The detection methods currently available for protein aggregation in neurological diseases.

Protein aggregation is a pathological feature in various neurodegenerative diseases and is thought to play a crucial role in the onset and progression of neurological disorders. This pathological phenomenon has attracted increasing attention from researchers, but the underlying mechanism has not been fully elucidated yet. Researchers are increasingly interested in identifying chemicals or methods that can effectively detect protein aggregation or maintain protein stability to prevent aggregation formation. To date, several methods are available for detecting protein aggregates, including fluorescence correlation spectroscopy, electron microscopy, and molecular detection methods. Unfortunately, there is still a lack of methods to observe protein aggregation in situ under a microscope. This article reviews the two main aspects of protein aggregation: the mechanisms and detection methods of protein aggregation. The aim is to provide clues for the development of new methods to study this pathological phenomenon.

Canine circovirus among dogs and cats in China: first identification in cats.

Canine circovirus (CanineCV) is a virus associated with respiratory and digestive diseases in dogs and often occurs in coinfections with other pathogens, thereby aggravating the symptoms of infected dogs. CanineCV was first reported in the United States in 2012. Subsequently, it was reported among dogs in Europe, Asia, and South America. To investigate the prevalence of CanineCV in dogs in China, 331 dog samples were collected in this study. The PCR results showed that 9.06% (30/331, 95% CI = 6.2% ~ 12.7%) of the dog samples were CanineCV positive. CanineCV has also been detected in some carnivorous wild animals, indicating the potential risk of cross-species transmission of this virus. And, cats are also one of the most common pets in our daily lives, who is close contact with dogs. Thus, this study first investigated the prevalence of CanineCV in cats. The PCR results showed that 3.42% (14/409, 95% CI = 1.9% ~ 5.7%) of the cat samples were CanineCV positive. Moreover, 14 canine-derived CanineCV whole genomes and the first cat-derived CanineCV whole genome were obtained in this study. Rep and Cap are the major nonstructural proteins and structural proteins of CanineCV, respectively. In nucleic acid homology analyses, these 15 CanineCV strains showed a high degree of variation in Rep (85.9 ~ 99%) and Cap (85.6 ~ 100%). In phylogenetic analyses, the 15 CanineCV strains clustered into 3 different genotypes (genotypes 1, 3, and 4). Among them, the first cat-derived CanineCV belonged to CanineCV-3. In addition, 4 genetic recombination events were predicted in these 15 CanineCV strains, occurring in multiple regions of the genome. In conclusion, this study is the first to provide evidence of CanineCV infection in cats and successfully obtained the first whole genome of cat-derived CanineCV. The complex circulation and high prevalence of CanineCV among dogs and cats emphasize the importance of continuous monitoring of this virus in various animal species.

A novel detection method for neuronal death indicates abnormalities in intracellular membranous components in neuronal cells that underwent delayed death.

Acute neuronal degeneration is always preceded under the light and electron microscopes by a stage called microvacuolation, which is characterized by a finely vacuolar alteration in the cytoplasm of the neurons destined to death. In this study, we reported a method for detecting neuronal death using two membrane-bound dyes, rhodamine R6 and DiOC6(3), which may be associated with the so-called microvacuolation. This new method produced a spatiotemporally similar staining pattern to Fluoro-Jade B in kainic acid-damaged brains in mice. Further experiments showed that increased staining of rhodamine R6 and DiOC6(3) was observed only in degenerated neurons, but not in glia, erythrocytes, or meninges. Different from Fluoro-Jade-related dyes, rhodamine R6 and DiOC6(3) staining is highly sensitive to solvent extraction and detergent exposure. Staining with Nile red for phospholipids and filipin III for non-esterified cholesterol supports that the increased staining of rhodamine R6 and DiOC6(3) might be associated with increased levels of phospholipids and free cholesterol in the perinuclear cytoplasm of damaged neurons. In addition to kainic acid-injected neuronal death, rhodamine R6 and DiOC6(3) were similarly useful for detecting neuronal death in ischemic models either in vivo or in vitro. As far as we know, the staining with rhodamine R6 or DiOC6(3) is one of a few histochemical methods for detecting neuronal death whose target molecules have been well defined and therefore may be useful for explaining experimental results as well as exploring the mechanisms of neuronal death.

