S100B Expression Research Articles

Nerve growth factor and S100B: Molecular marker of neuroregeneration after injection of freeze-Dried platelet rich plasma

IntroductionChronic orofacial pain is associated with nerve tissues damage. Pharmacological therapy has limited therapeutic results because it is generally only symptomatic treatment. Neuroregeneration is a process which is needed to repair damaged of nerve tissue through healing or regrowth of nerve tissue. The survival of nerve cells need neurotrophic factors including Nerve Growth Factor (NGF) and S100B. High platelet concentrations in Platelet Rich Plasma contain of many trophic factors which play an important role in peripheral nerve regeneration following nerve injury. The aim of the present study is to analyze the increased expression of NGF and S100B following injection of Freeze-Dried Platelet Rich Plasma (FD-PRP) on axonotmesis injury. MethodsFifty-four male wistar rats aged 3 months randomly divided into 3 groups; negative control group (without nerve injury and without FD-PRP injection), positive control group (nerve injury but without FD-PRP injection) and treatment group (nerve injury and FD-PRP injection). Axonotmesis nerve injury created by clamping the infraorbital nerve for 15 s. Application of FD-PRP by injection technique. Examination of NGF and S100B expression was obtained by immunohistochemistry examination with monoclonal antibodies (anti-NGF and anti-S100B). Samples were taken on the 14th day and 21st day. ResultsTreatment group showed significant increase on both NGF and S100B compare to positive control (p = 0,000 and p = 0,000, respectively). ConclusionFD-PRP injection is effective in inducing neuroregeneration by increasing NGF and S100B expression.

Preliminary Study of S100B and Sema3A Expression Patterns in Regenerating Muscle Implicates P75-Expressing Terminal Schwann Cells and Muscle Satellite Cells in Neuromuscular Junction Restoration.

Terminal Schwann cells (TSCs) help regulate the formation, maintenance, function, and repair of neuromuscular junctions (NMJs) and axon guidance after muscle injury. Premature activation of muscle satellite cells (SCs), induced by isosorbide dinitrate (ISDN) before injury, accelerates myogenic regeneration, disrupts NMJ remodeling and maturation, decreases Sema3A protein-induced neuro-repulsion, and is accompanied by time-dependent changes in S100B protein levels. Here, to study the effects of premature SC activation on TSCs and SCs, both expressing P75 nerve growth-factor receptor, in situ hybridization was used to identify transcripts of S100B and Sema3A, and the number, intensity, and diameter of expression sites were analyzed. The number of sites/fields expressing S100B and Sema3A increased with regeneration time (both p < 0.001). Expression-site intensity (S100B) and diameter (S100B and Sema3A) decreased during regeneration (p = 0.005; p < 0.05, p = 0.006, respectively). P75 protein colocalized with a subset of S100B and Sema3A expression sites. Principal component analyses of gene expression, protein levels, and histological variables (fiber diameter, vascular density) in control and ISDN-pretreated groups explained 83% and 64% of the dataset variance, respectively. A very strong loading coefficient for colocalization of P75 protein with S100B and Sema3A mRNAs (0.91) in control regenerating muscle dropped markedly during regeneration disrupted by premature SC activation (−0.10 in Factor 1 to 0.55 in Factor 3). These findings strongly implicate the triple-expression profile by TSCs and/or SCs as a strong correlate of the important synchrony of muscle and nerve regeneration after muscle tissue injury. The results have the potential to focus future research on the complex interplay of TSCs and SCs in neuromuscular tissue repair and help promote effective function after traumatic muscle injury.

Effect of senescence on the tyrosine hydroxylase and S100B immunoreactivity in the nigrostriatal pathway of the rat

Senescence is a natural and progressive physiological event that leads to a series of morphophysiological alterations in the organism. The brain is the most vulnerable organ to both structural and functional changes during this process. Dopamine is a key neurotransmitter for the proper functioning of the brain, directly involved in circuitries related with emotions, learning, motivation and reward. One of the main dopamine- producing nuclei is the substantia nigra pars compacta (SNpc), which establish connections with the striatum forming the so-called nigrostriatal pathway. S100B is a calcium binding protein mainly expressed by astrocytes, involved in both intracellular and extracellular processes, and whose expression is increased following injury in the nervous tissue, being a useful marker in altered status of central nervous system. The present study aimed to analyze the impact of senescence on the cells immunoreactive for tyrosine hydroxylase (TH) and S100B along the nigrostriatal pathway of the rat. Our results show an decreased expression of S100B+ cells in SNpc. In addition, there was a significant decrease in TH immunoreactivity in both projection fibers and TH+ cell bodies. In the striatum, a decrease in TH immunoreactivity was also observed, as well as an enlargement of the white matter bundles. Our findings point out that senescence is related to the anatomical and neurochemical changes observed throughout the nigrostriatal pathway.

