Meshed neuronal mitochondrial networks empowered by AI-powered classifiers and immersive VR reconstruction

Mitochondrial networks are defined as a continuous matrix lumen, but the morphological feature of neuronal mitochondrial networks is not clear due to the lack of suitable analysis techniques. The aim of the present study is to develop a framework to capture and analyze the neuronal mitochondrial networks by using 4-step process composed of 2D and 3D observation, primary and secondary virtual reality (VR) analysis, with the help of artificial intelligence (AI)-powered Aivia segmentation an classifiers. In order to fulfill this purpose, we first generated the PCs-Mito-GFP mice, in which green fluorescence protein (GFP) could be expressed on the outer mitochondrial membrane specifically on the cerebellar Purkinje cells (PCs), thus all mitochondria in the giant neuronal soma, complex dendritic arborization trees and long projection axons of Purkinje cells could be easily detected under a laser scanning confocal microscope. The 4-step process resolved the complicated neuronal mitochondrial networks into discrete neuronal mitochondrial meshes. Second, we measured the two parameters of the neuronal mitochondrial meshes, and the results showed that the surface area (μm²) of mitochondrial meshes was the biggest in dendritic trees (45.30 ± 53.21), the smallest in granular-like axons (3.99 ± 1.82), and moderate in soma (27.81 ± 22.22) and silk-like axons (17.50 ± 15.19). These values showed statistically different among different subcellular locations. The volume (μm³) of mitochondrial meshes was the biggest in dendritic trees (9.97 ± 12.34), the smallest in granular-like axons (0.43 ± 0.25), and moderate in soma (6.26 ± 6.46) and silk-like axons (3.52 ± 4.29). These values showed significantly different among different subcellular locations. Finally, we found both the surface area and the volume of mitochondrial meshes in dendritic trees and soma within the Purkinje cells in PCs-Mito-GFP mice after receiving the training with the simulating long-term pilot flight concentrating increased significantly. The precise reconstruction of neuronal mitochondrial networks is extremely laborious, the present 4-step workflow powered by artificial intelligence and virtual reality reconstruction could successfully address these challenges.

Pretreatment with Sodium Phenylbutyrate Alleviates Cerebral Ischemia/Reperfusion Injury by Upregulating DJ-1 Protein

Oxidative stress and mitochondrial dysfunction play critical roles in ischemia/reperfusion (I/R) injury. DJ-1 is an endogenous antioxidant that attenuates oxidative stress and maintains mitochondrial function, likely acting as a protector of I/R injury. In the present study, we explored the protective effect of a possible DJ-1 agonist, sodium phenylbutyrate (SPB), against I/R injury by protecting mitochondrial dysfunction via the upregulation of DJ-1 protein. Pretreatment with SPB upregulated the DJ-1 protein level and rescued the I/R injury-induced DJ-1 decrease about 50% both in vivo and in vitro. SPB also improved cellular viability and mitochondrial function and alleviated neuronal apoptosis both in cell and animal models; these effects of SPB were abolished by DJ-1 knockdown with siRNA. Furthermore, SPB improved the survival rate about 20% and neurological functions, as well as reduced about 50% of the infarct volume and brain edema, of middle cerebral artery occlusion mice 23 h after reperfusion. Therefore, our findings demonstrate that preconditioning of SPB possesses a neuroprotective effect against cerebral I/R injury by protecting mitochondrial function dependent on the DJ-1 upregulation, suggesting that DJ-1 is a potential therapeutic target for clinical ischemic stroke.

Blockade of RyRs in the ER Attenuates 6-OHDA-Induced Calcium Overload, Cellular Hypo-Excitability and Apoptosis in Dopaminergic Neurons

