Minor regulators include
adrenocorticotropic hormone (ACTH) from the pituitary, atrial natriuretic
peptide from the heart, and local adrenal secretion of โดพามีน. We
20 demonstrated that mood disorders are correlated with increased
concentrations of อัลโดสเทอรอน and digoxin in blood as well as urine.
Oxidative stress & เอนโดธีลิน dysfunction hypothesis
Major depression has been shown to be accompanied by increased
oxidative stress and lipid peroxidation. Plasma peroxides and serum
oxidized LDL (oxLDL) antibodies are known to be correlated to major
depression. (Maes, 2010). Atherosclerosis and depression are also known to be associated (Jones, 2003; Wiiteman, 2004; Hamer, 2010).
The endothelial injury, activation, and dysfunction caused by
oxidized LDL (oxLDL) in the pathogenesis of atherosclerosis are exerted via
lectin-like oxidized low-density lipoprotein รีเซปเตอร์-1 (LOX-1) activation. LOX-1, initially identified as the major รีเซปเตอร์ for oxLDL in endothelial cells, can also be expressed in macrophages and smooth muscle cells
(SMCs). The stage for atherosclerosis is set once endothelial dysfunction
5 occurs. LOX-1 may play a role in initiating and potentiating this crucial first
step.
Under conditions of hypercholesterolemia, hypertension, and diabetes, disease states that promote vascular injury, LOX-1 is highly expressed in blood vessels.
10 Induction of LOX-1 expression is mediated by แองจิโอเทนซิน II and
เอนโดธีลิน-1, both antagonists of NO. With elevated levels of LOX-1 on the endothelium, increased amounts of oxLDL can be endocytosed, an activity that further enhances LOX-1 expression. OxLDL through LOX-1 also
increases the expression of แองจิโอเทนซิน converting enzyme and reduces the 15 intracellular concentration of NO. In addition to being the main รีเซปเตอร์ for
oxLDL, LOX-1 hasthe ability to bind damaged or apoptotic cells, activated
platelets, advanced glycation end products, and pathogenic organisms. Once
bound, these ligands can be endocytosed or phagocytosed into the cell.
Under physiological conditions, LOX-1 may play a role in host defense or 20 serve to scavenge cellular debris. However, in pathological states, LOX-1
may be involved in binding proatherogenic materials, such as oxLDL, that
activate the endothelium. With its ability to bind products that induce
inflammation and endothelial activation, it is not surprising that elevated
LOX-1 expression is observed in both initial and advanced atherosclerotic 25 lesions. The stage for atherosclerosis is set once endothelial dysfunction
occurs. Under conditions of hypercholesterolemia, hypertension, and
diabetes which are all known to be associated with mood disorders, disease
states that promote vascular injury, LOX-1 is highly expressed in blood
vessels. Induction of LOX-1 expression is mediated by แองจิโอเทนซิน II and 30 เอนโดธีลิน-1, both antagonists of NO. With elevated levels of LOX-1 on the
endothelium, increased amounts of oxLDL can be endocytosed, an activity
that further enhances LOX-1 expression. OxLDL through LOX-1 also
increases the expression of แองจิโอเทนซิน converting enzyme and reduces the
intracellular concentration of NO. Thus, LOX-1 activity amplifies the extent 5 of endothelial dysfunction. However, oxLDL uptake by LOX-1 also mediates
endothelial cell apoptosis, potentially via nuclear factor (NF)_B activation.
This may result in direct vascular denudation and injury that may trigger
or enhance an existing inflammatory reaction (Szmitko, 2003).
We demonstrated that mood disorders are correlated with
10 increased concentrations of เอนโดธีลิน-1, F2-ไอโซโพรสเทน, LOX-1 and nitro-
tyrosine concentrations in blood as well as urine.
Tight junction hypothesis
Intestinal mucosal dysfunction characterized by an increased
15 translocation of gram-negative bacteria (leaky gut) has suggested to play a
role in the inflammatory pathophysiology of depression. It is suggested that the increased LPS translocation may mount an immune response and thus inflammatory response system activation in some patients with MDD and
may induce specific "sickness behaviour" symptoms (Maes, 2008; Painsipp, 20 2011). T cell-derived LIGHT is known to activate epithelial LTBR to disrupt
barrier function (Brad T. et al. 2007 ). Furthermore it was found that
individuals with recent-onset psychosis and with multi-episode
schizophrenia who have increased antibodies to gliadin may share some
immunologic features of celiac disease, but their immune response to gliadin
25 differs from that of celiac disease (Dickerson, 2010). Gliadin binds to CXCR3
and leads to MyD88-dependent โซนูลิน release and increased intestinal
permeability (Lammers, 2008). We demonstrated for the first time that the
โซนูลิน serum concentration is associated with mood disorders.