An imbalance between RAGE/MR/HMGB1 and ATP1α3 is associated with inflammatory changes in rat brain harboring cerebral aneurysms prone to rupture

Background and purposeAn aneurysmal subarachnoid hemorrhage is a devastating event. To establish an effective therapeutic strategy, its pathogenesis must be clarified, particularly the pathophysiology of brain harboring intracranial aneurysms (IAs). To elucidate the pathology in brain harboring IAs, we examined the significance of the receptor for advanced glycation end-products (RAGE)/mineralocorticoid receptor (MR) pathway and Na+/K+-ATPase (ATP1α3).MethodsTen-week-old female rats were subjected to oophorectomy as well as hypertension and hemodynamic changes to induce IAs, and were fed a high-salt diet. Brain damage in these rats was assessed by inflammatory changes in comparison to sham-operated rats fed a standard diet.ResultsSix weeks after IA induction (n = 30), irregular morphological changes, i.e., an enlarged vessel diameter and vascular wall, were observed in all of the left posterior cerebral arteries (Lt PCAs) prone to rupture. Approximately 20% of rats had ruptured IAs within 6 weeks. In brain harboring unruptured IAs at the PCA, the mRNA levels of RAGE and MR were higher, and that of ATP1α3 was lower than those in the sham-operated rats (p < 0.05, each). Immunohistochemically, elevated expression of RAGE and MR, and decreased expression of ATP1α3 were observed in the brain parenchyma adjacent to the Lt PCA, resulting in increased Iba-1 and S100B expression that reflected the inflammatory changes. There was no difference between the unruptured and ruptured aneurysm rat groups. Treatment with the MR antagonist esaxerenone abrogated these changes, and led to cerebral and vascular normalization and prolonged subarachnoid hemorrhage-free survival (p < 0.05).ConclusionsRegulation of the imbalance between the RAGE/MR pathway and ATP1α3 may help attenuate the damage in brain harboring IAs, and further studies are warranted to clarify the significance of the down-regulation of the MR/RAGE pathway and the up-regulation of ATP1α3 for attenuating the pathological changes in brain harboring IAs.

Astroglial and oligodendroglial markers in the cuprizone animal model for de- and remyelination

Myelin loss with consecutive axon degeneration and impaired remyelination are the underlying causes of progressive disease in patients with multiple sclerosis. Astrocytes are suggested to play a major role in these processes. The unmasking of distinct astrocyte identities in health and disease would help to understand the pathophysiological mechanisms in which astrocytes are involved. However, the number of specific astrocyte markers is limited. Therefore, we performed immunohistochemical studies and analyzed various markers including GFAP, vimentin, S100B, ALDH1L1, and LCN2 during de- and remyelination using the toxic murine cuprizone animal model. Applying this animal model, we were able to confirm overlapping expression of vimentin and GFAP and highlighted the potential of ALDH1L1 as a pan-astrocytic marker, in agreement with previous data. Only a small population of GFAP-positive astrocytes in the corpus callosum highly up-regulated LCN2 at the peak of demyelination and S100B expression was found in a subset of oligodendroglia as well, thus S100B turned out to have a limited use as a particular astroglial marker. Additionally, numerous GFAP-positive astrocytes in the lateral corpus callosum did not express S100B, further strengthening findings of heterogeneity in the astrocytic population. In conclusion, our results acknowledged that GFAP, vimentin, LCN2, and ALDH1L1 serve as reliable marker to identify activated astrocytes during cuprizone-induced de- and remyelination. Moreover, there were clear regional and temporal differences in protein and mRNA expression levels and patterns of the studied markers, generally between gray and white matter structures.

Impact of maternal desvenlafaxine exposure on brain development in pregnant albino rats and their fetuses.

