Biomimetic Nanovesicles as a Dual Gene Delivery System for the Synergistic Gene Therapy of Alzheimer's Disease.

The association between dysfunctional microglia and amyloid-ß (Aß) is a fundamental pathological event and increases the speed of Alzheimer's disease (AD). Additionally, the pathogenesis of AD is intricate and a single drug may not be enough to achieve a satisfactory therapeutic outcome. Herein, we reported a facile and effective gene therapy strategy for the modulation of microglia function and intervention of Aß anabolism by ROS-responsive biomimetic exosome-liposome hybrid nanovesicles (designated as TSEL). The biomimetic nanovesicles codelivery ß-site amyloid precursor protein cleaving enzyme-1 (BACE1) siRNA (siBACE1) and TREM2 plasmid (pTREM2) gene drug efficiently penetrate the blood-brain barrier and enhance the drug accumulation at AD lesions with the help of exosomes homing ability and angiopep-2 peptides. Specifically, an upregulation of TREM2 expression can reprogram microglia from a pro-inflammatory M1 phenotype to an anti-inflammatory M2 phenotype while also restoring its capacity to phagocytose Aß and its nerve repair function. In addition, siRNA reduces the production of Aß plaques at the source by knocking out the BACE1 gene, which is expected to further enhance the therapeutic effect of AD. The in vivo study suggests that TSEL through the synergistic effect of two gene drugs can ameliorate APP/PS1 mice cognitive impairment by regulating the activated microglial phenotype, reducing the accumulation of Aß, and preventing the retriggering of neuroinflammation. This strategy employs biomimetic nanovesicles for the delivery of dual nucleic acids, achieving synergistic gene therapy for AD, thus offering more options for the treatment of AD.

A Reactive Oxygen Species-Responsive Targeted Nanoscavenger to Promote Mitophagy for the Treatment of Alzheimer's Disease.

Mitophagy modulators are proposed as potential therapeutic intervention that enhance neuronal health and brain homeostasis in Alzheimer's disease (AD). Nevertheless, the lack of specific mitophagy inducers, low efficacies, and the severe side effects of nonselective autophagy during AD treatment have hindered their application. In this study, the P@NB nanoscavenger is designed with a reactive-oxygen-species-responsive (ROS-responsive) poly(l-lactide-co-glycolide) core and a surface modified with the Beclin1 and angiopoietin-2 peptides. Notably, nicotinamide adenine dinucleotide (NAD+ ) and Beclin1, which act as mitophagy promoters, are quickly released from P@NB in the presence of high ROS levels in lesions to restore mitochondrial homeostasis and induce microglia polarization toward the M2-type, thereby enabling it to phagocytose amyloid-peptide (Aß). These studies demonstrate that P@NB accelerates Aß degradation and alleviates excessive inflammatory responses by restoring autophagic flux, which ameliorates cognitive impairment in AD mice. This multitarget strategy induces autophagy/mitophagy through synergy, thereby normalizing mitochondrial dysfunction. Therefore, the developed method provides a promising AD-therapy strategy.

A Novel Homodimer Peptide-Drug Conjugate Improves the Efficacy of HER2-Positive Breast Cancer Therapy.

Tumor-targeting peptide-drug conjugates (PDCs) have become a focus of research in recent years. However, due to the instability of peptides and their short in vivo effective half-life, they have limited clinical application. Herein, we propose a new DOX PDC based on a homodimer HER-2-targeting peptide and acid-sensitive hydrazone bond, which could enhance the anti-tumor effect of DOX and reduce systemic toxicities. The PDC could accurately deliver DOX into HER2-positive SKBR-3 cells, with it showing 2.9 times higher cellular uptake than free DOX and enhanced cytotoxicity with respect to IC50 of 140 nM (vs. 410 nM for free DOX). In vitro assays showed that the PDC had high cellular internalization efficiency and cytotoxicity. In vivo anti-tumor experiments indicated that the PDC could significantly inhibit the growth of HER2-positive breast cancer xenografts in mice and reduce the side effects of DOX. In summary, we constructed a novel PDC molecule targeting HER2-positive tumors, which may overcome some deficiencies of DOX in breast cancer therapy.

