Neurotransmitter accumulation and Parkinson's disease-like phenotype caused by anion channelrhodopsin opto-controlled astrocytic mitochondrial depolarization in substantia nigra pars compacta.

Parkinson's disease (PD) is a mitochondria-related neurodegenerative disease characterized by locomotor deficits and loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNc). Majority of PD research primarily focused on neuronal dysfunction, while the roles of astrocytes and their mitochondria remain largely unexplored. To bridge the gap and investigate the roles of astrocytic mitochondria in PD progression, we constructed a specialized optogenetic tool, mitochondrial-targeted anion channelrhodopsin, to manipulate mitochondrial membrane potential in astrocytes. Utilizing this tool, the depolarization of astrocytic mitochondria within the SNc in vivo led to the accumulation of γ-aminobutyric acid (GABA) and glutamate in SNc, subsequently resulting in excitatory/inhibitory imbalance and locomotor deficits. Consequently, in vivo calcium imaging and interventions of neurotransmitter antagonists demonstrated that GABA accumulation mediated movement deficits of mice. Furthermore, 1 h/day intermittent astrocytic mitochondrial depolarization for 2 weeks triggered spontaneous locomotor dysfunction, α-synuclein aggregation, and the loss of DA neurons, suggesting that astrocytic mitochondrial depolarization was sufficient to induce a PD-like phenotype. In summary, our findings suggest the maintenance of proper astrocytic mitochondrial function and the reinstatement of a balanced neurotransmitter profile may provide a new angle for mitigating neuronal dysfunction during the initial phases of PD.

A sensitive mitochondrial thermometry 2.0 and the availability of thermogenic capacity of brown adipocyte.

The temperature of a living cell is a crucial parameter for cellular events, such as cell division, gene expressions, enzyme activities and metabolism. We previously developed a quantifiable mitochondrial thermometry 1.0 based on rhodamine B methyl ester (RhB-ME) and rhodamine 800 (Rh800), and the theory for mitochondrial thermogenesis. Given that the synthesized RhB-ME is not readily available, thus, a convenient mitochondrial thermometry 2.0 based on tetra-methyl rhodamine methyl ester (TMRM) and Rh800 for the thermogenic study of brown adipocyte was further evolved. The fluorescence of TMRM is more sensitive (∼1.4 times) to temperature than that of RhB-ME, then the TMRM-based mito-thermometry 2.0 was validated and used for the qualitatively dynamic profiles for mitochondrial thermogenic responses and mitochondrial membrane potential in living cells simultaneously. Furthermore, our results demonstrated that the heterogenous thermogenesis evoked by ß3 adrenoceptor agonist only used overall up to ∼46% of the thermogenic capacity evoked by CCCP stimulation. On the other hand, the results demonstrated that the maximum thermogenesis evoked by NE and oligomycin A used up to ∼79% of the thermogenic capacity, which suggested the maximum thermogenic capacity under physiological conditions by inhibiting the proton-ATPase function of the mitochondrial complex V, such as under the cold activation of sympathetic nerve and the co-release of sympathetic transmitters.

Donor BMSC-derived small extracellular vesicles relieve acute rejection post-renal allograft through transmitting Loc108349490 to dendritic cells.

Bone marrow-derived mesenchymal stem cell (BMSC)-derived small extracellular vesicles (sEVs) are potent candidates for the suppression of acute rejection post-renal allograft and have been reported to halt dendritic cells (DCs) maturation. However, whether BMSC-derived sEVs mitigate acute rejection post-renal allograft by targeting DCs is still unclear. In this study, donor BMSC-derived sEVs (sEVs) relieved the inflammatory response and suppressed mature DCs (mDCs) location in kidney grafts, and increased regulatory T (Treg) cell population in the spleens of the rats that underwent kidney allograft. In lipopolysaccharide (LPS)-stimulated immature DCs (imDCs), sEVs suppressed the maturation and migration of DCs and inactivated toll-like receptor 4 (TLR4) signaling. Compared with LPS-treated imDCs, imDCs treated with LPS+sEVs promoted CD4+ T cells differentiated toward Treg cells. Subsequently, we found that Loc108349490, a long non-coding RNA (lncRNA) abundant in sEVs, mediated the inhibitory effect of sEVs on DC maturation and migration by promoting TLR4 ubiquitination. In rats that underwent an allograft, Loc108349490 deficiency weakened the therapeutic effect of sEVs on acute rejection. The present study firstly found that sEVs alleviated acute rejection post-renal allograft by transferring lncRNA to DCs and screened out the functional lncRNA loaded in sEVs was Loc108349490.

