Neuroinflammation and endoplasmic reticulum stress are coregulated by crocin to prevent demyelination and neurodegeneration

Anti-inflammatory, antioxidant and anti-mitophagy effects of trans sodium crocetinate on experimental autoimmune encephalomyelitis in BALB/C57 mice

Multiple sclerosis (MS) is an autoimmune disorder characterized by the degeneration of myelin and inflammation in the central nervous system. Trans sodium crocetinate (TSC), a novel synthetic carotenoid compound, possesses antioxidant, anti-inflammatory and neuroprotective effects. This study aimed to evaluate the protective effects of TSC against the development of experimental autoimmune encephalomyelitis (EAE), a well-established model for MS. Female BALB/C57 mice were divided into different groups, including control, EAE, vehicle, TSC-treated (25, 50, and 100 mg/kg, administered via gavage) + EAE, methyl prednisone acetate + EAE, and TSC-treated (100 mg/kg, administered via gavage for 28 days) groups. EAE was induced using MOG35-55, complete Freund's adjuvant, and pertussis toxin. In the mice spinal cord tissues, the oxidative markers (GSH and MDA) were measured using spectrophotometry and histological evaluation was performed. Mitophagic pathway proteins (PINK1and PARKIN) and inflammatory factors (IL-1β and TNF-α) were evaluated by western blot. Following 21 days post-induction, EAE mice exhibited weight loss, and the paralysis scores increased on day 13 but recovered after TSC (100 mg/kg) administration on day 16. Furthermore, TSC (50 and 100 mg/kg) reversed the altered levels of MDA and GSH in the spinal cord tissue of EAE mice. TSC (100 mg/kg) also decreased microgliosis, demyelination, and the levels of inflammatory markers IL-1β and TNF-α. Notably, TSC (100 mg/kg) modulated the mitophagy pathway by reducing PINK1 and Parkin protein levels. These findings demonstrate that TSC protects spinal cord tissue against EAE-induced MS through anti-inflammatory, antioxidant, and anti-mitophagy mechanisms.

Endoplasmic reticulum stress response in immune cells contributes to experimental autoimmune encephalomyelitis pathogenesis in rats

We examined the role of endoplasmic reticulum (ER) stress and the ensuing unfolded protein response (UPR) in the development of the central nervous system (CNS)-directed immune response in the rat model of experimental autoimmune encephalomyelitis (EAE). The induction of EAE with syngeneic spinal cord homogenate in complete Freund's adjuvant (CFA) caused a time-dependent increase in the expression of ER stress/UPR markers glucose-regulated protein 78 (GRP78), X-box-binding protein 1 (XBP1), C/EBP homologous protein (CHOP), and phosphorylated eukaryotic initiation factor 2α (eIF2α) in the draining lymph nodes of both EAE-susceptible Dark Agouti (DA) and EAE-resistant Albino Oxford (AO) rats. However, the increase in ER stress markers was more pronounced in AO rats. CFA alone also induced ER stress, but the effect was weaker and less sustained compared to full immunization. The ultrastructural analysis of DA lymph node tissue by electron microscopy revealed ER dilatation in lymphocytes, macrophages, and plasma cells, while immunoblot analysis of CD3-sorted lymph node cells demonstrated the increase in ER stress/UPR markers in both CD3+ (T cell) and CD3- (non-T) cell compartments. A positive correlation was observed between the levels of ER stress/UPR markers in the CNS-infiltrated mononuclear cells and the clinical activity of the disease. Finally, the reduction of EAE clinical signs by ER stress inhibitor ursodeoxycholic acid was associated with the decrease in the expression of mRNA encoding pro-inflammatory cytokines TNF and IL-1β, and encephalitogenic T cell cytokines IFN-γ and IL-17. Collectively, our data indicate that ER stress response in immune cells might be an important pathogenetic factor and a valid therapeutic target in the inflammatory damage of the CNS.

Endogenous retroviruses in development and health

Endogenous retroviruses (ERVs) are evolutionary remnants of retroviral infections in which the viral genome became embedded as a dormant regulatory element within the host germline. When ERVs become activated, they comprehensively rewire genomic regulatory networks of the host and facilitate critical developmental events, such as preimplantation development and placentation, in a manner specific to species, developmental stage, and tissues. However, accumulating evidence suggests that aberrant ERV transcription compromises genome stability and has been implicated in cellular senescence and various pathogenic processes, underscoring the significance of host genomic surveillance mechanisms. Here, we revisit the prominent functions of ERVs in early development and highlight their emerging roles in mammalian post-implantation development and organogenesis. We also discuss their implications for aging and pathological processes such as microbial infection, immune response. Furthermore, we discuss recent advances in stem-cell-based models, single-cell omics, and genome editing technologies, which serve as beacons illuminating the versatile nature of ERVs in mammalian development and health.

Mechanisms Governing Oligodendrocyte Viability in Multiple Sclerosis and Its Animal Models

Multiple sclerosis (MS) is a chronic autoimmune inflammatory demyelinating disease of the central nervous system (CNS), which is triggered by an autoimmune assault targeting oligodendrocytes and myelin. Recent research indicates that the demise of oligodendrocytes due to an autoimmune attack contributes significantly to the pathogenesis of MS and its animal model experimental autoimmune encephalomyelitis (EAE). A key challenge in MS research lies in comprehending the mechanisms governing oligodendrocyte viability and devising therapeutic approaches to enhance oligodendrocyte survival. Here, we provide an overview of recent findings that highlight the contributions of oligodendrocyte death to the development of MS and EAE and summarize the current literature on the mechanisms governing oligodendrocyte viability in these diseases.

Immunomodulatory therapy with glatiramer acetate reduces endoplasmic reticulum stress and mitochondrial dysfunction in experimental autoimmune encephalomyelitis

Endoplasmic reticulum (ER) stress and mitochondrial dysfunction are found in lesions of multiple sclerosis (MS) and animal models of MS such as experimental autoimmune encephalomyelitis (EAE), and may contribute to the neuronal loss that underlies permanent impairment. We investigated whether glatiramer acetate (GA) can reduce these changes in the spinal cords of chronic EAE mice by using routine histology, immunostaining, and electron microscopy. EAE spinal cord tissue exhibited increased inflammation, demyelination, mitochondrial dysfunction, ER stress, downregulation of NAD+ dependent pathways, and increased neuronal death. GA reversed these pathological changes, suggesting that immunomodulating therapy can indirectly induce neuroprotective effects in the CNS by mediating ER stress.