A survey on the safety of the SARS-CoV-2 vaccine among a population with stroke risk in China.

Background: The safety of the COVID-19 vaccine in patients at stroke risk is poorly understood. Methods: A survey was conducted on risk factors related to stroke and adverse reactions to vaccines. The participants were divided into low-, medium-, and high-risk groups, according to the stroke risk scorecard recommended by the Stroke Prevention and Control Engineering Committee of the National Health and Family Planning Commission. Factors associated with adverse reactions were analyzed. Reasons for non-vaccination and the aggravation of underlying diseases after vaccination were investigated. Results: 1747 participants participated (138 unvaccinated) and 36.8, 22.1, 41.1% of the vaccinated participants had low, medium, high risk of stroke, respectively. The incidence of adverse reactions after the first and second injection was 16.6, 13.7%, respectively. There was no difference in the incidence of adverse reactions among different risk groups. Sex, vaccine type, sleep quality, worry of adverse reactions, age, and education level were significantly related to adverse reactions to vaccination. The most popular reason for non-vaccination for medium- or high risk-participants was the aggravation of the existing disease. Only 0.3% of vaccinated participants reported slight changes in blood pressure, sugar levels, and lipid levels. No aggravation of stroke sequelae, atrial fibrillation, or transient ischemic attack was reported. Conclusions: Vaccination against COVID-19 (inactive virus) is safe for people at risk of stroke when the existing disease condition is stable. It is suggested to strengthen vaccine knowledge and ensure good sleep before vaccination.

Expression of calmodulin-related genes in lead-exposed mice.

The toxic metal lead is a widespread environmental polutant that can adversely affect human health. However, the underlying mechanisms of lead-induced toxicity are still largely unknown. The mechanism of lead toxicity was presumed to involve cross reaction between Pb(2+) and Ca(2+) with calmodulin dependent systems. The aim of the present study was thus to identify differential expression of calmodulin-related genes in the spleen of lead-exposed mice. We performed microarray analysis to identify differentially expressed genes. RNAs from spleen tissue of lead exposed animals (n=6) and controls (n=6) were converted to labeled cRNA and hybridized to Illumina mouse WG-6_v2_Bead Chip. Expression profiles were analyzed using Illumina BeadStudio Application. Real-time RT-PCR was conducted to validate the microarray data. By microarray analysis 5 calmodulin-related genes (MAP2K6, CAMKK2, CXCR4, PHKA2, MYLK) were found to be differently expressed in lead exposed compared with control mice (p<0.05). The results of Real-time RT-PCR showed that MAP2K6 and CAMKK2 were up-regulated and CXCR4 was down-regulated in lead exposure, but there were no significant differences in PHKA2 and MYLK expression between the lead exposed and control group. These results show that lead exposure produced significant changes in expression of a variety of genes in the spleen and can affect calmodulin-related gene expression.

Lead-induced morphological changes and amyloid precursor protein accumulation in adult rat hippocampus.

Lead is an important environmental pollutant that exerts potent toxic effects on many organs. The toxic effects of lead are less well known for adult brain than for children. We investigated the morphological changes and amyloid precursor protein (APP) accumulation in the adult rat hippocampus following exposure to lead. Forty rats were divided into two groups of 20. One group was exposed to 580 parts per million (ppm) lead acetate and other group to an identical concentration of sodium acetate as a control group. After exposure to lead for 3 months, the hippocampus was examined by electron microscopy and APP levels in the hippocampus were detected using immunohistochemistry. Lead levels in the blood of rats exposed to lead were significantly higher than in the controls. The morphological changes in the hippocampus included mitochondrial degeneration, apoptosis and abnormal synapses in the rats exposed to lead. APP in hippocampus was increased significantly in the group exposed to lead compared to controls. We determined that lead exposure causes accumulation of APP and morphological changes in the adult rat hippocampus.

[Proliferation of the mesenchymal stem cells in a delayed fat flap: an experimental study in rabbits].

