Calpain-mediated Hsp70.1 cleavage in hippocampal CA1 neuronal death

Necrotic neuronal death is recently known to be mediated by the calpain-cathepsin cascade from simpler organisms to primates. The main event of this cascade is calpain-mediated lysosomal rupture and the resultant release of lysosomal cathepsins into the cytoplasm. However, the in-vivo substrate of calpain for inducing lysosomal destabilization still remains completely unknown. The recent proteomics data using the post-ischemic hippocampal CA1 tissues and glaucoma-suffered retina from the primates suggested that heat shock protein (Hsp) 70.1 might be the in-vivo substrate of activated μ-calpain at the lysosomal membrane of neurons. Hsp70.1 is known to stabilize lysosomal membrane by recycling damaged proteins and protect cells from oxidative stresses. Here, we studied the molecular interaction between activated μ-calpain and the lysosomal Hsp70.1 in the monkey hippocampal CA1 neurons after the ischemia-reperfusion insult. Immunofluorescence histochemistry showed a colocalization of the activated μ-calpain and upregulated Hsp70.1 at the lysosomal membrane of the post-ischemic CA1 neurons. In-vitro cleavage assay of hippocampal Hsp70.1 by Western blotting demonstrated that Hsp70.1 in the CA1 tissue is an in-vivo substrate of activated μ-calpain, and that carbonylated Hsp70.1 in the CA1 tissue by artificial oxidative stressors such as hydroxynonenal (HNE) or hydrogen peroxide is much more vulnerable to the calpain cleavage. These data altogether suggested that Hsp70.1 can become a target of the carbonylation by HNE, and Hsp70.1 is a modulator of calpain-mediated lysosomal rupture/permeabilization after the ischemia-reperfusion injury.     

Lysosomal enzymes promote mitochondrial oxidant production, cytochrome c release and apoptosis.

Exposure of mammalian cells to oxidant stress causes early (iron catalysed) lysosomal rupture followed by apoptosis or necrosis. Enhanced intracellular production of reactive oxygen species (ROS), presumably of mitochondrial origin, is also observed when cells are exposed to nonoxidant pro-apoptotic agonists of cell death. We hypothesized that ROS generation in this latter case might promote the apoptotic cascade and could arise from effects of released lysosomal materials on mitochondria. Indeed, in intact cells (J774 macrophages, HeLa cells and AG1518 fibroblasts) the lysosomotropic detergent O-methyl-serine dodecylamide hydrochloride (MSDH) causes lysosomal rupture, enhanced intracellular ROS production, and apoptosis. Furthermore, in mixtures of rat liver lysosomes and mitochondria, selective rupture of lysosomes by MSDH promotes mitochondrial ROS production and cytochrome c release, whereas MSDH has no direct effect on ROS generation by purifed mitochondria. Intracellular lysosomal rupture is associated with the release of (among other constituents) cathepsins and activation of phospholipase A2 (PLA2). We find that addition of purified cathepsins B or D, or of PLA2, causes substantial increases in ROS generation by purified mitochondria. Furthermore, PLA2 - but not cathepsins B or D - causes rupture of semipurified lysosomes, suggesting an amplification mechanism. Thus, initiation of the apoptotic cascade by nonoxidant agonists may involve early release of lysosomal constituents (such as cathepsins B and D) and activation of PLA2, leading to enhanced mitochondrial oxidant production, further lysosomal rupture and, finally, mitochondrial cytochrome c release. Nonoxidant agonists of apoptosis may, thus, act through oxidant mechanisms.     

Oxidative stress,growth factor starvation and Fas activation may all cause apoptosis through lysosomal leak