Natural products targeting cellular processes common in Parkinson's disease and multiple sclerosis

The hallmarks of Parkinson's disease (PD) include the loss of dopaminergic neurons and formation of Lewy bodies, whereas multiple sclerosis (MS) is an autoimmune disorder with damaged myelin sheaths and axonal loss. Despite their distinct etiologies, mounting evidence in recent years suggests that neuroinflammation, oxidative stress, and infiltration of the blood-brain barrier (BBB) all play crucial roles in both diseases. It is also recognized that therapeutic advances against one neurodegenerative disorder are likely useful in targeting the other. As current drugs in clinical settings exhibit low efficacy and toxic side effects with long-term usages, the use of natural products (NPs) as treatment modalities has attracted growing attention. This mini-review summarizes the applications of natural compounds to targeting diverse cellular processes inherent in PD and MS, with the emphasis placed on their neuroprotective and immune-regulating potentials in cellular and animal models. By reviewing the many similarities between PD and MS and NPs according to their functions, it becomes evident that some NPs studied for one disease are likely repurposable for the other. A review from this perspective can provide insights into the search for and utilization of NPs in treating the similar cellular processes common in major neurodegenerative diseases.

Crocin Attenuates NLRP3 Inflammasome Activation by Inhibiting Mitochondrial Reactive Oxygen Species and Ameliorates Monosodium Urate-Induced Mouse Peritonitis

Crocin is a hydrophilic carotenoid pigment found in the stigma of Crocus sativus or the fruit of Gardenia jasminoides. In this study, we investigated the effects of Crocin on the activation of the nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 3 (NLRP3) inflammasome in J774A.1 murine macrophage cells and monosodium urate (MSU)-induced peritonitis. Crocin significantly inhibited Nigericin-, adenosine triphosphate (ATP)-, MSU-induced interleukin (IL)-1β secretion, and caspase-1 cleavage without affecting pro-IL-1β and pro-caspase-1. Crocin also suppressed gasdermin-D cleavage and lactate dehydrogenase release and enhanced cell viability, indicating that Crocin reduces pyroptosis. Similar effects were observed in primary mouse macrophages. However, Crocin did not affect poly(dA:dT)-induced absent in melanoma 2 (AIM2) and muramyl dipeptide-induced NLRP1 inflammasomes. Crocin decreased Nigericin-induced oligimerization and the speck formation of apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC). Crocin also dramatically alleviated the ATP-induced production of mitochondrial reactive oxygen species (mtROS). Finally, Crocin ameliorated the MSU-induced production of IL-1β and IL-18 and the recruitment of neutrophils during peritoneal inflammation. These results suggest that Crocin suppresses NLRP3 inflammasome activation by blocking mtROS production and ameliorates MSU-induced mouse peritonitis. Thus, Crocin may have therapeutic potential in various NLRP3 inflammasome-related inflammatory diseases.

Transcriptome-wide analysis reveals the molecular mechanisms of cannabinoid type II receptor agonists in cardiac injury induced by chronic psychological stress

Background: Growing evidence has supported that chronic psychological stress would cause heart damage, However the mechanisms involved are not clear and effective interventions are insufficient. Cannabinoid type 2 receptor (CB2R) can be a potential treatment for cardiac injury. This study is aimed to investigate the protective mechanism of CB2R agonist against chronic psychological stress-induced cardiac injury. Methods: A mouse chronic psychological stress model was constructed based on a chronic unpredictable stress pattern. Mice were performed a three-week psychological stress procedure, and cardiac tissues of them were collected for whole-transcriptome sequencing. Overlap analysis was performed on differentially expressed mRNAs (DE-mRNAs) and ER stress-related genes (ERSRGs), and bioinformatic methods were used to predict the ceRNA networks and conduct pathway analysis. The expressions of the DE-ERSRGs were validated by RT-qPCR. Results: In the comparison of DE mRNA in Case group, Control group and Treatment group, three groups of ceRNA networks and ceRNA (circ) networks were constructed. The DE-mRNAs were mainly enriched in chromatid-relevant terms and Hematopoietic cell lineage pathway. Additionally, 13 DE-ERSRGs were obtained by the overlap analysis, which were utilized to establish a ceRNA network with 15 nodes and 14 edges and a ceRNA (circ) network with 23 nodes and 28 edges. Furthermore, four DE-ERSRGs (Cdkn1a, Atf3, Fkbp5, Gabarapl1) in the networks were key, which were mainly enriched in response to extracellular stimulus, response to nutrient levels, cellular response to external stimulus, and FoxO signaling pathway. Finally, the RT-qPCR results showed almost consistent expression patterns of 13 DE-ERSRGs between the transcriptome and tissue samples. Conclusion: The findings of this study provide novel insights into the molecular mechanisms of chronic psychological stress-induced cardiac diseases and reveal novel targets for the cardioprotective effects of CB2R agonists.

Crocins for Ischemic Stroke: A Review of Current Evidence

Crocins (CRs) and the related active constituents derived from Crocus sativus L. (Saffron) have demonstrated protective effects against cerebral ischemia and ischemic stroke, with various bioactivities including neuroprotection, anti-neuroinflammation, antioxidant, and cardiovascular protection. Among CRs, crocin (CR) has been shown to act on multiple mechanisms and signaling pathways involved in ischemic stroke, including mitochondrial apoptosis, nuclear factor kappa light chain enhancer of B cells pathway, S100 calcium-binding protein B, interleukin-6 and vascular endothelial growth factor-A. CR is generally safe and well-tolerated. Pharmacokinetic studies indicate that CR has poor bioavailability and needs to convert to crocetin (CC) in order to cross the blood-brain barrier. Clinical studies have shown the efficacy of saffron and CR in treating various conditions, including metabolic syndrome, depression, Alzheimer’s disease, and coronary artery disease. There is evidence supporting CR as a treatment for ischemic stroke, although further studies are needed to confirm their efficacy and safety in clinical settings.

Deltamethrin-Evoked ER Stress Promotes Neuroinflammation in the Adult Mouse Hippocampus

Endoplasmic reticulum (ER) stress and neuroinflammation are involved in the pathogenesis of many neurodegenerative disorders. Previously, we reported that exposure to pyrethroid insecticide deltamethrin causes hippocampal ER stress apoptosis, a reduction in neurogenesis, and learning deficits in adult male mice. Recently, we found that deltamethrin exposure also increases the markers of neuroinflammation in BV2 cells. Here, we investigated the potential mechanistic link between ER stress and neuroinflammation following exposure to deltamethrin. We found that repeated oral exposure to deltamethrin (3 mg/kg) for 30 days caused microglial activation and increased gene expressions and protein levels of TNF-α, IL-1β, IL-6, gp91phox, 4HNE, and iNOS in the hippocampus. These changes were preceded by the induction of ER stress as the protein levels of CHOP, ATF-4, and GRP78 were significantly increased in the hippocampus. To determine whether induction of ER stress triggers the inflammatory response, we performed an additional experiment with mouse microglial cell (MMC) line. MMCs were treated with 0-5 µM deltamethrin for 24-48 h in the presence or absence of salubrinal, a pharmacological inhibitor of the ER stress factor eIF2α. We found that salubrinal (50 µM) prevented deltamethrin-induced ER stress, as indicated by decreased levels of CHOP and ATF-4, and attenuated the levels of GSH, 4-HNE, gp91phox, iNOS, ROS, TNF-α, IL-1β, and IL-6 in MMCs. Together, these results demonstrate that exposure to deltamethrin leads to ER stress-mediated neuroinflammation, which may subsequently contribute to neurodegeneration and cognitive impairment in mice.

