LCN2 regulates the gut microbiota and metabolic profile in mice infected with Mycobacterium bovis.

Infection with Mycobacterium bovis precipitates a spectrum of pathologies in bovines, notably necrotic pneumonia, mastitis, and arthritis, impinging upon the health and nutritional assimilation of these animals. A pivotal factor, lipocalin 2 (Lcn2), is responsive to microbial invasion, inflammatory processes, and tissue damage, the extent of which Lcn2 modulates the gut environment, however, remains unclear in response to M. bovis-induced alterations. To explore the role of Lcn2 in shaping the gut milieu of mice during a 5-week period post-M. bovis infection, Lcn2 knockout Lcn2-/- mice were scrutinized for changes in the gut microbiota and metabolomic profiles. Results showed that Lcn2-/- mice infected with M. bovis exhibited notable shifts in the operational taxonomic units (OTUs) of gut microbiota, alongside significant disparities in α and ß diversity. Concomitantly, a marked increase was observed during the 5-week period in the abundance of Akkermansia, Oscillospira, and Bacteroides, coupled with a substantial decrease in Ruminococcus within the microbiome of Lcn2 knockout mice. Notably, Akkermansia muciniphila was significantly enriched in the gut flora of Lcn2-/- mice. Furthermore, the absence of Lcn2 significantly altered the gut metabolomic landscape, evidenced by elevated levels of metabolites such as taurodeoxycholic acid, 10-undecenoic acid, azelaic acid, and dodecanedioic acid in Lcn2-/- mice. Our findings demonstrated that the lack of Lcn2 in the context of M. bovis infection profoundly affected the regulation of gut microbiota and metabolomic components, culminating in a transformed gut environment. Our results revealed that Lcn2 may regulate gut microbiota and metabolome components, changing the intestinal environment, thereby affecting the infection status of M. bovis. IMPORTANCE: Our study addresses the critical knowledge gap regarding the specific influence of lipocalin 2 (LCN2) in the context of Mycobacterium bovis infection, particularly focusing on its role in the gut environment. Utilizing LCN2 knockout (Lcn2-/-) mice, we meticulously assessed changes in the gut microbiota and metabolic components following M. bovis infection. Our findings reveal alterations in the gut microbial community, emphasizing the potentially crucial role of LCN2 in maintaining stability. Furthermore, we observed significant shifts in specific microbial communities, including the enrichment of Akkermansia muciniphila, known for its positive impact on intestinal health and immune regulation. The implications of our study extend beyond understanding the dynamics of the gut microbiome, offering insights into the potential therapeutic strategies for gut-related health conditions and microbial dysbiosis.

Development of a CRISPR/Cas12a-based fluorescent detection method of Senecavirus A.

BACKGROUND: Senecavirus A (SVA), identified in 2002, is known to cause porcine idiopathic vesicular disease (PIVD), which presents with symptoms resembling other vesicular diseases. This similarity complicates field diagnosis. Conventional molecular diagnostic techniques are limited by their cost, sensitivity, and requirement for complicated instrumentation. Therefore, developing an effective and accurate diagnostic method is crucial for timely identification and isolation of affected pigs, thereby preventing further disease spread. METHODS: In this study, we developed a highly-specific and ultra-sensitive SVA detection method powered by CRISPR/Cas12a. To enhance the availability in laboratories with varied equipment conditions, microplate reader and ultraviolet light transilluminator were introduced. Moreover, PCR amplification has also been incorporated into this method to improve sensitivity. The specificity and sensitivity of this method were determined following the preparation of the recombinant Cas12a protein and optimization of the CRISPR/Cas12a-based trans-cleavage system. RESULTS: The method demonstrated no cross-reactivity with ten kinds of viruses of swine. The minimum template concentration required to activate substantial trans-cleavage activity was determined to be 106 copies/µL of SVA templates. However, when PCR amplification was incorporated, the method achieved a detection limit of one copy of SVA templates per reaction. It also exhibited 100% accuracy in simulated sample testing. The complete testing process does not exceed three hours. CONCLUSIONS: Importantly, this method utilizes standard laboratory equipment, making it accessible for use in resource-limited settings and facilitating widespread and ultra-sensitive screening during epidemics. Overall, the development of this method not only broadens the array of tools available for detecting SVA but also holds significant promise for controlling the spread of PIVD.

Tetrandrine (TET) inhibits African swine fever virus entry into cells by blocking the PI3K/Akt pathway.