Calcium (Ca²⁺) dyshomeostasis induced by endoplasmic reticulum (ER) stress is an important molecular mechanism of selective dopaminergic (DA) neuron loss in Parkinson's disease (PD). Inositol 1,4,5-triphosphate receptors (IP₃Rs) and ryanodine receptors (RyRs), which are located on the ER surface, are the main endogenous Ca²⁺ release channels and play crucial roles in regulating Ca²⁺ homeostasis. However, the roles of these endogenous Ca²⁺ release channels in PD and their effects on the function and survival of DA neurons remain unknown. In this study, using a 6-hydroxydopamine (6-OHDA)-induced in vitro PD model (SN4741 Cell line), we found that 6-OHDA significantly increased cytoplasmic Ca²⁺ levels ([Ca2+]_i), which was attenuated by pretreatment with 4-phenyl butyric acid (4-PBA; an ER stress inhibitor) or ryanodine (a RyRs blocker). In addition, in acute midbrain slices of male Sprague-Dawley rats, we found that 6-OHDA reduced the spike number and rheobase of DA neurons, which were also reversed by pretreatment with 4-PBA and ryanodine. TUNEL staining and MTT assays also showed that 4-PBA and ryanodine obviously alleviated 6-OHDA-induced cell apoptosis and devitalization. Interestingly, a IP₃Rs blocker had little effect on the above 6-OHDA-induced neurotoxicity in DA neurons. In conclusion, our findings provide evidence of the different roles of IP₃Rs and RyRs in the regulation of endogenous Ca²⁺ homeostasis, neuronal excitability, and viability in DA neurons, and suggest a potential therapeutic strategy for PD by inhibiting the RyRs Ca²⁺ channels in the ER.

Effect of skeletal muscle fibers on porcine meat quality at different stages of growth

In this study, we examined changes in meat quality and content of muscle types during porcine growth. The influence of the longissimus dorsi muscle fiber composition on meat quality and the correlation between 2 fiber-typing methods (histochemistry and real-time quantitative polymerase chain reaction) were examined. Type IIx and type IIb fibers accounted for most of the total number of fibers; the proportion of these fibers increased during porcine growth (75.42, 80.09, and 79.88%, respectively, at 3 different stages of growth). There was a strong positive correlation between the 2 fiber-typing methods; the correlation coefficients of type I, IIa, and IIx+IIb fiber contents were 0.65, 0.88, and 0.92, respectively. The a* value of meat color was significantly lower at 98 days and negatively correlated with white fiber content (r = -0.69, P < 0.01). Water-holding capacity decreased during porcine growth. The drip loss parameter was positively correlated with type IIx+IIb fiber content (r = 0.55, P < 0.05). Decreased pH was strongly positively correlated with type IIx+IIb fiber content (r = 0.61, P < 0.01) and negatively correlated with type IIa fiber content (r = -0.44, P < 0.05). Therefore, we found that the composition of muscle fibers influenced the establishment of meat quality and its alteration during the early postmortem period.

Inhibition of microglial activation contributes to propofol-induced protection against post-cardiac arrest brain injury in rats

It has been suggested that propofol can modulate microglial activity and hence may have potential roles against neuroinflammation following brain ischemic insult. However, whether and how propofol can inhibit post-cardiac arrest brain injury via inhibition of microglia activation remains unclear. A rat model of asphyxia cardiac arrest (CA) was created followed by cardiopulmonary resuscitation. CA induced marked microglial activation in the hippocampal CA1 region, revealed by increased OX42 and P2 class of purinoceptor 7 (P2X7R) expression, as well as p38 MAPK phosphorylation. Morris water maze showed that learning and memory deficits following CA could be inhibited or alleviated by pre-treatment with the microglial inhibitor minocycline or propofol. Microglial activation was significantly suppressed likely via the P2X7R/p-p38 pathway by propofol. Moreover, hippocampal neuronal injuries after CA were remarkably attenuated by propofol. In vitro experiment showed that propofol pre-treatment inhibited ATP-induced microglial activation and release of tumor necrosis factor-α and interleukin-1β. In addition, propofol protected neurons from injury when co-culturing with ATP-treated microglia. Our data suggest that propofol pre-treatment inhibits CA-induced microglial activation and neuronal injury in the hippocampus and ultimately improves cognitive function. We proposed a possible mechanism of propofol-mediated brain protection after cardiac arrest (CA). CA induces P2X7R upregulation and p38 phosphorylation in microglia, which induces release of TNF-α and IL-1β and consequent neuronal injury. Propofol could inhibit microglial activation and alleviate neuronal damage. Our results suggest propofol-induced anti-inflammatory treatment as a plausible strategy for therapeutic intervention in post-CA brain injury.

