{"id":6263,"date":"2026-05-27T21:19:39","date_gmt":"2026-05-28T01:19:39","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/?post_type=chapter&#038;p=6263"},"modified":"2026-05-27T22:35:59","modified_gmt":"2026-05-28T02:35:59","slug":"degenerative-diseases-and-cellular-accumulations","status":"web-only","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/chapter\/degenerative-diseases-and-cellular-accumulations\/","title":{"raw":"Section 6 Degenerative Diseases and Cellular Accumulations","rendered":"Section 6 Degenerative Diseases and Cellular Accumulations"},"content":{"raw":"<span class=\"transcription-time-part\" style=\"text-align: initial;font-size: 1em\" data-time-start=\"1537.339\" data-time-end=\"1539.71\">Aging is a significant risk factor for several <strong>degenerative diseases<\/strong>, particularly those affecting the <strong>nervous system<\/strong> (e.g. Alzheimer's, ALS, Parkinson's disease) or a resulting from a lifetime of wear and tear (e.g. Osteoarthritis).\u00a0 <\/span>\r\n\r\n<span class=\"transcription-time-part\" style=\"text-align: initial;font-size: 1em\" data-time-start=\"1537.339\" data-time-end=\"1539.71\">Some cells in the body have very long life spans.\u00a0 For example, <strong>neurons<\/strong> and most <strong>heart<\/strong> and <strong>skeletal muscle cells<\/strong> are as old as you are.\u00a0 Over time, these cells and tissues can accumulate different materials that become detrimental to their function.\u00a0 These compounds may take the form of <strong>intracellular accumulations<\/strong>, building up inside cells, or may collect outside of cells in the form of<strong> extracellular accumulations<\/strong>.\u00a0 When a cell can neither process nor eliminate these materials, its function deteriorates- and so does the health of the surrounding tissue. <\/span>\r\n<ul>\r\n \t<li><span class=\"transcription-time-part\" style=\"text-align: initial;font-size: 1em\" data-time-start=\"1565.84\" data-time-end=\"1567.685\"><strong>Endogenous compounds: <\/strong> substances that are a normal part of the body but accumulate at unhealthy levels, such as lipids,<\/span> <span class=\"transcription-time-part\" style=\"text-align: initial;font-size: 1em\" data-time-start=\"1567.685\" data-time-end=\"1570.924\">proteins, carbohydrates, pigments, and metabolic toxins.<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0 <\/span><\/li>\r\n \t<li><span style=\"text-align: initial;font-size: 1em\"><strong>Exogenous compounds:<\/strong>\u00a0 substance from the external environment such as lead, mercury, silica, coal dust, and smoke particles.\u00a0\u00a0<\/span><\/li>\r\n<\/ul>\r\n<span class=\"transcription-time-part\" style=\"text-align: initial;font-size: 1em\" data-time-start=\"1570.924\" data-time-end=\"1573.46\">As the brain ages and accumulates potentially harmful compounds, it becomes increasingly susceptible to different forms of <strong>dementia<\/strong> - all of which are considered <strong>degenerative diseases<\/strong>.\u00a0 This underscores the importance of healthy lifestyle choice throughout life in minimizing the accumulation of harmful compounds and preserving cellular function into old age<\/span><span class=\"transcription-time-part\" style=\"text-align: initial;font-size: 1em\" data-time-start=\"1587.679\" data-time-end=\"1589.569\">.<\/span>\r\n<h3><span style=\"color: #1f5c99\"><strong>Four Mechanisms of Intracellular Accumulation<\/strong><\/span><\/h3>\r\n<strong><span style=\"color: #2e75b6\">1. Abnormal Lipid Metabolism:\u00a0 Fatty Change<\/span><\/strong>\r\n\r\nUnder normal conditions, cells metabolize lipids through a balance of <strong>lipogenesis<\/strong> (the creation of new lipids) and <strong>lipolysis<\/strong> (the breakdown of lipids).\u00a0 When something disrupts this balance - for example, when liver cells are under stress - the cell may inappropriately increase lipogenesis while simultaneously reducing lipolysis.\u00a0 The net result is an abnormal buildup of lipid droplets inside the cell.\r\n\r\nThis phenomenon, called <strong>fatty change<\/strong> or <strong class=\"Yjhzub\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\">steatosis<\/strong>, is commonly seen in the liver of individuals with <strong>alcoholic liver disease<\/strong>.