African Swine Fever Virus (ASFV) infection causes an acute and highly contagious disease in swine, resulting in significant economic losses and societal harm worldwide. Currently, there are no effective vaccines or antiviral drugs available for ASFV. Tetrandrine (TET) is extracted from the traditional Chinese herb Stephania tetrandrae, possesses diverse biological functions such as anti-inflammatory, anti-tumor, and antiviral activities. The study comprehensively evaluated the anti-ASFV effect of TET and validated it through biological assays. The dose-dependent inhibition of TET against ASFV was confirmed and a novel mechanism of TET's anti-ASFV activity was elucidated. TET effectively inhibits ASFV during internalization by blocking macropinocytosis through the inhibition of the PI3K/Akt pathway. The specific inhibitor LY294002, targeting the PI3K/Akt pathway, exhibits similar antiviral activity against ASFV as TET. Furthermore, the inhibitory effect of TET against other viruses such as Lumpy Skin Disease Virus (LSDV) and Porcine Epidemic Diarrhea Virus (PEDV) was also identified. Our findings suggest that TET effectively inhibits ASFV and reveal the potential for broad-spectrum antiviral drugs targeting the PI3K/Akt pathway.

Quickly assessing disinfection effectiveness to control the spread of African swine fever virus.

Infectious African swine fever virus (ASFV) can cause the spread and morbidity of African swine fever, while the inactivated virus cannot. When they are not distinguished separately, the detection results will lack authenticity and cause unnecessary panic and detection cost. The detection technology based on cell culture is complex, high-cost, and time-consuming in practice, which is not conducive to the rapid detection of infectious ASFV. In this study, a propidium monoazide (PMA) qPCR detection method for rapid diagnosis of infectious ASFV was constructed. Parameters of PMA concentration, light intensity, and lighting time were under strict safety verification and comparative analysis for optimization. The results determined that the optimal condition for PMA to pretreat ASFV was the final concentration of PMA 100 µM. The light intensity was 40 W, the light duration was 20 min, the target fragment size of the optimal primer probe was 484 bp, and its detection sensitivity for infectious ASFV was 101.28 HAD50/mL. In addition, the method was innovatively applied to the rapid evaluation of disinfection effect. When ASFV concentration was less than 102.28 HAD50/mL, the method could still be effective for the evaluation of thermal inactivation effect, and the evaluation ability of chlorine-containing disinfectants was better, and the applicable concentration could reach 105.28 HAD50/mL. It is worth mentioning that this method can not only reflect whether the virus is inactivated, but also indirectly reflect the degree of damage to viral nucleic acid caused by disinfectants. In conclusion, the PMA-qPCR constructed in this study can be applied to laboratory diagnosis, disinfection effect evaluation, drug development, and other aspects of infectious ASFV and can provide new technical support for effective prevention and control of ASF. KEY POINTS: • A rapid detection method for infectious ASFV was developed • Provide a new scheme for rapid evaluation of disinfection effect of chlorine-containing disinfectants • PMA-qPCR can simultaneously show the survival status of the virus and the damage of nucleic acid.

Prevalence, antimicrobial resistance and genetic characterization of Vibrio parahaemolyticus isolated from retail aquatic products in Nanjing, China.

Vibrio parahaemolyticus, is one of the most frequently reported pathogenic microorganisms that causes foodborne illnesses worldwide. The aims of the current study were to determine the prevalence, virulence genes, antimicrobial resistance, biofilm formation ability (BFA) and genetic characterization of V. parahaemolyticus recovered from retail aquatic products in Nanjing, China. There were 131 samples (71.6%) that tested positive for V. parahaemolyticus. The thermostable direct hemolysin-related hemolysin (trh) gene was found in two isolates (1.5%). Antimicrobial susceptibility tests showed that 46.6% of isolates were multidrug resistant. High resistance was observed to ampicillin (100%), cephalosporin (99.2%), trimethoprim/sulfamethoxazole (38.2%) and tetracycline (16.0%). Ten resistance patterns were found. The crystal violet staining assay showed that 35.1% had strong BFA, and 52.7% had intermediate BFA; notably, five (3.8%) extremely strong BFA strains were obtained from wet markets. According to whole genome sequencing analysis of 59 randomly selected isolates, 46 sequence types (STs) were identified, including 22 novel STs, and ST1042 was the dominant sequence type. It is clear that the V. parahaemolyticus population exhibits a high level of genetic variation. Our findings provide comprehensive insight into the prevalence and phylogenetic relationship of V. parahaemolyticus in aquatic products, suggesting potential hazards to consumers in Nanjing.

