Evidence for chromium crosses blood brain barrier from the hypothalamus in chromium mice model.

It has been shown that exposure to hexavalent Chromium, Cr (Ⅵ), via nasal cavity can have neurotoxicological effects and induces behavioral impairment due to the fact that blood brain barrier (BBB) does not cover olfactory bulb. But whether Cr (Ⅵ) can cross the BBB and have a toxicological effects in central nervous system (CNS) remains unclear. Therefore, we investigated the effects of Cr (Ⅵ) on mice treated with different concentrations and exposure time (14 days and 28 days) of Cr (Ⅵ) via intraperitoneal injection. Results revealed that Cr accumulated in hypothalamus (HY) in a timely dependent manner. Much more severer neuropathologies was observed in the group of mice exposed to Cr (Ⅵ) for 28 days than that for 14 days. Gliosis, neuronal morphological abnormalities, synaptic degeneration, BBB disruption and neuronal number loss were observed in HY. In terms of mechanism, the Nrf2 related antioxidant stress signaling dysfunction and activated NF-κB related inflammatory pathway were observed in HY of Cr (Ⅵ) intoxication mice. And these neuropathologies and signaling defects appeared in a timely dependent manner. Taking together, we proved that Cr (Ⅵ) can enter HY due to weaker BBB in HY and HY is the most vulnerable CNS region to Cr (Ⅵ) exposure. The concentration of Cr in HY increased along with time. The accumulated Cr in HY can cause BBB disruption, neuronal morphological abnormalities, synaptic degeneration and gliosis through Nrf2 and NF-κB signaling pathway. This finding improves our understanding of the neurological dysfunctions observed in individuals who have occupational exposure to Cr (Ⅵ), and provided potential therapeutic targets to treat neurotoxicological pathologies induced by Cr (Ⅵ).

Research Status and Prospects of Non-Traumatic Fat Embolism in Forensic Medicine.

In the practice of forensic pathology, fat embolism is one of the common causes of death, which can be divided into two categories: traumatic and non-traumatic. Non-traumatic fat embolism refers to the blockage of small blood vessels by fat droplets in the circulatory blood flow caused by non-traumatic factors such as underlying diseases, stress, poisoning and lipid metabolism disorders. At present, it is believed that the production of non-traumatic fat embolism is related to the disturbance of lipid metabolism, C-reactive protein-related cascade reaction, the agglutination of chylomicron and very low-density lipoprotein. The forensic identification of the cause of death of non-traumatic fat embolism is mainly based on the case, systematic autopsy, HE staining and fat staining, but it is often missed or misdiagnosed by forensic examiners because of its unknown risk factors, hidden onset, the difficulty of HE staining observation and irregular implementation of fat staining. In view of the lack of attention to non-traumatic fat embolism in forensic identification, this paper reviews the concepts, pathophysiological mechanism, research progress, existing problems and countermeasures of non-traumatic fat embolism, providing reference for forensic scholars.

Forensic characteristics and phylogenetic analyses of one branch of Tai-Kadai language-speaking Hainan Hlai (Ha Hlai) via 23 autosomal STRs included in the Huaxia™ Platinum System.