OBJECTIVE: To investigate the possibility to enhance the proliferation of adipose-derived stem cells (ASCs) in a delayed fat flap in rabbits. METHODS: A delayed fat flap was formed in one side of inguinal region of a rabbit. 21 days after operation, the fat tissues at the delayed flaps and at the unoperated side were harvested and digested with 0.25% collagenase and sieved. The cell suspensions were centrifuged. The cells were obtained from tissue precipitate after centrifugation. The expression rates of the surface marker (CD29, CD44, CD14 and CD45) were measured by FCM and compared between the experimental and control groups. RESULTS: Expression rates of CD29 and CD44 were higher in the delayed fat flap (74.06% and 90.74%) than in the contralateral fat tissue (62.88% and 77.54%, P < 0.05), while those of CD14 and CD45 were lower in the delayed fat flap (57.66% and 4.84%) than in the contralateral fat tissue (72.10% and 75.82%, P < 0.05 and P < 0.01). CONCLUSIONS: Tissue hypoxic ischemia such as fat tissue in a delayed fat flap can promote proliferation of ASCs. It indicates that tissue in the delayed flap may be transplanted with better survival rate. The ischemia pretreatment of fat tissue may become a new method for fat transplantation.

Analysis of the nuclear localization signal of TRF1 in non-small cell lung cancer.

Several studies revealed a similar down-regulation of telomeric repeat binding factor 1 (TRF1) in tumors. We have previously reported the TRFl expression levels were down-regulation in non-small cell lung cancer (NSCLC). The regulation of TRFl localization is proposed to be important for the function and expression. The nuclear localization signal (NLS) and nuclear export signal (NES) are often important clues to localization of protein. The objective of the present study was to investigate the NLS and NES of TRFl in NSCLC patients. Thirty (30) patients with NSCLCs had undergone radical operations in The First Affiliated Hospital, College of Medicine, Zhejiang University. DNA sequences of NLSs and NESs were amplified by PCR. The PCR products were analyzed by DNA sequencing. There were four NLSs of the TRFl protein, including two monopartite and two bipartite NLSs. The NLSs sequences were included in 337KKERRVGTPQSTKKKKESRR356. The exon 8 and exon 9 of TRFl DNA were covered the NLS sequences. The sequences of predicted NESs were 11WMLDFLCLSL86 and 174NLLKLQALAV183, respectively. The exon 1, exon 3 and exon 4 of TRFl were covered the NES sequences. In NSCLCs, there was no a mutation, deletion, or substitution in NLS and NES of TRFl. We conclude that the NLS and NES sequences in NSCLCs patients did not have mutations. Down-expression of TRFl does not indicate gene mutation of NLS and NES in NSCLCs.

[Characteristics of genesis and development of peritoneal adhesion by different causes: experiment with rats].