Effects of prenatal exposure to inflammation coupled with prepubertal stress on prefrontal white matter structure and related molecules in adult mouse offspring

Maternal immune activation (MIA) by inflammatory agents such as lipopolysaccharide (LPS) and prepubertal stress (PS) may individually and collectively affect the central nervous system (CNS) during adulthood. Here, we intended to assess the effects of MIA, alone or combined with PS, on prefrontal white matter structure and its related molecules in adult mice offspring. Pregnant mice received either an i.p. dose of LPS (50 μg/kg) on gestational day 17 (GD17) or normal saline. Their pups were exposed to stress from postnatal days (PD) 30 to PD38 or no stress during prepubertal development. We randomly chose 56-day-old male offspring (n = 2 offspring per mother) from each group and isolated their prefrontal areas according to relevant protocols. The tissue samples were prepared for structural, histological, and molecular examinations. The LPS + stress group had evidence of increased damage in the white matter structures compared to the control, stress, and LPS groups (p < 0.05). The LPS + stress group also had significant downregulation of the genes involved in white matter formation (Sox10, Olig1, myelin regulatory factor, and Wnt compared with the control, stress, and LPS groups (p < 0.05). In conclusion, although each manipulation individually resulted in small changes in myelination, their combined effects were more pronounced. These changes were parallel to abnormal expression levels of the molecular factors that contribute to myelination.

Secondary Mechanisms of Neurotrauma: A Closer Look at the Evidence

Traumatic central nervous system injury is a leading cause of neurological injury worldwide. While initial neuroresuscitative efforts are focused on ameliorating the effects of primary injury through patient stabilization, secondary injury in neurotrauma is a potential cause of cell death, oxidative stress, and neuroinflammation. These secondary injuries lack defined therapy. The major causes of secondary injury in neurotrauma include endoplasmic reticular stress, mitochondrial dysfunction, and the buildup of reactive oxygen or nitrogenous species. Stress to the endoplasmic reticulum in neurotrauma results in the overactivation of the unfolded protein response with subsequent cell apoptosis. Mitochondrial dysfunction can lead to the release of caspases and the buildup of reactive oxygen species; several characteristics make the central nervous system particularly susceptible to oxidative damage. Together, endoplasmic reticulum, mitochondrial, and oxidative stress can have detrimental consequences, beginning moments and lasting days to months after the primary injury. Understanding these causative pathways has led to the proposal of various potential treatment options.

Endoplasmic Reticulum Stress and Its Role in Homeostasis and Immunity of Central and Peripheral Neurons

Neuronal cells are specialists for rapid transfer and translation of information. Their electrical properties relay on a precise regulation of ion levels while their communication via neurotransmitters and neuropeptides depends on a high protein and lipid turnover. The endoplasmic Reticulum (ER) is fundamental to provide these necessary requirements for optimal neuronal function. Accumulation of misfolded proteins in the ER lumen, reactive oxygen species and exogenous stimulants like infections, chemical irritants and mechanical harm can induce ER stress, often followed by an ER stress response to reinstate cellular homeostasis. Imbedded between glial-, endothelial-, stromal-, and immune cells neurons are constantly in communication and influenced by their local environment. In this review, we discuss concepts of tissue homeostasis and innate immunity in the central and peripheral nervous system with a focus on its influence on ER stress, the unfolded protein response, and implications for health and disease.

Analysis of Potential Hub Genes for Neuropathic Pain Based on Differential Expression in Rat Models

Objective

Neuropathic pain (NP) is a type of intractable chronic pain with complicated etiology. The exact molecular mechanism underlying NP remains unclear. In this study, we searched for molecular biomarkers of NP.

Methods

Differentially expressed genes (DEGs) were predicted by analyzing three NP-related microarray datasets in Gene Expression Omnibus with robust rank aggregation. A weighted gene coexpression network analysis was conducted to construct a network of differentially expressed genes, followed by the evaluation of correlations between gene sets and the determination of hub genes. The candidate genes from the key module were identified using a gene set enrichment analysis.

Results

In total, 353 upregulated and 383 downregulated genes were obtained, among which five hub genes were determined to be related to pain phenotypes. Reverse transcription-quantitative polymerase chain reaction was performed to verify the expression of these hub genes in the dorsal root ganglia of rats with spared nerve injury, which revealed the decreased expression of EMC4. Hence, EMC4 was defined as a biomarker for NP development.

Conclusions

The results of this study form a basis for further research into the mechanism of NP development and are expected to aid in the development of novel therapeutic strategies.

Endoplasmic Reticulum Stress-Associated Neuronal Death and Innate Immune Response in Neurological Diseases

Neuronal death and inflammatory response are two common pathological hallmarks of acute central nervous system injury and chronic degenerative disorders, both of which are closely related to cognitive and motor dysfunction associated with various neurological diseases. Neurological diseases are highly heterogeneous; however, they share a common pathogenesis, that is, the aberrant accumulation of misfolded/unfolded proteins within the endoplasmic reticulum (ER). Fortunately, the cell has intrinsic quality control mechanisms to maintain the proteostasis network, such as chaperone-mediated folding and ER-associated degradation. However, when these control mechanisms fail, misfolded/unfolded proteins accumulate in the ER lumen and contribute to ER stress. ER stress has been implicated in nearly all neurological diseases. ER stress initiates the unfolded protein response to restore proteostasis, and if the damage is irreversible, it elicits intracellular cascades of death and inflammation. With the growing appreciation of a functional association between ER stress and neurological diseases and with the improved understanding of the multiple underlying molecular mechanisms, pharmacological and genetic targeting of ER stress are beginning to emerge as therapeutic approaches for neurological diseases.

Effectiveness of crocin of saffron (Crocus sativus L.) against chemotherapy-induced peripheral neuropathy: A randomized, double-blind, placebo-controlled clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

Chemotherapy-induced peripheral neuropathy (CIPN) is one of the complications vexes patients treated with anti-cancer agents. Saffron has been demonstrated to attenuate symptoms of peripheral neuropathy in animal models. Also, there is a published clinical trial that investigated the pain relieving effect of saffron following nationally accepted rules and concluded that saffron was successful in alleviating pain symptoms in patients suffering from fibromyalgia.

AIM OF THE STUDY

We aimed to determine the efficacy of crocin as a constituent of saffron in CIPN as the first report.

MATERIALS AND METHODS

One hundred and seventy-seven enrolled eligible patients (between December 2018 and March 2020) for study entry were cases demonstrating mild to severe symptomatic CIPN for at least a month. These cases were randomly assigned to two main groups including 15 mg crocin tablet, bid (30 mg total daily target dose) and placebo tablet for 8 weeks. A crossover study was performed with a 2-week washout period. Patient outcomes were measured once a week for 8 consecutive weeks.

RESULTS

Grade of sensory, motor and neuropathic pain decreased considerably and significantly in the crocin group compared with placebo (P < 0.05). Observed toxicities were mild and adverse effects had no significant differences between the two groups (P > 0.05).