Different changes in pre- and postsynaptic components in the hippocampal CA1 subfield after transient global cerebral ischemia.

To date, ischemia-induced damage to dendritic spines has attracted considerable attention, while the possible effects of ischemia on presynaptic components has received relatively less attention. To further examine ischemia-induced changes in pre- and postsynaptic specializations in the hippocampal CA1 subfield, we modeled global cerebral ischemia with two-stage 4-vessel-occlusion in rats, and found that three postsynaptic markers, microtubule-associated protein 2 (MAP2), postsynaptic density protein 95 (PSD95), and filamentous F-actin (F-actin), were all substantially decreased in the CA1 subfield after ischemia/reperfusion (I/R). Although no significant change was detected in synapsin I, a presynaptic marker, in the CA1 subfield at the protein level, confocal microscopy revealed that the number and size of synapsin I puncta were significantly changed in the CA1 stratum radiatum after I/R. The size of synapsin I puncta became slightly, but significantly reduced on Day 1.5 after I/R. From Days 2 to 7 after I/R, the number of synapsin I puncta became moderately decreased, while the size of synapsin I puncta was significantly increased. Interestingly, some enlarged puncta of synapsin I were observed in close proximity to the dendritic shafts of CA1 pyramidal cells. Due to the more substantial decrease in the number of F-actin puncta, the ratio of synapsin I/F-actin puncta was significantly increased after I/R. The decrease in synapsin I puncta size in the early stage of I/R may be the result of excessive neurotransmitter release due to I/R-induced hyperexcitability in CA3 pyramidal cells, while the increase in synapsin I puncta in the later stage of I/R may reflect a disability of synaptic vesicle release due to the loss of postsynaptic contacts.

Effects of Apigenin on the Expression of LOX-1, Bcl-2, and Bax in Hyperlipidemia Rats.

We aimed to investigate the impact of apigenin on LOX-1, Bcl-2, and Bax expression in hyperlipidemia rats and explore the possible molecular pathological mechanism of apigenin in improving hyperlipidemia and preventing atherosclerosis. In hyperlipidemia models, the levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-c) and the LOX-1 protein expression were apparently increased (P<0.01), while the high-density lipoprotein cholesterol (HDL-c) levels and the ratio of Bcl-2/Bax were reduced significantly (P<0.01) in comparison with the standard control group. After the treatment of apigenin, the levels of TC, TG, LDL-c, and the LOX-1 protein expression were noticeably decreased (P<0.01), while the levels of HDL-c and the Bcl-2/Bax ratio were increased (P<0.01). The intima was thickened and had protrusions in the hyperlipidemia model group compared to the normal control group. In comparison with the atherosclerosis model group, the degree of aortic lesions in the low-dose, middle-dose, high-dose groups was alleviated. Apigenin can reduce the level of blood lipid, improve hyperlipidemia, and prevent atherosclerosis in hyperlipidemia rats. The molecular mechanism may be related to inhibiting LOX-1 gene expression and increasing the Bcl-2/Bax ratio.

What can cerebrospinal fluid testing and brain autopsies tell us about viral neuroinvasion of SARS-CoV-2.

To provide instructive clues for clinical practice and further research of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we analyzed the existing literature on viral neuroinvasion of SARS-CoV-2 in coronavirus disease 2019 (COVID-19) patients. To date, SARS-CoV-2 has been detected in the cerebrospinal fluid (CSF) or brain parenchyma in quite a few patients, which provide undeniable evidence for the neuroinvasive potential of this novel coronavirus. In contrast with the cerebrum and cerebellum, the detection rate of SARS-CoV-2 was higher in the olfactory system and the brainstem, both of which also showed severe microgliosis and lymphocytic infiltrations. As compared with the number of patients who underwent viral testing in the central nervous system (CNS), the number of patients showing positive results seems very small. However, it seems too early to conclude that the neuroinvasion of SARS-CoV-2 is rare in COVID-19 patients because the detection methods or sampling procedures in some studies may not be suitable or sufficient to reveal the CNS infection induced by neurotropic viruses. Moreover, the primary symptoms and/or causes of death were distinctly different among examined patients, which probably caused more conspicuous pathological changes than those due to the direct infection that usually localized to specific brain areas. Unfortunately, most autopsy studies did not provide sufficient details about neurological symptoms or suspected diagnoses of the examined patients, and the documentation of neuropathological changes was often incomplete. Given the complex pathophysiology of COVID-19 and the characteristics of neurotropic viruses, it is understandable that any study of the CNS infection may inevitably have limitations.