BACKGROUND: Hainan Island, located in the South China Sea and separated from the Leizhou Peninsula by Qiongzhou Strait, is the second largest island after Taiwan in China. With the expansion of Han Chinese and the gradual formation of "South Hlai and North Han", nowadays, Hainan Hlai is the second largest population after Han Chinese in Hainan Island. Ha Hlai, distributed in southwest and southern Hainan Island, is the dominant branch of Hlai and speaks Ha localism. METHODS: We utilized the Huaxia™ Platinum PCR Amplification System (including 23 autosomal STRs and 2 sex-linked markers) to obtain the first STR profiling batch of 657 Ha Hlai individuals (497 males and 160 females). In order to explore the genetic relationships between the studied Ha Hlai and other reference populations with different language families, population genetic analyses, including PCA, MDS, STRUCTURE, and phylogenetic analysis, were conducted based upon the raw data and allelic frequencies of the polymorphic autosomal STR markers. RESULTS: In total, 271 distinct alleles were observed at the 23 STR loci. The number of diverse alleles ranged from 7 at TPOX locus to 23 at FGA locus, and the allelic frequencies varied from 0.0008 to 0.5533. In addition, the CPE and CPD were 1-7.39 × 10-10 and 1-3.13 × 10-28 , respectively. The phylogenetic analyses indicated that Ha Hlai is a Tai-Kadai language-speaking and relatively isolated population which has a close genetic and geographical relationship with Hainan Hlai, and M95 is the dominant haplogroup in Ha Hlai (56.18%). CONCLUSION: The 23 autosomal STR genetic markers were highly polymorphic as well as potentially useful for forensic applications in Hainan Ha Hlai population. The phylogenetic analyses demonstrated that small geographic scale gene flows could not be ignored and the shaping of the unique gene pool for each population was the combination effects of geographic, language, and cultural isolations.

Transfer of pathological α-synuclein from neurons to astrocytes via exosomes causes inflammatory responses after METH exposure.

Methamphetamine (METH) is a highly addictive psychostimulant drug whose abuse can cause many health complications. Our previous studies have shown that METH exposure increases α-synuclein (α-syn) expression. Recently, it was shown that α-syn could be transferred from neurons to astrocytes via exosomes. However, the specific role of astrocytes in α-syn pathology involved in METH neurotoxicity remains unclear. The objective of this study was to determine whether exosomes derived from METH-treated neurons contain pathological α-syn and test the hypothesis that exosomes can transfer pathological α-syn from neurons to astrocytes. To this end, using animal and cell line coculture models, we show that exosomes isolated from METH-treated SH-SY5Y cells contained pathological α-syn. Furthermore, the addition of METH exosomes to the medium of primary cultured astrocytes induced α-syn aggregation and inflammatory responses in astrocytes. Then, we evaluated changes in nuclear receptor related 1 protein (Nurr1) expression and the levels of inflammatory cytokines in primary cultured astrocytes exposed to METH or α-syn. We found that METH or α-syn exposure decreased Nurr1 expression and increased proinflammatory cytokine expression in astrocytes. Our results indicate that α-syn can be transferred from neuronal cells to astrocytes through exosomes. When internalized α-syn accumulated in astrocytes, the cells produced inflammatory responses. Nurr1 may play a crucial role in this process and could be a therapeutic target for inflammatory damage caused by METH.

Role of alpha-synuclein phosphorylation at Serine 129 in methamphetamine-induced neurotoxicity in vitro and in vivo.

The phosphorylation and aggregation of alpha-synuclein (α-Syn) play a key role in methamphetamine (METH)-induced dopaminergic neurotoxicity. The exact mechanism underlying the interaction between METH-induced neurotoxicity and α-Syn was poorly clarified. We aimed to figure out the role of serine 129 phosphorylation (pS129) of α-Syn on its aggregation and neurotoxicity in vitro and in vivo. In this study, we examined pS129 α-Syn expression in vitro and in vivo at the protein phosphorylation and genetic levels and evaluated its effect on METH-induced neurotoxicity. Here, we found that pS129 α-Syn was significantly increased after METH treatment; moreover, the neuronal α-Syn aggregation and apoptosis caused by METH exposure were significantly attenuated after inhibiting α-Syn phosphorylation. We demonstrate that pS129 α-Syn contributes to the aggregation of α-Syn, and that phosphorylated and aggregated forms of α-Syn play an important role in METH-induced neurotoxicity in dopaminergic neurons and SH-SY5Y cells, supporting a potential insight into the treatment of METH-induced neurotoxicity.

Nontraumatic Multiple-Organ Fat Embolism: An Autopsy Case and Review of Literature.

