Dexmedetomidine attenuates ferroptosis by Keap1-Nrf2/HO-1 pathway in LPS-induced acute kidney injury.

Previous research has demonstrated that Dexmedetomidine (DEX), an α2 adrenergic agonist commonly used for its sedative and analgesic properties, can attenuate lipopolysaccharide (LPS)-induced acute kidney injury (AKI). This study explores the possibility that DEX's protective effects in LPS-induced AKI are mediated through the inhibition of ferroptosis, a form of regulated cell death characterized by iron-dependent lipid peroxidation, and the activation of the antioxidant response through the Keap1/Nrf2/HO-1 signaling pathway. We induced AKI in 42 mice using LPS and divided them into six groups: saline control, LPS, LPS + DEX, LPS + Ferrostatin-1 (LPS + Fer-1; a ferroptosis inhibitor), LPS + DEX with α2-receptor antagonist Altipamizole (LPS + DEX + ATI), and LPS + DEX with Nrf2 inhibitor ML385 (LPS + DEX + ML385). After 24 h, we analyzed blood and kidney tissues. LPS exposure resulted in AKI, with increased serum creatinine, BUN, and cystatin C, and tubular damage, which DEX and Fer-1 ameliorated. However, Altipamizole and ML385 negated these improvements. The LPS group exhibited elevated oxidative stress markers and mitochondrial damage, reduced by DEX and Fer-1, but not when α2-adrenergic or Nrf2 pathways were blocked. Nrf2 and HO-1 expression declined in the LPS group, rebounded with LPS + DEX and LPS + Fer-1, and fell again with inhibitors; inversely, Keap1 expression varied. Our results demonstrate that DEX may protect against LPS-induced AKI, at least partially by regulating ferroptosis and the α2-adrenergic receptor/Keap1/Nrf2/HO-1 pathway, suggesting a potential therapeutic role for DEX in AKI management by modulating cell death and antioxidant defenses.

Dexmedetomidine Alleviates Ischemia/Reperfusion-Associated Acute Kidney Injury by Enhancing Autophagic Activity via the α2-AR/AMPK/mTOR Pathway.

BACKGROUND: Dexmedetomidine (DEX) reportedly protects against ischemia-reperfusion (I/R) injury and associated damage to the kidneys, but the underlying mechanisms have yet to be established. METHODS: Unilateral nephrectomy was performed in Wistar rats, and the remaining kidney was clamped for 1 h prior to reperfusion to establish an experimental model system. These animals were then randomized into Sham, DEX + Sham, DEX + I/R, ATI (Altepamizole, α2-adrenergic receptor inhibitor) + DEX + I/R, and 3-MA (3-methyladenine, autophagy inhibitor) + DEX + I/R groups. Serum renal function biomarkers, acute kidney injury (AKI) histopathological scores, serum inflammatory factors, redox biomarkers, markers of autophagic flux, and autophagosome numbers were assessed. Levels of proteins related to the autophagic pathway, including mTOR and AMPK, were also analyzed. RESULTS: Serum creatinine and urea nitrogen levels in the I/R group were significantly elevated over those in sham control rats, as were AKI scores, serum inflammatory cytokine concentrations (IL-6, IL-1ß, and TNF-α), and serum levels of the oxidative stress biomarker malondialdehyde (MDA). All of these parameters were significantly reduced in the DEX + I/R group relative to I/R model rats. I/R group rats also exhibited significant decreases in renal levels of autophagic flux-related biomarkers and autophagosome numbers relative to sham controls, while DEX administration partially restored normal autophagic flux in these rats. Acute I/R also suppress the expression of AMPK in the kidney while increasing mTOR expression, and DEX reversed these effects. The beneficial impact of DEX on I/R-associated AKI was ablated by ATI or 3-MA administration. CONCLUSIONS: These analyses provide strong evidence for the ability of DEX to protect against I/R-associated AKI via the α2-AR/AMPK/mTOR pathway-mediated enhancement of autophagic activity.

Aberrant expression of CD227 is correlated with tumor characteristics and invasiveness of breast carcinoma.