CONCLUSIONS

Crocin considerably seems to be effective for relieving symptoms of CIPN in cancer patients receiving chemotherapy agents. However, further studies are needed about crocin with its beneficial neuropharmacological effects and lower adverse effects than the chemical agents such as antidepressants, lamotrigine, and gabapentin.

Protective effects of crocin on testicular torsion/detorsion in rats

Oxidative stress, caused by extreme accumulation of un-scavenged reactive oxygen species, plays an integral role in the Ischemia-Reperfusion (I/R) injury to the testicles following testicular torsion. The current research aimed to examine the protective effects of crocin as a natural antioxidant on testicular I/R injury in rats. Animals were divided randomly into five groups (seven each): (1) sham group, (2) torsion/detorsion (T/D) group, (3) intact group with 100 mg/kg crocin, (4) and (5) T/D groups followed by treatment with two different doses of crocin (50 and 100 mg/kg (IP)). I/R injury was induced by 720° clockwise torsion of the left testicles for 2 h. After 24 h of reperfusion, blood samples and epididymal sperms were collected to measure biochemical (GPx, SOD, and MDA), hormonal (testosterone), and sperm parameters (total sperm recovery, motility, viability, and morphology). Moreover, affected testicles were subjected to histopathology examination. I/R injury caused a significant reduction in sperm characteristics (except for morphology) (P < 0.05), which could not be significantly improved by crocin administration at either dose (P > 0.05). Johnsen's testicular score, mean seminiferous tubular diameter, and germinal epithelial cell thickness were significantly decreased in the T/D group compared to the intact and sham groups. However, crocin could significantly improve the histopathological parameters in both treatment groups compared to the T/D group (P < 0.05). T/D reduced SOD and GPx activity and testosterone level significantly (except for GPx) compared to the sham group (P < 0.05). However, crocin administration could significantly reverse them. Also, crocin reduced the amount of MDA significantly in the high-dose treatment group in comparison to T/D group (P < 0.05). The results of the current study revealed that crocin could be a promising agent to protect against I/R injury following surgical correction of the testicular torsion.

The role of endoplasmic reticulum stress in astrocytes

Astrocytes are glial cells that support neurological function in the central nervous system (CNS), in part, by providing structural support for neuronal synapses and blood vessels, participating in electrical and chemical transmission, and providing trophic support via soluble factors. Dysregulation of astrocyte function contributes to neurological decline in CNS diseases. Neurological diseases are highly heterogeneous but share common features of cellular stress including the accumulation of misfolded proteins. Endoplasmic reticulum (ER) stress has been reported in nearly all neurological and neurodegenerative diseases. ER stress occurs when there is an accumulation of misfolded proteins in the ER lumen and the protein folding demand of the ER is overwhelmed. ER stress initiates the unfolded protein response (UPR) to restore homeostasis by abating protein translation and, if the cell is irreparably damaged, initiating apoptosis. Although protein aggregation and misfolding in neurological disease has been well described, cell-specific contributions of ER stress and the UPR in physiological and disease states are poorly understood. Recent work has revealed a role for active UPR signaling that may drive astrocytes toward a maladaptive phenotype in various model systems. In response to ER stress, astrocytes produce inflammatory mediators, have reduced trophic support, and can transmit ER stress to other cells. This review will discuss the current known contributions and consequences of activated UPR signaling in astrocytes.

Brain glycogen serves as a critical glucosamine cache required for protein glycosylation

Glycosylation defects are a hallmark of many nervous system diseases. However, the molecular and metabolic basis for this pathology is not fully understood. In this study, we found that N-linked protein glycosylation in the brain is metabolically channeled to glucosamine metabolism through glycogenolysis. We discovered that glucosamine is an abundant constituent of brain glycogen, which functions as a glucosamine reservoir for multiple glycoconjugates. We demonstrated the enzymatic incorporation of glucosamine into glycogen by glycogen synthase, and the release by glycogen phosphorylase by biochemical and structural methodologies, in primary astrocytes, and in vivo by isotopic tracing and mass spectrometry. Using two mouse models of glycogen storage diseases, we showed that disruption of brain glycogen metabolism causes global decreases in free pools of UDP-N-acetylglucosamine and N-linked protein glycosylation. These findings revealed fundamental biological roles of brain glycogen in protein glycosylation with direct relevance to multiple human diseases of the central nervous system.

Scale-Up Preparation of Crocins I and II from Gardeniajasminoides by a Two-Step Chromatographic Approach and Their Inhibitory Activity Against ATP Citrate Lyase

Crocins are highly valuable natural compounds for treating human disorders, and they are also high-end spices and colorants in the food industry. Due to the limitation of obtaining this type of highly polar compound, the commercial prices of crocins I and II are expensive. In this study, macroporous resin column chromatography combined with high-speed counter-current chromatography (HSCCC) was used to purify crocins I and II from natural sources. With only two chromatographic steps, both compounds were simultaneously isolated from the dry fruit of Gardenia jasminoides, which is a cheap herbal medicine distributed in a number of countries. In an effort to shorten the isolation time and reduce solvent usage, forward and reverse rotations were successively utilized in the HSCCC isolation procedure. Crocins I and II were simultaneously obtained from a herbal resource with high recoveries of 0.5% and 0.1%, respectively, and high purities of 98.7% and 99.1%, respectively, by HPLC analysis. The optimized preparation method was proven to be highly efficient, convenient, and cost-effective. Crocins I and II exhibited inhibitory activity against ATP citrate lyase, and their IC₅₀ values were determined to be 36.3 ± 6.24 and 29.7 ± 7.41 μM, respectively.

Nutritional and health beneficial properties of saffron (Crocus sativus L): a comprehensive review

Saffron (Crocus sativus L., family Iridaceae) is used traditionally for medicinal purpose in Chinese, Ayurvedic, Persian and Unani medicines. The bioactive constituents such as apocarotenoids, monoterpenoids, flavonoids, phenolic acids and phytosterols are widely investigated in experimental and clinical studies for a wide range of therapeutic effects, especially on the nervous system. Some of the active constituents of saffron have high bioavailability and bioaccessibility and ability to pass the blood-brain barrier. Multiple preclinical and clinical studies have supported neuroprotective, anxiolytic, antidepressant, learning and memory-enhancing effect of saffron and its bioactive constituents (safranal, crocin, and picrocrocin). Thus, this plant and its active compounds could be a beneficial medicinal food ingredient in the formation of drugs targeting nervous system disorders. This review focuses on phytochemistry, bioaccessibility, bioavailability, and bioactivity of phytochemicals in saffron. Furthermore, the therapeutic effect of saffron against different nervous system disorders has also been discussed in detail.

Role of Muscarinic Receptors in Hypoalgesia Induced by Crocin in Neuropathic Pain Rats

Objective

Crocin as an important constituent of saffron has antineuropathic pain properties; however, the exact mechanism of this effect is not known. The aim of this study was whether the hypoalgesic effect of crocin can be exerted through muscarinic receptors.

