Pb induces ferroptosis in choroid plexus epithelial cells via Fe metabolism.

Pb can enhance blood-cerebrospinal fluid barrier (BCSFB) permeability and accumulate in brain tissue, leading to central nervous system (CNS) dysfunction. Choroid plexus (CP) epithelial cells are the main components of the BCSFB with crucial functions in BCSFB maintenance. However, the mechanism by which Pb exposure affects CP epithelial cells remains unclear. Here, ferroptosis was identified as the major programmed cell death modality by sophisticated high-throughput sequencing and biochemical investigations in primary cultured CP epithelial cells following Pb exposure. Bioinformatics analysis using the ferroptosis database revealed that 16 ferroptosis-related genes were differentially expressed in primary cultured CP epithelial cells following Pb exposure. Among them, Gpx4, Slc7a11, Tfrc, and Slc40a1 were hub ferroptosis-related genes. In addition, CP epithelial cells can be impaired when the concentration of the Pb2+ reached 2050 µg/L (10 µM PbAc), which included the decrease of cell viability, Gpx4 and Slc7a11 proteins expression, etc. Moreover, inhibition of ferroptosis enhanced CP epithelial cell viability and reduced BCSFB permeability in vitro following Pb exposure. In summary, ferroptosis of CP epithelial cells is involved in BCSFB dysfunction following Pb exposure. Gpx4, Slc7a11, Tfrc, and Slc40a1 are hub ferroptosis-related genes in CP epithelial cells.

The effects of aerobic exercise combined with resistance training on inflammatory factors and heart rate variability in middle-aged and elderly women with type 2 diabetes mellitus.

OBJECTIVE: This study investigated the effects of aerobic exercise combined with resistance training on serum inflammatory factors and heart rate variability (HRV) in women with type 2 diabetes mellitus (T2DM). METHODS: A total of 30 patients with diabetic cardiovascular autonomic neuropathy (DCAN) were randomly divided into a control group (n = 15) and an exercise group (n = 15). The control group was treated with routine hypoglycemic drugs, while the exercise group was treated with routine hypoglycemic drugs + resistance training (AE + RT). The levels of fasting plasma glucose (FBG), two-hour plasma glucose (2hPG), serum inflammatory factors C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) were measured before and after the intervention. The HRV was evaluated by 24-h ambulatory electrocardiogram. RESULTS: After the intervention, the levels of FBG, 2hPG, serum inflammatory factors, IL-6 and TNF-α in the exercise group were significantly lower than those in the control group (p < .05) with no significant differences in serum CRP (p > .05). After the intervention, the HRV time domain and frequency domain indexes in the two groups were significantly improved compared with those before the exercise experiment (p < .01) and with no significant difference in (lnlf) (p > .05). The time-domain indexes, i.e., SDNN and RMSSD, as well as the frequency domain index, i.e., (lnhf), were significantly higher in the exercise group than in the control group, whereas lnlf/lnhf were significantly lower than those in the control group (p < .05). CONCLUSIONS: Compared with routine hypoglycemic drug therapy, combining aerobic exercise and resistance training helped to reduce the level of blood glucose and serum inflammatory factors in T2DM patients with DCAN, and improved autonomic nerve function.

SecA inhibitors as potential antimicrobial agents: differential actions on SecA-only and SecA-SecYEG protein-conducting channels.

Sec-dependent protein translocation is an essential process in bacteria. SecA is a key component of the translocation machinery and has multiple domains that interact with various ligands. SecA acts as an ATPase motor to drive the precursor protein/peptide through the SecYEG protein translocation channels. As SecA is unique to bacteria and there is no mammalian counterpart, it is an ideal target for the development of new antimicrobials. Several reviews detail the assays for ATPase and protein translocation, as well as the search for SecA inhibitors. Recent studies have shown that, in addition to the SecA-SecYEG translocation channels, there are SecA-only channels in the lipid bilayers, which function independently from the SecYEG machinery. This mini-review focuses on recent advances on the newly developed SecA inhibitors that allow the evaluation of their potential as antimicrobial agents, as well as a fundamental understanding of mechanisms of SecA function(s). These SecA inhibitors abrogate the effects of efflux pumps in both Gram-positive and Gram-negative bacteria. We also discuss recent findings that SecA binds to ribosomes and nascent peptides, which suggest other roles of SecA. A model for the multiple roles of SecA is presented.

