Charnolophagy in Health and Disease

With Special Reference to Nanotheranostics

Sushil Sharma

• Publisher: CRC Press
• Year: 2021
• ISBN:
  9781000298451
• Edition: 1
• Topic: Tecnologia e ingegneria
• Subtopic: Scienza biomedica

This book introduces charnolophagy (CP) as energy-driven, lysosomal-dependent mitochondrial inclusion-specific pleomorphic Charnoly body (CB) autophagy (ATG) involving free radical-induced Ca 2+ dyshomeostasis, ?? collapse, and ATP depletion in congenital diseases, pressure ulcers, metabolic diseases, hepatic diseases, diabetes, obesity, inflammatory diseases, musculoskeletal diseases, sarcopenia, cachexia, respiratory diseases, gastrointestinal diseases, hyperlipidemia, skin and hair diseases, pulmonary diseases, cardiovascular diseases, renal diseases, sepsis-induced multi-organ failure, reproductive diseases, inflammatory diseases, ophthalmic diseases, neurodegenerative diseases, drug addiction, aging, microbial (including COVID-19) infections, and belligerent malignancies implicated in early morbidity and mortality and disease-specific spatiotemporal, targeted, safe, and effective evidence-based personalized theranostic charnolopharmacotherapeutics to cure them. Basic DRESS and GELS principles, nanoparticles to cure chronic multidrug-resistant (MDR) diseases, antioxidants as free radical scavengers, CB antagonists, CP regulators, and CS stabilizers to curb CB molecular pathogenesis (CBMP) are described for better quality of life and longevity. Specific guidelines for environmental protection and preservation of zoological and botanical species at the verge of extinction, Triple "I" Hypothesis for mitochondrial quality control, and transcriptional regulation of CSexR and CSendoR to cure chronic diseases are presented. Novel CP index is introduced to evaluate MDR malignancies and other chronic diseases. WHO, CDC, FDA, NIH, policy planners, cosmetologists, trichologists, players, athletes, dancers, wrestlers, equestrian s, young women, aging population, toxicologists, environmental protectionists, pharmaceutical industry, biomedical scientists, researchers, medical students, physicians, nurses, paramedical professionals, and global audience will be interested in this interesting book to prevent pandemics and raise healthcare awareness.

Part-1
Charnolophagy
(General Topics)

1


Charnolophagy as Immediate and Early ATG

INTRODUCTION

“Auto” means self and “phagy” means digestion. Hence, the literal meaning of ATG is “self-digestion” and CP is the most sensitive, immediate, and early process of inclusion-(CB)-specific ATG. CP is a highly intricate mechanism, which eliminates nonfunctional or damaged mitochondria to sustain MQC and IMD for NCF. Although, DPCI-induced free radical overproduction jeopardizes IMD to trigger CBMP, other nonfunctional, defective, and/or degenerating intracellular organelles including nucleus, lysosomes, peroxisomes, charnolosome (CS), Golgi body, and E.R membranes may be subjected to organelle-specific ATG. CP occurs more frequently in response to DPCIs in the most vulnerable neural progenitor cells, cardiac progenitor cells, pulmonary epithelial progenitor cells, hepatocyte progenitor cells, gastroepithelial progenitor cells, renal progenitor cells, and germinal progenitor cells, derived from iPPCs during embryonic development to trigger diversified congenital syndromes and other developmental anomalies in the CNS, cardiovascular system, musculoskeletal system, GIT, renal system, and integumentary system, broadly classified as developmental charnolopathies. DPCI induce mitochondrial oxidative and nitrative stress to enhance free radical overproduction to induce lipid peroxidation, characterized by structural and functional breakdown of polyunsaturated fatty acids (PUFA: linoeic acid, linolenic acid, and arachidonic acid) in the plasma membrane and mtDNA oxidation. The mitochondrial membranes are highly rich in PUFA and omega-3 fatty acids (docosahexanoic acid, icosapentanoic acid), which render them highly susceptible to free radical attack and trigger degenerative changes characterized by CP dysregulation and CBMP in chronic multidrug-resistant (MDR) diseases.

This chapter highlights CP as a highly orchestrated, sensitive, organelle (mitochondrial inclusion: CB)-specific immediate and early ATG which occurs in the most vulnerable cell in response to DPCI in health and disease.