PURPOSE: Increasing evidences demonstrate that CD227 plays a crucial role in the development and progression of breast cancer. However, the function of CD227 in breast carcinoma was still controversial and the investigation on CD227 in Asian race was scarce. METHODS: To investigate the relationship between CD227 and tumor characteristics of breast carcinoma, CD227, estrogen receptor (ER), progesterone receptor (PR), Her2/neu and Ki-67 were detected by immunohistochemistry in a series of 227 patients. The Kaplan-Meier method and log-rank tests were used to estimate the correlation between CD227 expression and patients' prognosis. Furthermore, in vitro invasion assay was performed to examine the effect of CD227 on the invasiveness of breast carcinoma cells after transfection with CD227 cDNA or antisense phosphorothioate oligodeoxynucleotides (ASODN) against CD227 mRNA. RESULTS: Our data demonstrate that the cytoplasm staining and high expression of CD227 were positively related to the aggressiveness of breast cancer. Both circumferential membrane staining and cytoplasm staining were associated with lymph node metastasis. Moreover, the cytoplasm staining and overexpression of CD227 were found to be related to Her-2/neu positivity, higher Ki-67 positivity and poorer survival of patients. We further demonstrated that the invasion ability of breast carcinoma cells could be enhanced or inhibited by CD227 cDNA or ASODN, respectively. CONCLUSIONS: We conclude that the aberrant expression of CD227, especially cytoplasm staining could be predictive for tumor aggressiveness, lymph node metastasis, poorer outcome of patients with breast cancers. And CD227 could promote the invasion ability of breast cancer cells, suggesting a potential role of CD227 as an oncogene in breast carcinoma.

Genetic relationship in mulberry (Morus L.) inferred through PCR-RFLP and trnD-trnT sequence data of chloroplast DNA.

Ten universal primer pairs of the plant chloroplast genome were used to amplify the chloroplast DNA (cpDNA) non-coding regions in eight mulberry (Morus spp.) genotypes, including M. mongolica, M. bombycis, M. alba, M. atropurpurea and M. multicaulis. Subsequently, the polymerase chain reaction (PCR) products were digested by seven restriction enzymes and the trnD-trnT fragment for sequence alignment, and the variations were expected to provide the genetic information for system classification. The results from this study showed that: (1) 10 cpDNA primer pairs could be used for successful amplification in the tested materials, with approximately 17.1 kb of the chloroplast genome analysed. The 152 marker loci were detected by 70 primer/restriction endonuclease combinations, among which the trnD-trnT non-coding region digested by AluI, HinfI, MvaI and RsaI was detected by visible fragment length variation in different genotypes of the genus Morus. (2) eight Morus L. genotypes were divided into two groups based on the digesting pattern discrepancy through cpDNA. The M. multicaulis genotypes displayed diversity on an intraspecies level. 'Nongsang No.12' was identical with the female parent 'Beiqu No.1' (M. atropurpurea) in the surveyed sequence, but different from the male parent 'Tongxiangqing' (M. multicaulis), suggesting that the cpDNA was maternal inheritance in Morus L. (3) There were two deletion fragments (451-456 bp; 840-863bp) and six base point mutations in the trnD-trnT region based on homologous sequence alignment. The sequence of trnD-trnT in the cpDNA of mulberry could provide more genetic information for phylogenetic analysis and pedigree identification.

Gene cloning of an important eukaryotic translation initiation factor family, eIF2A gene in halophytic Leymus chinensis (Trin.).