\u00a0 Under a microscope, the affected liver appears dramatically different from a healthy liver - cells are engorged with fat, and overall liver function is compromised.\r\n\r\n&nbsp;\r\n\r\n<strong><span style=\"color: #2e75b6\">2. Abnormal Protein Accumulation<\/span><\/strong>\r\n\r\nProteins produced in a cell undergo a precise process:\u00a0 a gene is transcribed and translated, and the resulting protein is folded into its functional shape and tagged for transport to its destination. If folding fails or if the transport process is disrupted, the protein remains inside the cell.\u00a0 Accumulations of these <strong>misfolded<\/strong> or <strong>mislabeled proteins<\/strong> are toxic and progressively impair cell function.\r\n\r\n&nbsp;\r\n\r\n<strong><span style=\"color: #2e75b6\">3. Enzyme Deficiency and Lysosomal Failure<\/span><\/strong>\r\n\r\n<span style=\"text-align: initial;font-size: 1em\">Cells rely on <strong>lysosomes<\/strong> - organelles filled with lytic enzymes - to break down and recycle old or damaged proteins.\u00a0 This <strong>recycling<\/strong> process keeps cells functioning optimally by ensuring a constant supply of fresh, functional proteins.\u00a0 If a critical <strong>lysosomal enzyme<\/strong> is deficient or absent, old proteins cannot be degraded.\u00a0 They accumulate inside the cell, progressively obstructing normal function.<\/span>\r\n\r\n&nbsp;\r\n\r\n<strong><span style=\"color: #2e75b6\">4. Accumulation of Exogenous Particles<\/span><\/strong>\r\n\r\n<span style=\"font-size: 1em;text-align: initial\">Cells can <strong>phagocytose<\/strong> (engulf) particles from the external environment - such as <strong>coal dust, lead, mercury, silica, asbestos,<\/strong> and <strong>wildfire smoke particles<\/strong>.\u00a0 If the cell is unable to degrade these particles, they accumulate and interfere with cellular function.\u00a0 Over time, the tissue as a whole deteriorates as more and more cells become burdened by these indigestible materials. <\/span>\r\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\"><strong>Clinical Examples of Intracellular Accumulation<\/strong><\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\n<strong>Fatty liver (Steatosis):<\/strong>\u00a0 Liver cells engorged with lipid droplets are visible on biopsy and are associated with conditions such as alcoholic liver disease.\u00a0 A fatty liver appears pale and swollen compared to a healthy liver.\r\n\r\n<strong>Silicosis:<\/strong>\u00a0 Prolonged inhalation of silica dust (e.g., in mining or sandblasting) leads to the accumulation of silicon particles in lung cells, causing progressive lung damage.\r\n\r\n<strong>Alzheimer's disease: <\/strong> Intracellular accumulations of <strong>tangles of tau protein<\/strong> and extracellular accumulations of beta-amyloid protein clumps (beta amyloid plaques) - disrupt normal brain cell function and contributes to the neurodegeneration seen in Alzheimer's disease.\u00a0 These will be explored in greater detail in the neurology chapter.\r\n\r\n<\/div>\r\n<\/div>\r\n&nbsp;\r\n\r\n[caption id=\"attachment_4043\" align=\"alignnone\" width=\"300\"]<a href=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2024\/09\/Figure_35_05_01-1024x457-1.jpg\" target=\"_blank\" rel=\"noopener\"><img class=\"wp-image-4043 size-medium\" src=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2024\/09\/Figure_35_05_01-1024x457-1-300x134.jpg\" alt=\"Alzheimer's Disease\" width=\"300\" height=\"134\" \/><\/a> Compared to a normal brain (left), the brain from a patient with Alzheimer\u2019s disease (right) shows a dramatic neurodegeneration, particularly within the ventricles and hippocampus.[\/caption]\r\n\r\n&nbsp;\r\n\r\n[caption id=\"attachment_445\" align=\"alignnone\" width=\"300\"]<img class=\"wp-image-445 size-medium\" src=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/Lipid-Hepatocytes-300x207.png\" alt=\"\" width=\"300\" height=\"207\" \/> Figure: Simplified cartoons of (left) healthy liver with normal hepatocytes flanked by a quiescent hepatic stellate cell (HSC) with large lipid droplets (LDs), and (right) injured liver with lipid-filled hepatocytes flanked by activated HSCs devoid of large LDs.