Depression during pregnancy adversely affects fetal development. Desvenlafaxine drug is used for the treatment of gestational depression. In light of the well-established role of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in regulating neurogenesis and neural survival, the role of S100b in nerve cell energetic metabolism, differentiation of neurons and glial cells, an aberrant increase in NGF, BDNF and S100b expression in the fetal brain may contribute to desvenlafaxine cognitive disorders by altering brain development. This study is trying to determine the effect of desvenlafaxine on brain development. Thirty timed pregnant rats (from the 5th to the 20th day) were divided into three groups: control, low dose (5.14 mg/kg/day) and high dose (10.28 mg/kg/day) of desvenlafaxine where all animals received the corresponding doses by gavage. Maternal and fetal brain samples were fixed for histological, immunohistochemical (IHC) study of NGF and evaluated for BDNF and S100b genes expression. Desvenlafaxine induced some of the histopathological alterations in maternal and fetal rat brains. Moreover, IHC analysis of maternal and fetal rat brains showed that groups treated with desvenlafaxine demonstrated a significant increase of NGF protein immunoreactivity compared with that in the controls. Gene expression results revealed upregulation of messenger RNA BDNF and S100B expression. According to developmental changes in the brain, desvenlafaxine affects neonatal growth during pregnancy, which may lead to delay of brain development. So, it is essential to survey the roles of antidepressant drugs on neonatal development during pregnancy.

Comprehensive analysis of the correlations of S100B with hypoxia response and immune infiltration in hepatocellular carcinoma.

S100B has been found to be dysregulated in many cancers including hepatocellular carcinoma (HCC). However, the functions of S100B and its underlying mechanisms in HCC remain poorly understood, especially in the tumor microenvironment. In this study, functions enrichment analysis indicated that S100B expression was correlated with hypoxia and immune responses. We found that hypoxia could induce S100B expression in an HIF-1α-dependent manner in HepG2 cells. Luciferase reporter and ChIP-qRCR assays demonstrated that HIF-1α regulates S100B transcription by directly binding to hypoxia-response elements (HREs) of the S100B promoter. Functionally, knockdown of S100B reduces hypoxia-induced HepG2 cell invasion and migration. Furthermore, GSVA enrichment results displayed that S100B and its co-expressed genes were positively correlated with EMT pathway in HCC. Additionally, GO/KEGG cluster analysis results indicated that co-expressed genes of S100B were involved in biological processes of immune response and multiple tumor immune-related signaling pathways in HCC. S100B expression was positively correlated with multiple immune cells tumor infiltration and associated with chemokines/chemokine receptors and immune checkpoint genes. Moreover, S100B is predominantly expressed in immune cells, especially NK (Natural Killer) cell. In addition, the hub genes of S100B co-expression and hypoxia response in HepG2 cell were also associated with immune cells infiltration in HCC. Taken together, these findings provide a new insight into the complex networks between hypoxia response and immune cells infiltration in tumor microenvironment of liver cancer. S100B maybe serve as a novel target for future HCC therapies.

Reduced Concentrations of NSE, S100β, Aβ, and Proinflammatory Cytokines in Elderly Patients Receiving Ultrasound-Guided Combined Lumbar Plexus-Sciatic Nerve Block during Hip Replacement.

