Effects of Gamma-Tocotrienol on Intestinal Injury in a GI-Specific Acute Radiation Syndrome Model in Nonhuman Primate

The gastrointestinal (GI) system is highly susceptible to irradiation. Currently, there is no Food and Drug Administration (FDA)-approved medical countermeasures for GI radiation injury. The vitamin E analog gamma-tocotrienol (GT3) is a promising radioprotector in mice and nonhuman primates (NHP). We evaluated GT3-mediated GI recovery in total-body irradiated (TBI) NHPs. Sixteen rhesus macaques were divided into two groups; eight received vehicle and eight GT3 24 h prior to 12 Gy TBI. Proximal jejunum was assessed for structural injuries and crypt survival on day 4 and 7. Apoptotic cell death and crypt cell proliferation were assessed with TUNEL and Ki-67 immunostaining. Irradiation induced significant shortening of the villi and reduced mucosal surface area. GT3 induced an increase in crypt depth at day 7, suggesting that more stem cells survived and proliferated after irradiation. GT3 did not influence crypt survival after irradiation. GT3 treatment caused a significant decline in TUNEL-positive cells at both day 4 (p < 0.03) and 7 (p < 0.0003). Importantly, GT3 induced a significant increase in Ki-67-positive cells at day 7 (p < 0.05). These data suggest that GT3 has radioprotective function in intestinal epithelial and crypt cells. GT3 should be further explored as a prophylactic medical countermeasure for radiation-induced GI injury.     

Differential Effects of Low and High Radiation Dose Rates on Mouse Spermatogenesis

The adverse effects of radiation are proportional to the total dose and dose rate. We aimed to investigate the effects of radiation dose rate on different organs in mice. The mice were subjected to low dose rate (LDR, ~3.4 mGy/h) and high dose rate (HDR, ~51 Gy/h) radiation. LDR radiation caused severe tissue toxicity, as observed in the histological analysis of testis. It adversely influenced sperm production, including sperm count and motility, and induced greater sperm abnormalities. The expression of markers of early stage spermatogonial stem cells, such as Plzf, c-Kit, and Oct4, decreased significantly after LDR irradiation, compared to that following exposure of HDR radiation, in qPCR analysis. The compositional ratios of all stages of spermatogonia and meiotic cells, except round spermatid, were considerably reduced by LDR in FACS analysis. Therefore, LDR radiation caused more adverse testicular damage than that by HDR radiation, contrary to the response observed in other organs. Therefore, the dose rate of radiation may have differential effects, depending on the organ; it is necessary to evaluate the effect of radiation in terms of radiation dose, dose rate, organ type, and other conditions.     

Investigation of Plasma-Derived Lipidome Profiles in Experimental Cerebral Malaria in a Mouse Model Study

Cerebral malaria (CM), a fatal complication of Plasmodium infection that affects children, especially under the age of five, in sub-Saharan Africa and adults in South-East Asia, results from incompletely understood pathogenetic mechanisms. Increased release of circulating miRNA, proteins, lipids and extracellular vesicles has been found in CM patients and experimental mouse models. We compared lipid profiles derived from the plasma of CBA mice infected with Plasmodium berghei ANKA (PbA), which causes CM, to those from Plasmodium yoelii (Py), which does not. We previously showed that platelet-free plasma (18k fractions enriched from plasma) contains a high number of extracellular vesicles (EVs). Here, we found that this fraction produced at the time of CM differed dramatically from those of non-CM mice, despite identical levels of parasitaemia. Using high-resolution liquid chromatography–mass spectrometry (LCMS), we identified over 300 lipid species within 12 lipid classes. We identified 45 and 75 lipid species, mostly including glycerolipids and phospholipids, with significantly altered concentrations in PbA-infected mice compared to Py-infected and uninfected mice, respectively. Total lysophosphatidylethanolamine (LPE) levels were significantly lower in PbA infection compared to Py infection and controls. These results suggest that experimental CM could be characterised by specific changes in the lipid composition of the 18k fraction containing circulating EVs and can be considered an appropriate model to study the role of lipids in the pathophysiology of CM.     