[Regulation of acupuncture on expression of AKT protein in lung tissues of asthma rats].

OBJECTIVE: To explore the effects of acupuncture on the expression of protein kinase B (PKB/AKT) in lung tissues of asthma rats. METHODS: Forty SPF male SD rats were randomly divided into a blank group, a model group, an acupuncture group and a blocker group, 10 rats in each one. The rat model of asthma was established by egg albumin stimulation in the model group, acupuncture group and blocker group. Since the establishment of rat model, the rats in the acupuncture group were treated with acupuncture at "Dazhui" (GV 14), "Feishu" (BL 13) and "Fengmen" (BL 12) before atomization; the rats in the blocker group were treated with intervention of blocker LY294002, once every two days, for 7 times. There was no treatment in the blank group and model group. HE staining was applied to observe the morphologic changes of lung tissues; the immunohistochemical method was applied to test the protein expression of AKT in lung tissue. RESULTS: HE staining indicated the infiltration and aggregation of a variety of inflammatory cells around airways, as well as bronchial smooth muscle spasm and confined lumen in the model group; in the acupuncture group and blocker group the inflammatory cells were less and confined lumen was relieved. Compared with the blank group, the protein expression of AKT was higher in the model group (P<0.05); compared with the model group, the protein expression of AKT in the acupuncture group and blocker group was reduced (both P<0.05); the differences between the acupuncture group and blank group, blocker group were not significant (both P>0.05). CONCLUSIONS: Acupuncture could reduce the protein expression of AKT in lung tissue in asthma rats, leading to relieved inflammation reaction and airway remodeling.

Using Chemical Probes to Assess the Feasibility of Targeting SecA for Developing Antimicrobial Agents against Gram-Negative Bacteria.

With the widespread emergence of drug resistance, there is an urgent need to search for new antimicrobials, especially those against Gram-negative bacteria. Along this line, the identification of viable targets is a critical first step. The protein translocase SecA is commonly believed to be an excellent target for the development of broad-spectrum antimicrobials. In recent years, we developed three structural classes of SecA inhibitors that have proven to be very effective against Gram-positive bacteria. However, we have not achieved the same level of success against Gram-negative bacteria, despite the potent inhibition of SecA in enzyme assays by the same inhibitors. In this study, we use representative inhibitors as chemical probes to gain an understanding as to why these inhibitors were not effective against Gram-negative bacteria. The results validate our initial postulation that the major difference in effectiveness against Gram-positive and Gram-negative bacteria is in the additional permeability barrier posed by the outer membrane of Gram-negative bacteria. We also found that the expression of efflux pumps, which are responsible for multidrug resistance (MDR), have no effect on the effectiveness of these SecA inhibitors. Identification of an inhibitor-resistant mutant and complementation tests of the plasmids containing secA in a secAts mutant showed that a single secA-azi-9 mutation increased the resistance, providing genetic evidence that SecA is indeed the target of these inhibitors in bacteria. Such results strongly suggest SecA as an excellent target for developing effective antimicrobials against Gram-negative bacteria with the intrinsic ability to overcome MDR. A key future research direction should be the optimization of membrane permeability.

[Chinese herbal medicine enhances sexual function and c-Fos/nNOS expression in the nucleus accumbens of orchidectomized rats].