Comparison of clinical efficacy of single-incision and traditional laparoscopic surgery for colorectal cancer: A meta-analysis of randomized controlled trials and propensity-score matched studies.

Background: Single-incision laparoscopy surgery (SILS) is a new laparoscopic technique that has emerged in the past decade. Whether it has advantages over conventionl laparoscopy surgery (CLS) is inconclusive. This article aimed to compare the short- and long-term outcomes of single-incision laparoscopic surgery and conventional laparoscopic surgery for colorectal cancer through high-quality literature text mining and meta-analysis. Methods: Relevant articles were searched on the PubMed, Embase, and Cochrane Library databases from January 2012 to November 2021. All data was from randomized controlled trials (RCTs) in order to increase the confidence of the analytical results.The main outcomes were intraoperative and postoperative complications. Results: A total of 10 RCTs were included, involving 1609 patients. The quality of the included studies was generally high. No significant difference was found between SILS and CLS in the postoperative complications, operation time, postoperative hospital stay, number of lymph nodes removed, readmission, reoperation, complication level I- II, complication level IIIa, complication level IIIb, prolonged Ileus, blood loss, infection, anastomotic leakage and operation time. The results showed that SILS group had a higher rate of intraoperative complications, but it had lower incision length and better cosmetic effects. Conclusion: These results indicate that SILS did not have a comprehensive and obvious advantage over the CLS. On the contrary, SILS has higher intraoperative complications, which may be related to the more difficulty of SILS operation, but SILS still has better cosmetic effects, which is in line with the concept of surgical development. Therefore, the SILS needs to be selected in patients with higher cosmetic requirements and performed by more experienced surgeons.

Prospects for the application of infectious virus detection technology based on propidium monoazide in African swine fever management.

African swine fever (ASF) is a hemorrhagic and often fatal disease occurring in domestic pigs and wild boars. ASF can potentially greatly impact the global trade of pigs and pork products and threaten global food security. Outbreaks of ASF must be notified to the World Organization for Animal Health. In this study, we analyzed the feasibility of applying propidium monoazide (PMA) pretreatment-based infectious virus detection technology to ASF prevention and control and investigated the prospects of applying this technology for epidemic monitoring, disinfection effect evaluation, and drug development. PMA as a nucleic acid dye can enter damaged cells and undergo irreversible covalent crosslinking with nucleic acid under halogen light to prevent its amplification. Although this technology has been widely used for the rapid detection of viable bacteria, its application in viruses is rare. Therefore, we analyzed the theoretical feasibility of applying this technology to the African swine fever virus (ASFV) in terms of gene and cell composition. Rapid infectious ASFV detection technology based on PMA pretreatment would greatly enhance all aspects of ASF prevention and control, such as epidemic monitoring, disinfection treatment, and drug development. The introduction of this technology will also greatly improve the ability to prevent and control ASF.

A highly adaptable platform powered by CRISPR-Cas12a to diagnose lumpy skin disease in cattle.

Lumpy skin disease (LSD) in cattle, a transboundary viral disease of cattle once restricted to Africa, has been spreading to many European and Asian countries in the past decade with huge economic losses. This emerging worldwide threat to cattle warrants the development of diagnostic methods for accurate disease screening of suspected samples to effectively control the spread of LSD. In this study, we integrated pre-amplification and three kinds of sensor systems with CRISPR and therefore established an LSD diagnosis platform with highly adaptable and ultra-sensitive advantages. It was the first CRISPR-powered platform that could identify lumpy skin disease virus from vaccine strains of goat pox virus and sheep pox virus. Its limit of detection (LOD) was one copy/reaction after introducing PCR or recombinase-aided amplification (RAA). Moreover, this platform achieved a satisfactory overall agreement in clinical diagnoses of 50 samples and its reproducibility and accuracy were superior to other qPCR methods we tested. The whole diagnostic procedure, from DNA extraction to the results, could complete in 5 h with a total cost of 1.7-9.6 $/test. Overall, this CRISPR-powered platform provided a novel diagnostic tool for portable, ultra-sensitive, rapid, and highly adaptable disease screening of LSD and may be an effective method to control this transboundary disease's spread.