[\/caption]\r\n\r\n&nbsp;\r\n\r\n[caption id=\"attachment_448\" align=\"alignnone\" width=\"300\"]<img class=\"wp-image-448 size-medium\" src=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/ProteinMisfoldingAccumulation-300x153.png\" alt=\"\" width=\"300\" height=\"153\" \/> Figure: Proposed aggregation cascade of the expanded polyglutamine (polyQ) proteins and potential therapeutic targets for polyQ accumulation\/aggregation diseases.[\/caption]\r\n\r\n[caption id=\"attachment_450\" align=\"alignnone\" width=\"300\"]<img class=\"wp-image-450 size-medium\" src=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/LysosomeDysfunction-300x192.png\" alt=\"\" width=\"300\" height=\"192\" \/> Figure: Schematic diagram of the events that lead to Lysosomal Storage Disorders (LSDs). Orange spheres: accumulation of undegraded substrates. LSDs are rare inherited metabolic disorders characterized by lysosomes that are impaired by having mutations in lytic enzymes. The inability of the lysosomes (the recycling centers) to breakdown either lipids or glycoproteins leading to the accumulation of large lipid or saccharide molecules that lead to cell death.[\/caption]","rendered":"<p><span class=\"transcription-time-part\" style=\"text-align: initial;font-size: 1em\" data-time-start=\"1537.339\" data-time-end=\"1539.71\">Aging is a significant risk factor for several <strong>degenerative diseases<\/strong>, particularly those affecting the <strong>nervous system<\/strong> (e.g. Alzheimer&#8217;s, ALS, Parkinson&#8217;s disease) or a resulting from a lifetime of wear and tear (e.g. Osteoarthritis).\u00a0 <\/span><\/p>\n<p><span class=\"transcription-time-part\" style=\"text-align: initial;font-size: 1em\" data-time-start=\"1537.339\" data-time-end=\"1539.71\">Some cells in the body have very long life spans.\u00a0 For example, <strong>neurons<\/strong> and most <strong>heart<\/strong> and <strong>skeletal muscle cells<\/strong> are as old as you are.\u00a0 Over time, these cells and tissues can accumulate different materials that become detrimental to their function.\u00a0 These compounds may take the form of <strong>intracellular accumulations<\/strong>, building up inside cells, or may collect outside of cells in the form of<strong> extracellular accumulations<\/strong>.\u00a0 When a cell can neither process nor eliminate these materials, its function deteriorates- and so does the health of the surrounding tissue. <\/span><\/p>\n<ul>\n<li><span class=\"transcription-time-part\" style=\"text-align: initial;font-size: 1em\" data-time-start=\"1565.84\" data-time-end=\"1567.685\"><strong>Endogenous compounds: <\/strong> substances that are a normal part of the body but accumulate at unhealthy levels, such as lipids,<\/span> <span class=\"transcription-time-part\" style=\"text-align: initial;font-size: 1em\" data-time-start=\"1567.685\" data-time-end=\"1570.924\">proteins, carbohydrates, pigments, and metabolic toxins.<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0 <\/span><\/li>\n<li><span style=\"text-align: initial;font-size: 1em\"><strong>Exogenous compounds:<\/strong>\u00a0 substance from the external environment such as lead, mercury, silica, coal dust, and smoke particles.\u00a0\u00a0<\/span><\/li>\n<\/ul>\n<p><span class=\"transcription-time-part\" style=\"text-align: initial;font-size: 1em\" data-time-start=\"1570.924\" data-time-end=\"1573.46\">As the brain ages and accumulates potentially harmful compounds, it becomes increasingly susceptible to different forms of <strong>dementia<\/strong> &#8211; all of which are considered <strong>degenerative diseases<\/strong>.\u00a0 This underscores the importance of healthy lifestyle choice throughout life in minimizing the accumulation of harmful compounds and preserving cellular function into old age<\/span><span class=\"transcription-time-part\" style=\"text-align: initial;font-size: 1em\" data-time-start=\"1587.679\" data-time-end=\"1589.569\">.<\/span><\/p>\n<h3><span style=\"color: #1f5c99\"><strong>Four Mechanisms of Intracellular Accumulation<\/strong><\/span><\/h3>\n<p><strong><span style=\"color: #2e75b6\">1. Abnormal Lipid Metabolism:\u00a0 Fatty Change<\/span><\/strong><\/p>\n<p>Under normal conditions, cells metabolize lipids through a balance of <strong>lipogenesis<\/strong> (the creation of new lipids) and <strong>lipolysis<\/strong> (the breakdown of lipids).