Splenic Atrophy Research Articles

Placenta-Expanded Stromal Cell Therapy in a Rodent Model of Simulated Weightlessness.

Long duration spaceflight poses potential health risks to astronauts during flight and re-adaptation after return to Earth. There is an emerging need for NASA to provide successful and reliable therapeutics for long duration missions when capability for medical intervention will be limited. Clinically relevant, human placenta-derived therapeutic stromal cells (PLX-PAD) are a promising therapeutic alternative. We found that treatment of adult female mice with PLX-PAD near the onset of simulated weightlessness by hindlimb unloading (HU, 30 d) was well-tolerated and partially mitigated decrements caused by HU. Specifically, PLX-PAD treatment rescued HU-induced thymic atrophy, and mitigated HU-induced changes in percentages of circulating neutrophils, but did not rescue changes in the percentages of lymphocytes, monocytes, natural killer (NK) cells, T-cells and splenic atrophy. Further, PLX-PAD partially mitigated HU effects on the expression of select cytokines in the hippocampus. In contrast, PLX-PAD failed to protect bone and muscle from HU-induced effects, suggesting that the mechanisms which regulate the structure of these mechanosensitive tissues in response to disuse are discrete from those that regulate the immune- and central nervous system (CNS). These findings support the therapeutic potential of placenta-derived stromal cells for select physiological deficits during simulated spaceflight. Multiple countermeasures are likely needed for comprehensive protection from the deleterious effects of prolonged spaceflight.

Metabolic reprogramming and epigenetic changes of vital organs in SARS-CoV-2-induced systemic toxicity.

Extrapulmonary manifestations of COVID-19 are associated with a much higher mortality rate than pulmonary manifestations. However, little is known about the pathogenesis of systemic complications of COVID-19. Here, we create a murine model of SARS-CoV-2–induced severe systemic toxicity and multiorgan involvement by expressing the human ACE2 transgene in multiple tissues via viral delivery, followed by systemic administration of SARS-CoV-2. The animals develop a profound phenotype within 7 days with severe weight loss, morbidity, and failure to thrive. We demonstrate that there is metabolic suppression of oxidative phosphorylation and the tricarboxylic acid (TCA) cycle in multiple organs with neutrophilia, lymphopenia, and splenic atrophy, mirroring human COVID-19 phenotypes. Animals had a significantly lower heart rate, and electron microscopy demonstrated myofibrillar disarray and myocardial edema, a common pathogenic cardiac phenotype in human COVID-19. We performed metabolomic profiling of peripheral blood and identified a panel of TCA cycle metabolites that served as biomarkers of depressed oxidative phosphorylation. Finally, we observed that SARS-CoV-2 induces epigenetic changes of DNA methylation, which affects expression of immune response genes and could, in part, contribute to COVID-19 pathogenesis. Our model suggests that SARS-CoV-2–induced metabolic reprogramming and epigenetic changes in internal organs could contribute to systemic toxicity and lethality in COVID-19.

Effects of dietary copper supplementation on serum and biochemical and histopathology of pubertal boars

The effects of dietary copper on some biochemistry and histopathology of organs of pubertal pigs were assessed using 32 large white male weanling pigs of 8-9 weeks of age in a 6-months feeding trial. The animals were randomly assigned to four diets containing 0, 100, 200 and 300ppm Cu/kg as the control diet (diet 1), diets 2, 3 and 4 respectively. The feeding trial was divided into 3 growth phases (weanling, pre-pubertal and pubertal) corresponding to 8, 18 and 24 weeks of life respectively. At the end of the feeding trial, all the animals were sacrificed by stunning, bled, decapacitated followed by blood collection and careful evisceration to obtain the kidney, liver, spleen and testes and samples of the small intestine. Selected organs and tissues collected from sacrificed animals were processed for histology. Results showed that dietary copper did not significantly (P>0.05) influence the blood serum biochemical composition and the histomorphology of the organs and tissues examined. The boars exposed to the diet containing the highest copper supplementation (diet 4) did not have severe splenic atrophy and/or lymphoid depletion, liver necrosis and/or lesions, intestinal mucosal erosion and testicular necrosis and/or sertoli cells degeneration as compared to those fed the control. There was no intestinal mucosal erosion with increased dietary copper in this study because the maximum level of copper that was used in this study was not above 500ppm; hence all the tissues studied did not show degeneration of any form.