Eukaryotic initiation factors eIF2A and eIF2 both play important roles in the mRNA translation of protein synthesis, whereas the functions of eIF2A are usually overlooked, as both functions of binding methyionly-tRNAi (Met-tRNAi) to 40S are similar under the same complementary factor and nucleotide requirements. Recently, the functions of eIF2A were reported to differ from those of eIF2 in manners when binding Met-tRNAi to 40S. Given that eukaryotic initiation factor eIF2 has been well known, eIF2A was still deficient in understanding of its sequence, structure and functions. In this work, we collected a high salt-tolerant grass Leymus chinensis (Trin.) as the object of study, and cloned and sequenced the eIF2A gene from this species. Based on the DNA alignment and analysis of eIF2A gene sequences from other organisms, an effective primer set was newly designed. Using this primer set, a DNA fragment with length of about 500 bp was obtained, and we have submitted this sequencing result to NCBI GenBank database (accession number: KF279515). The Basic Local Alignment Search Tool (BLAST) result showed that our sequence is highly identical to eIF2A gene sequences that existed in NCBI GenBank database. This work would help to further understand the function of eIF2A, and provide more potential target genes for studying their functions in relation to stress tolerance mechanisms.

[Physical exercise and mental health: cognition, anxiety, depression and self-concept].

This review focuses on the benefits of regular physical activity participation have mainly focused on cognitive functioning, anxiety and depression, and self-concept. It is well documented that ex- ercise can enhance cognitive functioning, improve executive function at old age, and improve mental abil- ity of children labeled as educational subnormal or disability. Regular exercise has been used to reduce stress and ward off anxiety and feelings of depression. In addition, exercise can improve self-esteem and positive outlook in life. Studies in these three main areas were reviewed and issues and future directions were highlighted.

Tomato (Solanum lycopersicum) variety discrimination and hybridization analysis based on the 5S rRNA region.

The tomato (Solanum lycopersicum) is a major vegetable crop worldwide. To satisfy popular demand, more than 500 tomato varieties have been bred. However, a clear variety identification has not been found. Thorough understanding of the phylogenetic relationship and hybridization information of tomato varieties is very important for further variety breeding. Thus, in this study, we collected 26 tomato varieties and attempted to distinguish them based on the 5S rRNA region, which is widely used in the determination of phylogenetic relations. Sequence analysis of the 5S rRNA region suggested that a large number of nucleotide variations exist among tomato varieties. These variable nucleotide sites were also informative regarding hybridization. Chromas sequencing of Yellow Mountain View and Seuwiteuking varieties indicated three and one variable nucleotide sites in the non-transcribed spacer (NTS) of the 5S rRNA region showing hybridization, respectively. Based on a phylogenetic tree constructed using the 5S rRNA sequences, we observed that 16 tomato varieties were divided into three groups at 95% similarity. Rubiking and Sseommeoking, Lang Selection Procedure and Seuwiteuking, and Acorn Gold and Yellow Mountain View exhibited very high identity with their partners. This work will aid variety authentication and provides a basis for further tomato variety breeding.

Restoration of chemosensitivity in cancer cells with MDR phenotype by deoxyribozyme, compared with ribozyme.

One of the main mechanisms for multidrug resistance (MDR) involves multidrug resistance gene 1 (MDR1) which encodes P-glycoprotein (Pgp). Pgp acts as a drug efflux pump and exports chemotherapeutic agents from cancer cells. Specific inhibition of Pgp expression by gene therapy is considered a well-respective strategy having less innate toxicities. At present, the investigation of DRz in reversal MDR is scarce. In the study, phosphorothioate DRz that targets to the translation initiation codon AUG was synthesized and transfected into breast cancer cells and leukemia cells with MDR phenotype. ASODN (antisense oligonucleotide) and ribozyme targets to the same region were also synthesized for comparison analysis. Alterations in MDR1 mRNA and Pgp were determined by RT-PCR, Northern blot, flow cytometry and Rh123 retention tests. Chemosensitivity of the treated cells was determined by MTT assay. The results showed that DRz could significantly suppress expression of MDR1 mRNA and inhibit synthesis of Pgp. The efflux activity of Pgp was inhibited accordingly. Chemosensitivity assay showed that a 21-fold reduction in drug resistance for Adriamycin and a 45-fold reduction in drug resistance for Vinblastine were found in the treated cells 36h after transfection. These data suggest that DRz targeted to the translation initiation codon AUG can reverse MDR phenotype in cancer cells and restore their chemosensitivity. Moreover, the reversal efficiency of DRz is better than that of ribozyme and ASODN targets to the same region of MDR1 mRNA.