Abstract

Oxidative stress, growth factor starvation, and activation of the Fas/APO-1/CD95 receptor all induce apoptosis in a variety of cell-types, including the established human Jurkat T-cell line. Oxidative stress, in the form of exposure of the cells to a bolus dose of hydrogen peroxide, results in intra-lysosomal, iron-catalyzed oxidative reactions. This is accompanied by a time- and dose-dependent lysosomal destabilization — as evaluated by a decreased lysosomal uptake of the metachromatic fluorochrome, and weak base, acridine orange —in combination with leakage to the cytosol of lysosomal contents, including hydrolytic enzymes. Moderate lysosomal rupture is followed by apoptosis within initially intact plasma membranes, while necrosis and cell lysis are associated with a more complete lysosomal breach. Prior endocytosis of the potent iron-chelator desferrioxamine,resulting in binding of intralysosomal low molecular weight iron in a non-redox active form, largely prevents not only oxidative stress-induced lysosomal labilization, but apoptosis as well. When apoptosis is induced by the use of a monoclonal IgM anti-human Fas/APO-1/CD95 receptor antibody, the apoptotic process is again found to be accompanied by lysosomal leak. It is, however, not prevented by a preceding endocytosis of desferrioxamine and, consequently, could not be a function of intralysosomal iron-catalyzed oxidative reactions,but must be due to other mechanisms. Growth factor starvation of Jurkat cultures for a few days results in a high proportion of apoptotic cells, which contain lysosomes many of which have lost their proton gradient and appear to have released their contents. Overall, our results indicate that lysosomal leakage/rupture precedes apoptosis in Jurkat cells regardless of the initiating agent, but that such rupture may occur through multiple mechanisms. Lysosomal enzymes, leaking out of their normal vacuolar compartment, may then induce apoptosis, perhaps by proteolytic activation of the caspase-family of enzymes. Regardless of the precise mechanism, these observations suggest that partial rupture of the acidic vacuolar compartment may be one of the finalpathways in apoptosis.     

Magnesium deprivation inhibits a MEK–ERK cascade and cell proliferation in renal epithelial Madin-Darby canine kidney cells

AimsLoss of magnesium (Mg²⁺) inhibits cell proliferation and augments nephrotoxicant-induced renal injury, but the role of Mg²⁺ has not been clarified in detail. We examined the effect of extracellular Mg²⁺ deprivation on a MEK–ERK cascade and cell proliferation using a renal epithelial cell line, Madin-Darby canine kidney (MDCK) cells.Main methodsMDCK cells were cultured in Mg²⁺-containing or Mg²⁺-free media. A HA-tagged constitutively active (CA)-MEK1 and a dominant negative (DN)-MEK1 were transfected into MDCK cells. The level of protein was examined by Western blotting. The intracellular free Mg²⁺ concentration ([Mg²⁺]_i) was measured using a fluorescent dye, mag-fura 2. Cell proliferation was determined by WST-1 assay. Dead cells were identified by staining with annexin V-FITC and propidium iodide.Key findingsIn the presence of fetal calf serum (FCS), Mg²⁺ deprivation decreased phosphorylated-ERK1/2 (p-ERK1/2) levels and [Mg²⁺]_i. Re-addition of Mg²⁺ increased p-ERK1/2 levels, which were inhibited by U0126, a specific inhibitor of a MEK–ERK cascade. Glutathione-S-transferase pull-down and coimmunoprecipitation assays showed that CA-MEK1 and DN-MEK1 binds with ERK1/2 in the presence of Mg²⁺. In contrast, neither CA-MEK1 nor DN-MEK1 bound to ERK1/2 in the absence of Mg²⁺. These results indicate that the MEK–ERK cascade is regulated by [Mg²⁺]_i. Cell proliferation was increased by the treatment with FCS or the expression of CA-MEK1 in the presence of Mg²⁺, but was inhibited by Mg²⁺ deprivation. Mg²⁺ deprivation did not increase the number of dead cells.SignificanceMg²⁺ is involved in the regulation of the MEK–ERK cascade and cell proliferation in MDCK cells.     