Perfluorooctanoic acid (PFOA) exposure induces splenic atrophy via overactivation of macrophages in male mice

Perfluorooctanoic acid (PFOA), a synthetic and widely used chemical, has aroused wide public concern due to its persistence, bioaccumulation, and potential toxicity. To investigate splenic atrophy induced by PFOA, male mice were exposed to 0, 0.4, 2, or 10 mg/kg/d PFOA for 28 d. Results demonstrated that spleen weight and relative spleen weight (RSW) decreased in the 2 and 10 mg/kg/d PFOA exposure groups. Iron levels in the spleen and serum were also reduced in all PFOA exposure groups. Weighted gene co-expression network analysis (WGCNA) of 7 043 genes highlighted enrichment in cell cycle, autoimmunity, and anemia in the spleen. In addition, changes in the levels of hemoglobin, platelets, bilirubin, and heme oxygenase-1 were consistent with anemia. The ratio of total macrophages to M1 macrophages in the spleen, phagocytic ability of macrophages, and levels of cytokines such as TNF-α, IL-1β, and IL-6 all increased, thus suggesting the occurrence of autoimmune disorder. Therefore, we concluded that overactivation of macrophages may be an important reason for splenic atrophy induced by PFOA exposure.

Effects of experimental cervical spinal cord injury on peripheral adaptive immunity.

Adaptive immunity is critical for controlling infections, which are a leading cause of morbidity and mortality in patients with spinal cord injury (SCI). In rats and mice, compromised peripheral adaptive immune responses, as shown by splenic atrophy and lowered frequencies of peripheral lymphocytes, were shown to result from high-level thoracic SCI. However, whether cervical SCI, which is the most common level of SCI in humans, impairs adaptive immunity remains largely unknown. In the present study, we induced cervical SCI in rats at the C7/T1 level by clip compression and looked at changes in peripheral adaptive immunity at 2-, 10- and 20-weeks post-injury. Specifically, we quantified changes in the frequencies of T- and B- lymphocytes in the blood and the mandibular and deep cervical lymph nodes, which drain the cervical spinal cord. We also assessed changes in serum IgG and IgM immunoglobulin levels, as well as spleen size. We found a significant decline in circulating T- and B- cell frequencies at 10 weeks post-SCI, which returned to normal at 20 weeks after injury. We found no effect of cervical SCI on T- and B- cell frequencies in the draining lymph nodes. Moreover, cervical SCI had no effect on net spleen size, although injured rats had a higher spleen/body weight ratio than sham controls at all time points of the study. Lastly, IgG and IgM immunoglobulin declined at 2 weeks, followed by a significant increase in IgM levels at 10 weeks of injury. These data indicate that cervical SCI causes a significant imbalance in circulating lymphocytes and immunoglobulin levels at 2 and 10 weeks. As we discuss in this article, these findings are largely in line with clinical observations, and we anticipate that this study will fuel more research on the effect of adaptive immunity on SCI recovery.

Sleeve Gastrectomy Ameliorates Diabetes-Related Spleen Damage by Improving Oxidative Stress Status in Diabetic Obese Rats.

Oxidative stress and inflammation are important pathogenic mediators in diabetes-related organ damage. Accumulating evidence suggests that immunodeficiency in diabetes is associated with diabetes-induced spleen damage. Sleeve gastrectomy (SG) has been proved to improve diabetes and its multiple associated complications. However, the ameliorative role of SG against spleen damage in diabetes has not been investigated. Animal model of diabetic obese rats induced by high-fat diet (HFD) combined with streptozotocin (STZ) was treated with sham operation, caloric restriction, and SG. Metabolic parameters were measured, and the morphological and histopathological changes, status of oxidative stress, and levels of inflammatory factors were evaluated. SG reduced body weight and improved glucose tolerance and insulin sensitivity in diabetic obese rats. SG significantly reversed splenic atrophy and alleviated abnormalities of white and red pulp. Additionally, SG also reversed the increased splenocyte apoptosis (P< 0.001). Meanwhile, indicators of oxidative stress including reactive oxygen species (ROS), nitric oxide (NO), malondialdehyde (MDA), and protein carbonylation were reduced, and the activity and expression of antioxidant enzymes including SOD and CAT were improved after SG. The mRNA expression of inflammatory factors in SG groups such as TNF-α (P< 0.001), IL-6 (P< 0.001), MCP-1 (P< 0.01), and ICAM-1 (P < 0.001) was also significantly reduced. SG ameliorates diabetes-related splenic injury by restoring the balance between oxidative stress process and antioxidant defense systems as well as reducing inflammation in the spleen. These findings indicate that SG is an appropriate therapeutic strategy for diabetes-related spleen damage.