Original Discovery of CB and CP

CB was discovered as a pleomorphic, multi-lamellar, electron-dense, quasi-crystalline stack of condensed and degenerated mitochondrial membranes in the developing UN rat Purkinje neuronal dendrites, hippocampal neural progenitor cells, and in the cardiac progenitor cells (derived from pluripotent stem cells) in response to the environmental neurotoxins, Kainic acid and Domoic acid. CB appears as a nonfunctional intracellular inclusion and is phagocytosed by the lysosomes through ATP-driven CP to sustain ICD. The lysosomes are involved in cell surveillance for maintaining intracellular homeostasis and NCF. CB formation and hence, CP induction, occur frequently due to the structural and functional vulnerability of mitochondrial membranes to free radical-induced lipid peroxidation (as these are highly rich in PUFA) and genetic and epigenetic vulnerability of mtDNA (as it is GC-rich and easily oxidized to form 8-OH, 2dG and methylated at the cytosine residues) as compared to nDNA which is double helical, condensed, and remains protected by histones and protamines. Hence, CP can be utilized as the most sensitive immediate and early biomarker of CB-ATG in any physico-chemically-injured cell. Other organelles including nucleus, lysosomes, peroxisomes, proteasome, and Golgi body, are not phagocytosed as frequently and are spared from the immediate, early, and direct attack of free radicals. The mtDNA is intron-less and remains in a hostile microenvironment of free radicals generated as a byproduct of O/P in the mitochondrial matrix. Moreover, mtDNA is naked, non-helical, devoid of histones and protamines, which render it highly susceptible to genetic and epigenetic modifications. The cytosine is readily methylated by S-adenosyl methionine (SAM) at position N-3 on the naked mtDNA to trigger CBMP. Hence, early detection of 2, 3 dihydroxy nonenal, 4-OH, nonenal and 8-OH, 2dG from the biological fluids can provide a quantitative estimate of mitochondrial bioenergetics (MB) of a patient. On the other hand, the nDNA is supercoiled, double helical, compact, and remains protected by the nuclear wall and nucleoplasm. Histones, protamines, and topoisomerases provide structural and functional stability to gyrases to maintain its helicity. Hence, genetic and epigenetic changes occur rarely in the nDNA because histone acetylation at the lysine moieties has to occur first to open the super helical structure to expose the cytosine residues for their methylation.

Mitochondrial Susceptibility to CBMP

CBMP is involved in almost all cell possessing mitochondria. As CB is a nonfunctional mitochondrial inclusion, it is phagocytosed upon ubiquitination by ATP-driven lysosomal activation. CP is the most sensitive, immediate and early event of CMB to form a CPS. The CPS is transformed to CS, when the phagocytosed CB is hydrolyzed by the lysosomal enzymes. Secondary free radical attack (SFA) causes CS destabilization.

Depending on the intensity and frequency of free radical attack, a CS is permeabilized, sequestered, or fragmented to release toxic metabolites to induce further activation of lysosomes, which can phagocytose other nonfunctional or degenerated organelle or ubiquitinated and denatured proteins as a final attempt of ICD through generalized ATG. No other organelle is as cytotoxic and generates free radicals as compared to CS (a byproduct of CB). Hence, it is logical to propose that CP is the immediate and early event that controls ATG of other defective, nonfunctional, and/or degenerating organelles and denatured ubiquitinated and aggregated proteins for ICD. In addition, mitochondria synthesize anti-inflammatory and membrane stabilizing steroid hormones (that is, testosterone, estrogen, and progesterone) by transport of cholesterol through the 18 kDa TSPO channel protein localized on the outer mitochondria membrane (OMM). The steroid hormone synthesis is compromised due to TSPO, BCl₂-Becline, Bax, xanthine oxidase (XO), heme oxygenase (HO), and monoamine oxidases (MAOs) delocalization during CBMP. The delocalized MAOs translocate to the nucleus to induce TGF-β gene which augments mitochondrial damage triggering CBMP and inflammation due to the induction of Drp-1 and inflammasomes and downregulation of mitofusin (MFN) in the absence of anti-inflammatory steroid hormones. These molecular events trigger carcinogenesis, which can be prevented by developing stem cell specific CS antagonists because the endocytosis of stem cell-specific CS is involved in malignant transformation of nonproliferative cells and induce metaplasia, dysplasia, invasion, and metastasis. CBMP is involved in the transformation of erythroblasts to myloblasts (which cause myeloid leukemia), columnar epithelial cells to squamous epithelial cells (which cause Barret’s esophagus), and pulmonary epithelial cells to squamous epithelial cells (which cause small cell lung carcinoma).

Free Radical-induced CBMP

In vivo as well as in vitro experimental data suggest that mitochondria in the most vulnerable cell exhibit differential susceptibility to free radical-induced CBMP in response to endogenous or exogenous DPCI. Depending on the metabolic and physiological needs, a cell may possess anywhere between 22-1000 mitochondria. For example, a sperm has 22-75 spirally-arranged compact mitochondria in the middle piece for motility and fertilization, whereas a neuron may have between 750-1000 mitochondria (Purkinje neurons). Terminally differentiated cells (including skeletal muscle, cardiac, hepatocytes, osteocytes, and CNS neurons) have a fixed number of mitochondria. An oocyte has the maximum mitochondria (250,000-600,000) because it needs sufficient energy to execute paternal CP as well as CS exocytosis during the pre-zygotic phase soon after fertilization, and during the development of the embryo in the post-zygotic phase for the normal growth of the fetus. Osteoblasts also possess a high number of mitochondria for osteogenesis. About 40% of the myocardial and skeletal muscles, 20% of the liver tissue, and 15% of the CNS is composed exclusively of mitochondria as these are metabolically high-energy-demanding tissues. Although, it depends primarily on the frequency and intensity of free radical attack, all mitochondria are not destroyed at any given time in response to DPCI. The exact molecular mechanism of differential and selective vulnerability of mitochondria to free radical-induced CBMP remains enigmatic.