[Study on quality of five hybrid corn kernels by FTIR spectroscopy].

The aim of this work was to study the feasibility of evaluating quality of corn kernels using Fourier transform infrared (FTIR) spectroscopy. The spectra of five kinds of hybrid corn kernels were obtained by infrared spectrometer rapidly. The infrared spectrum between 1 776 and 952 cm(-1) was composed of absorption bands of protein, starch and lipid mainly. The absorption band of starch was strong, and the band of protein was weak. The characteristic bands of starch, protein and lipid were highly overlapped, and main information was concealed. Curve-fitting the spectrum between 1 776 and 952 cm(-1), significant information was presented. The percentage of band area at 1 051 and 1 548 cm(-1) in total band area has a linear relationship with the concentration of starch and protein. The results showed that Fourier transform infrared spectroscopy combined with curve-fitting could be used to analyse the concentration of starch and protein in corn kernel, and provides a rapid and convenient method to study hybrid corn.

Sensitivity of translation initiation factor eIF1 as a molecular target of salt toxicity to sodic-alkaline stress in the halophytic grass Leymus chinensis.

Eukaryotic translation initiation factors (eIFs) have been shown to be critical in the initiation of protein synthesis. Here, we report the cloning and characterization of a novel gene, LceIF1, from a potentially interesting forage grass, Leymus chinensis (Trin.). The expression results show that LceIF1 is expressed in most organisms under normal conditions, but the transcription patterns differ under sodic-saline and sodic-alkaline stresses. Sodic-saline stress induced a persistent decrease, and sodic-alkaline stress induced overexpression of LceIF1. Potassic-saline and alkaline stresses did not cause any changes in expression of eIF1. These results indicate that not only pH but also Na(+) concentration affects overtranscription of LceIF1. The eIF1 transgenic lines showed relatively high eIF1 expression, resulting in potentially higher stress resistance. Combined with eIF1 transcription in transgenic lines, LceIF1 as a molecular target of salt toxicity is believed to help enhance salt tolerance.

Effect of chitinase on resistance to fungal pathogens in sea buckthorn, Hippophae rhamnoides, and cloning of Class I and III chitinase genes.

Sea buckthorn (Hippophae rhamnoides L.) is naturally distributed from Asia to Europe. It has been widely planted as an ornamental shrub and is rich in nutritional and medicinal compounds. Fungal pathogens that cause diseases such as dried-shrink disease are threats to the production of this plant. In this study, we isolated the dried-shrink disease pathogen from bark and total chitinase protein from leaves of infected plants. The results of the Oxford Cup experiment suggested that chitinase protein inhibited the growth of this pathogen. To improve pathogen resistance, we cloned chitinase Class I and III genes in H. rhamnoides, designated Hrchi1 and Hrchi3. The full-length cDNA of the open reading frame region of Hrchi1 contained 903 bp encoding 300 amino acids and Hrchi3 contained 894 bp encoding 297 amino acids. Active domain analysis, protein types, and secondary and 3D structures were predicted using online software.

[Effects of artificial microRNA targeting glucosylceramide synthase on drug sensitivity of breast cancer cells].

OBJECTIVE: To explore the inhibitory effects on glucosylceramide synthase (GCS) expression and drug sensitivity in breast cancer cells by transfecting artificial microRNA targeting GCS. METHODS: Two microRNA expression vectors targeting GCS were constructed and transfected into MCF-7/ADR cells via Lipofectamine 2000. The levels of GCS mRNA and protein were measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot respectively. Methyl thiazolyl tetrazolium (MTT) assay was used to assess the chemosensitivity of MCF-7/ADR cells to adriamycin (ADM) and vincristine. RESULTS: After transfection of two microRNA expression vectors, the expression of GCSmRNA in MCF-7/ADR cells was 0.098 ± 0.005 and 0.143 ± 0.007 respectively. Compared with the control cells (0.875 ± 0.008), the difference was significant (P < 0.01). The expression of GCS protein (0.127 ± 0.004, 0.165 ± 0.008) in MCF-7/ADR cells was lower than that in the control cells (0.765 ± 0.007; P < 0.01). Furthermore, in comparison with the control cells, the resistance factor to adriamycin significantly dropped to 4.06 and 6.06 while the drug resistance to vincristine decreased to 8.30 and 12.67 respectively (P < 0.01). CONCLUSION: Artificial microRNA targeting GCS inhibits the GCS expression and restores significantly the sensitivity of breast cancer cells to anticancer drugs. These findings may provide a novel strategy of enhancing the chemotherapy sensitivity of breast cancer.