SAT-071 Autoimmune Polyglandular Syndrome Type 1 with Common Variable Immunodeficiency

BACKGROUND:Autoimmune polyglandular syndrome (APS) is a rare disorder. It’s co-existence with common variable immunodeficiency (CVID) was reported in 5 cases before but, none of them was APS type 1up to our knowledge. The overlap between the 2 conditions indicates a possible association between Autoimmunity and immunodeficiency.CLINICAL CASE:A 21-year-old lady was diagnosed to have CVID since infancy, as she was presenting to the hospital with recurrent infections and sepsis. At the age of 7 months, she was diagnosed with type 1 diabetes and was started on insulin. Furthermore, at 2 years of age she was found to have primary hypothyroidism and in her teenage she was diagnosed with primary adrenal insufficiency. Her history became more complicated when she also started to develop recurrent oral and esophageal candidiasis that required systemic anti-fungal therapy. Later in her life, she was incidentally found to have hypoparathyroidism when her labs showed hypocalcemia with inappropriately normal parathyroid hormone. She had chronic diarrhea which was thought to be due to celiac disease based on intestinal biopsy showing villous atrophy. With her IgA deficiency, her Tissue transglutaminase IgA antibodies were not reliable. Splenic atrophy was also detected on abdominal imaging. She never reached puberty and elected with her parents to not start combined hormonal therapy.With the constellation of these features, we concluded that she has type 1 APS along with CVID.CONCLUSION:Autoimmunity and immunodeficiency might be interconnected. Early diagnosis will affect the quality of life and early targeted treatment will prevent morbidity and early mortality. KEY WORDS: Autoimmune Polyglandular Syndrome, Common Variable Immunodeficiency.

Abstract TMP29: Mesenchymal Stromal Cell Administration Attenuates Post-Stroke Susceptibility to Spontaneous Infection Through Prevention of Caspase-1-Dependent Splenic Marginal Zone B Cell Death

Spontaneous infection is one of most common complications of acute ischemic stroke (AIS) and leads to increased mortality and morbidity in stroke patients. However, current interventions fail to improve clinical outcomes in these patients. Since stroke-induced immunodeficiency is thought to contribute to the risk of infections, we suppose mesenchymal stromal cells (MSCs) therapy, based on its potent immunomodulatory capacities, could be a potential solution to this problem. Here, we show MSCs administration successfully ameliorates post-stroke infections and reduces the mortality in mouse middle cerebral artery occlusion (MCAO) model of AIS. Additionally, the intravenously infused MSCs preferentially migrate to the spleen and mainly distribute around the marginal zone (MZ). These grafted MSCs rescue stroke-induced splenic atrophy, especially the marginal zone B (MZB) cells loss, a subset of innate-like lymphocytes localized in MZ. Using the CD19-deficient mice model lacking MZB cells, we found that MSCs transplantation could not reduce post-stroke infections or mortality in CD19 -/- mice, reconfirming MZB cells are indispensable for the immunoprotective effects of MSCs. In terms of mechanism, we demonstrate that MSCs attenuate caspase-1-dependent MZB cells death partially through direct mitochondrial transfer and subsequent inhibition of NLRP3 activation. Taken together, this study suggests MSCs administration alleviates post-stroke immunodepression and spontaneous infections via MZB cells protection.

A Novel Partial MHC Class II Construct, DRmQ, Inhibits Central and Peripheral Inflammatory Responses to Promote Neuroprotection in Experimental Stroke.