30 โซนูลิน
Intercellular tight junctions are dynamic structures involved in vectorial transport of water and electrolytes across the cell membranes of the intestinal epithelium and brain blood barrier. Zonula occludens toxin
derived from Vibrio cholerae interacts with a specific intestinal epithelial 5 surface รีเซปเตอร์, with subsequent activation of a complex intracellular
cascade of events that regulate tight junction permeability. โซนูลิน likely
plays a pivotal role in tight junction regulation during developmental,
physiological, and pathological processes, including tissue morphogenesis,
movement of fluid, macromolecules and leukocytes between the intestinal 10 lumen and the interstitium, and inflammatory/autoimmune disorders
(Fasano, 2001; Wang, 2000).
Pro-inflammatory hypothesis
In the last 150 years, rapid expansion in Western populations has
15 been associated with a change in diet, with omega-3 polyunsaturated fatty
acids from fish, wild game, and plants being replaced by saturated fats from
domestic animals and omega-6 polyunsaturated fatty acids from common
vegetable oils (corn, safflower, and soybean) and other sources. These
changes have resulted in a large increase in the ratio of omega-6 to omega-3 20 fatty acids in the general diet from 1:1 to more than 10:1 (4, 5). This has
resulted in a high proportion of the common omega-6 fatty acid arachidonic
acid, rather than EPA, in the cell membranes of most tissues. As depicted in
figure 1 an increase in อะราคิโดนิกแอซิด also affects the production of EPA
and DHA, owing to competition for metabolizing enzymes. The AA/EPA
25 ratio can be used as a biomarker for mood disorders.
Antidepressant Efficacy of Omega-3 Fatty Acids (EPA) has been
well documented for both major depression and ภาวะซึมเศร้าแบบอารมณ์สองขั้ว (Pao-Yen
Lin, 2007). The two omega-3 fatty acids, EPA and DHA, compete with
30 อะราคิโดนิกแอซิด (AA) for incorporation into membrane ฟอสโฟไลปิด.
Phospholipases A2 are enzymes that catalytically hydrolyzes the bond
releasing อะราคิโดนิกแอซิด and lvsoฟอสโฟไลปิด. Phospholipases A2 include several protein families with common enzymatic activity. Two most notable families are CA2+ dependent secreted and cytosolic phospholipases A2.
5 Other families include Ca2+ independent PLA2 (iPLA2) and
lipoprotein-associated PLA2s (1p-PLA2), also known as platelet activating
factor acetylhydrolase (PAF-AH). Increased PLA2 activity and PLA2-
generated mediators are known to play a central role in acute inflammatory
responses in the brain but also in oxidative stress associated with
10 neurological disorders (Faraooqui, 2006). Phospholipase A2 and COX-2
genes also increase the risk of IFN-alpha induced depression by regulating
polyunsaturated fatty acid level (Su KP, Huang SY, 2010). EPA is important
in balancing the immune function and physical health by reducing
phospholipase A2, Platelet acitivating factor (PAF) , อะราคิโดนิกแอซิด (AA 15 level on cell membrane) prostaglandin E2 (PGE2) and LTB4 synthesis.
(Joel M. Kremer, 1996). We also demonstrated the correlation of PLA2 and
mood disorders.
The cellular calcium overload explained in the section "mineral
homeostasis" activates the PLA2 enzymes to release the อะราคิโดนิกแอซิด 20 (AA) from the cell membranes. Hence increased amounts of AA are
converted via cyclooxygenase and 5-lopoxygenase into
eicosanoid metabolites. The most important ones are depicted in figure 2.
This results in an increase of amongst others prostaglandins,
25 ทรอมบอกเซนs and leukotrienes. These proinflammatory eicosanoids have
all been linked to depression (Linnoila et al., 1983; Calabrese et al., 1986; Ohishi et al., 1998; Nishino et al., 1989; Song et al., 1998). We also
demonstrated that mood disorders are correlated with increased PGE2, LTB4, and ทรอมบอกเซน B2 concentrations in blood as well as urine.
EPA competes with อะราคิโดนิกแอซิด for the cyclo-oxygenase
enzyme system as is indicated in figure 1, inhibiting the production of
proinflammatory eicosanoids derived from อะราคิโดนิกแอซิด (e.g.
prostaglandins, leukotrienes and ทรอมบอกเซนs) which have been linked to
5 depression.
DHA and EPA also inhibit the release of proinflammatory
cytokines, such as interleukin-1 beta, interleukin-2, interleukin-6,
interferon-gamma, and tumor necrosis factor alpha (Guixiang, 2007), which 10 depend on eicosanoid release, and are also associated with depression.
Further, omega-3 fatty acids affect brain-derived neurotrophic factor, which
encourages synaptic plasticity, provides neuroprotection, enhances
neurotransmission, and has antidepressant effects (Ikemoto, 2000)
AA, DGLA and all cyclooxygenase & 5-lipoxygenase based
15 metabolites thereof can be used as