Clustered Regularly Interspaced Short Palindromic Repeat/Cas12a Mediated Multiplexable and Portable Detection Platform for GII Genotype Porcine Epidemic Diarrhoea Virus Rapid Diagnosis.

Porcine epidemic diarrhoea virus (PEDV) is a member of the genus Alphacoronavirus in the family Coronaviridae. It causes acute watery diarrhoea and vomiting in piglets with high a mortality rate. Currently, the GII genotype, PEDV, possesses a high separation rate in wild strains and is usually reported in immunity failure cases, which indicates a need for a portable and sensitive detection method. Here, reverse transcription-recombinase aided amplification (RT-RAA) was combined with the Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)/Cas12a system to establish a multiplexable, rapid and portable detection platform for PEDV. The CRISPR RNA (crRNA) against Spike (S) gene of GII PEDV specifically were added into the protocol. This system is suitable for different experimental conditions, including ultra-sensitive fluorescence, visual, UV light, or flow strip detection. Moreover, it exhibits high sensitivity and specificity and can detect at least 100 copies of the target gene in each reaction. The CRISPR/Cas12a detection platform requires less time and represents a rapid, reliable and practical tool for the rapid diagnosis of GII genotype PEDV.

Multiplex and on-site PCR detection of swine diseases based on the microfluidic chip system.

BACKGROUND: At present, the process of inspection and quarantine starts with sampling at the customs port, continues with transporting the samples to the central laboratory for inspection experiments, and ends with the inspected results being fed back to the port. This process had the risks of degradation of biological samples and generation of pathogenic microorganisms and did not meet the rapid on-site detection demand because it took a rather long time. Therefore, it is urgently needed to develop a rapid and high-throughput detection assay of pathogenic microorganisms at the customs port. The aim of this study was to develop a microfluidic chip to rapidly detect swine pathogenic microorganisms with high-throughput and higher accuracy. Moreover, this chip will decrease the risk of spreading infection during transportation. RESULTS: A series of experiments were performed to establish a microfluidic chip. The resulting data showed that the positive nucleic acid of four swine viruses were detected by using a portable and rapid microfluidic PCR system, which could achieve a on-site real-time quantitative PCR detection. Furthermore, the detection results of eight clinical samples were obtained within an hour. The lowest concentration that amplified of this microfluidic PCR detection system was as low as 1 copies/µL. The results showed that the high specificity of this chip system in disease detection played an important role in customs inspection and quarantine during customs clearance. CONCLUSION: The microfluidic PCR detection system established in this study could meet the requirement for rapid detection of samples at the customs port. This chip could avoid the risky process of transporting the samples from the sampling site to the testing lab, and drastically reduce the inspection cycle. Moreover, it would enable parallel inspections on one chip, which greatly raised the efficiency of inspection.

Rapid and accurate detection of Escherichia coli O157:H7 in beef using microfluidic wax-printed paper-based ELISA.

Escherichia coli O157:H7 is a severe foodborne pathogen that causes lots of life-threatening diseases. In the search for a rapid, sensitive, portable and low-cost method to detect this pathogen, we developed a wax-printed paper-based enzyme-linked immunosorbent assay (P-ELISA) based on microfluidic paper-based analytical devices (µPADs), with the whole operation time being less than 3 h and only needing 5 µl samples for detection. The limit of detection (LOD) of E. coli O157:H7 reached 104 CFU ml-1, which is an order of magnitude higher than that of conventional ELISA (C-ELISA). The LOD in artificially contaminated beef samples is 1 CFU per 25 g after enriching the culture for 8 h. This method is superior to the molecular biology method in detection sensitivity and superior to C-ELISA and the national standard method in detection time and cost. Thus, the established P-ELISA method has good sensitivity, specificity and repeatability. It can be suitable for point-of-care testing without expensive and bulky instruments and can also provide a platform for detecting other pathogens, especially in areas that lack advanced clinical equipment.

An improved assay for rapid detection of viable Staphylococcus aureus cells by incorporating surfactant and PMA treatments in qPCR.