Estrogen regulates the expression of Ndrg2 in astrocytes

N-myc downstream-regulated gene 2 (Ndrg2) is a newly identified molecule that is mainly expressed in astrocytes within the central nervous system (CNS) and is involved in the proliferation and activation of astrocytes. 17β-estradiol (E2) is one of the most important circulating hormones, and in the CNS, astrocytes are a target and potential mediator of the action of E2. Our most recent study found that DPN, an estrogen receptor (ER) β-specific agonist, activated the Ndrg2 promoter and elevated endogenous NDRG2 protein expression in MCF7, HSG and T-47D cells. However, whether E2 regulates Ndrg2 expression in astrocytes remains unknown. Here, we conducted both in vivo and in vitro experiments and found that ERβ co-localized with NDRG2 in astrocytes. Furthermore, in primary cultured astrocytes, we demonstrated that E2 up-regulated Ndrg2 mRNA and protein expression in a dose- and time-dependent manner and that the ERβ agonist DPN but not the ERα agonist PPT up-regulated Ndrg2 expression. In vivo, we found that in the hippocampus of adult ovariectomized (OVX) female mice, Ndrg2 mRNA and protein expression were significantly decreased compared with those in normal adult female mice. After the OVX mice received continuous subcutaneous injections of 50μg/kg E2, 100μg/kg E2 or the ERβ agonist DPN for 10 days, the Ndrg2 expression significantly increased compared with that of the OVX mice. Our results indicate that E2 may affect astrocytes by regulating Ndrg2 expression.

Genetic association of CHEK2, GSTP1, and ERCC1 with glioblastoma in the Han Chinese population

Glioblastoma (GBM), a deadly brain tumor, is the most malignant glioma. It mainly occurs in adults and occurs significantly more in males than in females. We genotyped 19 tag single nucleotide polymorphisms (tSNPs) from 13 genes in a case-control study of the Han Chinese population to identify genetic factors contributing to the risk of GBM. These tSNPs were genotyped by Sequenom MassARRAY RS1000. Statistical analysis was performed using χ(2) test and SNPStats, a website software. Using χ(2) test, we found that the distribution of two tSNPs (rs2267130 in checkpoint kinase 2 (CHEK2), p = 0.040; rs1695 in GSTP1, p = 0.023) allelic frequencies had significant difference between cases and controls. When we analyzed all of the tSNPs using the SNPStats software, we found that rs1695 in GSTP1 decreased the risk of GBM in log-additive model (OR = 0.56, 95% CI, 0.34-0.94, p = 0.022). Besides, we found that there is an interaction between rs3212986 in excision repair cross-complementing group 1 (ERCC1) and gender under codominant and recessive models. The gene polymorphisms in CHEK2, GSTP1, and ERCC1 may be involved in GBM in the Han Chinese population. Since our sample size is small, further investigation needs to be performed.

Effects of constant and cyclic heat stress on muscle metabolism and meat quality of broiler breast fillet and thigh meat

This study investigated the effects of constant and cyclic heat stress on muscle metabolism and meat quality of broiler breast fillet and thigh meat from 4 to 6 wk of age. Male Arbor Acres (AA) broilers (n = 270, 4 wk old) were raised under different temperature conditions: standard (temperature was 23°C); constant high temperature (temperature was 34°C); and cyclic high temperature (temperature was 36°C from 1000 h to 1600 h and 23°C from 1600 h to 1000 h). On d 42, broilers were stunned and sampled. The results showed that chronic high temperature significantly decreased the proportion of breast muscle and significantly increased the proportion of thigh muscle (P < 0.05). The moisture concentration was significantly higher in the breast muscle of the birds exposed to constant high temperature (P < 0.05), whereas the protein content was significantly lower (P < 0.05) and fat deposition was significantly higher (P < 0.05) in the breast muscle of the birds exposed to constant or diurnal cyclic high temperature than those grown under standard temperature. The breast and thigh muscle of the birds grown under constant high temperature had significantly higher lightness, cook loss, and shear force (P < 0.05) and significantly lower initial pH (pH(i)), ultimate pH (pH(u)), and redness compared with those grown under standard temperature (P < 0.05). The pH(i), pH(u), and redness were significantly lower (P < 0.05) while the lightness and shear force were significantly higher for the breast muscle of the chickens raised under diurnal cyclic high temperature (P < 0.05) than those grown under standard temperature. In contrast, lightness and yellowness of thigh muscle were significantly higher (P < 0.05) in the chickens grown under diurnal cyclic high temperature than under standard temperature. Breast and thigh muscle of broilers exposed to constant high temperature produced higher (P < 0.05) lactic acid and pyruvate kinase activities than those exposed to the standard temperature. These results indicated that chronic heat stress significantly increased lactate production, reduced meat pH value by accelerating meat glycolysis, and eventually reduced meat quality.

