Iron deficiency promotes aortic media degeneration by activating endoplasmic reticulum stress-mediated IRE1 signaling pathway

Can Iron Absorption in Molasses Be Increased with Probiotic Additives? "Molasses with Increased Bioavailability"

Introduction: There are many studies on the chemical and enzymatic interactions of probiotics, and the effects of Lactobacillus plantarum 299v on iron absorption have been clearly shown. The aim of this study was to investigate the effect of probiotics on the absorption of iron in molasses. Material and method: Wistar rats (n = 46) were taken four weeks after birth and divided into seven groups. Iron deficiency anemia was induced by giving "iron purified pellet" to the groups except the control group for four weeks and then the groups were given nutrients for eight weeks. In addition to iron deficiency anemia tests, immunohistochemical markers such as SCL11a, IRE1, Wnt2, and CD71 were examined. Results: The mean weight of the subjects was 309.5 ± 63.9 (226-424) g and no significant difference was observed in the laboratory values of metabolic data. When the laboratory values of iron deficiency anemia were examined, a statistically significant difference was found between the mean ferritin (p = 0.03) and hepcidin (p = 0.02) values of the groups. Discussion: Iron absorption analysis values were generally higher in the group receiving Fe3+ as expected. However, when the groups receiving molasses and additives were compared, the highest plasma iron level and Hb value were found in the Lactobacillus plantarum 299v group, and the highest ferritin and hepcidin levels were found in the Multiprobiotic group. No difference was observed between the body weights and fasting serum glucose levels of the groups despite daily molasses consumption, indicating the metabolic proactive effects of probiotics. Conclusions: Although no significant difference was detected between the groups receiving probiotics, iron absorption in molasses was increased with probiotic supplementation.

The interplay of ferroptosis and oxidative stress in the pathogenesis of aortic dissection

Aortic dissection (AD) is a life-threatening vascular condition marked by the separation or tearing of the aortic media. Ferroptosis, a form of iron-dependent programmed cell death, occurs alongside lipid peroxidation and the accumulation of reactive oxygen species (ROS). The relationship between ferroptosis and AD lies in its damaging effect on vascular cells. In AD, ferroptosis worsens the damage to vascular smooth muscle cells (VSMCs) and endothelial cells (ECs), thereby weakening the vascular wall's structural integrity and accelerating the onset and progression of the condition. However, the molecular mechanisms through which ferroptosis regulates the onset and progression of AD remain poorly understood. This article explores the relationship between ferroptosis and AD.

[Research progress on the role of ferroptosis in aortic dissection]

Recent studies have shown that iron metabolism dysregulation and lipid peroxidation-induced ferroptosis, triggered by oxidative stress, play a key role in the development of aortic dissection. Dysregulated iron metabolism leads to excessive production of hydroxyl radicals due to abnormal iron levels and heme metabolism, while lipid peroxidation is linked to system Xc－ dysfunction and accumulation of phospholipid hydroperoxides. These factors synergistically disrupt aortic homeostasis and drive ferroptosis in vascular cells, including endothelial and smooth muscle cells. Furthermore, disruptions in ferroptosis-related genes, along with risk factors such as smoking, epigenetic modifications such as protein methylation, and abnormalities in immune cells, particularly T cells, are closely linked to aortic dissection. Several small molecules and nanomaterials have shown potential in inhibiting ferroptosis in this context. This review elucidates the roles of ferroptosis in aortic dissection and proposes strategies for its targeted prevention and treatment.

Emerging role of IRE1α in vascular diseases

A mounting body of evidence suggests that the endoplasmic reticulum stress and the unfolded protein response are involved in the underlying mechanisms responsible for vascular diseases. Inositol-requiring protein 1α (IRE1α), the most ancient branch among the UPR-related signaling pathways, can possess both serine/threonine kinase and endoribonuclease (RNase) activity and can perform physiological and pathological functions. The IRE1α-signaling pathway plays a critical role in the pathology of various vascular diseases. In this review, we provide a general overview of the physiological function of IRE1α and its pathophysiological role in vascular diseases.