A novel nonsense variant of the AGXT identified in a Chinese family: special variant research in the Chinese reference genome.

BACKGROUND: Primary hyperoxaluria(PH)is a rare autosomal recessive genetic disease that contains three subtypes (PH1, PH2 and PH3). Approximately 80% of PH patients has been reported as subtype PH1, this subtype of PH has been related to a higher risk of renal failure at any age. Several genetic studies indicate that the variants in gene AGXT are responsible for the occurrence of PH1. However, the population heterogeneity of the variants in AGXT makes the genetic diagnosis of PH1 more challenging as it is hard to locate each specific variant. It is valuable to have a complete spectrum of AGXT variants from different population for early diagnosis and clinical treatments of PH1. CASE PRESENTATION: In this study, We performed high-throughput sequencing and genetic analysis of a 6-year-old male PH1 patient from a Chinese family. Two variants (c.346G > A: p.Gly116Arg; c.864G > A: p.Trp288X) of the gene AGXT were identified. We found a nonsense variant (c.864G > A: p.Trp288X) that comes from the proband's mother and has never been reported previously. The other missense variant (c.346G > A: p.Gly116Arg) was inherited from his father and has been found previously in a domain of aminotransferase, which plays an important role in the function of AGT protein. Furthermore, we searched 110 pathogenic variants of AGXT that have been reported worldwide in healthy local Chinese population, none of these pathogenic variants was detected in the local genomes. CONCLUSIONS: Our research provides an important diagnosis basis for PH1 on the genetic level by updating the genotype of PH1 and also develops a better understanding of the variants in AGXT by broadening the variation database of AGXT according to the Chinese reference genome.

Preparation of osthole-loaded nano-vesicles for skin delivery: Characterization, in vitro skin permeation and preliminary in vivo pharmacokinetic studies.

The main objective of the present research was to evaluate the flexible nano-vesicles for transdermal delivery of osthole. The nano-vesicles were formulated, characterized and evaluated for their physicochemical properties, in vitro skin permeation and in vivo plasma concentration. The encapsulation efficiency of osthole in ethosome and transfersome was measured to be 83.3±4.8% and 80.9±3.6%, respectively. In vitro studies showed that osthole ethosome provided an enhanced transdermal flux of 6.98±1.6µg/cm(2)/h and a decreased lag time of 2.45h across porcine ear skin. Moreover, ethosome also showed increased skin deposition of the drug over transfersome (1.5-fold) and saturated solution of osthole in 35% ethanol (2.1-fold). Data from in vivo pharmacokinetic studies showed that AUC and Cmax of the osthole loaded-ethosome were remarkably increasing compared with the other formulations. Thus, osthole ethosome was considered as an effective delivery system for the drug.

Suppression of spermatogenesis by testosterone undecanoate-loaded injectable in situ-forming implants in adult male rats.