The patient was an 88-year-old woman with a 10-year history of hypertension. She was suspected to have been hit by a car. At the time of the event, she was conscious and able to stand on her own and had no obvious injuries. She was sent home, but she lapsed into unconsciousness and was nonresponsive after 2 hours. She was sent to the hospital, and her heartbeat and breathing stopped. After half an hour of rescue attempts, her heartbeat did not recover, and she was declared dead. During the autopsy, a small subcutaneous hemorrhage was observed below the right knee joint. No obvious internal organ injuries or bone fractures were observed. The deceased also had mild atherosclerosis in the coronary arteries and an old cerebral infarction in the right cerebellum. The tissue histopathological tests showed distinct fat embolism in multiple organs, including the brain, lungs, kidneys, liver, and pancreas. A postmortem blood biochemistry test of the heart blood showed that the levels of low-density lipoprotein, cholesterol, triglycerides, and free fatty acids in the blood were increased, and the level of C-reactive protein was elevated. According to the autopsy results, the direct cause of death was multiorgan fat embolism. This case suggests that aging, hypertension, and hyperlipidemia may be risk factors for nontraumatic fat embolism under stressful conditions.

Alpha-Synuclein deficiency ameliorates chronic methamphetamine induced neurodegeneration in mice.

The α-Synuclein (α-syn) and tau have synergistic effects on neurodegenerative diseases induced by environmental factors or genetic mutation. Thus, we investigated the role of α-syn and tau in neurodegeneration induced by chronic methamphetamine (METH) exposure (1.0∼20.0 mg/kg/d body weight, for 14 consecutive days). Here, we present a mice model with evidences of α-syn and tau participating in toxicology in chronic METH. METH increased α-syn level in the stratum oriens, pyramidal layer, stratum radiatum and stratum moleculare of hippocampal CA1, CA2 and CA3, polymorph layer of hippocampal dentate gyrus (DG), and substantia nigra (SN). The subcellular locations of the upregulated α-syn were mainly found in mitochondria and axons. The METH upregulated α-syn may directly induce mitochondrial damage, myelin sheath destruction, and synaptic failure. Also, the excess α-syn might indirectly promote tau phosphorylation through tau kinase GSK3ß and CDK5, leading to microtubule depolymerization and eventually fusion deficit of autophagosome and lysosome. In the in vitro experiment, the autophagic vacuoles failed to fuse with the lysosome. The neuropathology induced by both the direct and indirect effects of α-syn could be alleviated by α-syn knockout. Taking together, these results indicate that the α-syn mediates the neurodegenerative process induced by chronic METH and that reducing α-syn might be a potential approach to protect the toxic effects of METH and also be, to a broader view, of therapeutic value in neurodegenerative diseases.

Effect of Parkin on methamphetamine-induced α-synuclein degradation dysfunction in vitro and in vivo.

INTRODUCTION: Methamphetamine (METH) is a psychostimulant drug with complicated neurotoxicity, and abuse of METH is very common. Studies have shown that METH exposure causes alpha-synuclein (α-syn) accumulation. However, the mechanism of α-syn accumulation has not been determined. METHODS: In this study, we established cell and animal models of METH intoxication to evaluate how METH affects α-syn expression. In addition, to explore METH-induced neurotoxicity, we measured the level of Parkin and the phosphorylation levels of α-syn, Polo-like kinase 2 (PLK2), the proteasome activity marker CD3δ, and the apoptosis-related proteins Caspase-3 and PARP. Parkin is a key enzyme in the ubiquitin-proteasome system. In addition, the effect of Parkin on METH-induced neurotoxicity was investigated by overexpressing it in vitro and in vivo. RESULTS: METH exposure increased polyubiquitin and α-syn expression, as did MG132. Furthermore, the level of Parkin and the interaction between Parkin and α-syn decreased after METH exposure. Importantly, the increases in α-syn expression and neurotoxicity were relieved by Parkin overexpression. CONCLUSIONS: By establishing stable cell lines and animal models that overexpress Parkin, we confirmed Parkin as an important factor in METH-induced α-syn degradation dysfunction in vitro and in vivo. Parkin may be a promising target for the treatment of METH-induced neurotoxicity.