The Role of Iron in Intestinal Mucus: Perspectives from Both the Host and Gut Microbiota

Although research on the role of iron in host immunity has a history spanning decades, it is only relatively recently that attention has been directed toward the biological effects of iron on the intestinal mucus layer, prompted by an evolving understanding of the role of this material in immune defense. The mucus layer, secreted by intestinal goblet cells, covers the intestinal epithelium, and given its unique location, interactions between the host and gut microbiota, as well as among constituent microbiota, occur frequently within the mucus layer. Iron, as an essential nutrient for the vast majority of life forms, regulates immune responses from both the host and microbial perspectives. In this review, we summarize the iron metabolism of both the host and gut microbiota and describe how iron contributes to intestinal mucosal homeostasis via the intestinal mucus layer with respect to both host and constituent gut microbiota. The findings described herein offer a new perspective on iron-mediated intestinal mucosal barrier function.

Stearic acid alleviates aortic medial degeneration through maintaining mitochondrial dynamics homeostasis via inhibiting JNK/MAPK signaling

Aortic dissection is characterized pathologically by aortic medial degeneration (AMD) where disturbance of mitochondrial dynamics may be involved. Stearic acid (SA) can promote mitochondrial fusion and improve mitochondrial function. Here, we established an AMD mouse model through oral administration of β-aminopropionitrile (BAPN) and a cellular model by treating primary vascular smooth muscle cells (VSMCs) with Angiotensin-II to explore the potential role of SA in AMD. Our results showed SA reduced AMD and prolonged survival of BAPN-treated mice. Excessive mitochondrial fission was observed during AMD both in vivo and in vitro, and SA reduced mitochondrial fission and increased fusion. Additionally, SA promoted expression of contractile phenotype markers of VSMCs. At the molecular level, SA reduced AMD by inhibiting JNK/MAPK signaling. Our study suggests SA can promote mitochondrial fusion and increase the contractile phenotype of VSMCs by inhibiting JNK/MAPK signaling, thereby reducing AMD formation and possibly the consequent risk of aortic dissection.

A new insight into Cd exposure-induced hemocyte reduction in Lymantria dispar larvae: Involvement of the ROS-ATF6-ER stress-apoptosis pathway

Hemocytes are important targets for heavy metal-induced immunotoxicity in insects. This study aimed to investigate the mechanism by which cadmium (Cd) exposure affects the hemocyte count in Lymantria dispar larvae. The results showed that the number of larval hemocytes was significantly decreased under Cd exposure, accompanied by a significant increase in the apoptosis rate and the expression of Caspase-3. The endoplasmic reticulum (ER) of hemocytes in the Cd-treated group showed irregular swelling. Expression levels of ER stress indicator genes (CHOP, Bip1, Bip2, Bip3, and Bip4) were significantly higher in the Cd-treated group. Among the three pathways that potentially mediate ER stress, only the key genes in the ATF6 pathway (ATF6, S1P-1, S1P-2, and WFS1) exhibited differential responses to Cd exposure. Cd exposure significantly increased the levels of reactive oxygen species (ROS) and the expression of oxidative stress-related genes (CNCC, P38, and ATF2) in hemocytes. Studies using inhibitors confirmed that apoptosis mediated the decrease in hemocyte count, ER stress mediated apoptosis, ATF6 pathway mediated ER stress, and ROS or oxidative stress mediated ER stress through the activation of the ATF6 pathway. Taken together, the ROS-ATF6-ER stress-apoptosis pathway is responsible for the reduction in the hemocyte count of Cd-treated L. dispar larvae.