Defects in calcium homeostasis and mitochondria can be reversed in Pompe disease

Mitochondria-induced oxidative stress and flawed autophagy are common features of neurodegenerative and lysosomal storage diseases (LSDs). Although defective autophagy is particularly prominent in Pompe disease, mitochondrial function has escaped examination in this typical LSD. We have found multiple mitochondrial defects in mouse and human models of Pompe disease, a life-threatening cardiac and skeletal muscle myopathy: a profound dysregulation of Ca²⁺ homeostasis, mitochondrial Ca²⁺ overload, an increase in reactive oxygen species, a decrease in mitochondrial membrane potential, an increase in caspase-independent apoptosis, as well as a decreased oxygen consumption and ATP production of mitochondria. In addition, gene expression studies revealed a striking upregulation of the β 1 subunit of L-type Ca²⁺ channel in Pompe muscle cells. This study provides strong evidence that disturbance of Ca²⁺ homeostasis and mitochondrial abnormalities in Pompe disease represent early changes in a complex pathogenetic cascade leading from a deficiency of a single lysosomal enzyme to severe and hard-to-treat autophagic myopathy. Remarkably, L-type Ca²⁺channel blockers, commonly used to treat other maladies, reversed these defects, indicating that a similar approach can be beneficial to the plethora of lysosomal and neurodegenerative disorders.     

脾全切除术与脾部分切除术治疗外伤性脾破裂的临床疗效对比

目的:比较脾全切除术和脾部分切除术治疗外伤性脾破裂的临床疗效和安全性。方法:选择我院2013年3月~2016年3月收治的84例外伤性脾破裂患者并平均分为两组,脾全切除组42例采用脾全切除术治疗,脾部分切除组42例采用脾部分切除术治疗,比较两组的手术效果、治疗前后血小板计数、血清Ig A、Ig G、Ig M、CD3~+、CD4~+、CD8~+及CD4~+/CD8~+水平的变化以及术后并发症的发生情况。结果:部分切除组术中失血量、排气时间、住院时间均短于全切除组,但部分切除组手术时间显著长于全切除组,差异有统计学意义(P0.05)。部分切除组血小板计数、Ig M、CD8~+水平明显低于对照组,Ig A、Ig G、CD3~+、CD4~+、CD8~+、CD4~+/CD8~+显著高于全切除组(P0.05)。部分切除组并发症发生率显著低于全切除组(P0.05)。结论:脾部分切除术治疗外伤性脾裂的手术效果优于脾全切除术,且对患者血小板及免疫功能的影响较小。     

脾脏保留手术对外伤性脾破裂患者免疫功能的影响

目的:探究脾脏保留手术对外伤性脾破裂患者免疫功能的影响。方法:选取2015年8月~2018年9月我院收治的外伤性脾破裂患者83例进行回顾性分析,根据手术方式不同分为两组,对照组(41例)患者给予脾脏切除术,观察组(42例)患者给予脾脏保留手术。比较两组患者的手术时间、术中出血量、下床活动时间、术后1d引流量、抢救成功率及治疗前后CD3~+、CD4~+、CD8~+和Tuftsin因子水平和并发症的发生情况。结果:治疗后,观察组患者的手术时间、术中出血量、术后下床时间和术后1d引流量均显著短于或低于对照组,而救治成功率显著高于对照组(P0.05)。两组患者治疗后的CD3~+、CD4~+和CD4~+/CD8~+水平均较治疗前显著下降,且观察组以上指标均显著高于对照组(P0.05)。对照组治疗后血清Tuftsin因子水平较治疗前显著下降,而观察组血清Tuftsin因子水平较治疗前显著升高,并显著高于对照组(P0.05)。观察组患者的总并发症发生率为7.14%,较对照组(24.39%)显著降低(P0.05)。结论:与脾脏切除术相比,脾脏保留手术可显著改善外伤性脾破裂患者的免疫功能,且手术效果更好,安全性更高。     

Immunological and cytotoxicological responses of the Asian clam,Corbicula fluminea (M.), experimentally exposed to cadmium

Abstract

Bivalve molluscs, as filter-feeding organisms, are known to accumulate metals that can produce deleterious effects on organisms. The phagocytic activity of haemocytes and lysosomal alterations in the digestive gland cells were measured in the freshwater Asian clam exposed to cadmium, in order to assess the possible use of immunocompetence and lysosomal responses as biomarkers of freshwater quality. Clams were exposed in the laboratory to nominal concentrations of 3, 10, 21.4, 46.5 and 100 µg l^?1 of cadmium and sampled after 7, 15 and 30 days of exposure. The results show a decrease of phagocytic activity after only 7 days of exposure to 10 µg l^?1 of cadmium. This response was also observed as the exposure time was increased. Lysosomes in the digestive cells increased in size and number after 7 days of exposure as cadmium concentration increased. After 30 days of exposure, a decrease in size and number indicated a change in the response to the metal from concentrations of 46.5 µg l^?1 of cadmium. A dose and time response both in phagocytic activity of haemocytes and lysosomal structure demonstrated a possible use of these biomarkers in freshwater biomonitoring.     