Objective The increase of hip fractures is related to the aging of the population, which has caused a huge medical burden in many countries. Hip replacement has been approved as a highly successful surgical intervention for the patients with hip fractures. Different anesthesia choices in the surgical intervention are associated with the prognosis of patients. This study focused on investigating the application of ultrasound-guided combined lumbar plexus-sciatic nerve block in elderly patients with hip fractures. Methods In this retrospective study, 62 elderly patients received combined spinal-epidural anesthesia and 58 elderly patients underwent ultrasound-guided combined lumbar plexus-sciatic nerve block during the surgery. Hemodynamic monitoring including pulse oxygen saturation (SpO2), heart rate and blood pressure, the assessment of pain intensity using Visual Analogue Scale (VAS), cognitive function assessment through Montreal Cognitive Assessment (MoCA) and biomarkers consisting of serum levels of neuron specific-enolase (NSE), S100 beta protein (S100-β), and amyloid beta protein (Aβ), as well as immune function by interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and high sensitivity C-reactive protein (hs-CRP) were detected in this study. Furthermore, length of hospital stay (LOS) and adverse reactions including hematoma, hypotension, nausea, and vomit were analyzed. Results The findings indicated that comparing with the patients receiving combined spinal-epidural anesthesia, those undergoing ultrasound-guided combined lumbar plexus-sciatic nerve block showed significantly lower level of heart rate, higher level of SpO2, and lower level of diastolic pressure and systolic pressure at 5 minutes and 30 minutes after anesthesia and after surgery (P < 0.05), indicated obviously lower VAS score at 12, 24, and 48 hours after surgery (P < 0.05), and revealed higher MoCA score at 12 days after surgery (P < 0.05). A significantly higher level of NSE, S100β, Aβ, IL-6, IL-1β, TNF-α, and hs-CRP was revealed in the two groups receiving different anesthesia methods at 10 days after surgery compared with that before surgery (P < 0.05). However, the patients receiving ultrasound-guided combined lumbar plexus-sciatic nerve block had obviously lower expression of NSE, S100β, Aβ, IL-6, IL-1β, TNF-α, and hs-CRP compared with the group accepting combined spinal-epidural anesthesia (P < 0.05). The two groups indicated no significant difference in incidence of hypotension and vomit, etc. (P < 0.05), but showed remarkable difference referring to total incidence of adverse reactions and LOS (P < 0.05). Conclusion The application of ultrasound-guided combined lumbar plexus-sciatic nerve block in hip replacement contributes to the stability of hemodynamics and alleviation of postoperative pain intensity. It can reduce cognitive and immune impairment of the elderly patients with hip fractures.

Characterization of pituitary stem/progenitor cell populations in spontaneous dwarf rats.

Spontaneous dwarf rat (SDR) is a primary experimental animal model for the study of pituitary dwarfism with a point mutation in the Gh gene encoding growth hormone (GH). In previous studies, SDR has been reported to be associated with the GH deficiency as well as combined hormone deficiencies, the cause of which is unknown. In this study, we focused on the characteristics of pituitary stem/progenitor cell populations, which are a source of hormone-producing cells, in SDR. Immunofluorescence and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) analyses confirmed the defects in GH-producing cells, the decreased number of prolactin- and thyroid-stimulating hormone-producing cells, and the increased number of adrenocorticotropic hormone- and luteinizing hormone-producing cells. Additionally, qRT-PCR analysis showed increased Prop1 (an embryonic stem/progenitor cell marker) expression and decreased S100b (a putative adult stem/progenitor cell marker) expression in SDRs. In the pituitary stem/progenitor cell niche, the marginal cell layer, the proportion of SOX2/PROP1-double positive cells was higher in adult SDRs than in adult Sprague Dawley (SD) rats but that of SOX2/S100β-double positive cells was much lower. Furthermore, the number of SOX2/PROP1-double positive cells in SD rats significantly decreased with growth; however, the decrease was smaller in SDRs. In contrast, the number of SOX2/S100β-double positive cells in SD rats significantly increased with growth; however, they were few in SDRs. Thus, S100β-positive pituitary stem/progenitor cells failed to settle in pituitary dwarfism with the Gh gene mutation, leading to multiple hypopituitarism including GH deficiency.

Expression and localization of tight junction-related proteins in adult rat pituitary stem/progenitor cell niches.

Pituitary endocrine cells are supplied by Sox2-expressing stem/progenitor cells in the anterior lobe of the adult pituitary gland. These SOX2-positive cells are maintained in two types of microenvironments (niches): the marginal cell layer (MCL)-niche and the parenchymal-niche. Recently, we isolated dense SOX2-positive cell clusters from the parenchymal-niche by taking advantage of their resistance to protease treatment as parenchymal stem/progenitor cell (PS)-clusters. In the present study, by analyzing these isolated PS-clusters, we attempted to identify novel structural characteristics of pituitary stem/progenitor cell niches. Quantitative real-time PCR showed that tight junction-related genes were distinctly expressed in the isolated PS-clusters. Immunocytostaining showed that the tight junction molecules, ZO-1 and occludin, were localized in the apical membrane facing the pseudo-follicle-like structure of the isolated PS-clusters regardless of the expression of S100β, which distinguishes the sub-population of SOX2-positive cells. Furthermore, immunohistochemistry of the pituitary glands of adult rats clearly demonstrated that ZO-1 and occludin were densely present in the parenchymal-niche encircling the pseudo-follicle, while they were observed in the apical membrane in the MCL-niche facing the residual lumen. Collectively, these tight junction-related proteins might be involved in the architecture and maintenance of the plasticity of pituitary stem/progenitor cell niches.