Inhibition of the endoplasmic reticulum stress-associated IRE-1 pathway alleviates preterm birth

BACKGROUND

Premature birth (PTB) remains a major global health concern due to its association with neonatal morbidity and mortality. The unfolded protein response (UPR) within the endoplasmic reticulum (ER) is tightly regulated by Inositol-requiring enzyme type 1 (IRE-1), a pivotal cellular modulator. This study seeks to elucidate the role of the ER stress (ERS)-related IRE-1 pathway in PTB.

METHODS

Human placental trophoblast cells HTR8/Svneo were exposed to the ER-stress inducer tunicamycin (TM). The expression of IRE-1 and ERS-associated proteins ATF6, GRP78, and XBP-1 was assessed in placental tissues and TM-treated cells. Cellular viability, migration, invasion, and apoptosis were evaluated through a series of experimental assays. Additionally, various methods were employed to assess and verify the activation of autophagy, using the autophagy marker, microtubule-associated protein 1A/1B-light chain 3 (LC3). Additionally, TUDCA (an ERS inhibitor) was used to assess its potential to counteract the TM-induced cell effects.

RESULTS

Elevated levels of ATF6, GRP78, and XBP-1 were observed in PTB tissues and cells. TM treatment substantially reduced cell viability, migration, and invasion while promoting apoptosis. Treatment with TUDCA (an ERS inhibitor) counteracted the effects of TM on the cells. Furthermore, we identified an overexpression of IRE-1 in PTB tissues and cells and its knockdown enhanced cell viability, migration, and invasion while suppressed apoptosis and autophagy under TM stimulation. Notably, IRE-1 was found to modulate the activity of the IRE-1/XBP1/CHOP signaling pathway in TM-treated cells.

CONCLUSION

The upregulation of IRE-1 in PTB placental tissues is implicated in the pathogenesis of PTB. Importantly, inhibiting the ERS-associated IRE-1/XBP1/CHOP pathway may be a good strategy in mitigating PTB.

Mitochondrial protein prohibitin promotes learning memory recovery in mice following intracerebral hemorrhage via CAMKII/CRMP signaling pathway

Prohibitin (PHB) is a mitochondrial inner membrane protein with neuroprotective, antioxidant, and apoptosis-reducing effects. This study aimed to explore the role of PHB in pathological symptoms, behavioral deficits, and cognitive impairment in a collagenase-IV-induced intracerebral hemorrhage (ICH) murine model. In this study, mice that received collagenase IV injection were pretreated with PHB or saline 21 days prior to modeling. The role of PHB in memory and learning ability was monitored using the Morris water maze, Y-maze, and rotarod, social, startle, and nest-building tests. The effect of PHB on depression-like symptoms was examined using the forced swimming, tail suspension, and sucrose preference tests. Subsequently, mouse samples were analyzed using immunohistochemistry, western blotting, Perls staining, Nissl staining, and gene sequencing. Results showed that collagenase IV significantly induced behavioral deficits, brain edema, cognitive impairment, and depressive symptoms. PHB overexpression effectively alleviated memory, learning, and motor deficits in mice with ICH. PHB markedly inhibited the number of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling-positive cells and protein levels of ionized calcium-binding adapter molecule 1, glial fibrillary acidic protein, and interleukin-1β in the perihematomal region of ICH mice. PHB overexpression also remarkably promoted production of neurologin1 (NLGL1), and upregulated levels of Ca2+-calmodulin-dependent kinase II (CaMKII) and collapsin response mediator protein-1 (CRMP1) proteins. In conclusion, PHB overexpression can effectively alleviate the neurological deficits and neurodegeneration around the hematoma region. This may play a protective role by upregulating the expression of NLGL1 and promoting expression of CaMKII and CRMP1.