RESULTS: There was a decrease in accessory genital organ weight, plasma testosterone, and sexual behavior, as well as a low number of c-Fos-positive cells and a large nNOS-positive cell area in orchidectomized rats. Administration of the herbal medicine increased accessory genital organ weight, testosterone level, mating behavior, and c-Fos-positive cell number, while it decreased the nNOS-positive cell area in orchidectomized rats. CONCLUSION: An increase of plasma testosterone after administration of "kidney-nourishing" herbal medicine might contribute to the elevated sexual function and activity in orchidectomized rats. In addition, a central nervous system mechanism, such as the functional alteration of NAc, might be involved. Abstract OBJECTIVE: To determine whether the central nervous system is involved in the effect of Chinese herbal medicine on sexual function recovery in orchidectomized rats. METHODS: Orchidectomized rats were administered intragastrically with a decoction of "kidney-nourishing" Chinese herbal medicine once per day for 28 days. Accessory genital organ weight, plasma testosterone, and mating behavior were investigated. The expression of c-Fos and neuronal nitric oxide synthase (nNOS) in neuronal cells in the nucleus accumbens (NAc) was analyzed by immunohistochemistry.

[Effect of Acupuncture on c-fos Expression in the Lung Tissue of Bronchial Asthmatic Rats].

Objective To observe the effect of acupuncture on c-fos expression in the lung tissue of asthmatic rats. Methods Totally 70 SPF grade male SD rats were randomly divided into 7 groups, i.e., the blank group (A) , the asthma model group (B) , the blank control group (C) , the asthma-model acupuncture control group (D) , the asthma model acupuncture group ( E) , the asthma model sham-acu- puncture group (F) , the blank acupuncture group (G) , 10 rats in each group. Corresponding interventions were performed to each group. The protein expression of c-fos in lung tissue of rats was detected u- sing immunohistochemistry and Western blot respectively. Results Immunohistochemistry showed negative expression of c-fos protein in Group A, C, G, and E, and weakly positive in Group B, D, and F. Results of Western blot showed the protein expression of c-fos was higher in Group B than in Group A and E (P <0. 01). The protein expression of c-fos was lower in Group E than in Group D and F (P <0. 05, P < 0. 01). Conclusion Acupuncture could reduce the protein expression of c-fos in lung tissue, thus attenu- ating inflammation reaction.

Design, Synthesis and Evaluation of Triazole-Pyrimidine Analogues as SecA Inhibitors.

SecA, a key component of the bacterial Sec-dependent secretion pathway, is an attractive target for the development of new antimicrobial agents. Through a combination of virtual screening and experimental exploration of the surrounding chemical space, we identified a hit bistriazole SecA inhibitor, SCA-21, and studied a series of analogues by systematic dissections of the core scaffold. Evaluation of these analogues allowed us to establish an initial structure-activity relationship in SecA inhibition. The best compounds in this group are potent inhibitors of SecA-dependent protein-conducting channel activity and protein translocation activity at low- to sub-micromolar concentrations. They also have minimal inhibitory concentration (MIC) values against various strains of bacteria that correlate well with the SecA and protein translocation inhibition data. These compounds are effective against methicillin-resistant Staphylococcus aureus strains with various levels of efflux pump activity, indicating the capacity of SecA inhibitors to null the effect of multidrug resistance. Results from studies of drug-affinity-responsive target stability and protein pull-down assays are consistent with SecA as a target for these compounds.

Evaluation of small molecule SecA inhibitors against methicillin-resistant Staphylococcus aureus.

Due to the emergence and rapid spread of drug resistance in bacteria, there is an urgent need for the development of novel antimicrobials. SecA, a key component of the general bacterial secretion system required for viability and virulence, is an attractive antimicrobial target. Earlier we reported that systematical dissection of a SecA inhibitor, Rose Bengal (RB), led to the development of novel small molecule SecA inhibitors active against Escherichia coli and Bacillus subtilis. In this study, two potent RB analogs were further evaluated for activities against methicillin-resistant Staphylococcus aureus (MRSA) strains and for their mechanism of actions. These analogs showed inhibition on the ATPase activities of S. aureus SecA1 (SaSecA1) and SecA2 (SaSecA2), and inhibition of SaSecA1-dependent protein-conducting channel. Moreover, these inhibitors reduce the secretion of three toxins from S. aureus and exert potent bacteriostatic effects against three MRSA strains. Our best inhibitor SCA-50 showed potent concentration-dependent bactericidal activity against MRSA Mu50 strain and very importantly, 2-60 fold more potent inhibitory effect on MRSA Mu50 than all the commonly used antibiotics including vancomycin, which is considered the last resort option in treating MRSA-related infections. Protein pull down experiments further confirmed SaSecA1 as a target. Deletion or overexpression of NorA and MepA efflux pumps had minimal effect on the antimicrobial activities against S. aureus, indicating that the effects of SecA inhibitors were not affected by the presence of these efflux pumps. Our studies show that these small molecule analogs target SecA functions, have potent antimicrobial activities, reduce the secretion of toxins, and have the ability to overcome the effect efflux pumps, which are responsible for multi-drug resistance. Thus, targeting SecA is an attractive antimicrobial strategy against MRSA.