\u00a0 When something disrupts this balance &#8211; for example, when liver cells are under stress &#8211; the cell may inappropriately increase lipogenesis while simultaneously reducing lipolysis.\u00a0 The net result is an abnormal buildup of lipid droplets inside the cell.<\/p>\n<p>This phenomenon, called <strong>fatty change<\/strong> or <strong class=\"Yjhzub\" data-sfc-root=\"c\" data-sfc-cb=\"\" data-complete=\"true\">steatosis<\/strong>, is commonly seen in the liver of individuals with <strong>alcoholic liver disease<\/strong>.\u00a0 Under a microscope, the affected liver appears dramatically different from a healthy liver &#8211; cells are engorged with fat, and overall liver function is compromised.<\/p>\n<p>&nbsp;<\/p>\n<p><strong><span style=\"color: #2e75b6\">2. Abnormal Protein Accumulation<\/span><\/strong><\/p>\n<p>Proteins produced in a cell undergo a precise process:\u00a0 a gene is transcribed and translated, and the resulting protein is folded into its functional shape and tagged for transport to its destination. If folding fails or if the transport process is disrupted, the protein remains inside the cell.\u00a0 Accumulations of these <strong>misfolded<\/strong> or <strong>mislabeled proteins<\/strong> are toxic and progressively impair cell function.<\/p>\n<p>&nbsp;<\/p>\n<p><strong><span style=\"color: #2e75b6\">3. Enzyme Deficiency and Lysosomal Failure<\/span><\/strong><\/p>\n<p><span style=\"text-align: initial;font-size: 1em\">Cells rely on <strong>lysosomes<\/strong> &#8211; organelles filled with lytic enzymes &#8211; to break down and recycle old or damaged proteins.\u00a0 This <strong>recycling<\/strong> process keeps cells functioning optimally by ensuring a constant supply of fresh, functional proteins.\u00a0 If a critical <strong>lysosomal enzyme<\/strong> is deficient or absent, old proteins cannot be degraded.\u00a0 They accumulate inside the cell, progressively obstructing normal function.<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><strong><span style=\"color: #2e75b6\">4. Accumulation of Exogenous Particles<\/span><\/strong><\/p>\n<p><span style=\"font-size: 1em;text-align: initial\">Cells can <strong>phagocytose<\/strong> (engulf) particles from the external environment &#8211; such as <strong>coal dust, lead, mercury, silica, asbestos,<\/strong> and <strong>wildfire smoke particles<\/strong>.\u00a0 If the cell is unable to degrade these particles, they accumulate and interfere with cellular function.\u00a0 Over time, the tissue as a whole deteriorates as more and more cells become burdened by these indigestible materials. <\/span><\/p>\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\"><strong>Clinical Examples of Intracellular Accumulation<\/strong><\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p><strong>Fatty liver (Steatosis):<\/strong>\u00a0 Liver cells engorged with lipid droplets are visible on biopsy and are associated with conditions such as alcoholic liver disease.\u00a0 A fatty liver appears pale and swollen compared to a healthy liver.<\/p>\n<p><strong>Silicosis:<\/strong>\u00a0 Prolonged inhalation of silica dust (e.g., in mining or sandblasting) leads to the accumulation of silicon particles in lung cells, causing progressive lung damage.<\/p>\n<p><strong>Alzheimer&#8217;s disease: <\/strong> Intracellular accumulations of <strong>tangles of tau protein<\/strong> and extracellular accumulations of beta-amyloid protein clumps (beta amyloid plaques) &#8211; disrupt normal brain cell function and contributes to the neurodegeneration seen in Alzheimer&#8217;s disease.\u00a0 These will be explored in greater detail in the neurology chapter.