Antiviral and Anti-Inflammatory Activities of Fluoxetine in a SARS-CoV-2 Infection Mouse Model

The coronavirus disease 2019 (COVID-19) pandemic continues to cause significant morbidity and mortality worldwide. Since a large portion of the world’s population is currently unvaccinated or incompletely vaccinated and has limited access to approved treatments against COVID-19, there is an urgent need to continue research on treatment options, especially those at low cost and which are immediately available to patients, particularly in low- and middle-income countries. Prior in vitro and observational studies have shown that fluoxetine, possibly through its inhibitory effect on the acid sphingomyelinase/ceramide system, could be a promising antiviral and anti-inflammatory treatment against COVID-19. In this report, we evaluated the potential antiviral and anti-inflammatory activities of fluoxetine in a K18-hACE2 mouse model of SARS-CoV-2 infection, and against variants of concern in vitro, i.e., SARS-CoV-2 ancestral strain, Alpha B.1.1.7, Gamma P1, Delta B1.617 and Omicron BA.5. Fluoxetine, administrated after SARS-CoV-2 infection, significantly reduced lung tissue viral titres and expression of several inflammatory markers (i.e., IL-6, TNFα, CCL2 and CXCL10). It also inhibited the replication of all variants of concern in vitro. A modulation of the ceramide system in the lung tissues, as reflected by the increase in the ratio HexCer 16:0/Cer 16:0 in fluoxetine-treated mice, may contribute to explain these effects. Our findings demonstrate the antiviral and anti-inflammatory properties of fluoxetine in a K18-hACE2 mouse model of SARS-CoV-2 infection, and its in vitro antiviral activity against variants of concern, establishing fluoxetine as a very promising candidate for the prevention and treatment of SARS-CoV-2 infection and disease pathogenesis.     

植物纤维有氧条件下的热稳定特性的研究

在有氧体系中,植物纤维的理化性能随温度、时间将发生一系列变化,主要表现为性能上的不同程度的劣化。运用均匀设计的方法对105－240℃温度区间内．不同作用时间植物纤维的主要理化描述参数的热反应关系进行多元非线性回归分析,研究认为植物纤维的热反应首先发生在纤维素大分子的非结晶区域,并逐渐向结晶区域扩展。这对于植物纤维的合理利用（包括实施稳定化处理）具有指导意义,并对研究植物纤维的反应特性有重要意义。     

圆柱状人工肝生物反应器中溶解氧浓度动态分布模型及其氧浓度变化速率

从人工肝治疗的需要出发,建立了圆柱状专用生物反应器中溶解氧浓度动态分布的数学机理模型,并分析了反应器内部实时氧浓度变化速率,设计出了溶氧变化的在线检测方法,结合模型推导出反应器内部总氧浓度变化量与实时氧浓度变化速率之间的关系. 通过仿真数据与实测实验的对比验证了该模型的正确性,其平均误差在±5%以内,氧浓度变化速率误差在±1%以内,验证了总氧浓度变化量dDO与实时氧浓度变化速率R之间满足dDO=MNDhR/V.     

Effect of Placenta-Derived Mesenchymal Stromal Cells Conditioned Media on an LPS-Induced Mouse Model of Preeclampsia

We tested the pro-angiogenic and anti-inflammatory effects of human placenta-derived mesenchymal stromal cells (hPDMSCs)-derived conditioned media (CM) on a mouse model of preeclampsia (PE), a severe human pregnancy-related syndrome characterized by maternal hypertension, proteinuria, endothelial damage, inflammation, often associated with fetal growth restriction (FGR). At d11 of pregnancy, PE was induced in pregnant C57BL/6N mice by bacterial lipopolysaccharide (LPS) intravenous injection. At d12, 300 μL of unconditioned media (control group) or 300 μL PDMSCs-CM (CM group) were injected. Maternal systolic blood pressure was measured from 9 to 18 days of pregnancy. Urine protein content were analyzed at days 12, 13, and 17 of pregnancy. At d19, mice were sacrificed. Number of fetuses, FGR, fetal reabsorption, and placental weight were evaluated. Placentae were analyzed for sFlt-1, IL-6, and TNF-α gene and protein expressions. No FGR and/or reabsorbed fetuses were delivered by PDMSCs-CM-treated PE mice, while five FGR fetuses were found in the control group accompanied by a lower placental weight. PDMSCs-CM injection significantly decreased maternal systolic blood pressure, proteinuria, sFlt-1, IL-6, and TNF-α levels in PE mice. Our data indicate that hPDMSCs-CM can reverse PE-like features during pregnancy, suggesting a therapeutic role for hPDMSCs for the treatment of preeclampsia.     