Materials and Methods

In the present project, 36 male Wistar rats (200 ± 20 g) were used. Animals randomly divided into six groups (sham, neuropathy, neuropathy + crocin, neuropathy + atropine 0.5 mg/kg, neuropathy + atropine 1 mg/kg, and neuropathy + atropine 1 mg/kg + crocin). Neuropathy was induced by the chronic constriction injury (CCI) method on the sciatic nerve. Crocin and atropine was administered intraperitoneally during 14 days following the 14^th day after surgery. Pain response was detected every three days, two hours after each injection and 3 days following last injection. Mechanical allodynia and thermal hyperalgesia were detected using the Von Frey filaments and plantar test device, respectively.

Results

CCI significantly reduced the paw withdrawal response to mechanical and thermal stimulus (P < 0.01 and P < 0.05, respectively). Crocin therapy significantly reduced mechanical allodynia and thermal hyperalgesia induced by CCI (P < 0.05). Atropine pretreatment significantly blocked the hypoalgesic effect of crocin (P < 0.05 in mechanical allodynia and P < 0.01 in thermal hyperalgesia). Fourteen days administration of atropine alone at a dose of 0.5 mg/kg but not 1 mg/kg significantly reduced CCI-induced mechanical allodynia at day 30 after surgery.

Conclusion

Crocin significantly decreased CCI-induced neuropathic pain. The hypoalgesic effect of crocin was blocked by atropine pretreatment, which indicates an important role for muscarinic receptors in the effect of crocin.

Effects of Retinal Transcription Regulation After GB20 Needling Treatment in Retina With Optic Neuritis

Optic neuritis (ON) is one of the most frequent symptoms of multiple sclerosis (MS) that results in progressive loss of axons and neurons. In clinical trials of Traditional Chinese Medicine, needling at the GB20 acupoint has been widely used for the treatment of ocular diseases, including ON. However, the molecular mechanisms of needling at this site are still unclear. In this study, we generated an experimental autoimmune encephalomyelitis (EAE) mouse model and investigated the effects of needling treatment at the GB20 acupoint on retina with EAE-associated ON. RNA sequencing of the retinal transcriptome revealed that, of the 234 differentially expressed genes induced by ON, 100 genes were upregulated, and 134 genes were downregulated by ON, while needling at the GB20 acupoint specifically reversed the expression of 21 genes compared with control treatment at GV16 acupoint. Among the reversed genes, Nr4a3, Sncg, Uchl1, and Tppp3 were involved in axon development and regeneration and were downregulated by ON, indicating the beneficial effect of needling at GB20. Further gene ontology (GO) enrichment analysis revealed that needling at GB20 affected the molecular process of Circadian rhythm in mouse retina with ON. Our study first reported that needling treatment after ON at the GB20 acupoint regulated gene expression of the retina and reversed the expression of downregulated axon development-related genes. This study also demonstrated that GV16 was a perfect control treatment site for GB20 in animal research. Our study provided a scientific basis for needling treatments at GB20 for ocular diseases.

Neuroprotective Potency of Saffron Against Neuropsychiatric Diseases, Neurodegenerative Diseases, and Other Brain Disorders: From Bench to Bedside

The increasing morbidity rates of brain disorders and conditions such as anxiety, depression, Alzheimer’s disease, and Parkinson’s disease have become a severe problem in recent years. Although researchers have spent considerable time studying these diseases and reported many positive outcomes, there still are limited drugs available for their treatment. As a common traditional Chinese medicine (TCM), saffron was employed to treat depression and some other inflammatory diseases in ancient China due to its antioxidant, anti-inflammatory, and antidepressant properties. In modern times, saffron and its constituents have been utilized, alone and in TCM formulas, to treat neuropsychiatric and neurodegenerative diseases. In this review, we mainly focus on recent clinical and preclinical trials of brain disorders in which saffron was applied, and summarize the neuroprotective properties of saffron and its constituents from chemical, pharmacokinetic, and pharmacological perspectives. We discuss the properties of saffron and its constituents, as well as their applications for treating brain disorders; we hope that this review will serve as a comprehensive reference for studies aimed at developing therapeutic drugs based on saffron.

Novel Neuroprotective Potential of Crocin in Neurodegenerative Disorders: An Illustrated Mechanistic Review

Neurodegenerative disorders are characterized by mitochondrial dysfunction and subsequently oxidative stress, inflammation, and apoptosis that contribute to neuronal cytotoxicity and degeneration. Recent studies reported that crocin, a carotenoid chemical compound common in crocus and gardenia flowers, has protective effects in neurodegenerative disorders due to its anti-oxidative, anti-inflammatory, and anti-apoptotic properties in the nervous system. This article reviews the new experimental, clinical, and pharmacological studies on the neuroprotective properties of crocin and its potential mechanisms to modulate metabolic oxidative stress and inflammation in neurodegenerative disorders.

Suppressor capacity of copper nanoparticles biosynthesized using Crocus sativus L. leaf aqueous extract on methadone-induced cell death in adrenal phaeochromocytoma (PC12) cell line

In this research, we prepared and formulated a neuroprotective supplement (copper nanoparticles in aqueous medium utilizing Crocus sativus L. Leaf aqueous extract) for determining its potential against methadone-induced cell death in PC12. The results of chemical characterization tests i.e., FE-SEM, FT-IR, XRD, EDX, TEM, and UV–Vis spectroscopy revealed that the study showed that copper nanoparticles were synthesized in the perfect way possible. In the TEM and FE-SEM images, the copper nanoparticles were in the mean size of 27.5 nm with the spherical shape. In the biological part of the present research, the Rat inflammatory cytokine assay kit was used to measure the concentrations of inflammatory cytokines. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) test was used to show DNA fragmentation and apoptosis. Caspase-3 activity was assessed by the caspase activity colorimetric assay kit and mitochondrial membrane potential was studied by Rhodamine123 fluorescence dye. Also, the cell viability of PC12 was measured by trypan blue assay. Copper nanoparticles-treated cell cutlers significantly (p ≤ 0.01) decreased the inflammatory cytokines concentrations, caspase-3 activity, and DNA fragmentation and they raised the cell viability and mitochondrial membrane potential in the high concentration of methadone-treated PC12 cells. The best result of neuroprotective properties was seen in the high dose of copper nanoparticles i.e., 4 µg. According to the above results, copper nanoparticles containing C. sativus leaf aqueous extract can be used in peripheral nervous system treatment as a neuroprotective promoter and central nervous system after approving in the clinical trial studies in humans.

Effect of crocin on morphine tolerance and serum BDNF levels in a rat model of neuropathic pain

BACKGROUND

Chronic use of morphine treatment for neuropathic pain leads to morphine-induced analgesic tolerance. Crocin contained in Crocus sativus L., exerts anti-inflammatory and analgesic effects. This study examined the effects of crocin on morphine tolerance and serum BDNF levels on neuropathic pain induced by chronic constriction injury (CCI) in rats.