The clinical and prognostic role of S100B expression in meningiomas

The clinical and prognostic role of S100B expression in meningiomas

Enhanced S100B expression in T and B lymphocytes in spontaneous preterm birth and preeclampsia.

S100B belongs to the family of danger signaling proteins. It is mainly expressed by glial-specific cells in the brain. However, S100B was also detected in other cell likewise immune cells. This molecule was suggested as biomarker for inflammation and fetal brain damage in spontaneous preterm birth (sPTB), preeclampsia (PE) and HELLP (hemolysis, elevated liver enzymes, and low platelet count). The aim of our study was to determine the concentration of S100B in maternal and cord blood (CB) plasma and placenta supernatant as well as the expression of S100B in maternal and CB CD4+ Tcells and CD19+ Bcells in sPTB and patients delivering following PE/HELLP diagnosis compared to women delivering at term (TD). The S100B expression was further related to the birth weight in our study cohort. S100B concentration was enhanced in maternal and CB plasma of sPTB and PE/HELLP patients and positively correlated with interleukin-6 (IL-6) levels. Increased S100B was also confirmed in CB of small-for-gestational-age (SGA) infants. S100B expression in maternal blood was elevated in CD4+ Tcells of PE/HELLP patients and patients who gave birth to SGA newborns as well as in CD19+ Bcells of sPTB and PE/HELLP patients and patients with SGA babies. In CB, the expression of S100B was increased in CD19+ Bcells of sPTB, PE/HELLP and SGA babies. Our results support the hypothesis that S100B expression is enhanced in inflammatory events associated with preterm birth and that S100B expression in immune cells is a relevant marker for inflammation during pregnancy complications.

The clinical value of EEG monitoring and silver nanoparticles to detect the levels of serum Nesfatin-1, S100β and neuron-specific enolase in evaluating the severity and prognosis of epilepsy

This study aimed to explore the clinical value of electroencephalogram (EEG) monitoring and the use of silver nanoparticles to detect serum levels of Nesfatin-1, S100β and Neuron-specific enolase (NSE) in assessing the severity and prognosis of epilepsy. A total of 54 epilepsy patients treated at our hospital from June 2017 to June 2019 were selected as the epilepsy group, and 54 healthy subjects were selected as the control group. EEG and serum levels of Nesfatin-1, S100β, and NSE in epilepsy patients without seizure and within 1 hour of seizure were ascertained and compared. The Liverpool Seizure Severity Scale (LSSS) score was used to evaluate the severity of epilepsy in patients, and the correlation between EEG findings and serum Nesfatin-1, S100β , and NSE levels was analyzed. ROC analysis was also conducted on the levels of the three factors. The patients were followed up for 1 year, the mortality rate was calculated, and the levels of Nesfatin-1, S100β, and NSE in deceased and non-deceased patients were compared. There were 50 cases (92.6%) with EEG abnormalities in the epilepsy group and 31 cases (57.4%) with epileptic EEGs in the epileptic non-seizure group. There was a significant difference in the proportion of abnormal EEGs between the two groups of epilepsy patients (P &lt;0.05); the biomarker (Nesfatin-1, S100β, and NSE) serum levels were higher in both the non-seizure group and epileptic group than the control group, and the levels in the seizure group were higher than those in the non-seizure group (P &lt; 0.05); seizures in patients with epilepsy were positively correlated with EEG abnormalities and biomarker serum levels. There was, however, no significant correlation between EEG abnormalities and biomarker serum levels. ROC analysis of epilepsy patients and their serum levels of Nesfatin-1, S100β and NSE showed that the area under the curve corresponding to each index was 0.850, 0.881, and 0.868, respectively (P &lt; 0.05). With regards to deceased patients, the proportion with an abnormal EEG was 100% (15/15), which was higher than 41.0% (16/39) of non-deceased patients. Serum levels of biomarkers were also significantly higher than those in non-deceased patients (P &lt; 0.05). Changes in EEG and biomarker serum levels were closely related to the severity of epilepsy. The proportion of patients with abnormal EEGs during seizure periods was higher, and the expression of serum Nesfatin-1, S100β and NSE was also increased, which means they can be used as markers of epilepsy and have an impact on its prognosis