The Relevance of miRNA-21 in HSV-Induced Inflammation in a Mouse Model

The purpose of this study was to clarify the correlation between microRNA-21 (miR-21) expression and inflammation in a herpes simplex virus (HSV)-induced Behçet’s Disease (BD) mouse model. miR-21 was compared between BD patients and healthy controls in peripheral blood mononuclear cells (PBMC). For miR-21 inhibition, miR-21 antagomir was applied to BD mice. The change of symptoms was monitored. The levels of cytokines and related molecules were determined by ELISA and real time qPCR. Treatment with colchicine or pentoxifylline down-regulated the level of miR-21 with improved symptoms in mice. miR-21 inhibition was accompanied by down-regulated serum levels of IL-17 and IL-6. The expression levels of PDCD4, RhoB, PD-1, IL-12p35, and toll-like receptor-4 were also regulated by miR-21 inhibition. miR-21 was correlated with HSV-induced BD-like inflammation in mice and BD patients. The expression of miR-21 was regulated by antagomir in mice.     

Lipid Metabolism Is Dysregulated before,during and after Pregnancy in a Mouse Model of Gestational Diabetes

The aim of the current study was to test the hypothesis that maternal lipid metabolism was modulated during normal pregnancy and that these modulations are altered in gestational diabetes mellitus (GDM). We tested this hypothesis using an established mouse model of diet-induced obesity with pregnancy-associated loss of glucose tolerance and a novel lipid analysis tool, Lipid Traffic Analysis, that uses the temporal distribution of lipids to identify differences in the control of lipid metabolism through a time course. Our results suggest that the start of pregnancy is associated with several changes in lipid metabolism, including fewer variables associated with de novo lipogenesis and fewer PUFA-containing lipids in the circulation. Several of the changes in lipid metabolism in healthy pregnancies were less apparent or occurred later in dams who developed GDM. Some changes in maternal lipid metabolism in the obese-GDM group were so late as to only occur as the control dams’ systems began to switch back towards the non-pregnant state. These results demonstrate that lipid metabolism is modulated in healthy pregnancy and the timing of these changes is altered in GDM pregnancies. These findings raise important questions about how lipid metabolism contributes to changes in metabolism during healthy pregnancies. Furthermore, as alterations in the lipidome are present before the loss of glucose tolerance, they could contribute to the development of GDM mechanistically.     

Tenomodulin Inhibits Retinal Neovascularization in a Mouse Model of Oxygen-Induced Retinopathy

We aimed to determine the anti-angiogenic effect of tenomodulin (TeM) on retinal neovascularization in an oxygen-induced retinopathy (OIR) mouse model. OIR was induced in C57BL/6 mice by exposing seven-day-old mice to 75% oxygen for five days followed by room air for five days. Control mice were exposed to room air from birth until postnatal day 17. Mice received intravitreal injections of 1 μg of TeM in one eye and PBS in the contralateral eye at P7 before being exposed to 75% oxygen. Eyes were collected at postnatal day 17. Retinal blood vessel patterns were visualized by fluorescein angiography. We quantified the number of neovascular nuclei that were present beyond the inner limiting membrane (ILM) using histological methods with a masked approach. Furthermore, double immunohistochemical staining of TeM was performed on retinas to identify nuclei protruding into the vitreous cavity. Western blot was used to detect exogenous TeM protein. The central nonperfusion area (NPA, mm²) of TeM-injected eyes was significantly different from that of OIR and PBS-injected eyes, and the number of nuclei in new blood vessels breaking through the ILM in each retinal cross-section significantly differed from that of OIR eyes and PBS-injected control eyes. Cellular nuclei of new blood vessels protruding into the vitreous cavity were also observed in TeM-injected retinas by immunohistochemistry. Western blotting revealed a 16-kDa immunoreactive protein, indicating incorporation of an exogenous TeM fragment into the retina. Our data shows that TeM can effectively inhibit pathological angiogenesis in mouse eyes; indicating its potential role in prevention and treatment of ocular neovascularization.     

Aquaporin-4 Mediates Permanent Brain Alterations in a Mouse Model of Hypoxia-Aged Hydrocephalus

Aquaporin-4 (AQP4) is the principal water channel in the brain being expressed in astrocytes and ependymal cells. AQP4 plays an important role in cerebrospinal fluid (CSF) homeostasis, and alterations in its expression have been associated with hydrocephalus. AQP4 contributes to the development of hydrocephalus by hypoxia in aged mice, reproducing such principal characteristics of the disease. Here, we explore whether these alterations associated with the hydrocephalic state are permanent or can be reverted by reexposure to normoxia. Alterations such as ventriculomegaly, elevated intracranial pressure, and cognitive deficits were reversed, whereas deficits in CSF outflow and ventricular distensibility were not recovered, remaining impaired even one month after reestablishment of normoxia. Interestingly, in AQP4^−/− mice, the impairment in CSF drainage and ventricular distensibility was completely reverted by re-normoxia, indicating that AQP4 has a structural role in the chronification of those alterations. Finally, we show that aged mice subjected to two hypoxic episodes experience permanent ventriculomegaly. These data reveal that repetitive hypoxic events in aged cerebral tissue promote the permanent alterations involved in hydrocephalic pathophysiology, which are dependent on AQP4 expression.     