Recognizing that the pathologic progression of stroke is closely associated with aberrant immune responses, in particular the activation of peripheral leukocytes, namely T cells, we hypothesized that finding a treatment designed to inhibit neuroantigen-specific T cells and block cytotoxic monocytes and macrophages may render therapeutic effects in stroke. We previously reported that subcutaneous administration of partial MHC class II constructs promote behavioral and histological effects in stroke mice by centrally promoting a protective M2 macrophage/microglia phenotype in the CNS and peripherally reversing stroke-associated splenic atrophy. Here, we employed a second species using adult Sprague-Dawley rats exposed to the middle cerebral artery occlusion stroke model and observed similar therapeutic effects with a mouse partial MHC class II construct called DRmQ, as evidenced by reductions in stroke-induced motor deficits, infarcts, and peri-infarct cell loss and neuroinflammation. More importantly, we offered further evidence of peripheral sequestration of inflammation at the level of the spleen, which was characterized by attenuation of stroke-induced spleen weight reduction and TNF-ɑ and IL-6 upregulation. Collectively, these results satisfy the Stroke Therapy Academic Industry Roundtable criteria of testing a novel therapeutic in a second species and support the use of partial MHC class II constructs as a stroke therapeutic designed to sequester both central and peripheral inflammation responses in an effort to retard, or even halt, the neuroinflammation that exacerbates the secondary cell death in stroke.

Attenuating Neurogenic Sympathetic Hyperreflexia Robustly Improves Antibacterial Immunity After Chronic Spinal Cord Injury.

Spinal cord injury (SCI) disrupts critical physiological systems, including the cardiovascular and immune system. Plasticity of spinal circuits below the injury results in abnormal, heightened sympathetic responses, such as extreme, sudden hypertension that hallmarks life-threatening autonomic dysreflexia. Moreover, such sympathetic hyperreflexia detrimentally impacts other effector organs, including the spleen, resulting in spinal cord injury-induced immunodeficiency. Consequently, infection is a leading cause of mortality after SCI. Unfortunately, there are no current treatments that prophylactically limit sympathetic hyperreflexia to prevent subsequent effector organ dysfunction. The cytokine soluble tumor necrosis factor α (sTNFα) is upregulated in the CNS within minutes after SCI and remains elevated. Here, we report that commencing intrathecal administration of XPro1595, an inhibitor of sTNFα, at a clinically feasible, postinjury time point (i.e., 3 d after complete SCI) sufficiently diminishes maladaptive plasticity within the spinal sympathetic reflex circuit. This results in less severe autonomic dysreflexia, a real-time gauge of sympathetic hyperreflexia, for months postinjury. Remarkably, delayed delivery of the sTNFα inhibitor prevents sympathetic hyperreflexia-associated splenic atrophy and loss of leukocytes to dramatically improve the endogenous ability of chronic SCI rats to fight off pneumonia, a common cause of hospitalization after injury. The improved immune function with XPro1595 correlates with less noradrenergic fiber sprouting and normalized norepinephrine levels in the spleen, indicating that heightened, central sTNFα signaling drives peripheral, norepinephrine-mediated organ dysfunction, a novel mechanism of action. Thus, our preclinical study supports intrathecally targeting sTNFα as a viable strategy to broadly attenuate sympathetic dysregulation, thereby improving cardiovascular regulation and immunity long after SCI.SIGNIFICANCE STATEMENT Spinal cord injury (SCI) significantly disrupts immunity, thus increasing susceptibility to infection, a leading cause of morbidity in those living with SCI. Here, we report that commencing intrathecal administration of an inhibitor of the proinflammatory cytokine soluble tumor necrosis factor α days after an injury sufficiently diminishes autonomic dysreflexia, a real time gauge of sympathetic hyperreflexia, to prevent associated splenic atrophy. This dramatically improves the endogenous ability of chronically injured rats to fight off pneumonia, a common cause of hospitalization. This preclinical study could have a significant impact for broadly improving quality of life of SCI individuals.

Suppression of the Peripheral Immune System Limits the Central Immune Response Following Cuprizone-Feeding: Relevance to Modelling Multiple Sclerosis.