We have investigated the feasibility of administration of testosterone undecanoate (TU)-loaded injectable in situ-forming implant (ISFI) for contraception in adult male Sprague-Dawley rats. Male rats were treated with vehicle, TU-loaded ISFIs (540, 270 and 135 mg TU kg-1 ) or TU injections (45 mg TU kg-1 every 30 days) for 120 days. Fertility tests served for determining infertility or restoration of fertility in treated rats. Serum testosterone concentration, epididymal sperm count, motility, morphology, and histology of the testis were monitored. The TU-loaded ISFIs increased serum testosterone levels in rats steadily without fluctuation over 3 months. One month after TU administration, the epididymal sperm count decreased significantly in all experimental groups. After 3 months, the animals treated with 270 and 135 mg kg-1 TU-loaded ISFIs were 100% infertile, and no implantation sites were produced in the mated females. However, some of males treated with 540 mg kg-1 ISFI or TU injections were still fertile but numbers of implantation sites were also significantly lower than control values. TU-loaded ISFI at an appropriate dose has potential as a long-acting male contraceptive drug that suppresses spermatogenesis consistently over a period of 3 months.

[Biological limit value for occupational exposure to N, N-dimethylacetamide].

OBJECTIVE: To establish Biological Limit Value (BLV) for N, N-dimethylacetamide (DMAC). METHOD: 201 workers in 3 spandex factories exposed to DMAC were recruited. Air samples were collected using personal air samplers, and urine samples from each works were collected at the end of shift at end of workweek. The urinary metabolite NMAC and air samples of DMAC were determined by gas chromatography (GC). Percentile and relative internal exposure (RIE) were analyzed and proposed a BLV for DMAC. RESULTS: The number of workers who exposure to DMAC below OELs were 133 (66.2%) among 201 workers monitored. Geometric mean (range) concentration of DMAC in air was 19.4 (0.40 ∼ 300.12) mg/m(3), and that of NMAC in urine was 23.7 (1.30 ∼ 189.42) mg/g Cr. A linear correlation was found between the personal air DMAC and creatinine-adjusted NMAC levels in urine collected at the end of shift at end of workweek (F = 188.872, R(2) = 0.487,P < 0.001). The relationship can be described by the equation Log (NMAC mg/g Cr) = 0.685 + 0.455 log (DMAC mg/m(3)). According to the equation the current China OELs value of 20 mg/m(3) would lead to a mean NMAC concentration of 18.92 mg/g Cr. The 90th percentile biomonitoring result below 20 mg/m(3) 8-hour TWA is 23.9 mg MMAC mg/g Cr, and that of NMAC in urine calculated by relative internal exposure (RIE) was 19.0 mg/g Cr. CONCLUSION: A BLV of 20 mg/g Cr NMAC in urine at the end of shift at end of workweek for DMAC was recommend by reference to official values from other countries.

[The analysis of urinary N-methylacetamide by GC-NPD with a direct injection].

OBJECTIVE: To establish a method to detect N-methylacetamide (NMAC) concentration in urine of workers occupationally exposed to NMAC with directly injecting the sample into capillary gas chromatography. METHODS: After frozen urine samples were isolated from precipitation by centrifugation, the aliquot of supernatant was pretreated by protein precipitation with dilution of methanol. The methanol supernatant was separated by Polyethylene Glycol (PEG) capillary columns and detected by nitrogen phosphorous detector (NPD). RESULTS: Good linearity was obtained in the concentration range of 1.0 ∼ 250 mg/L. The correlation coefficient was 1.0000. The minimum detection limit of NMAC in urine was 0.2 mg/L. The method recovery rates were 96.0% ∼ 99.4% at three different concentrations. The mean recovery rate was 97.8%. The relative standard deviations (RSD) of intra- and inter-day were between 1.5% ∼ 3.4%. CONCLUSION: The method was simple, rapid, selective and sensitive and was applicable to detect the urinary NMAC concentration for monitoring occupational exposure levels.

[Determination of trimethyltin chloride in urine by headspace-gas chromatography].