Epigallocatechin Gallate Ameliorates the Effects of Prenatal Alcohol Exposure in a Fetal Alcohol Spectrum Disorder-Like Mouse Model

Fetal alcohol spectrum disorder is the main preventable cause of intellectual disability in the Western world. Although binge drinking is the most studied prenatal alcohol exposure pattern, other types of exposure, such as the Mediterranean, are common in specific geographic areas. In this study, we analyze the effects of prenatal alcohol exposure in binge and Mediterranean human drinking patterns on placenta and brain development in C57BL/6J mice. We also assess the impact of prenatal treatment with the epigallocatechin-3-gallate antioxidant in both groups. Study experimental groups for Mediterranean or binge patterns: (1) control; (2) ethanol; (3) ethanol + epigallocatechin-3-gallate. Brain and placental tissue were collected on gestational Day 19. The molecular pathways studied were fetal and placental growth, placental angiogenesis (VEGF-A, PLGF, VEGF-R), oxidative stress (Nrf2), and neurodevelopmental processes including maturation (NeuN, DCX), differentiation (GFAP) and neural plasticity (BDNF). Prenatal alcohol exposure resulted in fetal growth restriction and produced imbalances of placental angiogenic factors. Moreover, prenatal alcohol exposure increased oxidative stress and caused significant alterations in neuronal maturation and astrocyte differentiation. Epigallocatechin-3-gallate therapy ameliorated fetal growth restriction, attenuated alcohol-induced changes in placental angiogenic factors, and partially rescued neuronal nuclear antigen (NeuN), (doublecortin) DCX, and (glial fibrillary acidic protein) GFAP levels. Any alcohol consumption (Mediterranean or binge) during pregnancy may generate a fetal alcohol spectrum disorder phenotype and the consequences may be partially attenuated by a prenatal treatment with epigallocatechin-3-gallate.     

无外界氧补偿条件下乳状液中多不饱和脂肪酸氧化模型

建立了在无外界氧补偿条件下乳状液中多不饱和脂肪酸(PUFA)氧化的数学模型。该模型综合考虑了乳化剂形成的液膜边界层阻力、PUFA自催化氧化反应以及油水相比表面积等因素的影响。实验验证了该模型能较好地拟合无外界氧补偿条件下乳状液中氧的扩散和亚油酸的氧化过程,并模拟计算了乳化剂膜传质系数和油水相比表面积等因素对扩散-氧化的影响程度。结果表明,乳化剂膜传质系数和油水相比表面积是影响乳状液中PUFA的氧化的主要因素。     

Additive Benefits of Radium-223 Dichloride and Bortezomib Combination in a Systemic Multiple Myeloma Mouse Model

Osteolytic bone disease is a hallmark of multiple myeloma (MM) mediated by MM cell proliferation, increased osteoclast activity, and suppressed osteoblast function. The proteasome inhibitor bortezomib targets MM cells and improves bone health in MM patients. Radium-223 dichloride (radium-223), the first targeted alpha therapy approved, specifically targets bone metastases, where it disrupts the activity of both tumor cells and tumor-supporting bone cells in mouse models of breast and prostate cancer bone metastasis. We hypothesized that radium-223 and bortezomib combination treatment would have additive effects on MM. In vitro experiments revealed that the combination treatment inhibited MM cell proliferation and demonstrated additive efficacy. In the systemic, syngeneic 5TGM1 mouse MM model, both bortezomib and radium-223 decreased the osteolytic lesion area, and their combination was more effective than either monotherapy alone. Bortezomib decreased the number of osteoclasts at the tumor–bone interface, and the combination therapy resulted in almost complete eradication of osteoclasts. Furthermore, the combination therapy improved the incorporation of radium-223 into MM-bearing bone. Importantly, the combination therapy decreased tumor burden and restored body weights in MM mice. These results suggest that the combination of radium-223 with bortezomib could constitute a novel, effective therapy for MM and, in particular, myeloma bone disease.     