Design, synthesis and biological evaluation of rose bengal analogues as SecA inhibitors.

SecA, a key component of bacterial Sec-dependent secretion pathway, is an attractive target for exploring novel antimicrobials. Rose bengal (RB), a polyhalogenated fluorescein derivative, was found from our previous study as a potent SecA inhibitor. Here we describe the synthesis and structure-activity relationships (SAR) of 23 RB analogues that were designed by systematical dissection of RB. Evaluation of these analogues allowed us to establish an initial SAR in SecA inhibition. The antimicrobial effects of these SecA inhibitors are confirmed in experiments using E. coli and B. subtilis.

The early asthmatic response is associated with glycolysis, calcium binding and mitochondria activity as revealed by proteomic analysis in rats.

BACKGROUND: The inhalation of allergens by allergic asthmatics results in the early asthmatic response (EAR), which is characterized by acute airway obstruction beginning within a few minutes. The EAR is the earliest indicator of the pathological progression of allergic asthma. Because the molecular mechanism underlying the EAR is not fully defined, this study will contribute to a better understanding of asthma. METHODS: In order to gain insight into the molecular basis of the EAR, we examined changes in protein expression patterns in the lung tissue of asthmatic rats during the EAR using 2-DE/MS-based proteomic techniques. Bioinformatic analysis of the proteomic data was then performed using PPI Spider and KEGG Spider to investigate the underlying molecular mechanism. RESULTS: In total, 44 differentially expressed protein spots were detected in the 2-DE gels. Of these 44 protein spots, 42 corresponded to 36 unique proteins successfully identified using mass spectrometry. During subsequent bioinformatic analysis, the gene ontology classification, the protein-protein interaction networking and the biological pathway exploration demonstrated that the identified proteins were mainly involved in glycolysis, calcium binding and mitochondrial activity. Using western blot and semi-quantitative RT-PCR, we confirmed the changes in expression of five selected proteins, which further supports our proteomic and bioinformatic analyses. CONCLUSIONS: Our results reveal that the allergen-induced EAR in asthmatic rats is associated with glycolysis, calcium binding and mitochondrial activity, which could establish a functional network in which calcium binding may play a central role in promoting the progression of asthma.

Chronic deep brain stimulation in the rat nucleus accumbens and its effect on morphine reinforcement.

In order to explore a novel method for the treatment of drug abuse, we evaluated the effect of chronic deep brain stimulation (DBS) of the rat nucleus accumbens (NAc) on morphine reinforcement, using a DBS apparatus and an implant method we developed. Thirty-two adult rats weighing 240-260 g were divided into three groups, which included a DBS group (n = 10, administration of surgery, morphine and DBS), a sham DBS group (n = 12, administration of surgery and morphine) and a control group (n = 10, administration of physiological saline). The DBS electrode was stereotaxically implanted into the core of unilateral NAc and connected to an implantable pulse generator. Then, they were fixed to the rat skull. One week later, the rats in each group were intraperitoneally injected with morphine at an increasing dose (10-60 mg/kg) once daily. The rats in the DBS group were administered a 130-Hz high-frequency stimulation (HFS) once daily. A 900-second conditioned place preference (CPP) paradigm was used for determining the effect of electrical stimulation on morphine reinforcement in rats. The data showed that 7-10 days later, the preference score of the DBS group was significantly lower than that of the sham DBS group. The results suggest that chronic HFS of the rat NAc can block CPP induced by morphine and attenuate morphine reinforcement.