Observation of the effect of the pregnancy complicated with the hepatitis B infection on the lying-in women and neonates

ObjectiveTo investigate the effect of pregnancy complicated with the hepatitis B infection on the pregnancy outcome, immunological factors and the subgroup of lymphocytes in neonates.MethodsSubjects admitting to this hospital between January 1, 2016 and January 1, 2018 in this study were divided into two groups according to the hepatitis B infection, i.e. the observation group (infection) and the control group (healthy), with 60 subjects in each group. Pregnancy complications and the neonatal complications were all recorded, and furthermore, the subgroups of lymphocytes and the levels of immunoglobin in the umbilical cord blood were measured.ResultsThe incidence rates of the premature rupture of fetal membranes, premature delivery, postpartum hemorrhage and pregnancy-induced hypertension syndrome in the observation group were all higher than those in the control group, and the differences had statistical significance. In the observation group, the incidence rates of the neonatal distress and asphyxia, and the levels of neonatal CD3^＋, CD4^＋, CD19^＋, IgA and IgM varied significantly from those in the control group, and the differences showed statistical significance. However, no significant differences were identified in comparison of the incidence rate of the cesarean delivery, neonatal deformity, neonatal death, or levels of neonatal CD8⁺ and IgG.ConclusionDuring pregnancy, complications of hepatitis B infection results in the increases in the incidence rates of the premature rupture of fetal membranes and neonatal asphyxia, with influences on the levels of immunological factors and lymphocyte subgroups in the umbilical cord blood.     

-Lipoic acid and -lipoamide prevent oxidant-induced lysosomal rupture and apoptosis

Abstract

-Lipoic acid (LA) and its corresponding derivative, -lipoamide (LM), have been described as antioxidants, but the mechanisms of their putative antioxidant effects remain largely uncharacterised. The vicinal thiols present in the reduced forms of these compounds suggest that they might possess metal chelating properties. We have shown previously that cell death caused by oxidants may be initiated by lysosomal rupture and that this latter event may involve intralysosomal iron which catalyzes Fenton-type chemistry and resultant peroxidative damage to lysosomal membranes. Here, using cultured J774 cells as a model, we show that both LA and LM stabilize lysosomes against oxidative stress, probably by chelating intralysosomal iron and, consequently, preventing intralysosomal Fenton reactions. In preventing oxidant-mediated apoptosis, LM is significantly more effective than LA, as would be expected from their differing capacities to enter cells and concentrate within the acidic lysosomal compartment. As previously reported, the powerful iron-chelator, desferrioxamine (Des) (which also locates within the lysosomal compartment), also provides protection against oxidant-mediated cell death. Interestingly, although Des enhances the partial protection afforded by LA, it confers no additional protection when added with LM. Therefore, the antioxidant actions of LA and LM may arise from intralysosomal iron chelation, with LM being more effective in this regard.     

The radioprotective agent,amifostine, suppresses the reactivity of intralysosomal iron