Silica Induces Plasminogen Activator Inhibitor-1 Expression through a MAPKs/AP-1-Dependent Mechanism in Human Lung Epithelial Cells

ABSTRACT Plasminogen activator inhibitor-1 (PAI-1) plays an important role in the silica-induced pulmonary fibrosis. The effect of silica on the expression of PAI-1 was investigated in human lung epithelial cells (A549). Silica induced PAI-1 expression in a concentration-(50-200 mug/mL) and time-(4-24 h) dependent manner in A549 cells. Furthermore, the roles of mitogen-activated protein kinase (MAPK)/activator protein-1 (AP-1) signaling pathways in silica-induced PAI-1 expression were examined. We found that silica (200 mug/mL) treatment for 4 to 24 h resulted in AP-1 activation in A549 cells. Cells were pretreated with the AP-1 inhibitor curcumin (10, 25, 50 muM), and silica-induced PAI-1 expression was reduced by 20%, 63%, and 65%, respectively. In addition, dominant-negative mutant c-Jun (TAM67) down-regulated silica-induced PAI-1 expression by 59%. P38 kinase inhibitor SB203580 (20 muM) and Erk inhibitor PD98059 (50 muM) suppressed silica-induced PAI-1 expression by 35% and 51%, respectively. Additionally, PD98059 but not SB203580 inhibited the AP-1 DNA binding activity induced by silica. The results suggest that the PAI-1 expression induced by silica may be involved in the activation of MAPKs/AP-1 signaling pathways in human lung epithelial cells.

Effect of transarterial pulsed perfusion with heated saline on tumor vascular permeability in a rabbit VX2 liver tumor model

PURPOSE

To evaluate the effect of transarterial pulsed perfusion with 60 °C saline on vascular permeability of tumor tissue, as well as its hepatic and renal toxicity, in a rabbit VX2 liver model.

MATERIALS AND METHODS

VX2 carcinomas were grown in rabbit livers, forty male New Zealand white tumor-bearing rabbits were randomly divided into four groups, followed by transarterial perfusion with 37 °C saline 60 ml (n=10) (control 1 group), transarterial pulsed perfusion with 37 °C saline 60 ml (n=10) (control 2 group), transarterial continuous perfusion with 60 °C saline 60 ml (n=10) (TCP group), transarterial pulsed perfusion with 60 °C saline 60 ml (n=10) (TPP group), the duration of time for tumor tissues in the range 43-45 °C of the treated groups was measured with needle thermometer during perfusion. Vascular permeability was assessed using the extravasation of Evans blue (EB) dye in the tumor or normal liver tissues of the four groups separately, the tumor or normal liver tissues of the four groups were estimated by histopathologic examination, and hepatic and renal toxicity was evaluated by means of blood biochemical analysis. The vascular endothelial cells in the tumor were observed by transmission electron microscopy (TEM).