S100B is selectively expressed by gray matter protoplasmic astrocytes and myelinating oligodendrocytes in the developing CNS

Studies on the development of central nervous system (CNS) primarily rely on the use of specific molecular markers for different types of neural cells. S100B is widely being used as a specific marker for astrocytes in the CNS. However, the specificity of its expression in astrocyte lineage has not been systematically investigated and thus has remained a lingering issue. In this study, we provide several lines of molecular and genetic evidences that S100B is expressed in both protoplasmic astrocytes and myelinating oligodendrocytes. In the developing spinal cord, S100B is first expressed in the ventral neuroepithelial cells, and later in ALDH1L1+/GS+ astrocytes in the gray matter. Meanwhile, nearly all the S100B+ cells in the white matter are SOX10+/MYRF+ oligodendrocytes. Consistent with this observation, S100B expression is selectively lost in the white matter in Olig2-null mutants in which oligodendrocyte progenitor cells (OPCs) are not produced, and dramatically reduced in Myrf-conditional knockout mutants in which OPCs fail to differentiate. Similar expression patterns of S100B are observed in the developing forebrain. Based on these molecular and genetic studies, we conclude that S100B is not a specific marker for astrocyte lineage; instead, it marks protoplasmic astrocytes in the gray matter and differentiating oligodendrocytes.

Palmitoylethanolamide Counteracts Enteric Inflammation and Bowel Motor Dysfunctions in a Mouse Model of Alzheimer's Disease.

Palmitoylethanolamide (PEA), an endogenous lipid mediator, is emerging as a promising pharmacological agent in multiple neurodegenerative disorders for its anti-inflammatory and neuroprotective properties. However, its effects on enteric inflammation and colonic dysmotility associated with Alzheimer’s disease (AD) are lacking. This study was designed to investigate the beneficial effect of PEA administration in counteracting the enteric inflammation and relieving the bowel motor dysfunctions in an AD mouse model, SAMP8 mice. In addition, the ability of PEA in modulating the activation of enteric glial cells (EGCs), pivotally involved in the pathophysiology of bowel dysfunctions associated with inflammatory conditions, has also been examined. SAMP8 mice at 4 months of age were treated orally with PEA (5 mg/kg/day) for 2 months. SAMR1 animals were employed as controls. At the end of treatment, parameters dealing with colonic motility, inflammation, barrier integrity and AD protein accumulation were evaluated. The effect of PEA on EGCs was tested in cultured cells treated with lipopolysaccharide (LPS) plus β-amyloid 1–42 (Aβ). SAMP8 treated with PEA displayed: 1) an improvement of in vitro colonic motor activity, citrate synthase activity and intestinal epithelial barrier integrity and 2) a decrease in colonic Aβ and α-synuclein (α-syn) accumulation, S100-β expression as well as enteric IL-1β and circulating LPS levels, as compared with untreated SAMP8 mice. In EGCs, treatment with PEA counteracted the increment of S100-β, TLR-4, NF-κB p65 and IL-1β release induced by LPS and Aβ. These results suggest that PEA, under a condition of cognitive decline, prevents the enteric glial hyperactivation, reduces AD protein accumulation and counteracts the onset and progression of colonic inflammatory condition, as well as relieves intestinal motor dysfunctions and improves the intestinal epithelial barrier integrity. Therefore, PEA represents a viable approach for the management of the enteric inflammation and motor contractile abnormalities associated with AD.

κ-Opioid Receptor Agonist Ameliorates Postoperative Neurocognitive Disorder by Activating the Ca2+/CaMKII/CREB Pathway.