It was discovered in the developing UN rat cerebellar Purkinje neurons that numerous mitochondria remain small in size, single layered, with only few cristae (2-4), devoid of mtDNA. Occasionally, these immature mitochondria contained electron-dense lipoprotein aggregates as inclusion bodies in the form of LDs. Immature and physiologically-inactive mitochondria directly incorporated with the electron-dense, degenerated membranes to initially form pleomorphic multi-tubular loose CB (cis-CB), followed by multi-lamellar condensed membrane stacks forming mature quasi-crystaline CB (trans-CB); Trans-CBs were subsequently phagocytosed by lysosomes following Akt-ubiquitination. Developmentally-immature and nonfunctional mitochondria devoid of cristae and mtDNA are frequently destroyed by free radicals as these are unable to synthesize ATP due to the downregulation of ETC, O/P, and a lack of steroid hormones. A physico-chemically-injured cell may have between 7-8 mature CBs at any given time because other pleomorphic CB phenotypes existing in immature primordial and in different developmental stages are readily phagocytosed by the activated lysosomes upon Akt-ubiquitination. CB is variable and exhibits differential phenotypes and vulnerability, depending on the cellular, molecular, genetic predisposition, biochemical composition, inducers, and microenvironment. CBMP is highly complex and intricate in MDR malignancies, because inflammation, apoptosis, necrosis, proliferation, infection, immortalization, CP, MTG, and ATG occur concomitantly in these cells. Hence, it will be highly prudent to discover immediate and early molecular events of CBMP of particular cancer stem cells involved in MDR malignancies for their timely eradication. It will be promising to develop specific CPTs for the eradication of stem cell-specific CS (CSscs) in MDR malignancies.

CP vs ATG

Although both CP and ATG require (i) Akt-ubiquitination of nonfunctional organelles and associated proteins in response to DPCI-induced free radical attack on the most vulnerable stem cell and ATP-driven lysosomal activation, CP involves predominantly phagocytosis of CB during mitochondrial remodeling (MR) and degeneration. Generally, ATG is nonspecific and can phagocytose any nonfunctional, degenerated, and/or undesired intracellular organelle. CP can selectively influence cell death, inflammation, immune response, and exert both adaptive and maladaptive roles in disease pathogenesis. CBMP involving CB formation, CP induction, and CS destabilization are deleterious events as these are implicated in chronic MDR diseases. Although, increased lysosomal activity triggers pro-inflammatory cascade in a physicochemical-injured cell during the acute phase; enhanced CP increases the incidence of CS destabilization which triggers inflammasome to cause MDR diseases during chronic phase. Hence, CP-mediated CB elimination is highly prudent to sustain IMD and ICD for NCF.

There are primarily three major stages of IMD and ICD: (a) CB formation (b) CP induction, and (c) CS exocytosis. CP involves Akt-ubiquitination of CB for lysosomal recognition followed by energy (ATP)-driven phagocytosis for CB elimination, whereas, ATG is an intracellular homeostatic mechanism for the turnover of various cellular organelles and proteins, in which double-membraned autophagosomes sequester cytoplasmic cargos, delivered to the lysosome for degradation. ATG as an important modulator of human disease including acute kidney injury, which can arise in response to nephrotoxins, sepsis, I/R, and in chronic renal diseases, including comorbidities (diabetes and kidney injury). Roles of ATG in polycystic kidney disease and renal carcinoma have been described. Hence, targeting both CP and ATG pathway may confer the TSE-EBPT of diabetes and associated comorbidities as described in this edition.

CONCLUSION

This chapter presented an introduction to generalized ATG and inclusion (CB)-specific ATG (also named as CP). Differential susceptibility of RONS-induced CBMP in the most vulnerable iPPCs and the basic difference between CP and ATG to accomplish the TSE-EBPT of chronic MDR diseases were also highlighted.

2


Charnolophagy in Intramitochondrial and Intracellular Detoxification

INTRODUCTION

CP is an immediate and early event as it occurs initially when the cell undergoes degenerative changes due to free radical-induced toxic insult. Free radicals are reactive oxygen, nitrogen, and carbonyl (OH, NO, CO) species with a half-life of 10⁻¹³ to 10⁻¹⁴ seconds and possess a highly reactive and unstable lone pair of electrons which induce lipid peroxidation of plasma membranes. Since the mitochondrial membranes are constantly exposed to free radicals, these are degenerated more readily during DPCI in the most vulnerable cell as compared to other cellular organelles. Thus, CP occurs earlier than ATG as a mechanism of ICD.

CP-mediated IMD and ICD are highly crucial events which occur throughout our lives to replace damaged and nonfunctional (particularly mitochondria) organelles. Certain intracellular organelles are highly susceptible to CP as compared to generalized ATG for disease progression or remission. When IMD and ICD of the liver, kidney and lymphatics are optimized, the macrophages from these key o...