RESULTS

The duration of time for tumor tissues in the range 43-45 °C of TPP group showed significantly longer than that of TCP group (12.3±3.3 min vs. 5.7±2.5 min) (P<0.01). After perfusion, the EB content of tumor tissue in TPP group showed significantly higher than that in TCP group (15.21±0.94 μg/100 mg vs. 10.71±0.84 μg/100 mg) (P<0.01), and also showed significantly higher than that in the two control group (3.42±0.87 μg/100 mg, 3.57±0.64 μg/100 mg) (P<0.01). Blood chemical analysis indicating there was an increase (P<0.05) in the serum ALT, AST levels in the two heated perfusion groups at 1, 2, 4, 8 h after infusion when compared to that in the two control group, but there was no significant difference in the serum ALT, AST levels among the four groups at 24 h after perfusion (P>0.05), and there was no significant difference in the serum BUN, Cr levels among the four groups at 1, 2, 4, 8, 24 h after perfusion. Observed by hematoxylin and eosin staining, there were no obvious signs of tissue destruction in liver tissue and tumor tissue. TEM indicating the endothelial cell gap was broadened and the endothelial cells' microvillus was decreased after heated perfusion.

CONCLUSIONS

The vascular permeability of the rabbit VX2 tumor was significantly increased after transarterial pulsed perfusion with 60°C saline without significant increase in hepatic and renal toxicity.

[p16 and cyclinD1 protein expression and p16 gene mutation in primary human hepatocellular carcinoma]

OBJECTIVE

To elucidate the relationship between expression of p16 and cyclinD1 proteins and evaluate the role of p16 gene exon 2 mutation in hepatocellular carcinogenesis.

METHODS

Streptavidin-peroxidase conjugated method(SP) was used to detect expressions of p16 and cyclinD1 proteins in 44 cases of hepatocellular carcinoma(HCC), and polymerase chain reaction single-strand conformation polymorphism analysis(PCR-SSCP) to detect p16 gene mutation in exon 2 in 12 cases of HCC and liver tissues adjacent to HCC.

RESULTS

Expression rate and positive signal intensity of p16 protein in HCC were significantly lower(P < 0.01) and those of cyclinD1 protein in HCC were significantly higher (P < 0.05) than those in pericarcinomatous tissues. Of 12 fresh HCC tissues, p16 gene mutation in exon 2 was found in 2 cases, whereas that was not found in pericarcinomatous tissues.

CONCLUSIONS

1. Inactivation or/ and deletion of p16 protein may be one of important reasons which result in proliferation unbalance of cells. 2. p16 gene mutation in exon 2 presents in HCC, but it does not frequently occur in Chinese hepatocarcinogenesis. 3. p16 gene abnormality and cyclinD1 over expression may coact in HCC.

[Expressions of p-MAPK, cyclin D1, p53 protein and their relationship in osteosarcoma]

OBJECTIVE

To detect the expressions of p-MAPK, cyclin D1 and p53 protein, and investigate their relationship in osteosarcomas.

METHODS

SP immunohistochemical technique was used to detect the expressions of of p-MAPK, cyclin D1 and p53 protein among the 58 osteosarcomas and 14 osteoid osteomas samples.

RESULTS

The positive rates of p-MAPK, cyclin D1 and p53 protein were 77.6% (45/58), 60.3% (35/58) and 44.8% (26/58) respectively in 58 osteosarcomas, and 21.4% (3/14), 21.4% (3/14) and 7.1% (1/14) in 14 osteoid osteomas. Their positive rates and expressive intensities in osteosarcomas were higher than those in osteiod osteomas. Their positive correlation was significantly observed between p-MAPK and cyclin D1 proteins (P < 0.01), and wasn't observed between p-MAPK and p53 proteins (P < 0.05) in osteosarcomas.

CONCLUSIONS

MAPK phosporylation may be one of causes for activation of cyclin D1, which play an important role in osteosarcogenesis. The mutation of p53 oncogene may not result in osteosarcogenesis by MAPK signaling pathway. Detecting p-MAPK by immunohistochemistry may be one of diagnostic indexes for osteosarcoma and benign osteoma.

[Effect of hepatitis C virus NS3 protein on expression of iNOS mRNA in hepatocarcinogenesis]

OBJECTIVE

To investigate hepatocarcinogenesis by detecting the effect of HCV NS3 protein on expression of inducible nitric oxide synthase (iNOS) mRNA in hepatocellular carcinoma (HCC) and pericarcinomatous liver tissues(PCLT).