Objective Cardiopulmonary bypass (CPB) is an important cardiac operation and also a high-risk procedure, leading to postoperative neurocognitive disorder. However, there are few effective drugs to treat the aftermath of CPB. Therefore, we observe the effect of kappa opioid receptor (KOR) agonist on cognitive disorders of rats after cardiopulmonary bypass (CPB) and investigate the mechanism of the Ca2+/calmodulin-dependent protein kinase (CaMKII)/cAMP responsive element-binding protein (CREB) pathway. Methods A total of 40 Sprague Dawley rats were randomly divided into the sham operation group (sham group, n = 10), CPB model group (CPB group, n = 10), CPB + KOR agonist U50488H group (UH group, n = 10), and CPB + specific CaMKII antagonist + U50488H group (CKU group, n = 10). The changes in the rats' cognitive function were evaluated using the Morris water maze, the hippocampal histopathological changes were observed via hematoxylin-eosin (H&E) staining, and the apoptosis rate of neuronal cells was detected through terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. Moreover, enzyme-linked immunosorbent assay (ELISA) was applied to examine the changes in brain injury markers, inflammatory factors, and oxidative stress factors. The hippocampal variations in Ca2+ concentration and oxidative stress index (ROS) levels were measured by immunofluorescence staining, and western blotting was performed to determine the expression changes in the Ca2+/CaMKII/CREB pathway. Results The KOR agonist could shorten latency, increase the swimming distance and residence time in the target quadrant, and ameliorate postoperative neurocognitive disorder (PND). Meanwhile, the KOR agonist relieved CPB-induced hippocampal and oxidative stress injuries, reduced NSE and S-100β expression, decreased the apoptosis rate, and repressed the inflammatory response, which alleviated the brain injury. In addition, U50488H was able to decrease Ca2+ influx and glutamate (Glu) level, inhibit N-methyl-D-aspartate receptor (NMDAR) expression, upregulate CaMKII expression, promote CREB phosphorylation, and increase the brain-derived neurotrophic factor (BDNF) level in CPB rats. However, the protective effects of KORs against PND were suppressed following the application of the CaMKII-specific antagonist. Conclusion The KOR agonist activates the Ca2+/CaMKII/CREB pathway, which improves the brain injury and relieves PND in CPB rats.

S100B Inhibition Attenuates Intestinal Damage and Diarrhea Severity During Clostridioides difficile Infection by Modulating Inflammatory Response

The involvement of the enteric nervous system, which is a source of S100B, in Clostridioides difficile (C. difficile) infection (CDI) is poorly understood although intestinal motility dysfunctions are known to occur following infection. Here, we investigated the role of S100B in CDI and examined the S100B signaling pathways activated in C. difficile toxin A (TcdA)- and B (TcdB)-induced enteric glial cell (EGC) inflammatory response. The expression of S100B was measured in colon tissues and fecal samples of patients with and without CDI, as well as in colon tissues from C. difficile-infected mice. To investigate the role of S100B signaling in IL-6 expression induced by TcdA and TcdB, rat EGCs were used. Increased S100B was found in colonic biopsies from patients with CDI and colon tissues from C. difficile-infected mice. Patients with CDI-promoted diarrhea exhibited higher levels of fecal S100B compared to non-CDI cases. Inhibition of S100B by pentamidine reduced the synthesis of IL-1β, IL-18, IL-6, GMCSF, TNF-α, IL-17, IL-23, and IL-2 and downregulated a variety of NFκB-related genes, increased the transcription (SOCS2 and Bcl-2) of protective mediators, reduced neutrophil recruitment, and ameliorated intestinal damage and diarrhea severity in mice. In EGCs, TcdA and TcdB upregulated S100B-mediated IL-6 expression via activation of RAGE/PI3K/NFκB. Thus, CDI appears to upregulate colonic S100B signaling in EGCs, which in turn augment inflammatory response. Inhibition of S100B activity attenuates the intestinal injury and diarrhea caused by C. difficile toxins. Our findings provide new insight into the role of S100B in CDI pathogenesis and opens novel avenues for therapeutic interventions.

Expression and related mechanisms of miR-330-3p and S100B in an animal model of cartilage injury.

ObjectiveTo investigate the roles of and relationship between microRNA (miR)-330-3p and S100 calcium-binding protein B (S100B) in an animal model of cartilage injury.MethodsThis study included 30 New Zealand male rabbits randomly divided into three groups: an intervention group, a model group and a sham surgery control group. Modelling was performed in the intervention and model groups, but in the sham surgery group, only the skin was cut. After modelling, the intervention and model groups were injected with the miR-330-3p overexpression vector GV268-miR-330-3p or the control GV268-N-ODN vector, respectively, twice a week for 7 weeks.ResultsLevels of interleukin-1β and tumour necrosis factor-α in the synovial fluid were significantly higher in the model group than in the intervention and control groups. The level of miR-330-3p in the cartilage tissue was significantly higher in the control group than in the model group but it was significantly lower compared with the intervention group. Levels of S100B, fibroblast growth factor receptor 1 and fibroblast growth factor-2 in the cartilage tissue of rabbits in the model group were significantly higher compared with the control and intervention groups.ConclusionThese findings demonstrate that the upregulation of miR-330-3p can inhibit the expression of S100B.