Abstract

Amifostine (2-[(3-aminopropyl)amino]ethane-thiol dihydrogen phosphate ester; WR-2721) is a radioprotective agent used clinically to minimize damage from radiation therapy to adjacent normal tissues. This inorganic thiophosphate requires dephosphorylation to produce the active, cell-permeant thiol metabolite, WR-1065. The activation step is presumably catalyzed by membrane-bound alkaline phosphatase, activity of which is substantially higher in the endothelium of normal tissues. This site-specific delivery may explain the preferential protection of normal versus neoplastic tissues. Although it was developed several decades ago, the mechanisms through which this agent exerts its protective effects remain unknown. Because WR-1065 is a weak base (pKa = 9.2), we hypothesized that the drug should preferentially accumulate (via proton trapping) within the acidic environment of intracellular lysosomes. These organelles contain abundant 'loose' iron and represent a likely initial target for oxidant- and radiation-mediated damage. We further hypothesized that, within the lysosomal compartment, the thiol groups of WR-1065 would interact with this iron, thereby minimizing iron-catalyzed lysosomal damage and ensuing cell death. A similar mechanism of protection via intralysosomal iron chelation has been invoked for the hexadentate iron chelator, desferrioxamine (DFO; although DFO enters the lysosomal compartment by endocytosis, not proton trapping). Using cultured J774 cells as a model system, we found substantial accumulation of WR-1065 within intracellular granules as revealed by reaction with the thiol-binding fluorochrome, BODIPY FL L-cystine. These granules are lysosomes as indicated by co-localization of BODIPY staining with LysoTracker Red. Compared to 1 mM DFO, cells pre-treated with 0.4 μM WR-1065 are protected from hydrogen peroxide-mediated lysosomal rupture and ensuing cell death. On a molar basis in this experimental system, WR-1065 is approximately 2500 times more effective than DFO in preventing oxidant-induced lysosomal rupture and cell death. This increased effectiveness is most likely due to the preferential concentration of this weak base within the acidic lysosomal apparatus. By electron spin resonance, we found that the generation of hydroxyl radical, which normally occurs following addition of hydrogen peroxide to J774 cells, is totally blocked by pretreatment with either WR-1065 or DFO. These findings suggest a single and plausible explanation for the radioprotective effects of amifostine and may provide a basis for the design of even more effective radio- and chemoprotective drugs.     

The accumulation and metabolism of glycosphingolipids in primary kidney cell cultures from beige mice

In the normal C57BL/6J male mouse a specific subset of the kidney glycosphingolipids which is associated with multilamellar bodies of lysosomal origin and represents about 10% of the total kidney glycolipids, is excreted into the urine each day. This excretion is blocked and glycosphingolipids accumulate in the kidney of bg ^J/bg^J mutants of this strain. To examine this process in vitro, glycosphingolipid metabolism and excretion were studied in beige mouse kidney cell cultures. Primary kidney cell cultures from male C57BL/6J control and bg ^J/bg ^J beige mutants were grown in D-valine medium and glycosphingolipids labeled with [³H]palmitate. As we have shown previously, the giant lysosomes of altered morphology were maintained in cultures of the beige kidney cells. Beige-J and control cells synthesized the same types of glycosphingolipids, but the mutant cells had quantitatively higher levels of these compounds than control cells, as determined by high performance liquid chromatography. Beige-J cells incorporated more [³H]palmitate into glycospingholipids than control cells on a cpm/mg protein basis and the specific activity (cpm/pmole glycosphingolipid) was lower in beige cells. Medium from beige-J cells accumulated more glycosphingolipids than that from control cells in a 24 h period. The glycosphingolipids released into the medium as determined by HPLC were primarily non-lysosomal types and both control and mutant cells retained the glycosphingolipids associated with lysosomal multilamellar bodies excreted in vivo. The elevated levels of lysosomal glycosphingolipids and the dysmorphic lysosomes in primary cultures of beige cells, then, are not caused by a mutant block in secretion of lysosomes. (Mol Cell Biochem 118: 61–66, 1992)     

Bafilomycin A1 inhibits lysosomal,phagosomal, and plasma membrane H+-ATPase and induces lysosomal enzyme secretion in macrophages

Bafilomycin A₁, a specific inhibitor of H⁺-ATPases of the vacuolar type, was in the present study shown, at similar concentrations, to induce secretion of lysosomal enzyme and to elevate lysosomal pH in mouse macrophages. These results lend support to the previous suggestion of a triggering role for an increase in lysosomal pH and a permissive role for cytosolic pH in the exocytosis of macrophage lysosomal enzyme. Vacuolar H⁺-ATPases are present in the macrophage plasma membrane as well as in intracellular membranes, for example, those of the lysosomal and phagosomal compartments. Phagosomal acidification was shown to be achieved in part by a mechanism with a similar sensitivity to bafilomycin A₁ as lysosomal H⁺ transport and in part by an early, bafilomycin A₁-insensitive mechanism. We found a lesser sensitivity towards bafilomycin A₁ of the lysosomal and phagosomal H⁺-ATPase than that localized in the plasma membrane, indicating differences among H⁺-ATPases at the subcellular level. Also, by attempts to mobilize lysosomal H⁺-ATPase to the plasma membrane, support was obtained for the notion that subcellular H⁺-ATPase populations differ and thus possibly could be differentially regulated. © 1995 Wiley-Liss, Inc.     