METHODS

CCI model of neuropathic pain was done in male Wistar rats (200-250 g). Rats were treated with crocin (15 or 30 mg/kg, intraperitoneally) alone or simultaneously with morphine (10 mg/kg, subcutaneously) during or after induction of CCI. Pain behavioral responses including mechanical allodynia and thermal hyperalgesia were measured from days of 15-27 after CCI. Then, rats were evaluated for serum BDNF levels on days 14 and/or 27.

RESULTS

We found that morphine tolerance developed after the induction of neuropathic pain. The injection of crocin (15 and 30 mg/kg) was able to enhance analgesic effect of morphine by reduction of mechanical allodynia on days 15-27 post-surgery in CCI rats. While preemptive administration of crocin at a lower dose (15 mg/kg) maintained the analgesic effect of morphine. Morphine injection and/or co-administration with crocin (15, 30 mg/kg) decreased serum BDNF levels in CCI rats.

CONCLUSION

These findings indicate that crocin may have a therapeutic effect to maintain morphine analgesic efficacy and also to prevent the development of morphine tolerance in neuropathic pain, but probably not through BDNF.

Unfolded protein response in myelin disorders

Activation of the unfolded protein response in response to endoplasmic reticulum stress preserves cell viability and function under stressful conditions. Nevertheless, persistent, unresolvable activation of the unfolded protein response can trigger apoptosis to eliminate stressed cells. Recent studies show that the unfolded protein response plays an important role in the pathogenesis of various disorders of myelin, including multiples sclerosis, Charcot-Marie-Tooth disease, Pelizaeus-Merzbacher disease, vanishing white matter disease, spinal cord injury, tuberous sclerosis complex, and hypoxia-induced perinatal white matter injury. In this review we summarize the current literature on the unfolded protein response and the evidence for its role in the pathogenesis of myelin disorders.

Therapeutic effects of Crocin in autoimmune diseases: A review

The immune system when acts against selfmolecules results in an imbalance in immunologic tolerance leading to the development of several autoimmune diseases (ADs) such as rheumatoid arthritis, asthma, ulcerative colitis, type 1 diabetes, and multiple sclerosis. Improved recognition of the mechanisms of ADs has led to the advancement of the management of these diseases. The principal mediators of ADs are inflammatory molecules. The herbal medicines due to their antioxidant and antiinflammatory properties have an important role in the management of ADs. Crocin is the principal chemical component extracted from saffron, which is a medicinal plant. This review focuses on the therapeutic effects of Crocin in various ADs.

Janus Kinase 1 Is Required for Transcriptional Reprograming of Murine Astrocytes in Response to Endoplasmic Reticulum Stress

Neurodegenerative diseases are associated with the accumulation of misfolded proteins in the endoplasmic reticulum (ER), leading to ER stress. To adapt, cells initiate the unfolded protein response (UPR). However, severe or unresolved UPR activation leads to cell death and inflammation. The UPR is initiated, in part, by the trans-ER membrane kinase PKR-like ER kinase (PERK). Recent evidence indicates ER stress and inflammation are linked, and we have shown that this involves PERK-dependent signaling via Janus Kinase (JAK) 1. This signaling provokes the production of soluble inflammatory mediators such as interleukin-6 (IL-6) and chemokine C-C motif ligand 2 (CCL2). We, therefore, hypothesized that JAK1 may control widespread transcriptional changes in response to ER stress. Here, using RNA sequencing of primary murine astrocytes, we demonstrate that JAK1 regulates approximately 10% of ER stress-induced gene expression and is required for a subset of PERK-dependent genes. Additionally, ER stress synergizes with tumor necrosis factor-α (TNF-α) to drive inflammatory gene expression in a JAK1-dependent fashion. We identified that JAK1 contributes to activating transcription factor (ATF) 4-dependent gene expression, including expression of the genes growth arrest and DNA damage (GADD) 45α and tribbles (TRIB) 3 that have not previously been associated with JAK signaling. While these genes are JAK1 dependent in response to ER stress, expression of GADD45α and TRIB3 are not induced by the JAK1-activating cytokine, oncostatin M (OSM). Transcriptomic analysis revealed that JAK1 drives distinct transcriptional programs in response to OSM stimulation versus ER stress. Interestingly, JAK1-dependent genes induced by ER stress in an ATF4-dependent mechanism were unaffected by small molecule inhibition of JAK1, suggesting that, in response to UPR activation, JAK1 initiates gene expression using non-canonical mechanisms. Overall, we have identified that JAK1 is a major regulator of ER stress-induced gene expression.

The IRE1α Arm of UPR Regulates Muscle Cells Immune Characters by Restraining p38 MAPK Activation

Skeletal muscle repair and systemic inflammation/immune responses are linked to endoplasmic reticulum stress (ER stress) pathways in myopathic muscle, and muscle cells play an active role in muscular immune reactions by exhibiting immunological characteristics under persistent proinflammation stimuli. Whether ER stress affects the intrinsic immunological capacities of myocytes in the inflammatory milieu, as it does to immune cells, and which arms of the unfolded protein response (UPR) mainly participate in these processes remain mostly unknown. We investigated this issue and showed that inflammatory stimuli can induce the activation of the protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) and inositol-requiring enzyme 1α (IRE1α) arms of the UPR in myocytes both in vivo and in vitro. UPR stressor administration reversed the increased IFN-γ-induced expression of the MHC-II molecule H2-Ea, the MHC-I molecule H-2K^b, toll-like receptor 3 (TLR3) and some proinflammatory myokines in differentiated primary myotubes in vitro. However, further IRE1α inhibition thoroughly corrected the trend in the UPR stressor-triggered suppression of immunobiological molecules. In IFN-γ-treated myotubes, dramatic p38 MAPK activation was observed under IRE1α inhibitory conditions, and the pharmacological inhibition of p38 reversed the immune molecule upregulation induced by IRE1α inhibition. In parallel, our coculturing system verified that the ovalbumin (OVA) antigen presentation ability of inflamed myotubes to OT-I T cells was enhanced by IRE1α inhibition, but was attenuated by further p38 inhibition. Thus, the present findings demonstrated that p38 MAPK contributes greatly to IRE1α arm-dependent immunobiological suppression in myocytes under inflammatory stress conditions.

White matter loss and oligodendrocyte dysfunction in HIV: A consequence of the infection, the antiretroviral therapy or both?

While the severe cognitive effects of HIV-associated dementia have been reduced by combined antiretroviral therapy (cART), nearly half of HIV-positive (HIV+) patients still suffer from some form of HIV-Associated Neurocognitive Disorders (HAND). While frank neuronal loss has been dramatically reduced in HAND patients, white matter loss, including dramatic thinning of the corpus callosum, and loss of volume and structural integrity of myelin persists despite viral control by cART. It remains unclear whether changes in white matter underlie the clinical manifestation seen in patients or whether they are the result of persistent viral reservoirs, remnant damage from the acute infection, the antiretroviral compounds used to treat HIV, secondary effects due to peripheral toxicities or other associated comorbid conditions. Both HIV infection itself and its treatment with antiretroviral drugs can induce metabolic syndrome, lipodystrophy, atherosclerosis and peripheral neuropathies by increased oxidative stress, induction of the unfolded protein response and dysregulation of lipid metabolism. These virally and/or cART-induced processes can also cause myelin loss in the CNS. This review aims to highlight existing data on the contribution of white matter damage to HAND and explore the mechanisms by which HIV infection and its treatment contribute to persistence of white matter changes in people living with HIV currently on cART.