Progressive spinal cord compression technique in experimental rabbit animal model for cervical spondylotic myelopathy

IntroductionCervical spondylotic myelopathy (CSM) presently estimated at 54% population, commonly cause of myelopathy due to chronic compression of the spinal cord in older people. Physiological injuries caused by static and dynamic forces including compressed, pinched, and pulled out inducing secondary injuries at the molecular level. MethodsWe examined the rabbit model approach with the clinical case of spondylotic myelopathy, in which the disk and facet maintained the cervical spine mobility, and compression was given 0.5 mm per week three times in this model. In this study, a group of 14 days was made (early into the chronic phase) and the 21 day group had a chronic process for 1 week, that period can be categorized as a chronic process and CSM is a chronic process. By examining motor scores, histological examination and immunohistochemistry of the spinal cord, this model efficiently produces myelopathy. The distribution of microglia expressing GFAP, S100-β, and Neurofilaments were observed by immunohistochemical techniques. ResultsThere was a significant difference in the number of cells expressing GFAP between the control group and the 21-day compression group (p = 0.001). There is a decrease in S100-β expression of spinal cord tissue after receiving compression exposure. There was a significant difference in the number of cells expressing NF between the control group, the 14-day compression group (p = 0.04) and 21-day compression group (p = 0.04). DiscussionNeurons have the intrinsic ability to regenerate after injury, although not spontaneously. Cervical spondylotic myelopathy causes permanent neurological disorders, partly due to glial scar formation consisting of astrocytes and microglia. The difference between our study and previous research methods is that we perform compression of the spinal cord in stages (0.5 mm, 1.0 mm & 1.5 mm) so that it is more like the natural occurrence of chronic spinal cord compression. ConclusionAn increasing of GFAP value in this study indicates the presence of astrocyte activity which can be associated with chronic spinal cord injury. There is a decrease in S100-β expression of spinal cord tissue neuron cells after receiving compression exposure. The expression of NF decreased indicating degenerative axons.

Deficiency in MT5-MMP Supports Branching of Human iPSCs-Derived Neurons and Reduces Expression of GLAST/S100 in iPSCs-Derived Astrocytes.

For some time, it has been accepted that the β-site APP cleaving enzyme 1 (BACE1) and the γ-secretase are two main players in the amyloidogenic processing of the β-amyloid precursor protein (APP). Recently, the membrane-type 5 matrix metalloproteinase (MT5-MMP/MMP-24), mainly expressed in the nervous system, has been highlighted as a new key player in APP-processing, able to stimulate amyloidogenesis and also to generate a neurotoxic APP derivative. In addition, the loss of MT5-MMP has been demonstrated to abrogate pathological hallmarks in a mouse model of Alzheimer’s disease (AD), thus shedding light on MT5-MMP as an attractive new therapeutic target. However, a more comprehensive analysis of the role of MT5-MMP is necessary to evaluate how its targeting affects neurons and glia in pathological and physiological situations. In this study, leveraging on CRISPR-Cas9 genome editing strategy, we established cultures of human-induced pluripotent stem cells (hiPSC)-derived neurons and astrocytes to investigate the impact of MT5-MMP deficiency on their phenotypes. We found that MT5-MMP-deficient neurons exhibited an increased number of primary and secondary neurites, as compared to isogenic hiPSC-derived neurons. Moreover, MT5-MMP-deficient astrocytes displayed higher surface area and volume compared to control astrocytes. The MT5-MMP-deficient astrocytes also exhibited decreased GLAST and S100β expression. These findings provide novel insights into the physiological role of MT5-MMP in human neurons and astrocytes, suggesting that therapeutic strategies targeting MT5-MMP should be controlled for potential side effects on astrocytic physiology and neuronal morphology.