Neurological involvement in the respiratory manifestations of COVID-19 patients.

The peculiar features of coronavirus disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), are challenging the current biological knowledge. Early in Feb, 2020, we suggested that SARS-CoV-2 may possess neuroinvasive potential similar to that of many other coronaviruses. Since then, a variety of neurological manifestations have been associated with SARS-CoV-2 infection, which was supported in some patients with neuroimaging and/or cerebrospinal fluid tests. To date, at least 27 autopsy studies on the brains of COVID-19 patients can be retrieved through PubMed/MEDLINE, among which neuropathological alterations were observed in the brainstem in 78 of 134 examined patients, and SARS-CoV-2 nucleic acid and viral proteins were detected in the brainstem in 16/49 (32.7%) and 18/71 (25.3%) cases, respectively. To shed some light on the peculiar respiratory manifestations of COVID-19 patients, this review assessed the existing evidence about the neurogenic mechanism underlying the respiratory failure induced by SARS-CoV-2 infection. Acknowledging the neurological involvement has important guiding significance for the prevention, treatment, and prognosis of SARS-CoV-2 infection.

Ultrastructural clarification of the peripherally located actin network in the myelinated axons / Aclaración ultraestructural de la red de actina localizada periféricamente en los axones mielinizados

SUMMARY: Despite the existence of a large amount of actin in the axons, the concentration F-actin was quite low in the myelinated axons and almost all the F-actin were located in the peripheries of the myelinated axons. Until now, the ultrastructural localization of F-actin has still not been reported in the myelinated axons, probably due to the lack of an appropriate detection method. In the present study, a phalloidin-based FITC-anti-FITC technique was adopted to investigate the subcellular localization of F-actin in the myelinated axons. By using this technique, F-actin is located in the outer and inner collars of myelinated cytoplasm surrounding the intermodal axon, the Schmidt-Lanterman incisures, the paranodal terminal loops and the nodal microvilli. In addition, the satellite cell envelope, which encapsulates the axonal initial segment of the peripheral sensory neuron, was also demonstrated as an F-actin-enriched structure. This study provided a hitherto unreported ultrastructural view of the F-actin in the myelinated axons, which may assist in understanding the unique organization of axonal actin cytoskeleton.

RESUMEN: A pesar de la existencia de una gran cantidad de actina en los axones, la concentración de F-actina era bastante baja en los axones mielinizados y casi la totalidad de F-actina se localizaba en las periferias de los axones mielinizados. A la fecha aún no se ha reportado la localización ultraestructural de F-actina en los axones mielinizados, probablemente debido a la falta de un método de detección apropiado. En el presente estudio, se adoptó una técnica FITC-anti-FITC basada en faloidina para investigar la localización subcelular de F-actina en los axones mielinizados. Mediante el uso de esta técnica, la F-actina se localiza en los collares externo e interno del citoplasma mielinizado que rodea el axón intermodal, a las incisiones de Schmidt-Lanterman,a las asas terminales paranodales y a las microvellosidades nodales. Además, la envoltura de la célula satélite, que encapsula el segmento axonal inicial de la neurona sensorial periférica, también se demostró como una estructura enriquecida con F-actina. Este estudio proporcionó una vista ultraestructural de la F-actina en los axones mielinizados, que puede ayudar a comprender la organización única del citoesqueleto de actina axonal.

Evidence of central nervous system infection and neuroinvasive routes, as well as neurological involvement, in the lethality of SARS-CoV-2 infection.

