMPK activators Metformin AD, Taupathies
Evirolimus HD,approved for cancer treatment and as an
immunosuppressant for organ transplant
recipients , preclinical in
atherosclerosis/myocardial infarction and
pathologic cardiac remodeling
trehalose HD, PD, ALS, DLB
rilmenidine HD
Ca Ch B (activate the Ca2+/calpain
pathway
Fluspirilene HD
Nicardipine, nitrendipine HD,AD
Verapamil HD
K channel activator Minoxidil PD and HD
Inhibit autophago-some formation Calpastatin HD
Lysosomal activator Nicotinamide AD

15. Proteasome (cellular complexes that break down proteins)a inhibitor → prevent
degradation of pro-apoptotic factors such as the p53 protein, permitting activation
of programmed cell death in neoplastic cells dependent upon suppression of pro-
apoptotic pathways.
Effect / Current clinical trials (CTs)
Rev
ersi
ble
Bortezomib Approved in refractory multiple myeloma
; improve the activity of Niemann-Pick type C mutant proteins
caused by specific missense variants
Ixazomib in combination with lenalidomide and dexamethasone for the
treatment of multiple myeloma
Delanzomib Phase I/II Relapsed and Refractory Multiple Myeloma
Irre
vers
ible
Carfilzomib approved for use for relapsed/refractory myeloma patients
Marizomib Phase I in malignant gliomas: cross the blood-brain barrier
Oprozomib Phase I Relapsed and Refractory Multiple Myeloma

16. Gene therapy: Non-pharmacological modulation of chaperones
Effect / Current clinical trials (CTs)
Adeno-associated virus
vector of gene delivery
Several CTs for viral-mediated gene
delivery in PD patients

17. THANK YOU