Cuprizone (CPZ) preferentially affects oligodendrocytes (OLG), resulting in demyelination. To investigate whether central oligodendrocytosis and gliosis triggered an adaptive immune response, the impact of combining a standard (0.2%) or low (0.1%) dose of ingested CPZ with disruption of the blood brain barrier (BBB), using pertussis toxin (PT), was assessed in mice. 0.2% CPZ(±PT) for 5 weeks produced oligodendrocytosis, demyelination and gliosis plus marked splenic atrophy (37%) and reduced levels of CD4 (44%) and CD8 (61%). Conversely, 0.1% CPZ(±PT) produced a similar oligodendrocytosis, demyelination and gliosis but a smaller reduction in splenic CD4 (11%) and CD8 (14%) levels and no splenic atrophy. Long-term feeding of 0.1% CPZ(±PT) for 12 weeks produced similar reductions in CD4 (27%) and CD8 (43%), as well as splenic atrophy (33%), as seen with 0.2% CPZ(±PT) for 5 weeks. Collectively, these results suggest that 0.1% CPZ for 5 weeks may be a more promising model to study the ‘inside-out’ theory of Multiple Sclerosis (MS). However, neither CD4 nor CD8 were detected in the brain in CPZ±PT groups, indicating that CPZ-mediated suppression of peripheral immune organs is a major impediment to studying the ‘inside-out’ role of the adaptive immune system in this model over long time periods. Notably, CPZ(±PT)-feeding induced changes in the brain proteome related to the suppression of immune function, cellular metabolism, synaptic function and cellular structure/organization, indicating that demyelinating conditions, such as MS, can be initiated in the absence of adaptive immune system involvement.

Disorganization of spleen compartments and dermatitis in canine visceral leishmaniasis

Canine visceral leishmaniasis is associated with splenic changes that may interfere with the surveillance of blood borne antigens. Dogs with terminal visceral leishmaniasis present with a variety of skin lesions that may reflect a failure of the immune system to cope with infection. In this study, we compare the frequency of dermatitis in dogs from an endemic area of visceral leishmaniasis and take account of the following parameters: presence/absence of laboratory markers of infection and susceptibility to visceral leishmaniasis, and presence/absence of splenic structural changes associated with severe forms of the disease. Dermatitis was present in 48 of 64 (75%) of the animals. Dermatitis was more frequent in animals with positive splenic culture and negative leishmanin skin test (14/15, 93%) than in non-infected controls (P = 0.01). Diffuse dermatitis was present only in animals with evidence of Leishmania infection. Diffuse dermatitis was also more frequent in animals with positive (9/27, 33%) as opposed to negative (3/34, 9%) serology against Leishmania (P = 0.01). Presence of dermatitis correlated with both perisplenitis (P = 0.03) and with an increase in plasma cell density in the splenic tissue (P = 0.02). Diffuse dermatitis also correlated with splenic lymphoid tissue disorganization (P = 0.03) and germinal center atrophy (P < 0.01). The relationship between chronic dermatitis and spleen disorganization suggests an impairment of immune response to deal with skin aggressions in dogs with severe forms of visceral leishmaniasis. It also suggest that skin biopsy can be used in a model to define severity of canine visceral leishmaniasis.

An ulcerative colitis case with splenic atrophy, portal and renal vein thrombosis

An ulcerative colitis case with splenic atrophy, portal and renal vein thrombosis

SUN-040 Autoimmune Polyendocrinopathy Candidiasis Ectodermal Dystrophy (APECED) Syndrome: Prospective Screening of Asplenism and Pneumonitis in a Cohort of 25 Patients