<\/p>\n<\/div>\n<\/div>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_4043\" aria-describedby=\"caption-attachment-4043\" style=\"width: 300px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2024\/09\/Figure_35_05_01-1024x457-1.jpg\" target=\"_blank\" rel=\"noopener\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-4043 size-medium\" src=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2024\/09\/Figure_35_05_01-1024x457-1-300x134.jpg\" alt=\"Alzheimer's Disease\" width=\"300\" height=\"134\" srcset=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2024\/09\/Figure_35_05_01-1024x457-1-300x134.jpg 300w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2024\/09\/Figure_35_05_01-1024x457-1-768x343.jpg 768w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2024\/09\/Figure_35_05_01-1024x457-1-65x29.jpg 65w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2024\/09\/Figure_35_05_01-1024x457-1-225x100.jpg 225w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2024\/09\/Figure_35_05_01-1024x457-1-350x156.jpg 350w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2024\/09\/Figure_35_05_01-1024x457-1.jpg 1024w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><figcaption id=\"caption-attachment-4043\" class=\"wp-caption-text\">Compared to a normal brain (left), the brain from a patient with Alzheimer\u2019s disease (right) shows a dramatic neurodegeneration, particularly within the ventricles and hippocampus.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_445\" aria-describedby=\"caption-attachment-445\" style=\"width: 300px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-445 size-medium\" src=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/Lipid-Hepatocytes-300x207.png\" alt=\"\" width=\"300\" height=\"207\" srcset=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/Lipid-Hepatocytes-300x207.png 300w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/Lipid-Hepatocytes-1024x705.png 1024w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/Lipid-Hepatocytes-768x529.png 768w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/Lipid-Hepatocytes-1536x1058.png 1536w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/Lipid-Hepatocytes-2048x1410.png 2048w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/Lipid-Hepatocytes-65x45.png 65w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/Lipid-Hepatocytes-225x155.png 225w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/Lipid-Hepatocytes-350x241.png 350w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><figcaption id=\"caption-attachment-445\" class=\"wp-caption-text\">Figure: Simplified cartoons of (left) healthy liver with normal hepatocytes flanked by a quiescent hepatic stellate cell (HSC) with large lipid droplets (LDs), and (right) injured liver with lipid-filled hepatocytes flanked by activated HSCs devoid of large LDs.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_448\" aria-describedby=\"caption-attachment-448\" style=\"width: 300px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-448 size-medium\" src=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/ProteinMisfoldingAccumulation-300x153.png\" alt=\"\" width=\"300\" height=\"153\" srcset=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/ProteinMisfoldingAccumulation-300x153.png 300w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/ProteinMisfoldingAccumulation-1024x522.png 1024w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/ProteinMisfoldingAccumulation-768x391.png 768w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/ProteinMisfoldingAccumulation-1536x782.png 1536w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/ProteinMisfoldingAccumulation-2048x1043.png 2048w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/ProteinMisfoldingAccumulation-65x33.png 65w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/ProteinMisfoldingAccumulation-225x115.png 225w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/ProteinMisfoldingAccumulation-350x178.png 350w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><figcaption id=\"caption-attachment-448\" class=\"wp-caption-text\">Figure: Proposed aggregation cascade of the expanded polyglutamine (polyQ) proteins and potential therapeutic targets for polyQ accumulation\/aggregation diseases.