BACKGROUND: Staphylococcus aureus is an important human pathogen causing a variety of life-threatening diseases. Rapid and accurate detection of Staphylococcus aureus is a necessity for prevention of outbreaks caused by this pathogen. PCR is a useful tool for rapid detection of foodborne pathogens, however, its inability to differentiate DNA from dead cells and live cells in amplification severely limits its application in pathogen detection. The aim of this study was to develop an improved assay was developed by incorporating the sample treatments with a surfactant and propidium monoazide (PMA) in qPCR for detection of viable S. aureus cells. RESULTS: The cell toxic effect testing with the two surfactants showed that the viability of S. aureus was virtually not affected by the treatment with 0.5% triton x-100 or 0.025% sarkosyl. Triton x-100 was coupled with PMA for sample treatments for detection of viable S. aureus cells in artificially contaminated milk. The qPCR results indicated that the assay reached high an amplification efficiency of 98.44% and the live S. aureus cells were accurately detected from the triton-treated spiked milk samples by the PMA-qPCR assay. CONCLUSIONS: The qPCR assay combined with treatments of PMA and surfactants offers a sensitive and accurate means for detection of viable S. aureus cells. Cell toxic effect testing with the two surfactants showed that the viability of S. aureus was virtually not affected by the treatment with 0.5% triton x-100 or 0.025% sarkosyl. The information on sample treatment with surfactants to improve the dead cell DNA removal efficiency in qPCR by increasing PMA's permeability to dead cells can be used for other pathogens, especially for Gram-positive bacteria.

Selected microRNA-192 mutant indicates association with several function genes in bovine cells.

MicroRNAs are implicated in many cellular processes such as cell differentiation and development, tumorigenesis, and immune regulation. In this study, miR192 was detected using quantitative real-time polymerase chain reaction (qRT-PCR) when MDBK cells were exposed to Escherichia coli. Cells with malfunction of bta-miR-192 were established using transcription activator-like effector nuclease (TALEN) technology. Finally, bta-miR-192 mutant cells were screened for differentially expressed genes using RNA-sequencing (RNA-seq). The results showed that miR192 significantly decreased in cells exposed to E. coli F18ac and E. coli K88ac. The RNA-seq results showed that 1673 differentially expressed transcripts were identified; 890 genes were upregulated and 775 genes were downregulated. With the gene ontology enrichment analysis, 431 differentially expressed genes (DEGs) were classified into 937 gene ontology terms. The pathway enrichment analysis showed that 535 genes were involved in 254 pathway terms. Interestingly, most of these DEGs were associated with the pathways in cancers or infectious diseases. When the selected DEGs (n = 162) in these pathways were intersected with 120 differential transcripts, 11 DEGs were identified. Subsequently, several genes associated with regulation, cancers, or viral infections, such as LEF1, AXIN2, MX1, and FCGR2B, were identified among the DEGs using functional analysis. Furthermore, associations between bta-miR-192 and DEGs were detected by intersecting the bta-miR-192's target genes with the DEGs, indicating that three genes including CBL, DICER1 and TRERF1 were involved in this relationship. These findings provided useful guidance for investigating the role played by bta-miR-192 in cellular functionality in bovine cells.

Advances and Challenges in Viability Detection of Foodborne Pathogens.

Foodborne outbreaks are a serious public health and food safety concern worldwide. There is a great demand for rapid, sensitive, specific, and accurate methods to detect microbial pathogens in foods. Conventional methods based on cultivation of pathogens have been the gold standard protocols; however, they take up to a week to complete. Molecular assays such as polymerase chain reaction (PCR), sequencing, microarray technologies have been widely used in detection of foodborne pathogens. Among molecular assays, PCR technology [conventional and real-time PCR (qPCR)] is most commonly used in the foodborne pathogen detection because of its high sensitivity and specificity. However, a major drawback of PCR is its inability to differentiate the DNA from dead and viable cells, and this is a critical factor for the food industry, regulatory agencies and the consumer. To remedy this shortcoming, researchers have used biological dyes such as ethidium monoazide and propidium monoazide (PMA) to pretreat samples before DNA extraction to intercalate the DNA of dead cells in food samples, and then proceed with regular DNA preparation and qPCR. By combining PMA treatment with qPCR (PMA-qPCR), scientists have applied this technology to detect viable cells of various bacterial pathogens in foods. The incorporation of PMA into PCR-based assays for viability detection of pathogens in foods has increased significantly in the last decade. On the other hand, some downsides with this approach have been noted, particularly to achieve complete suppression of signal of DNA from the dead cells present in some particular food matrix. Nowadays, there is a tendency of more and more researchers adapting this approach for viability detection; and a few commercial kits based on PMA are available in the market. As time goes on, more scientists apply this approach to a broader range of pathogen detections, this viability approach (PMA or other chemicals such as platinum compound) may eventually become a common methodology for the rapid, sensitive, and accurate detection of foodborne pathogens. In this review, we summarize the development in the field including progress and challenges and give our perspective in this area.