Background: APECED syndrome is a rare monogenic disease caused by homozygous mutation of AIRE gene. It classically presents with chronic mucocutaneous candidiasis, hypoparathyroidism, and adrenal insufficiency with an early onset in childhood. Non-endocrine manifestations as ectodermic dystrophy, asplenism and pneumonitis are also observed but their incidence remains unknown and their mechanisms not well understood. APECED has been poorly reported in France although it is widely described in several European countries. The aim of this study was to report on rare manifestations of APECED syndrome in a French cohort. Patients and methods: We performed a multicentric prospective observational study in France in order to collect clinical, biological, immunological and genetic data, after written informed consent in the frame of a PHRC (Hospital Project of Clinical Research #1927). Bronchiolitis, splenic atrophy and ocular manifestations were systematically investigated. Results We enrolled 25 patients between 2009 and 2016. Clinically, the median age at diagnosis was 12 while the median age of the first manifestation was 6, so there was diagnostic delay. The median number of manifestations was seven. 76 % of patients presented with the classical triad. Reduction of lung function was observed in 62% of patients, asplenism in 26%, and ocular manifestation in 33%. Genetically, eleven mutations of the AIRE gene were identified, two of which never previously reported: an intronic variation c.653-70G>A (intron 5) in a patient with hypoparathyroidism as unique manifestation , and c.1066del (p.Arg356GlyfsX22) (exon 9) in a patient from Guadeloupe with composite heterozygous mutations (c.967_979del13; exon 8). The most common AIRE mutation was the mutation R257X. Median age was 26 and sex ratio was 1.1. Biologically, 100% of tested sera were positive for anti-IFNα-antibodies, 15/18 for anti-IL-22, and 13/18 for anti-IL-17F antibodies. Conclusion: This series shows a high genotypic and phenotypic variability of APECED in France, that could be explained by different ethnic origins. The systematic screening for non-classic manifestations shows a more frequent occurrence than in other series. Systematic screening of asplenism and bronchiolitis could be a useful strategy to make an earlier diagnosis, to prevent infections by vaccination and to treat earlier pulmonary involvement. Lastly, antibodies against Th17 cytokines appear as good soluble markers for diagnosis of non-classical presentation of the syndrome.

A novel leptin receptor antagonist uncouples leptin\u2019s metabolic and immune functions

Leptin links body energy stores to high energy demanding processes like reproduction and immunity. Based on leptin’s role in autoimmune diseases and cancer, several leptin and leptin receptor (LR) antagonists have been developed, but these intrinsically lead to unwanted weight gain. Here, we report on the uncoupling of leptin’s metabolic and immune functions based on the cross talk with the epidermal growth factor receptor (EGFR). We show that both receptors spontaneously interact and, remarkably, that this complex can partially overrule the lack of LR activation by a leptin antagonistic mutein. Moreover, this leptin mutant induces EGFR phosphorylation comparable to wild-type leptin. Exploiting this non-canonical leptin signalling pathway, we identified a camelid single-domain antibody that selectively inhibits this LR-EGFR cross talk without interfering with homotypic LR signalling. Administration in vivo showed that this single-domain antibody did not interfere with leptin’s metabolic functions, but could reverse the leptin-driven protection against starvation-induced thymic and splenic atrophy. These findings offer new opportunities for the design and clinical application of selective leptin and LR antagonists that avoid unwanted metabolic side effects.

RETRACTED: Hydroxyfasudil alleviates demyelination through the inhibition of MOG antibody and microglia activation in cuprizone mouse model

Multiple sclerosis (MS) is an immune-mediated demyelinating disease of the central nervous system characterized by oligodendrocyte loss and progressive neurodegeneration. The cuprizone (CPZ)-induced demyelination is widely used to investigate the demyelination/remyelination. Here, we explored the therapeutic effects of Hydroxyfasudil (HF), an active metabolite of Fasudil, in CPZ model. HF improved behavioral abnormality and reduced myelin damage in the corpus callosum. Splenic atrophy and myelin oligodendrocyte glycoprotein (MOG) antibody were observed in CPZ model, which were partially restored and obviously inhibited by HF, therefore reducing pathogenic binding of MOG antibody to oligodendrocytes. HF inhibited the percentages of CD4+IL-17+ T cells from splenocytes and infiltration of CD4+ T cells and CD68+ macrophages in the brain. HF also declined microglia-mediated neuroinflammation, and promoted the production of astrocyte-derived brain derived neurotrophic factor (BDNF) and regeneration of NG2+ oligodendrocyte precursor cells. These results provide potent evidence for the therapeutic effects of HF in CPZ-induced demyelination.

Temporary Loading Prevents Cancer Progression and Immune Organ Atrophy Induced by Hind-Limb Unloading in Mice.

Although the body’s immune system is altered during spaceflight, the effects of microgravity (μG) on tumor growth and carcinogenesis are, as yet, unknown. To assess tumor proliferation and its effects on the immune system, we used a hind-limb unloading (HU) murine model to simulate μG during spaceflight. HU mice demonstrated significantly increased tumor growth, metastasis to the lung, and greater splenic and thymic atrophy compared with mice in constant orthostatic suspension and standard housing controls. In addition, mice undergoing temporary loading during HU (2 h per day) demonstrated no difference in cancer progression and immune organ atrophy compared with controls. Our findings suggest that temporary loading can prevent cancer progression and immune organ atrophy induced by HU. Further space experiment studies are warranted to elucidate the precise effects of μG on systemic immunity and cancer progression.