The outbreak of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has become a significant and urgent threat to global health. This review provided strong support for central nervous system (CNS) infection with SARS-CoV-2 and shed light on the neurological mechanism underlying the lethality of SARS-CoV-2 infection. Among the published data, only 1.28% COVID-19 patients who underwent cerebrospinal fluid (CSF) tests were positive for SARS-CoV-2 in CSF. However, this does not mean the absence of CNS infection in most COVID-19 patients because postmortem studies revealed that some patients with CNS infection showed negative results in CSF tests for SARS-CoV-2. Among 20 neuropathological studies reported so far, SARS-CoV-2 was detected in the brain of 58 cases in nine studies, and three studies have provided sufficient details on the CNS infection in COVID-19 patients. Almost all in vitro and in vivo experiments support the neuroinvasive potential of SARS-CoV-2. In infected animals, SARS-CoV-2 was found within neurons in different brain areas with a wide spectrum of neuropathology, consistent with the reported clinical symptoms in COVID-19 patients. Several lines of evidence indicate that SARS-CoV-2 used the hematopoietic route to enter the CNS. But more evidence supports the trans-neuronal hypothesis. SARS-CoV-2 has been found to invade the brain via the olfactory, gustatory, and trigeminal pathways, especially at the early stage of infection. Severe COVID-19 patients with neurological deficits are at a higher risk of mortality, and only the infected animals showing neurological symptoms became dead, suggesting that neurological involvement may be one cause of death.

The possible impairment of respiratory-related neural loops may be associated with the silent pneumonia induced by SARS-CoV-2.

As compared to many other viral pulmonary infections, there existed several peculiar manifestations in the COVID-19 patients, including the "silence" of pneumonia in both mild and severe cases and a long intensive care unit stay for those requiring invasive mechanical ventilation. Similar silent pneumonia has been documented in the infectioninduced by H5N1 influenza virus HK483 and was found to result from the direct attack of the virus on the bronchopulmonary C-fibers at the early stage and the final infection in the brainstem at the late stage. The long stay of critical patients in the intensive care unit is possibly due to the depression of central respiratory drive, which resulted in the failure to wean from the mechanic ventilation. Carotid and aortic bodies and bronchopulmonary C-fibers are two key peripheral components responsible for the chemosensitive responses in the respiratory system, while triggering respiratory reflexes depends predominantly on the putative chemosensitive neurons located in the pontomedullary nuclei. In view of the findings for the H5N1 influenza virus, the silence of pneumonia induced by SARS-CoV-2 may be due to the possible impairment of peripheral chemosensitive reflexes as well as the damage to the respiratory-related central neurons.

Response to Commentary on "The neuroinvasive potential of SARS-CoV-2 may play a role in the respiratory failure of COVID-19 patients".

In a recent review, we have suggested a neuroinvasive potential of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its possible role in the causation of acute respiratory failure of coronavirus disease 2019 (COVID-19) patients (J Med Viol doi: 10.1002/jmv.25728), based upon the clinical and experimental data available on the past SARS-CoV-1 and the recent SARS-CoV-2 pandemic. In this article, we provide new evidence recently reported regarding the neurotropic potential of SARS-CoV-2 and respond to several comments on our previously published article. In addition, we also discuss the peculiar manifestations of respiratory failure in COVID-19 patients and the possible involvement of nervous system.

The neuroinvasive potential of SARS-CoV2 may play a role in the respiratory failure of COVID-19 patients.

Following the severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), another highly pathogenic coronavirus named SARS-CoV-2 (previously known as 2019-nCoV) emerged in December 2019 in Wuhan, China, and rapidly spreads around the world. This virus shares highly homological sequence with SARS-CoV, and causes acute, highly lethal pneumonia coronavirus disease 2019 (COVID-19) with clinical symptoms similar to those reported for SARS-CoV and MERS-CoV. The most characteristic symptom of patients with COVID-19 is respiratory distress, and most of the patients admitted to the intensive care could not breathe spontaneously. Additionally, some patients with COVID-19 also showed neurologic signs, such as headache, nausea, and vomiting. Increasing evidence shows that coronaviruses are not always confined to the respiratory tract and that they may also invade the central nervous system inducing neurological diseases. The infection of SARS-CoV has been reported in the brains from both patients and experimental animals, where the brainstem was heavily infected. Furthermore, some coronaviruses have been demonstrated able to spread via a synapse-connected route to the medullary cardiorespiratory center from the mechanoreceptors and chemoreceptors in the lung and lower respiratory airways. Considering the high similarity between SARS-CoV and SARS-CoV2, it remains to make clear whether the potential invasion of SARS-CoV2 is partially responsible for the acute respiratory failure of patients with COVID-19. Awareness of this may have a guiding significance for the prevention and treatment of the SARS-CoV-2-induced respiratory failure.