Metal-Binding Proteins Cross-Linking with Endoplasmic Reticulum Stress in Cardiovascular Diseases

The endoplasmic reticulum (ER), an essential organelle in eukaryotic cells, is widely distributed in myocardial cells. The ER is where secreted protein synthesis, folding, post-translational modification, and transport are all carried out. It is also where calcium homeostasis, lipid synthesis, and other processes that are crucial for normal biological cell functioning are regulated. We are concerned that ER stress (ERS) is widespread in various damaged cells. To protect cells' function, ERS reduces the accumulation of misfolded proteins by activating the unfolded protein response (UPR) pathway in response to numerous stimulating factors, such as ischemia or hypoxia, metabolic disorders, and inflammation. If these stimulatory factors are not eliminated for a long time, resulting in the persistence of the UPR, it will aggravate cell damage through a series of mechanisms. In the cardiovascular system, it will cause related cardiovascular diseases and seriously endanger human health. Furthermore, there has been a growing number of studies on the antioxidative stress role of metal-binding proteins. We observed that a variety of metal-binding proteins can inhibit ERS and, hence, mitigate myocardial damage.

Targeting Iron Metabolism and Ferroptosis as Novel Therapeutic Approaches in Cardiovascular Diseases

Iron functions as an essential micronutrient and participates in normal physiological and biochemical processes in the cardiovascular system. Ferroptosis is a novel type of iron-dependent cell death driven by iron accumulation and lipid peroxidation, characterized by depletion of glutathione and suppression of glutathione peroxidase 4 (GPX4). Dysregulation of iron metabolism and ferroptosis have been implicated in the occurrence and development of cardiovascular diseases (CVDs), including hypertension, atherosclerosis, pulmonary hypertension, myocardial ischemia/reperfusion injury, cardiomyopathy, and heart failure. Iron chelators deferoxamine and dexrazoxane, and lipophilic antioxidants ferrostatin-1 and liproxstatin-1 have been revealed to abolish ferroptosis and suppress lipid peroxidation in atherosclerosis, cardiomyopathy, hypertension, and other CVDs. Notably, inhibition of ferroptosis by ferrostatin-1 has been demonstrated to alleviate cardiac impairments, fibrosis and pathological remodeling during hypertension by potentiating GPX4 signaling. Administration of deferoxamine improved myocardial ischemia/reperfusion injury by inhibiting lipid peroxidation. Several novel small molecules may be effective in the treatment of ferroptosis-mediated CVDs. In this article, we summarize the regulatory roles and underlying mechanisms of iron metabolism dysregulation and ferroptosis in the occurrence and development of CVDs. Targeting iron metabolism and ferroptosis are potential therapeutic strategies in the prevention and treatment of hypertension and other CVDs.

Mitochondrial Dysfunction and Therapeutic Perspectives in Cardiovascular Diseases

High mortality rates due to cardiovascular diseases (CVDs) have attracted worldwide attention. It has been reported that mitochondrial dysfunction is one of the most important mechanisms affecting the pathogenesis of CVDs. Mitochondrial DNA (mtDNA) mutations may result in impaired oxidative phosphorylation (OXPHOS), abnormal respiratory chains, and ATP production. In dysfunctional mitochondria, the electron transport chain (ETC) is uncoupled and the energy supply is reduced, while reactive oxygen species (ROS) production is increased. Here, we discussed and analyzed the relationship between mtDNA mutations, impaired mitophagy, decreased OXPHOS, elevated ROS, and CVDs from the perspective of mitochondrial dysfunction. Furthermore, we explored current potential therapeutic strategies for CVDs by eliminating mtDNA mutations (e.g., mtDNA editing and mitochondrial replacement), enhancing mitophagy, improving OXPHOS capacity (e.g., supplement with NAD+, nicotinamide riboside (NR), nicotinamide mononucleotide (NMN), and nano-drug delivery), and reducing ROS (e.g., supplement with Coenzyme Q10 and other antioxidants), and dissected their respective advantages and limitations. In fact, some therapeutic strategies are still a long way from achieving safe and effective clinical treatment. Although establishing effective and safe therapeutic strategies for CVDs remains challenging, starting from a mitochondrial perspective holds bright prospects.