Vibrio parahaemolyticus Strains of Pandemic Serotypes Identified from Clinical and Environmental Samples from Jiangsu, China.

Vibrio parahaemolyticus has emerged as a major foodborne pathogen in China, Japan, Thailand, and other Asian countries. In this study, 72 strains of V. parahaemolyticus were isolated from clinical and environmental samples between 2006 and 2014 in Jiangsu, China. The serotypes and six virulence genes including thermostable direct hemolysin (TDR) and TDR-related hemolysin (TRH) genes were assessed among the isolates. Twenty five serotypes were identified and O3:K6 was one of the dominant serotypes. The genetic diversity was assessed by multilocus sequence typing (MLST) analysis, and 48 sequence types (STs) were found, suggesting this V. parahaemolyticus group is widely dispersed and undergoing rapid evolution. A total of 25 strains of pandemic serotypes such as O3:K6, O5:K17, and O1:KUT were identified. It is worth noting that the pandemic serotypes were not exclusively identified from clinical samples, rather, nine strains were also isolated from environmental samples; and some of these strains harbored several virulence genes, which may render those strains pathogenicity potential. Therefore, the emergence of these "environmental" pandemic V. parahaemolyticus strains may poses a new threat to the public health in China. Furthermore, six novel serotypes and 34 novel STs were identified among the 72 isolates, indicating that V. parahaemolyticus were widely distributed and fast evolving in the environment in Jiangsu, China. The findings of this study provide new insight into the phylogenic relationship between V. parahaemolyticus strains of pandemic serotypes from clinical and environmental sources and enhance the MLST database; and our proposed possible O- and K- antigen evolving paths of V. parahaemolyticus may help understand how the serotypes of this dispersed bacterial population evolve.

Phenotypic Characters and Molecular Epidemiology of Campylobacter Jejuni in East China.

In this study, we investigated the distribution, phenotypic and molecular typing characters of Campylobacter jejuni in domestic fowl, and livestock populations in East China, to provide some reference for researches on its molecular epidemiology. A total of 1250 samples were collected from different animal sources, and C. jejuni strains were then isolated and tested for antibiotic sensitivity. Antibiotics-resistance gene and pathogenic genes were detected by polymerase chain reaction. Phylogenic analysis on the C. jejuni strains was performed by multilocus sequence typing (MLST) method. The results showed that 108 out of the 1250 samples (mean 8.64%) were C. jejuni positive. These 108 C. jejuni strains were highly sensitive to antibiotics such as chloramphenicol, amoxicillin, amikacin, cefotaxime, and azithromycin, whereas they were highly resistant to antibiotics such as cefoperazone, cotrimoxazole, cefamandole, sulfamethoxazole, and cefradine. Pathogenicity related gene identification indicated that the mean carrying rate of adhesion related gene cadF and racR, flagellin gene flaA, toxin regulating gene cdtA, cdtB, cdtC, wlaN and virB11, heat shock proteins and transferring proteins related genes dnaJ and ceuE, CiaB and pldA were 92.45%, 38.69%, 73.58%, 71.70%, 52.83%, 96.23%, 12.26%, 1.89%, 0.94%, 65.09%, 39.62% and 9.43%, respectively. A total of 58.82% of these strains contained more than 6 pathogenicity-related genes. MLST typed 58 ST types from the 108 isolated C. jejuni strains, including 24 new types, and ST-21 was the major type, accounting for 39.3% of the total strains.

Gene expression profile of Campylobacter jejuni-induced GBS in Bama miniature pigs.