[Studies on normal and mildewy Auricularia auricular by Fourier transform infrared spectroscopy].

In order to verify the capability of Fourier transform infrared spectroscopy in food safety, Fourier transform infrared spectroscopy (FTIR) was used to obtain the spectra of normal and mildewy auricularia auricula, The result showed the frequency of hydroxyl and aliphatic absorption band in their spectra had evident differentia, with the dispersion being 23.31 and 13.41 cm(-1) respectively. The curve-fitting analysis was used for the fold peaks of hydroxyl and amido, and it presented that the content of hydroxyl and amido had evident change. The substances in the auricularia auricula generated chemical change, and Fourier transform infrared spectroscopy could show the differentia easily. The results show that Fourier transform infrared spectroscopy can provide valuable information about the auricularia auricula. It could be used as a reference method for identification of the normal and mildewy auricularia auricula.

Reduced bone perfusion in osteoporosis: likely causes in an ovariectomy rat model.

PURPOSE: To investigate the cause of reduced vertebral perfusion in a rat ovariectomy model. MATERIALS AND METHODS: Experimental protocol was approved by the local Animal Experiment Ethics Committee. Twenty-two Sprague-Dawley rats were studied. Computed tomographic bone densitometry and magnetic resonance perfusion imaging were performed at baseline and 2, 4, and 8 weeks after ovariectomy (n = 11) or sham surgery (n = 11). Perfusion parameters analyzed were maximum enhancement (E(max)) and enhancement slope (E(slope)). After the animals were sacrificed, the aorta and femoral artery were analyzed for vessel reactivity, and the lumbar vertebrae were analyzed for marrow content. RESULTS: In control rats, bone mineral density (BMD), E(max), and E(slope) remained constant. In ovariectomy rats, a comparable reduction in BMD and the perfusion parameters at two weeks post-ovariectomy (BMD, 9.3%; E(max), 11.6%; E(slope), 9%) was seen 2 weeks after ovariectomy, and further reductions were seen 4 weeks (BMD, 17.5%; E(max), 15.6%; E(slope), 33%) and 8 weeks (BMD, 18.8%; E(max), 14.2%; E(slope), 33%) after ovariectomy. Endothelial dysfunction was observed in both the aorta and femoral artery of the ovariectomy group but not of the control group. Increased marrow fat area was seen in the ovariectomy group (52.9% vs 21.6%; P < .01) owing to an increase in fat cell number. Decreased erythropoetic marrow area (32.5% vs 48.6%; P < .05) was also observed in the ovariectomy group. CONCLUSION: Reduced bone perfusion occurs in synchrony with reduced BMD. The most likely causes of reduced bone perfusion are a reduction in the amount of erythropoetic marrow and endothelial dysfunction after ovariectomy. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.09090608/-/DC1.

Pitfalls in interpreting rat knee joint magnetic resonance images and their histological correlation.