Protective and therapeutic role of Bilobalide in cuprizone-induced demyelination

Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system characterized by recurrent and progressive demyelination, neuroinflammation and oligodendrocyte loss. The cuprizone (CPZ) model is characterized by primary and reversible demyelination, accompanied by oligodendrocyte loss and neuroinflammation. In the current study, we explored the efficiency of Bilobalide in the demyelination and remyelination. The results demonstrate that Bilobalide improved behavioral abnormality and promoted remyelination in the corpus callosum by using Luxol Fast Blue, Black Gold II and myelin basic protein (MBP) staining. We for the first time found that CPZ caused the splenic atrophy and induced the formation of myelin oligodendrocyte glycoprotein (MOG) antibody, which was attenuated by Bilobalide. Thus, Bilobalide decreased the loss of O4+ oligodendrocytes possibly through MOG antibody-dependent cell cytotoxicity. Bilobalide also prevented the infiltration of CD4+ T cells, CD68+ macrophages and B220+ B cells within the brain, and reduced the inflammatory microenvironment mediated with Iba1+iNOS+ and Iba1+NF-kB+ microglia after CPZ challenge, accompanied by the inhibition of IL-1β and IL-6 in the brain. These results identify a potent therapeutic efficiency for Bilobalide and highlight clear pleiotropic effects of the compound beyond specific autoantibody and inflammatory microenvironment in CPZ-mediated demyelination.

English

Punica granatum, specifically the fruit, has a long ethno medical history and is a phytochemical reservoir of great medicinal value. The phytochemistry and pharmacological actions of all P. granatum components suggest a wide range of clinical applications. The aim of the present study is to investigate the anticancer potential of aqueous extract of P. granatum (AEPG) in experimental models. The chemical composition of the AEPG was assessed by HPLC-DAD. In vivo antitumor activity was assessed in sarcoma 180 bearing mice. To evaluate the toxicological aspects related to the AEPG treatment, hematological, biochemical, histopathological and morphological analyses of treated animals were performed. Gallic acid, punicalagin α, punicalagin β, and ellagic acid were identified as the major phytochemical compounds of the extract. AEPG and 5-fluorouracil (5-FU) induced significant inhibition of tumor growth when compared with saline (p < 0.05). The percentage of apoptotic cells was significantly increased in 5-FU (p < 0.01) and AEPG treated groups (p < 0.01). No significant difference was observed between 5-FU and the three doses of AEPG. 5-FU induced toxic effects, such as decrease of body weight, splenic atrophy, and leukopenia, but these effects were not found in AEPG treated groups. The results provide evidence that AEPG exhibits comparable antitumor effects as 5-FU in a murine model, likely the result of increased apoptotic rate, but with no remarkable side effects presented by 5-FU. Key words: Cancer, chemotherapy, Punica granatum, sarcoma 180.

CLEC16A regulates splenocyte and NK cell function in part through MEK signaling.

CLEC16A is implicated in multiple autoimmune diseases. We generated Clec16a inducible knockout (KO) mice to examine the functional link between CLEC16A auto-inflammation and autoimmunity. Clec16a KO mice exhibited weight loss and thymic and splenic atrophy. Mitochondrial potential was lowered in KO mice splenocytes resulting in aggregation of unhealthy mitochondria in B, T, and NK cells. In Clec16a KO mice we detected disrupted mitophagy in splenic B and T cells. NK cells from Clec16a KO mice exhibited increased cytotoxicity. Incomplete mitophagy was attenuated with PI3K and/or MEK inhibition in Clec16a KO mice. Our results demonstrate a functional link between CLEC16A and disrupted mitophagy in immune cells and show that incomplete mitophagy predisposes the KO mice to inflammation. Taken together, loss of function variants in CLEC16A that are associated with decreased CLEC16A expression levels may contribute to inflammation in autoimmunity through disrupted mitophagy. Drugs modulating mitophagy reverse the process and may be effective in treating and preventing autoimmunity in individuals with risk associated CLEC16A variants.