The temporal and spatial changes of microtubule cytoskeleton in the CA1 stratum radiatum following global transient ischemia.

The down-regulation of microtubule proteins has been widely documented in the ischemic brain, but the temporal or spatial alteration of microtubules has not been systematically investigated in the vulnerable areas after ischemia. By examining the stability and distribution of microtubules following transient global ischemia, we found that the biomarkers of stable microtubules, MAP2 and acetylated α-tubulin, became significantly down-regulated in the CA1 stratum radiatum of rat hippocampus and that the neuron-specific microtubule protein, class III ß-tubulin, was progressively decreased in the same region. Surprisingly, pan-ß-tubulin, which is expressed at a low level in glial cells under physiological conditions, was significantly increased in reactive astrocytes after ischemia. The finding was supported by protein quantification and confocal microscopy analysis, and consistent with the different vulnerabilities of neuronal and glial cells to the ischemic insult. To our knowledge, the different responses of microtubules between neuronal and glial cells have not been described in the ischemic brain before. The deconstruction of microtubules in the neurons is expected to contribute to the selective and delayed neuronal death in the vulnerable brain regions, while the increased microtubules in the reactive astrocytes may play an important role in the shape conversion of astrocytes induced by ischemia.

The temporal and spatial changes of actin cytoskeleton in the hippocampal CA1 neurons following transient global ischemia.

Transient global ischemia usually results in delayed neuronal death in selective brain regions, prior to which a rapid loss of dendritic spines has been widely reported in these regions. Dendritic spines are characterized by a highly branched meshwork of actin cytoskeleton (F-actin), which is extremely vulnerable to the ATP-depleted conditions such as hypoxia/ischemia. However, the ischemia-induced changes of F-actin are still not clarified in the vulnerable brain areas. This study was designed to examine the temporal and spatial alterations of F-actin in the CA1 subfield of rat hippocampus following reperfusion after global cerebral ischemia. Phalloidin staining and confocal microscopic examination showed that F-actin disappeared from the dentritic spines in the CA1 stratum radiatum, but aggregated into thread- or fiber-like structures on days 1.5-2 after ischemia. This was followed by a nearly complete loss of F-actin in the CA1 subfield on days 3-7 after ischemia. Colocalization analysis demonstrated that the F-actin threads or fibers were located mainly within the dentritic trunks. As revealed by Nissl and Fluoro-Jade B staining, the decrease of F-actin proceeded concurrently with the evolution of ischemic damage. Consistently, western blots detected a significant decrease of F-/G-actin ratio in the dissected CA1 subfield after ischemia. To our knowledge, this is the first report on the change of F-actin in the ischemic brain. Although the underlying mechanisms remain to be elucidated, our findings may provide an important structural clue for the neuronal dysfunction induced by ischemia.

Dexamethasone ameliorates the damage of hippocampal filamentous actin cytoskeleton but is not sufficient to cease epileptogenesis in pilocarpine induced epileptic mice.

Rogressive deconstruction of filament actin (F-actin) in hippocampal neurons in the epileptic brain have been associated with epileptogenesis. Previous clinical studies suggest that glucocorticoids treatment plays beneficial roles in refractory epilepsy. Glucocorticoids treatment affects dendritic spine morphology by regulating local glucocorticoid receptors and F-actin cytoskeleton dynamics. However, how glucocorticoids regulate epileptogenesis by controlling F-actin cytoskeleton is not clear yet. Here we study the function of glucocorticoids in epileptogenesis by examining F-actin abundance, hippocampal neuron number, and synaptic markers in pilocarpine-induced epileptic mice in the presence or absence of dexamethasone (DEX) treatment. We found that spontaneous seizure duration was significantly reduced; F-actin damage in hippocampal subfields was remarkably attenuated; loss of pyramidal cells was dramatically decreased; more intact synaptic structures indicated by pre- and postsynaptic markers were preserved in multiple hippocampal regions after DEX treatment. However, the number of ZNT3 positive particles in the molecular layer in the hippocampus of pilocarpine epileptic mice was not altered after DEX treatment. Although not sufficient to cease epileptogenesis, our results suggest that dexamethasone treatment ameliorates the damage of epileptic brain by stabilizing F-actin cytoskeleton in the pilocarpine epileptic mice.