BACKGROUND: Magnetic resonance (MR) imaging has been increasingly used as an investigational tool for assessing the structure and function of animal joint disease models, while to date MR tomographic knowledge of laboratory animal skeletal microanatomy remains limited. PURPOSE: To describe pitfalls in interpreting rat knee joint MR images and their histological correlation. MATERIAL AND METHODS: MR scans of the right knee of five 3-month-old Sprague-Dawley (SD) rats were carried out using a 4.7T magnet, using a fat-suppressed three-dimensional (3D) gradient echo sequence with a spatial resolution of 59 x 117 x 234 microm. Histology assessment with hematoxylin and eosin staining and Safranin O staining was carried out in the five 3-month-old SD rats and two SD rats of 1 month and 6 months old, respectively. MR images were analyzed by a radiologist, and histology data were assessed by a radiologist and a pathologist. RESULTS: Though the MR images were acquired in normal rats, many signs unfamiliar to radiologists were noted, including notch-like bright signal areas in the epiphysis, gray signal areas in the epiphysis, and fuzzy joint surface of the epiphysis of the femur and tibia. Detailed inspection of the histology specimen showed more unfamiliar features of rat knee microanatomy, including curvy or dipped surface of the femur/tibia epiphysis, areas composed of a mixture of cartilage and bone components, normal notch structure, cyst-like structure, and cavity between cortical lamellae under the joint cartilage. CONCLUSION: There are a number of normal microstructures of the rat knee joint that can be potentially misinterpreted as arthritic changes on MR images. Recognizing these rat knee microstructures can help correct image reading during biomedical research.

Clinicopathological significance of peritumoral lymphatic vessel density in gastric carcinoma.

Lymphangiogenesis has recently been considered important for spread of malignant tumors. In the present study, lymphatic vessel density (LVD) including peritumoral LVD (P-LVD) and intratumoral LVD (I-LVD) was determined, respectively, by immunohistochemical staining with the antibody to LYVE-1 in 63 cases of early gastric carcinoma and 105 cases of advanced gastric carcinoma. The aim of the study is to investigate whether or not increased LVD could be a risk factor for nodal metastasis and survival. We conclude that increased P-LVD, but not I-LVD, could serve as an independent risk factor for nodal metastasis, recurrence and overall survival in gastric carcinoma.

[Construction of glucosylceramide synthase-specific siRNA expression vector and its efficiency in reversal of drug resistance in breast carcinoma cells].

OBJECTIVE: To construct a glucosylceramide synthase (GCS)-specific small interfering RNA (siRNA) expression vector and to investigate the inhibitory effect of this siRNA on GCS expression and drug resistance in breast carcinoma cells. METHODS: Two GCS gene-specific siRNAs were designed and cloned into the expression vector pSUPER to generate the plasmids pSUPER-GCS1 and pSUPER-GCS2. Human adriamycin (ADM)-resistant breast carcinoma cells of the line MCF-7/ADR and human adriamycin-sensitive breast carcinoma cells of the line MCF-7 were cultured and transfected with pSUPER-GCS1, pSUPER-GCS2, and blank vector pSUPER as controls. The expression of GCS mRNA was assayed by RT-PCR and the expression of GCS protein was observed by flow cytometry. The 50% inhibition concentration of ADM on MCF-7/ADR cells was evaluated by MTT method. Flow cytometry was performed to determine the ratio of apoptosis. RESULTS: Double enzyme digestion analysis and DNA sequencing confirmed that pSUPER-GCS1 and pSUPER-GCS2 were successfully constructed. The GCS protein positive rate of the MCF-7/ADR cells 48 hours after transfection with pSUPER-GCS1 and pSUPER-GCS2 were 8.3% +/- 1.0% and 9.2% +/- 0.8% respectively, significantly lower than that before transfection (68.3% +/- 0.6%), with a inhibition rate of 89.4% and 88.5% respectively (both P < 0.01). Forty-eight hours after transfection with pSUPER-GCS1 and pSUPER-GCS2, the relative reversal rates of sensitivity to ADM of the MCF-7/ADR cells were 93.7% and 91.6%. Flow cytometry showed that the apoptotic rate of the MCF-7/ADR cells was 0.80 +/- 0.06 before transfection, 15.38 +/- 1.16 after transfection with pSUPER-GCS1 and 13.92 +/- 1.73 after transfection with pSUPER-GCS2 (both P < 0.05), and was 0.87 +/- 0.12 in the cells transfected with blank vector (P > 0.05). CONCLUSION: A GCS-specific small interfering RNA expression vector has been constructed successfully that suppresses the GCS expression and reverses the multidrug resistance in breast carcinoma cells by increasing the ratio of apoptosis in drug-resistant cells.