Lysosomal and mitochondrial pathways in miltefosine-induced apoptosis in U937 cells

Hexadecylphosphocholine (HePC) is an anticancer agent whose effect has been shown to involve apoptosis induction but the signaling pathways leading to apoptosis remain to be elucidated. We show here that HePC induces activation of caspase-9, -3, and -8 via the intrinsic pathway, release of cytochrome c, activation and relocation of Bax to the mitochondria as well as the cleavage of Bid. Moreover, a lysosomal pathway characterized by partial lysosomal rupture, cathepsin B activation and relocation from lysosomes to the cytosol, is involved in HePC-induced apoptosis. A cathepsin B/L inhibitor partially suppresses caspase activation and apoptosis induction, indicating signaling between lysosomes and mitochondria. Conversely, the pancaspase inhibitor Q-VD-OPH inhibits lysosomal rupture, but only at early time points, suggesting that immediate lysosomal rupture involves caspases. Overexpression of Bcl-2, an anti-apoptotic protein known to prevent mitochondrial dysfunction, totally abrogates lysosomal destabilization and cell death.     

Loss of membrane cholesterol influences lysosomal permeability to potassium ions and protons

Cholesterol is an essential component of lysosomal membranes. In this study, we investigated the effects of membrane cholesterol on the permeability of rat liver lysosomes to K⁺ and H⁺, and the organelle stability. Through the measurements of lysosomal β-hexosaminidase free activity, membrane potential, membrane fluidity, intra-lysosomal pH, and lysosomal proton leakage, we established that methyl-β-cyclodextrin (MβCD)-produced loss of membrane cholesterol could increase the lysosomal permeability to both potassium ions and protons, and fluidize the lysosomal membranes. As a result, potassium ions entered the lysosomes through K⁺/H⁺ exchange, which produced osmotic imbalance across the membranes and osmotically destabilized the lysosomes. In addition, treatment of the lysosomes with MβCD caused leakage of the lysosomal protons and raised the intra-lysosomal pH. The results indicate that membrane cholesterol plays important roles in the maintenance of the lysosomal limited permeability to K⁺ and H⁺. Loss of this membrane sterol is critical for the organelle acidification and stability.     

Murine leukemic lymphoblasts: homogenization and fractionation procedures for plasma membrane vesicles isolation

Plasma membrane vesicles were isolated from murine leukemic lymphoblasts L5178Y. The isolation procedure selected involved a method of mechanical disruption in a hypoosmotic-buffered solution and the separation of plasma membrane vesicles by an adaptation of the fractionation method described by D. W. McKeel and L. Jarett for fat cells (J. Cell Biol., 44, 417, 1970). In order to select the homogenization method we took into account several parameters: the extent of cell and nuclear disruption, the integrity of the nuclear membrane, the 5′-nucleotidase activity recovered at the first step of fractionation and the mitochondrial rupture. The homogenization method finally used yielded 89% of cellular rupture with only 9% of nuclear damage. The isolation procedure showed an overall yield of 70–90%. A plasma membrane fraction was isolated with an enrichment in 5′-nucleotidase and ouabain-sensitive (Na⁺K⁺)-ATPase specific activities of 15- and 13-fold, respectively, and essentially free of mitochondrial, lysosomal, and endoplasmic reticulum contamination. The electron microscopy demonstrated that the plasma membrane fraction essentially consisted of smooth vesicles of several sizes.     