Antioxidant Properties of Crocus Sativus L. and Its Constituents and Relevance to Neurodegenerative Diseases; Focus on Alzheimer's and Parkinson's Disease

BACKGROUND

Reactive oxygen species and reactive nitrogen species, which are collectively called reactive oxygen-nitrogen species, are the inevitable by-products of cellular metabolic redox reactions, such as oxidative phosphorylation in the mitochondrial respiratory chain, phagocytosis, reactions of biotransformation of exogenous and endogenous substrata in endoplasmic reticulum, eicosanoid synthesis, and redox reactions in the presence of metal with variable valence. Among medicinal plants, there is growing interest in Crocus Sativus L. It is a perennial, stemless herb, belonging to Iridaceae family, cultivated in various countries such as Greece, Italy, Spain, Israel, Morocco, Turkey, Iran, India, China, Egypt and Mexico.

OBJECTIVE

The present study aims to address the protective role of Crocus Sativus L. in neurodegeneration with an emphasis in Parkinson's and Alzheimer's disease.

MATERIALS AND METHODS

An electronic literature search was conducted by two of the authors from 1993 to August 2017. Original articles and systematic reviews (with or without meta-analysis), as well as case reports were selected. Titles and abstracts of papers were screened by a third reviewer to determine whether they met the eligibility criteria, and full texts of the selected articles were retrieved.

RESULTS

Hence, the authors focused on the literature concerning the role of Crocus Sativus L. on its anti-oxidant and neuroprotective properties.

CONCLUSION

Literature findings represented in current review herald promising results for using Crocus Sativus L. and/or its active constituents as antioxidants, anti-inflammatory, and neuroprotective agents.

Neural Cell Responses Upon Exposure to Human Endogenous Retroviruses

Human endogenous retroviruses (HERVs) are ancient retroviral elements, which invaded the human germ line several million years ago. Subsequent retrotransposition events amplified these sequences, resulting in approximately 8% of the human genome being composed of HERV sequences today. These genetic elements, normally dormant within human genomes, can be (re)-activated by environmental factors such as infections with other viruses, leading to the expression of viral proteins and, in some instances, even to viral particle production. Several studies have shown that the expression of these retroviral elements correlates with the onset and progression of neurological diseases such as multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS). Further studies provided evidence on additional roles for HERVs in schizophrenia (SCZ). Since these diseases are still not well understood, HERVs might constitute a new category of pathogenic components that could significantly change our understanding of these pathologies. Moreover, knowledge about their mode of action might also help to develop novel and more powerful approaches for the treatment of these complex diseases. Therefore, the main scope of this review is a description of the current knowledge on the involvement of HERV-W and HERV-K in neurological disease specifically focusing on the effects they exert on neural cells of the central nervous system.

Protective properties of the aqueous extract of saffron (Crocus sativus L.) in ischemic stroke, randomized clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

Crocus sativus L. has been used throughout the world in traditional medicine as a treatment for neurological disorders such as depression. Growing attention is currently being paid to the use of neuroprotective agents in ischemic strokes.

AIM OF THE STUDY

This study assed the effect of saffron as a neuroprotective natural product in cerebral ischemia in human.

STUDY DESIGN

Patients with acute ischemic stroke were randomly allocated to receive either routine stroke care (control group, n = 20) or routine care plus aqueous extract of saffron capsule (200 mg/day) (saffron-treated group, n = 19). Both groups were monitored during their four-day hospital stay and the three-month follow-up period. The groups were compared in terms of short- and long-term effects of saffron capsules using the National Institute of Health Stoke Scale (NIHSS), Barthel Scale, and serum neuron specific enolase (NSE), Brain-derived neurotrophic factor (BDNF), S100 levels.

RESULTS

Based on the NIHSS, the severity of stroke during the first four days was significantly lower in the saffron-treated group than in the control group (P < 0.05). Compared to the levels on the first day, serum NSE and s100 levels were significantly decreased and BDNF concentration was increased in the saffron-treated group on the fourth day. Also, our results showed there was a negative significant non-linear cubic regression between BDNF concentration and score of NIHSS. At the end of the three-month follow-up period, the mean Barthel index was significantly higher in the saffron-treated group than in the control group (P < 0.001).

CONCLUSION

The results of this study confirmed the short and long-term neuroprotective effects of aqueous extract of saffron on ischemic stroke in humans.

Moderating effects of crocin on some stress oxidative markers in rat brain following demyelination with ethidium bromide

Background

The purpose of this study was to investigate the effects of Crocin on oxidative markers (GPx, SOD, MDA) in animal model of demyelination with Ethidium bromide (EB).

Methods

Female Wistar rats were assigned in to 4 groups; Sham, with no receiving any agent (Sham), Sham Operated group with injection of EB into the brain received no agent (SO), Sham Treatment group with injection of EB and receiving PBS as vehicle and Treatment group with injection of EB and receiving Crocin (100 mg/kg). Demyelination was induced by single dose injection of 10 μl of EB 0.1% into the Cisterna magna of the brain. Crocin was diluted and applied to each animal for 21 days, once per day gavage. The levels of oxidative markers (GPx, SOD and MDA) were measured by related standard kits. Data were analyzed by paired t-test and ANOVA with post hoc test.

Results

The results showed that crocin decreases the levels of GPx and SOD significantly as well as MDA level after 21 days (α ≤ 0.05). In addition, results showed that there were significant differences in the GPx, SOD and MDA levels between all groups at post treatment phase (α ≤ 0.05).

Conclusion

It can be concluded that crocin can moderate the level of oxidative markers after demyelination of the brain cells in MS cases. Due to this effect, crocin can be considered as an effective anti-oxidant in management of degenerative nervous system diseases.

Oligodendrocyte-specific ATF4 inactivation does not influence the development of EAE

Background

Multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), are inflammatory demyelinating and neurodegenerative diseases of the CNS. Although recent studies suggest the neuroprotective effects of oligodendrocytes in neurodegenerative diseases, it remains unknown whether oligodendrocyte death induced by inflammatory attacks contributes to neurodegeneration in MS and EAE. Upon endoplasmic reticulum (ER) stress, activation of pancreatic ER kinase (PERK) promotes cell survival through induction of activating transcription factor 4 (ATF4) by phosphorylating eukaryotic translation initiation factor 2α (eIF2α). We have generated a mouse model that allows for temporally controlled activation of PERK specifically in oligodendrocytes. Our previous study has demonstrated that PERK activation specifically in oligodendrocytes attenuates EAE disease severity and ameliorates EAE-induced oligodendrocyte apoptosis, demyelination, and axon degeneration, without altering inflammation.