Hypoxic and Hypercapnic Responses in Transgenic Murine Model of Alzheimer’s Disease Overexpressing Human AβPP: The Effects of Pretreatment with Memantine and Rivastigmine

Despite the severe respiratory problems reducing the quality of life for Alzheimer’s disease (AD) patients, their causes are poorly understood. We aimed to investigate hypoxic and hypercapnic respiratory responses in a transgenic mouse model of AD (AβPP V717I) overexpressing AβPP and mimicking early-onset AD. The cholinesterase inhibitor rivastigmine and the NMDA receptor antagonist memantine were used to investigate the effects of drugs, used to treat AD cognitive dysfunction, on breathing in hypoxia and hypercapnia. We found a significant increase in the respiratory response to hypercapnia and no difference in the hypoxic response in APP+ mice, compared with the control group (APP−). Memantine had no effect on respiration in either group, including responses to hypoxia and hypercapnia. Rivastigmine depressed resting ventilation and response to hypercapnia irrespective of the mice genotype. Reduction in hypoxia-augmented ventilation by rivastigmine was observed only in APP+ mice, which exhibited lower acetylcholinesterase activity in the hippocampus. Treatment with rivastigmine reduced the enzyme activity in both groups equally in the hippocampus and brainstem. The increased ventilatory response to hypercapnia in transgenic mice may indicate alterations in chemoreceptive respiratory nuclei, resulting in increased CO₂ sensitivity. Rivastigmine is a potent reductant of normoxic and hypercapnic respiration in APP+ and APP− mice.     

Aberrant Mitochondrial Dynamics and Exacerbated Response to Neuroinflammation in a Novel Mouse Model of CMT2A

Charcot-Marie-Tooth disease type 2A (CMT2A) is the most common hereditary axonal neuropathy caused by mutations in MFN2 encoding Mitofusin-2, a multifunctional protein located in the outer mitochondrial membrane. In order to study the effects of a novel MFN2^K357T mutation associated with early onset, autosomal dominant severe CMT2A, we generated a knock-in mouse model. While Mfn2^K357T/K357T mouse pups were postnatally lethal, Mfn2^+/K357T heterozygous mice were asymptomatic and had no histopathological changes in their sciatic nerves up to 10 months of age. However, immunofluorescence analysis of Mfn2^+/K357T mice revealed aberrant mitochondrial clustering in the sciatic nerves from 6 months of age, in optic nerves from 8 months, and in lumbar spinal cord white matter at 10 months, along with microglia activation. Ultrastructural analyses confirmed dysmorphic mitochondrial aggregates in sciatic and optic nerves. After exposure of 6-month-old mice to lipopolysaccharide, Mfn2^+/K357T mice displayed a higher immune response, a more severe motor impairment, and increased CNS inflammation, microglia activation, and macrophage infiltrates. Overall, ubiquitous Mfn2^K357T expression renders the CNS and peripheral nerves of Mfn2^+/K357T mice more susceptible to mitochondrial clustering, and augments their response to inflammation, modeling some cellular mechanisms that may be relevant for the development of neuropathy in patients with CMT2A.     

Size-Based Effects of Anthropogenic Ultrafine Particles on Lysosomal TRPML1 Channel and Autophagy in Motoneuron-like Cells

Background: An emerging body of evidence indicates an association between anthropogenic particulate matter (PM) and neurodegeneration. Although the historical focus of PM toxicity has been on the cardiopulmonary system, ultrafine PM particles can also exert detrimental effects in the brain. However, only a few studies are available on the harmful interaction between PM and CNS and on the putative pathomechanisms. Methods: Ultrafine PM particles with a diameter < 0.1 μm (PM0.1) and nanoparticles < 20 nm (NP20) were sampled in a lab-scale combustion system. Their effect on cell tracking in the space was studied by time-lapse and high-content microscopy in NSC-34 motor neurons while pHrodo™ Green conjugates were used to detect PM endocytosis. Western blotting analysis was used to quantify protein expression of lysosomal channels (i.e., TRPML1 and TPC2) and autophagy markers. Current-clamp electrophysiology and Fura2-video imaging techniques were used to measure membrane potential, intracellular Ca²⁺ homeostasis and TRPML1 activity in NSC-34 cells exposed to PM0.1 and NP20. Results: NP20, but not PM0.1, reduced NSC-34 motor neuron movement in the space. Furthermore, NP20 was able to shift membrane potential of motor neurons toward more depolarizing values. PM0.1 and NP20 were able to enter into the cells by endocytosis and exerted mitochondrial toxicity with the consequent stimulation of ROS production. This latter event was sufficient to determine the hyperactivation of the lysosomal channel TRPML1. Consequently, both LC3-II and p62 protein expression increased after 48 h of exposure together with AMPK activation, suggesting an engulfment of autophagy. The antioxidant molecule Trolox restored TRPML1 function and autophagy. Conclusions: Restoring TRPML1 function by an antioxidant agent may be considered a protective mechanism able to reestablish autophagy flux in motor neurons exposed to nanoparticles.