OBJECTIVE: To investigate the characteristics of genesis and development of peritoneal adhesion by different causes. METHODS: 236 rats underwent laparotomy with their vermiform processes lifted up and were randomly divided into 5 groups: Group A (control group), with the vermiform process exposed to air for 5 min, Group B, with the vermiform process smeared with talcum powder; Group C, with the vermiform process scraped by scalpel; Group D, with the tip of vermiform process stabbed by needle so as to squeeze the contents of intestine to cause infection; and Group E, with the artery of vermiform process ligated. Then the abdominal incision was sutured. 1, 2, 4, and 6 weeks after the treatment 11-12 rats from each group were randomly to undergo laparotomy. The degree of adhesion was graded blindly by Bhatia's method. The vermiform process was resected to undergo pathological examination and examination of the level of organ hydroxyproline (OHP) was detected. RESULTS: (1) At different time points the adhesive grades of Groups B-E were all significantly higher than that of Group A (all P < 0.05) and the adhesive grades of Groups B and D were both significantly higher than those of Groups C and E (both P < 0.05). There were no significant differences in the adhesive degree 1, 2, and 4 weeks after the treatment between Groups C and E, however, the adhesive degree of Group E was significantly lower than that of Group C (P < 0.05). (2) There were not significant differences in the OHP levels at any time points in Group A (all P > 0.05). There were not significant differences in the OHP levels 1, 2, and 4 weeks after the treatment (all P > 0.05), and the levels 8 weeks after the treatment were all significantly lower than those 1, 2, and 4 weeks after the treatment (all P < 0.05) in Groups B, D, and E. In Group C the OHP level 2 weeks after the treatment was 0.275 +/- 0.031 microg/mg protein, significantly lower than that 1 week after (0.221 +/- 0.036 microg/mg protein, P < 0.05), and the OHP level 8 weeks after the treatment was 0.254 +/- 0.039 microg/mg protein, significantly lower than those 1, 2, and 4 weeks after (all P < 0.05). The OH levels 1, 2, and 4 weeks after the treatment of the 4 experimental groups were all significantly higher than that of the control group (all P < 0.05). 8 weeks after the treatment the level of OHP of Groups B was significantly higher than that of Group A (P < 0.05), however, the OHP levels of Group C, D, and E had all decreased to almost similar to that of Group A (all P > 0.05). (3) The adhesive degrees of Groups C and E were significantly positively correlated with the OHP level (both P < 0.05), however, the adhesive degrees of Groups B and D were not significantly correlated with the OHP level (both P > 0.05). The adhesive degrees 1, 2, and 4 weeks after the treatment of the 5 groups were all significantly positively correlated with the OHP levels (all P < 0.05, however, the adhesive degrees 8 weeks after the treatment of the 5 groups were all not significantly correlated with the OHP levels (all P > 0.05). (4) The main pathological changes of Group B were foreign body granuloma reaction and fibroplasia in Group B and unspecific inflammatory reaction and fibroplasia in Groups C, D, and E. CONCLUSION: Abdominal adhesions resulting from different causes show different characteristics. The abdominal adhesion caused by foreign bodies and that caused by infection are relatively severe and more difficult to recover than those caused by injury and ischemia. It is more reliable to use OHP level as a marker of abdominal adhesion in the early stage.

Therapeutic effect of mild hypothermia on severe traumatic head injury.

OBJECTIVE: To investigate the therapeutic effect of mild hypothermia on severe traumatic brain injury. METHODS: Eighty-six in-patients with severe traumatic brain injury treated ordinarily were consecutively randomized into two groups: a hypothermia group (n=43) and a normothermia group (the control group, n=43). In the hypothermia group, the core temperature (i.e., nasopharyngeal or brain temperature) of the patient was reduced to and maintained at 33-35 degrees C with a systemic cooling blanket. Natural rewarming began after 3-5 days (mean: 4.3 days) of hypothermia treatment. In the control group, the patient received no hypothermia treatment. The vital sign, extradural pressure and serum superoxide dismutase were observed and measured during treatment, and the complications as well as the Glasgow outcome scale were evaluated at 2 years after injury. RESULTS: The mean extradural pressure in the hypothermia group (27.38 mm Hg +/- 4.88 mm Hg at 24 hours, 29.40 mm Hg +/- 4.50 mm Hg at 48 hours and 26.40 mm Hg +/- 4.13 mm Hg at 72 hours after injury) was much lower than that in the control group (32.63 mm Hg +/- 3.00 mm Hg, 34.80 mm Hg +/- 6.00 mm Hg and 31.81 mm Hg +/- 4.50 mm Hg respectively at 24, 48 and 72 hours, P<0.05). The mean serum superoxide dismutase levels in the hypothermia group on days 3 and 7 (583.7 microg/L +/- 99.6 microg/L and 699.4 microg/L +/- 217.3 microg/L, respectively) were much higher than those in the control group at the same time period (446.6 microg/L +/- 79.5 microg/L and 497.1 microg/L +/- 101.2 microg/L, respectively, P<0.01). The recovery rates at 2 years after injury were 65.1% in the hypothermia group and 37.2% in the control group (P<0.05). The mortality rates were 25.6% in the hypothermia group and 51.2% in the control group (P<0.05). The complications, including pulmonary infections, thrombocytopenia (platelet count < 100 x 10(9)/L), hemorrhage in the digestive tract, electrolyte disorders and renal malfunction, were managed without severe sequelae. CONCLUSIONS: Mild hypothermia is a safe and effective therapeutic method, which can lower the extradural pressure, increase the serum superoxide dismutase and improve the neurological outcomes without severe complications in the patients with severe traumatic brain injury.