The effects of epothilone D on microtubule degradation and delayed neuronal death in the hippocampus following transient global ischemia.

Disruption of microtubule cytoskeleton plays an important role during the evolution of brain damage after transient cerebral ischemia. However, it is still unclear whether microtubule-stabilizing drugs such as epothilone D (EpoD) have a neuroprotective action against the ischemia-induced brain injury. This study examined the effects of pre- and postischemic treatment with different doses of EpoD on the microtubule damage and the delayed neuronal death in the hippocampal CA1 subfield on day 2 following reperfusion after 13-min global cerebral ischemia. Our results showed that systemic treatment with 0.5 mg/kg EpoD only slightly alleviated the microtubule disruption and the CA1 neuronal death, while treatment with 3.0 mg/kg EpoD was not only ineffective against the CA1 neuronal death, but also produced additional damage in the dentate gyrus in some ischemic rats. Since the pyramidal cells in the CA1 subfield and the granule neurons in the dentate gyrus are known to be equipped with dynamically different microtubule systems, this finding indicates that the effects of microtubule-disrupting drugs may be unpredictably complicated in the central nervous system.

The effects of calcineurin inhibitor FK506 on actin cytoskeleton, neuronal survival and glial reactions after pilocarpine-induced status epilepticus in mice.

After status epilepticus (SE), actin cytoskeleton (F-actin) becomes progressively deconstructed in the hippocampus, which is consistent with the delayed pyramidal cell death in both time course and spatial distribution. A variety of experiments show that calcineurin inhibitors such as FK506 are able to inhibit the SE-induced actin depolymerization. However, it is still unclear what changes happen to the F-actin in the epileptic brain after FK506 treatment. A pilocarpine model of SE in mice was used to examine the effects of FK506 on the F-actin in the hippocampal neurons. The post SE (PSE) mice with or without FK506 treatment were monitored consecutively for 14 days to examine the frequency and duration of spontaneous seizures. The effects of FK506 on the activity of cofilin and actin dynamics were assessed at 7 and 14 d PSE by western blots. The organization of F-actin, neuronal cell death, and glial reactions were investigated by phalloidin staining, histological and immunocytochemical staining, respectively. As compared to the PSE + vehicle mice, FK506 treatment significantly decreased the frequency and duration of spontaneous seizures. Relative to the PSE + vehicle mice, western blots detected a partial restoration of phosphorylated cofilin and a significant increase of F/G ratio in the hippocampus after FK506 treatment. In the PSE + vehicle mice, almost no F-actin puncta were left in the CA1 and CA3 subfields at 7 and 14 d PSE. FK506-treated PSE mice showed a similar decrease of F-actin, but the extent of damage was significantly ameliorated. Consistently, the surviving neurons became significantly increased in number after FK506 treatment, relative to the PSE + vehicle groups. After FK506 treatment, microglial reaction was partially inhibited, but the expression of GFAP was not significantly changed, compared to the PSE + vehicle mice. The results suggest that post-epileptic treatment with FK506 ameliorated, but could not stop the deconstruction of F-actin or the delayed neuronal loss in the PSE mice.

The unique organization of filamentous actin in the medullary canal of the medulla oblongata.

In the central canal, F-actin is predominantly localized in the apical region, forming a ring-like structure around the circumference of the lumen. However, an exception is found in the medulla oblongata, where the apical F-actin becomes interrupted in the ventral aspect of the canal. To clarify the precise localization of F-actin, the fluorescence signals for F-actin were converted to the peroxidase/DAB reaction products in this study by a phalloidin-based ultrastructural technique, which demonstrated that F-actin is located mainly in the microvilli and terminal webs in the ependymocytes. It is because the ventrally oriented ependymocytes do not possess well-developed microvilli or terminal web that led to a discontinuous labeling of F-actin in the medullary canal. Since spinal motions can change the shape and size of the central canal, we next examined the cytoskeletons in the medullary canal in both rats and monkeys, because these two kinds of animals show different kinematics at the atlanto-occipital articulation. Our results first demonstrated that the apical F-actin in the medullary canal is differently organized in the animals with different head-neck kinemics, which suggests that the mechanic stretching of spinal motions is capable of inducing F-actin reorganization and the subsequent cell-shape changes in the central canal.