<\/figcaption><\/figure>\n<figure id=\"attachment_450\" aria-describedby=\"caption-attachment-450\" style=\"width: 300px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-450 size-medium\" src=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/LysosomeDysfunction-300x192.png\" alt=\"\" width=\"300\" height=\"192\" srcset=\"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/LysosomeDysfunction-300x192.png 300w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/LysosomeDysfunction-1024x656.png 1024w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/LysosomeDysfunction-768x492.png 768w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/LysosomeDysfunction-65x42.png 65w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/LysosomeDysfunction-225x144.png 225w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/LysosomeDysfunction-350x224.png 350w, https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-content\/uploads\/sites\/1961\/2023\/06\/LysosomeDysfunction.png 1459w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><figcaption id=\"caption-attachment-450\" class=\"wp-caption-text\">Figure: Schematic diagram of the events that lead to Lysosomal Storage Disorders (LSDs). Orange spheres: accumulation of undegraded substrates. LSDs are rare inherited metabolic disorders characterized by lysosomes that are impaired by having mutations in lytic enzymes. The inability of the lysosomes (the recycling centers) to breakdown either lipids or glycoproteins leading to the accumulation of large lipid or saccharide molecules that lead to cell death.<\/figcaption><\/figure>\n<div class=\"media-attributions clear\" prefix:cc=\"http:\/\/creativecommons.org\/ns#\" prefix:dc=\"http:\/\/purl.org\/dc\/terms\/\"><h2>Media Attributions<\/h2><ul><li about=\"https:\/\/opentextbc.ca\/biology\"><a rel=\"cc:attributionURL\" href=\"https:\/\/opentextbc.ca\/biology\" property=\"dc:title\">Private: Figure_35_05_01-1024&#215;457-1<\/a>  &copy;  <a rel=\"dc:creator\" href=\"https:\/\/opentextbc.ca\/biology\" property=\"cc:attributionName\">Charles Molnar and Jane Gair, (credit: modification of work by \u201cGarrando\u201d\/Wikimedia Commons based on original images by ADEAR: \u201cAlzheimer\u2019s Disease Education and Referral Center, a service of the National Institute on Aging\u201d)<\/a>    is licensed under a  <a rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY (Attribution)<\/a> license<\/li><li about=\"https:\/\/doi.org\/10.3390\/cells9102244\"><a rel=\"cc:attributionURL\" href=\"https:\/\/doi.org\/10.3390\/cells9102244\" property=\"dc:title\">Lipid Hepatocytes<\/a>  &copy;  Molenaar, M.R.; Penning, L.C.; Helms, J.B. Playing Jekyll and Hyde    is licensed under a  <a rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY (Attribution)<\/a> license<\/li><li about=\"https:\/\/doi.org\/10.3390\/brainsci7100128\"><a rel=\"cc:attributionURL\" href=\"https:\/\/doi.org\/10.3390\/brainsci7100128\" property=\"dc:title\">ProteinMisfoldingAccumulation<\/a>  &copy;  Takeuchi, T.; Nagai, Y    is licensed under a  <a rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY (Attribution)<\/a> license<\/li><li about=\"https:\/\/www.researchgate.net\/publication\/322965875_Impact_Characterization_and_Rescue_of_Pre-mRNA_Splicing_Mutations_in_Lysosomal_Storage_Disorders\"><a rel=\"cc:attributionURL\" href=\"https:\/\/www.researchgate.net\/publication\/322965875_Impact_Characterization_and_Rescue_of_Pre-mRNA_Splicing_Mutations_in_Lysosomal_Storage_Disorders\" property=\"dc:title\">LysosomeDysfunction<\/a>  &copy;  Dardis, Andrea & Buratti, Emanuele.    is licensed under a  <a rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY (Attribution)<\/a> license<\/li><\/ul><\/div>","protected":false},"author":1370,"menu_order":8,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":["zoe-soon"],"pb_section_license":"cc-by-nc-sa"},"chapter-type":[],"contributor":[60],"license":[57],"class_list":["post-6263","chapter","type-chapter","status-web-only","hentry","contributor-zoe-soon","license-cc-by-nc-sa"],"part":3,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/6263","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/users\/1370"}],"version-history":[{"count":3,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/6263\/revisions"}],"predecessor-version":[{"id":6310,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/6263\/revisions\/6310"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/parts\/3"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapters\/6263\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/media?parent=6263"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/pressbooks\/v2\/chapter-type?post=6263"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/contributor?post=6263"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/pathophysiology\/wp-json\/wp\/v2\/license?post=6263"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}