脾动脉介入栓塞治疗外伤性脾破裂的临床效果及对患者免疫功能的影响

目的:探讨脾动脉介入栓塞治疗外伤性脾破裂的临床效果及对患者免疫功能的影响。方法:选择2013年4月到2017年2月在中国人民解放军第九七医院进行急诊治疗的116例外伤性脾破裂患者,根据治疗方法的不同将其分为观察组60例与对照组56例,对照组接受脾脏切除手术,观察组给予脾动脉介入栓塞治疗,记录和比较两组的术后下床活动时间、术后住院时间、术后肛门排便时间、术后肛门排气时间、术中输血量、手术时间与治疗前后CD4~+/CD8~+、CD8~+、CD4~+、CD3~+的变化及不良反应的发生情况。结果:所有患者都完成治疗并抢救成功,观察组的术后下床活动时间、术后住院时间、术后肛门排便时间、术后肛门排气时间、术中输血量、手术时间都少于对照组(P0.05)。观察组围手术期间的急性肠梗阻、急性胰腺炎、肺炎等并发症发生率为3.33%,对照组为17.86%,观察组低于对照组(P0.05)。术后14天,两组白细胞与血小板含量均显著高于术前1天(P0.05),而观察组血小板含量显著低于对照组(P0.05),但两组白细胞含量比较差异无统计学意义(P0.05)。观察组术后14天与术后1个月的CD4+/CD8+、CD4+、CD3+值均明显高于对照组(P0.05),两组CD8+对比差异无统计学意义(P0.05)。结论:脾动脉介入栓塞治疗外伤性脾破裂能提高治疗的临床效果,减少术后并发症的发生,促进患者免疫功能的恢复。     

Heritability: the link between development and the microevolution of molar tooth form

Abstract

The developmental gene expression, morphogenesis, and population variation in mammalian molar teeth has become increasingly well understood, providing a model system for synthesizing evolution and developmental genetics. In this study, we estimated additive genetic covariances in molar shape (G) using parent-offspring regression in Cryptotis parva, the Least Shrew. We found that crown shape had an overall h² value of 0.34 (±0.08), with higher heritabilities in molar cusps than notches. We compared the genetic covariances to phenotypic (P) and environmental (E) covariances, and to the covariances in crown features expected from the enamel knot developmental cascade (D). We found that G and D were not strongly correlated and that major axes of G (evolutionary lines of least resistance) are better predictors of evolutionary divergences in soricines than is D. We conclude that the enamel knot cascade does impose constraints on the evolution of molar shape, but that it is so permissive that the divergences among soricines (whose last common ancestor lived about 14 million years ago) do not fully explore its confines. Over tens of millions of years, G will be a better predictor of the major axes of evolution in molar shape than D.     

Methods for monitoring Ca2+ and ion channels in the lysosome

Lysosomes and lysosome-related organelles are emerging as intracellular Ca²⁺ stores and play important roles in a variety of membrane trafficking processes, including endocytosis, exocytosis, phagocytosis and autophagy. Impairment of lysosomal Ca²⁺ homeostasis and membrane trafficking has been implicated in many human diseases such as lysosomal storage diseases (LSDs), neurodegeneration, myopathy and cancer. Lysosomal membrane proteins, in particular ion channels, are crucial for lysosomal Ca²⁺ signaling. Compared with ion channels in the plasma membrane, lysosomal ion channels and their roles in lysosomal Ca²⁺ signaling are less understood, largely due to their intracellular localization and the lack of feasible functional assays directly applied to the native environment. Recent advances in biomedical methodology have made it possible to directly investigate ion channels in the lysosomal membrane. In this review, we provide a summary of the newly developed methods for monitoring lysosomal Ca²⁺ and ion channels, as well as the recent discovery of lysosomal ion channels and their significances in intracellular Ca²⁺ signaling. These new techniques will expand our research scope and our understanding of the nature of lysosomes and lysosome-related diseases.     

Polymer-mediated cyclodehydration of alditols and ketohexoses

The polymer PEDOT⁺ (1 or 2) mediates a cyclodehydration reaction with alditols 3, 5, 7, 9, in hydrocarbon solvents, to give cyclic ethers 4, 6, 8, or 10, respectively, in high yield with a trivial isolation protocol. Polymers 1 or 2 also mediate the cyclodehydration of ketohexoses such as d-fructose, but not aldohexoses, to the important industrial intermediate 5-hydroxymethylfurfural (17), under milder conditions when compared to reactions mediated by mineral acids. A cascade reaction with ketohexoses is observed in toluene via cyclodehydration followed by Friedel–Crafts alkylation of the initially formed benzylic alcohol to give 16.