OBJECTIVE: To establish a detection method for trimethyltin chloride in urine by the Head space-GC. METHOD: After derivatizing trimethyltin chloride, the urines was separated by the head space-gc, and then the trimethyltin chloride detected qualitatively and quantificationally. RESULTS: In the concentration range of 0.02 ∼ 0.40 mg/L urinary trimethyltin chloride, showed a quadratic, r = 0.9992, detection limit was 0.005 mg/L, the relative standard deviation was 1.9% ∼ 2.5%, recovery was 92.0% to 100%, the urine samples can be saved at least 90 days in -18°C refrigerator. CONCLUSION: The instrument, reagents involved in the detection require low, the operations to processing samples are simple, high sensitivity, less interference, good reproducibility, and suitable for quantitative and qualitative analysis, convenient to promotion.

[The impact of N, N-dimethylacetamide on the health of workers].

OBJECTIVE: To explore the hepatic toxicity and the exposure biomarkers of N, N-Dimethylacetamide. METHODS: One hundred forty five objects were chosen by stratified random sampling method. The investigation was performed using questionnaire and physical examination. The air concentrations of DMAC in the workshops were monitored. The urine samples were collected and analyzed after work everyday or at the weekend. The correlation between the air concentrations of DMAC in the workshops and the concentrations of urinary NMAC wee analyzed by regression. RESULTS: The air concentration of DMAC in the spinning workshop was higher than others. The morbidity of abnormal hepatic function was 12.4%, 61.1% of workers with abnormal hepatic function appeared in one year after exposure to DMAC in the workshops ( r=0.44, P<0.01). CONCLUSION: The abnormal heptic function was found in workers exposed to DMAC for short period. The concentration of urinary NMAC can serve as the exposure biomarker of DMAC.

[Investigation on dermal contamination among workers occupationally exposed to dimethylformamide].

OBJECTIVE: To establish a method for the determination of dimethylformamide (DMF) and investigate dermal contamination and absorption among workers occupationally exposed to DMF. METHOD: 37 workers exposed to DMF were divided randomly into two groups. DMF was washed down by isopropyl alcohol in A group (16 workers) and water in B group(21 workers).Gas chromatography was used for the quantification of dermal contamination and N-methylformamide(NMF) in urine, correlative study was done between them. RESULTS: DMF could be detected in all samples in A group, but could not be detected in B group. The miscellaneous peaks could be completely separated from the DMF peak in the sample spectrum, without manual inference. The highest degree of total dermal contamination was observed in wet spinning workshop [(2.84 +/- 1.31) mg], postprocessing workshop [(2.50 +/- 0.95) mg] and dry spinning workshop [(1.95 +/- 0.61) mg] were lower. The respiratory cumulative exposure dosages were 351.3, 201.3 and 135.2 mg respectively. The average DMP concentration in air of the third printing processing workshop, the dry spinning workshop and the wet spinning workshop was 60.2, 89.6, 156.4 mg/m3 respectively, and the respiratory tract contamination in the workers of the three workshops were 135.2, 201.3 and 351.3 mg respectively. There was statistical independence between the quantification of total dermal contamination and NMF in urine (r = 0.176, P > 0.05). CONCLUSION: Isopropyl alcohol is the effective washing solvent.When the concentration of DMF in workplace air is above the occupational exposure limit, respiratory tract absorption is the principal pathway of DMF absorption,but dermal contamination of DMF should not be ignored.

[Study on the extraction of indirubin from Isatis indigotica Fort].

OBJECTIVE: To study the optimal process of the extraction of indirubin from Isatis indigotica Fort. METHODS: The process was studied by supersonic extraction, refluxing and orthogonal design with the content of indirubin as the detective marker. Then the extraction of indirubin with supersonic extraction and other methods were compared basing on the yield of extracts. RESULTS: Among them, the supersonic extraction was the simplest and the most rapid and the most complete in extraction. And the optimal conditions were A1 B1 C2 D3: supersonic extraction with 60% ethanol, 1 hour, 10-fold solvent and 3 times. CONCLUSION: The supersonic extraction can extract more indirubin from Isatis indigotica Fort in shorter time with less energy. It also shows a promising prospect for leaching the effective constituents from Chinese herbal medicine by supersonic extraction.