[Influence on coagulation function and the therapy effect of damage control orthopaedics for unstable pelvic fractures and multiple fractures of extremities].

OBJECTIVE: To retrospectively explore the effects of damage control orthopaedics concept on coagulation and curative effects in unstable pelvic fractures and multiple fractures of limbs. METHODS: From March 2014 to December 2015, 40 patients with unstable pelvic fractures and limbs multiple fractures in treatment group included 22 males and 18 females with an average age of (39.00±4.12) years old were treated with the damage control orthopaedics concept, the ISS score was (25.36±10.81) on average;Other 40 patients with the same trauma in conventional group included 25 males and 15 females with an average age of (38.00±3.24) years old were treated with conventional method from January 2012 to January 2014 served as control, the average ISS score was 26.56±11.44. Matta criteria and Majeed function standard were used respectively to evaluate the fracture reduction and therapeutic effects postoperatively. Coagulation function on the 7th day postoperatively was compared between two groups. RESULTS: All patients were followed up for 6 to 24 months. According to Matta criteria, the fracture reduction of the treatment group and the conventional group were (7.38±5.09) mm and (10.11±6.53) mm, respectively (P<0.05). Majeed functional results of the treatment group and the conventional group were (86.12±6.84) points and (77.53±8.30) points, respectively (P<0.05). On the 7th day after surgery, PT, APTT, TT of the treatment group were significantly higher than that of the control group;and Fib of the treatment group was also significantly lower than that of the conventional group(P<0.05). CONCLUSIONS: The concept of damage control orthopaedics could effectively improve coagulation function of the patients with unstable pelvic fractures and limbs multiple fractures, thus are beneficial to the functional recovery as well as improve the curative effect postoperatively.

Type III Transforming Growth Factor-ß Receptor Drives Cardiac Hypertrophy Through ß-Arrestin2-Dependent Activation of Calmodulin-Dependent Protein Kinase II.

The role of type III transforming growth factor-ß receptor (TßRIII) in the pathogenesis of heart diseases remains largely unclear. Here, we investigated the functional role and molecular mechanisms of TßRIII in the development of myocardial hypertrophy. Western blot and quantitative real time-polymerase chain reaction analyses revealed that the expression of TßRIII was significantly elevated in human cardiac hypertrophic samples. Consistently, TßRIII expression was substantially increased in transverse aortic constriction (TAC)- and isoproterenol-induced mouse cardiac hypertrophy in vivo and in isoproterenol-induced cardiomyocyte hypertrophy in vitro. Overexpression of TßRIII resulted in cardiomyocyte hypertrophy, whereas isoproterenol-induced cardiomyocyte hypertrophy was greatly attenuated by knockdown of TßRIII in vitro. Cardiac-specific transgenic expression of TßRIII independently led to cardiac hypertrophy in mice, which was further aggravated by isoproterenol and TAC treatment. Cardiac contractile function of the mice was not altered in TßRIII transgenic mice; however, TAC led to significantly decreased cardiac contractile function in TßRIII transgenic mice compared with control mice. Conversely, isoproterenol- and TAC-induced cardiac hypertrophy and TAC-induced cardiac contractile function impairment were partially reversed by suppression of TßRIII in vivo. Our data suggest that TßRIII mediates stress-induced cardiac hypertrophy through activation of Ca(2+)/calmodulin-dependent protein kinase II, which requires a physical interaction of ß-arrestin2 with both TßRIII and calmodulin-dependent protein kinase II. Our findings indicate that stress-induced increase in TßRIII expression results in cardiac hypertrophy through ß-arrestin2-dependent activation of calmodulin-dependent protein kinase II and that transforming growth factor-ß and ß-adrenergic receptor signaling are not involved in spontaneous cardiac hypertrophy in cardiac-specific transgenic expression of TßRIII mice. Our findings may provide a novel target for control of myocardial hypertrophy.