Methods

We determined whether oligodendrocyte-specific PERK activation reduced neuron loss in the CNS of EAE mice using the mouse model that allows for temporally controlled activation of PERK specifically in oligodendrocytes. We further generated a mouse model that allows for inactivation of ATF4 specifically in oligodendrocytes, and determined the effects of ATF4 inactivation in oligodendrocytes on mice undergoing EAE.

Results

We showed that protection of oligodendrocytes resulting from PERK activation led to attenuation of neuron loss in the CNS gray matter of EAE mice. Surprisingly, we found that ATF4 inactivation specifically in oligodendrocytes did not alter EAE disease severity and had no effect on oligodendrocyte loss, demyelination, axon degeneration, neuron loss, and inflammation in EAE mice.

Conclusions

These findings suggest the neuroprotective effects of PERK activation in oligodendrocytes in EAE, and rule out the involvement of ATF4 in oligodendrocytes in the development of EAE. These results imply that the protective effects of PERK activation in oligodendrocytes in MS and EAE are not mediated by ATF4.

Neuron-specific PERK inactivation exacerbates neurodegeneration during experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), are chronic inflammatory demyelinating and neurodegenerative diseases of the CNS. Although neurodegeneration is the major contributor to chronic disability in MS, mechanisms governing the viability of axons and neurons in MS and EAE remain elusive. Data indicate that activation of pancreatic endoplasmic reticulum kinase (PERK) influences, positively or negatively, neuron and axon viability in various neurodegenerative diseases through induction of ATF4. In this study, we demonstrate that the PERK pathway was activated in neurons during EAE. We found that neuron-specific PERK inactivation impaired EAE resolution and exacerbated EAE-induced axon degeneration, neuron loss, and demyelination. Surprisingly, neuron-specific ATF4 inactivation did not alter EAE disease course or EAE-induced axon degeneration, neuron loss, and demyelination. These results suggest that PERK activation in neurons protects axons and neurons against inflammation in MS and EAE through ATF4-independent mechanisms.

The physiology of foamy phagocytes in multiple sclerosis

Multiple sclerosis (MS) is a chronic disease of the central nervous system characterized by massive infiltration of immune cells, demyelination, and axonal loss. Active MS lesions mainly consist of macrophages and microglia containing abundant intracellular myelin remnants. Initial studies showed that these foamy phagocytes primarily promote MS disease progression by internalizing myelin debris, presenting brain-derived autoantigens, and adopting an inflammatory phenotype. However, more recent studies indicate that phagocytes can also adopt a beneficial phenotype upon myelin internalization. In this review, we summarize and discuss the current knowledge on the spatiotemporal physiology of foamy phagocytes in MS lesions, and elaborate on extrinsic and intrinsic factors regulating their behavior. In addition, we discuss and link the physiology of myelin-containing phagocytes to that of foamy macrophages in other disorders such atherosclerosis.

C/EBP homologous protein investigation in the serum and cerebro-spinal fluid of relapsing-remitting multiple sclerosis patients

The exact determination of endoplasmic reticulum (ER) stress-associated proteins is not completely elucidated in the multiple sclerosis (MS) patients. We measured CHOP concentrations in the serum and cerebro-spinal fluid (CSF) of relapsing-remitting MS (RRMS) patients (n = 20) in comparison with the non-MS control group (n = 20) to determine whether this marker could be detected in the body fluids of RRMS patients. CHOP marker was not detectable in all harvested CSF samples. However, its levels were detectable in all serums harvested from both non-MS and RRMS patients and its levels in the latter group were not significantly higher than those of the non-MS control group (P value = 0.265). CHOP was not detectable in the CSF of RRMS patients in spite of the recent reports on the RRMS autopsies. Additionally, there were not any significant correlations (Spearman's correlation) between both of EDSS score and age with CHOP serum concentrations in all subjects.

Protective effect of crocin on ultraviolet B‑induced dermal fibroblast photoaging

Ultraviolet B (UVB) radiation induces the production of reactive oxygen species (ROS), resulting in the aging of dermal fibroblasts. Crocin, a bioactive constituent of Crocus sativus, possesses anti‑oxidation effects. The purpose of the present study was to evaluate the protective effect of crocin on UVB‑induced dermal fibroblast photoaging. Human dermal fibroblasts were isolated and cultured with different concentrations of crocin prior to and following exposure to UVB irradiation. The senescent phenotypes of cells were evaluated, including cell proliferation, cell cycle, senescence‑associated β‑galactosidase (SA‑β‑gal) expression, intracellular ROS, expression of antioxidant protein glutathione peroxidase 1 (GPX‑1) and extracellular matrix protein collagen type 1 (Col‑1). Crocin rescued the cell proliferation inhibited by UVB irradiation, prevented cell cycle arrest and markedly decreased the number of SA‑β‑gal‑positive cells. In addition, crocin reduced UVB‑induced ROS by increasing GPX‑1 expression and other direct neutralization effects. Furthermore, crocin promoted the expression of the extracellular matrix protein Col‑1. Crocin could effectively prevent UVB‑induced cell damage via the reduction of intracellular ROS; thus, it could potentially be used in the prevention of skin photoaging.

Effects of Crocin on The Pituitary-Gonadal Axis and Hypothalamic Kiss-1 Gene Expression in Female Wistar Rats

BACKGROUND

Saffron (Crocus sativus L.) has been traditionally used as a spice for coloring and flavoring in some countries cuisine. One of the main components of saffron is Crocin. Recent research have shown that crocin has various pharmacological effects. The aim of this study was to assess the effects of crocin on the Pituitary-Gonadal axis and Kiss-1 gene expression in hypothalamus and ovarian tissue organization in female Wistar rats.

MATERIALS AND METHODS

In this experimental study, 18 adult female Wistar rats were randomly divided into three groups. Control group received normal saline and experimental groups received two different doses of crocin (100 and 200 mg/kg) every two days for 30 days. After the treatment period, blood samples were obtained from the heart and centrifuged. Next, the serum levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), estrogen and progesterone hormones were measured by ELISA assay. The ovarian tissues were removed and fixed for histological investigation. The hypothalamic Kiss-1 gene expression was measured using real-time polymerase chain reaction (PCR). All data were analyzed using one-way ANOVA.

RESULTS

A significant reduction (P=0.038) in the number of atretic graafian follicles (0.5 ± 0.31) was observed in rats treated with 200 mg/kg crocin. In addition, estrogen concentration in experimental groups (35.04 ± 0.85 and 36.18 ± 0.69 in crocin 100 and 200 mg/kg groups, respectively) compared to control group (38.35 ± 0.64) and progesterone concentration in rats treated with crocin 200 mg/kg (2.06 ± 0.07) compared to control group (2.16 ± 0.04), significantly decreased. Interestingly, relative expressions of Kiss-1 mRNA significantly decreased in experimental groups (0.00053 ± 0.00051 and 0.0011 ± 0.00066 in crocin 100 and 200 mg/kg groups, respectively) (P=0.000) compared to control group (1 ± 0).

CONCLUSION

Crocin, at hypothalamic level, reduces Kiss-1 gene expression and it can prevent follicular atresia and reduce serum levels of estrogen and progesterone.