The effect of α-synuclein and Tau in methamphetamine induced neurotoxicity in vivo and in vitro.

The upregulated α-synuclein (α-syn) and Tau co-occur in methamphetamine (METH) abusers' brains. Here, we designed experiments mainly to investigate whether α-syn and Tau interact in METH exposure. We detected the expression of α-syn, total Tau, and phosphorylation of Tau at Serine 396 (pSer396 Tau) under in vitro and in vivo conditions after METH exposure to determine the co-occurrence of α-syn and Tau. We also explored the effect of α-syn or Tau on one another by silencing and knocking-out one of them in METH treatment. We found that METH increased the α-syn, total Tau, and pSer396 Tau protein level in SH-SY5Y cells, primary cultured neurons, and in mice brains. In additional, reducing α-syn level can relieve and even normalize the pSer396 Tau and total Tau overexpression after treatment of METH. Furthermore, knocking out Tau can effectively inhibit METH induced overexpression of α-syn in mice brains. Finally, knocking out α-syn or Tau can effectively reduce METH-induced neurotoxicity in mice brains. This research could provide potential therapeutic approaches targeting the vicious circle between α-syn and Tau in METH abusers and patients with neurodegenerative disorders.

The role of chaperone-mediated autophagy in neurotoxicity induced by alpha-synuclein after methamphetamine exposure.

INTRODUCTION: Chaperone-mediated autophagy (CMA) is an autophagy-lysosome pathway (ALP) that is different from the other two lysosomal pathways, namely, macroautophagy and microautophagy, and can selectively degrade cytosolic proteins in lysosomes without vesicle formation. CMA activity declines in neurodegenerative diseases such as Parkinson's disease, and similar neurotoxicity can occur after methamphetamine (METH) treatment. The relationship between CMA and METH-induced neurotoxicity is not clear. METHODS: We detected changes in the chaperone protein Hsc70 and the lysosomal surface receptor Lamp-2a after METH treatment and then regulated these two proteins by small interfering RNA and DNA plasmid transfection to investigate how CMA influences METH-induced neurotoxicity. RESULTS: We found that CMA activity is decreased after METH exposure in neurons and downregulated Lamp-2a can aggravate the neurotoxicity induced by α-Syn after METH exposure and that Hsc70 overexpression can relieve the abnormal levels of alpha-synuclein and its aggregate forms and the increase in cell apoptosis induced by METH. CONCLUSIONS: The results provide in vivo evidence for CMA plays a pivotal role in METH-induced neurotoxicity, and upregulation of Hsc70 expression significantly protects neuronal cells against METH-induced toxicity. This research may pave the way for potential therapeutic approaches targeting CMA for METH abuse and neurodegenerative disorders.

Blunt Trauma-Induced Pericardial Tamponade After Video-Assisted Thoracoscopic Surgery.

This report describes a case of blunt cardiac injury and pericardial tamponade after video-assisted thoracoscopic surgery in a patient with lung cancer, hypertension, and cardiac hypertrophy. Anatomic findings included massive hemorrhage in the pericardium, cardiac hypertrophy, and a superficial contusion with a ruptured blood vessel on the epicardium at the lateral wall of the left ventricle. The patient died of pericardial tamponade secondary to blunt trauma from the tip of the thoracoscopic instrument. This case suggests that detailed assessment of the cardiovascular system, especially cardiac hypertrophy, careful preoperative preparation, and careful monitoring of postoperative conditions are important.

SUMOylation of Alpha-Synuclein Influences on Alpha-Synuclein Aggregation Induced by Methamphetamine.