Our aim was to investigate the in vivo gene expression pattern of the Guillain-Barre syndrome (GBS) with DNA microarrays and bioinformatics tools. Oral-infusion model animals mimicking human infection of GBS were analyzed. Tissue samples and body fluids were collected to perform antibody tests and biopsy assays. Gene-expression microarray was conducted with nerve tissues and GBS-related genes were elucidated via bioinformatics tools. Model animals showed typical symptoms of GBS in that mild demyelination was shown by cerebellar white matter and by lumbar enlargement of model animals. Then, 81.25% of the model animals were positive with GM1-IgG antibodies by ELISA. In the microarray analysis, 1,261 genes were identified with statistically different expression (P < 0.05), 21 of which were associated with gene function analysis, gene pathway identification, signal transduction and co-expression network construction. Furthermore, quantitative PCR was used to characterize the gene expression level. We found that genes of HPRT1, PKC and PPARGC-1 were in the core of the network, while the expression of PPARGC-1, SUS2DD and AMPKA2 were significantly inhibited. A total of 21 genes were found to be actively involved in the process of protein transportation, transcriptional regulation, antigen identification and cell cycle regulation during the GBS infection period. The co-expression network indicated an important association between GBS and the 21 genes, especially the down-regulated ones. In conclusion, we demonstrated that GBS-affected hosts had a specific gene expression profile, which may guide the direction of GBS research and therapy.

The effect of therapeutic ultrasound to apoptosis of chondrocyte and caspase-3 and caspase-8 expression in rabbit surgery-induced model of knee osteoarthritis.

Recent studies have shown a positive correlation between the degree of severity of OA and the number of apoptotic chondrocytes. The purpose of our study was to determine the effect of therapeutic ultrasound on apoptosis in articular cartilage of rabbits with knee osteoarthritis (KOA). Thirty 3-month New Zealand White rabbits were randomizingly divided into three groups, 10 in each group. Two groups underwent anterior cruciate ligament transaction in the right knee and another group left intact. Six weeks later, one group of the operated rabbits (OA-US) underwent ultrasound therapy (300 mW/cm(2), 1 MHz, 20% duty cycle, 10 min each day) for 2 weeks, while the other two groups (OA-Control and Normal Control) left untreated. Eight weeks after transection, all animals were killed. Microscopic morphologic grading was made for histological assessment. The caspases expressions and chondrocytes apoptosis were tested using the immunohistochemistry and TUNEL assessment, respectively. The mean grading of OA-US group was significantly higher than Normal Control group (P = 0.002), but significantly lower than OA-Control group (P = 0.002). Percentage of apoptosis and the optic density of cells expressing caspase-3 and caspase-8 in the three groups showed no statistical significances. Therapeutic ultrasound (300 mW/cm(2), 1 MHz, and 20% duty cycle) could relieve the degree of severity of induced KOA, while it had no effect on apoptosis and the expression of caspase-3 and caspase-8. These findings may provide a certain support for therapeutic ultrasound as an effective access to managing KOA.

The effect of low-level laser to apoptosis of chondrocyte and caspases expression, including caspase-8 and caspase-3 in rabbit surgery-induced model of knee osteoarthritis.

The purpose of this study was to observe the effect of 810-nm low-level laser to apoptosis of chondrocyte and related proteins, including caspase-3 and caspase-8, in rabbit surgery-induced model of knee osteoarthritis. A total of 24 New Zealand White rabbits were randomly assigned into 3 groups: test group, model group, and normal group. The rabbits in test group and model group received anterior cruciate ligament transection in the right knee. Six weeks after transection, the rabbits in test group were given 10-session 810-nm laser illumination. Eight weeks after transection, all animal were killed. Modified Mankin Score was made for histological assessment. The caspases expressions and chondrocytes apoptosis were tested using the immunohistochemistry and TUNEL assessment, respectively. The modified Mankin Score of test group was significantly lower than model group (P < 0.01) and higher than normal group (P < 0.01). The caspase-8 expression of test group was lower than model group and higher than normal group, but no significant difference was found (P > 0.05). This study revealed that the 810-nm low-level laser can improve cartilage structure, prevent articular cartilage degradation and significantly decrease the expression of caspase-3 in this surgery-induced OA model. Further studies are needed.

[Role of microRNAs on regulation of bone and cartilage tissue].

OBJECTIVE: To review the regulation and mechanism of the microRNAs (miRNAs) in the bone and cartilage tissue. METHODS: Recent literature concerning the regulation and mechanism of the miRNAs in the bone and cartilage tissue was extensively reviewed, summarized, and analyzed. RESULTS: Recently miRNAs is a hot topic in the bone and cartilage tissue. More and more materials show its important regulatory role in osteogenesis and cartilage growth and regeneration, but the definite mechanisms have not been clear yet. CONCLUSION: The study on miRNAs of bone and cartilage tissue can provide a new access to understanding the degenerative osteoarthritic diseases.