Methamphetamine (METH) is an illegal and widely abused psychoactive stimulant. METH abusers are at high risk of neurodegenerative disorders, including Parkinson's disease (PD). Previous studies have demonstrated that METH causes alpha-synuclein (α-syn) aggregation in the both laboratory animal and human. In this study, exposure to high METH doses increased the expression of α-syn and the small ubiquitin-related modifier 1 (SUMO-1). Therefore, we hypothesized that SUMOylation of α-syn is involved in high-dose METH-induced α-syn aggregation. We measured the levels of α-syn SUMOylation and these enzymes involved in the SUMOylation cycle in SH-SY5Y human neuroblastoma cells (SH-SY5Y cells), in cultures of C57 BL/6 primary mouse neurons and in brain tissues of mice exposure to METH. We also demonstrated the effect of α-syn SUMOylation on α-syn aggregation after METH exposure by overexpressing the key enzyme of the SUMOylation cycle or silencing SUMO-1 expression in vitro. Then, we make introduced mutations in the major SUMOylation acceptor sites of α-syn by transfecting a lentivirus containing the sequence of WT α-syn or K96/102R α-syn into SH-SY5Y cells and injecting an adenovirus containing the sequence of WT α-syn or K96/102R α-syn into the mouse striatum. Levels of the ubiquitin-proteasome system (UPS)-related makers ubiquitin (Ub) and UbE1, as well as the autophagy-lysosome pathway (ALP)-related markers LC3, P62 and lysosomal associated membrane protein 2A (LAMP2A), were also measured in SH-SY5Y cells transfected with lentivirus and mice injected with adenovirus. The results showed that METH exposure decreases the SUMOylation level of α-syn, although the expression of α-syn and SUMO-1 are increased. One possible cause is the reduction of UBC9 level. The increase in α-syn SUMOylation by UBC9 overexpression relieves METH-induced α-syn overexpression and aggregation, whereas the decrease in α-syn SUMOylation by SUMO-1 silencing exacerbates the same pathology. Furthermore, mutations in the major SUMOylation acceptor sites of α-syn also aggravate α-syn overexpression and aggregation by impairing degradation through the UPS and the ALP in vitro and in vivo. These results suggest that SUMOylation of α-syn plays a fundamental part in α-syn overexpression and aggregation induced by METH and could be a suitable target for the treatment of neurodegenerative diseases.

[Morphological analysis of cardiac rupture due to blunt injury, cardiopulmonary resuscitation and myocardial infarction in forensic pathology].

OBJECTIVE: To analyze the morphological features and forensic pathological characteristics of cardiac ruptures of different causes for their differential diagnosis. METHODS: We analyzed the data of 44 autopsy cases of cardiac rupture from 2014 to 2017 in our institute, including 11 cases caused by blunt violence with intact pericardium, 4 caused by cardiopulmonary resuscitation (CPR), 9 by myocardial infarction, and 20 by aorta dissection rupture.The gross features and histopathological characteristics of cardiac rupture and pericardial effusion were analyzed and compared. RESULTS: Cardiac ruptures caused by blunt violence varied in both morphology and locations, and multiple ruptures could be found, often accompanied with rib or sternum fractures; the volume of pericardial effusion was variable in a wide range; microscopically, hemorrhage and contraction band necrosis could be observed in the cardiac tissue surrounding the rupture.Cardiac ruptures caused by CPR occurred typically near the apex of the right ventricular anterior wall, and the laceration was often parallel to the interventricular septum with frequent rib and sternum fractures; the volume of pericardial blood was small without blood clots; microscopic examination only revealed a few hemorrhages around the ruptured cardiac muscular fibers.Cardiac ruptures due to myocardial infarction caused massive pericardial blood with blood clots, and the blood volume was significantly greater than that found in cases of CPR-induced cardiac rupture (P < 0.05);lacerations were confined in the left ventricular anterior wall, and the microscopic findings included myocardial necrosis, inflammatory cell infiltration, and mural thrombus.Cardiac tamponade resulting from aorta dissection rupture was featured by massive pericardial blood with blood clots, and the blood volume was much greater than that in cases of cardiac ruptures caused by blunt violence, myocardial infarction and CPR (P < 0.05). CONCLUSIONS: Hemorrhage, inflammatory cell infiltration, and lateral thrombi around the cardiac rupture, along with pericardial blood clots, are all evidences of antemortem injuries.