METHODS

The expression of HCV NS3 protein and iNOSmRNA was detected by immunohistochemical technique (SP method) and in situ hybridization in specimens of HCC and PCLT from 52 patients with HBV(-). The relationship between the positive rate and the signal strength was tested statistically.

RESULTS

The positive rate of HCV NS3 protein in HCC was lower (46.2% vs. 67.3%), and signal strength was weaker than those in PCLT. The signal strength of HCV NS3 protein was correlated with the degree of carcinomatous cells differentiation in HCC (P < 0.01). The positive rates (80.8% and 90.4%) of iNOSmRNA in HCC and PCLT had no statistical difference. Signal intensity of iNOSmRNA in HCC was weaker than that in PCLT. The higher HCVNS3 protein expression level was, the stronger iNOSmRNA signals in PCLT (P < 0.01). In particular, the localization and patterns of HCV NS3 protein were much similar to those of iNOSmRNA in the PCLT of some patients.

CONCLUSIONS

HCV NS3 protein may exert its hepatocarcinogenic effect in the early stage on host cells by increasing product of nitric oxide, which may bring about transformation of hepatocytes.

[Role of functional inactivation of p53 from MDM2 overexpression in hepatocarcinogenesis]

OBJECTIVE

This paper was to evaluate the role of p53 mutation, and p53 and MDM2 proteins expression in hepatocarcinogenesis.

METHODS

Using streptavidin-peroxidase conjugation method (SP), the expression of p53 and MDM2 proteins was observed in 61 cases of primary hepatocarcinomas (HCC) and 59 cases of corresponding paracancerous tissue, among which p53 mutations in exons 5-8 were detected in 21 cases by polymerase chain reaction single-strand confirmation polymorphism analysis (PCR-SSCP).

RESULTS

Positive nuclear p53 and MDM2 immunostainings were demonstrated in 57.38% (35/61) and 26.23% (16/61) of HCC, and 1.69% (1/59) and 3.39% (2/59) of corresponding paracancerous tissue, respectively. The expressions of p53 and MDM2 proteins in HCCs were significantly higher than those in paracancerous tissues (P < 0.01). The expressions of p53 and MDM2 were not significantly correlated (P > 0.05). There were 42.86% (9/21) mutations in exon 7 of p53 gene and no mutation was observed in exons 5, 6, 8 in HCCs and in paracancerous tissues. In cases of p53 mutations, there were 66.67% (6/9) of p53 overexpression and 11.11% (1/9) of overexpression of both p53 and MDM2. MDM2 overexpression also appeared in 25% (3/12) of cases without mutation.

CONCLUSIONS

Mutation of p53 gene and functional inactivation of p53 resulting from MDM2 overexpression play an important role in carcinogenesis of HCC. It is possible that p53 mutations and MDM2 overexpression induced by other mechanisms are involved in carcinogenesis of HCC.

[Effects of Stat3 phosphorylation and expression of c-fos and c-jun proteins on hepatocarcinogenesis]

Expression of phosphorylated Stat3 (p-Stat3), c-fos and c-jun proteins was detected by immunohistochemical technique in 55 hepatocellular carcinomas (HCC) and their surrounding liver tissues. The results showed that the positive rates and signal intensity of p-Stat3, c-fos and c-jun protein in HCCs were significantly higher than those in pericarcinomatous tissues. The expressive intensity of c-fos and c-jun proteins was positively related to p-Stat3 expression in HCCs, whereas the positive correlation of expressive intensity was only observed between c-jun protein and p-Stat3 in pericarcinomatous tissues. The data suggest that the phosphorylation of Stat3 may be an early event in hepatocarcinogenesis; the overexpression of p-Stat3 protein, which activates c-fos and c-jun genes, may contribute to malignant transformation of hepatocytes; hepatocytes which expressed p-Stat3, c-fos or c-jun proteins may be potentially malignant pre-cancer cells in pericarcinomatous liver tissues.

[Effect of activation of p-MAPK on activating c-fos and c-jun proteins in breast cancer]

OBJECTIVE

This paper was to investigate the relationship between expression of p-MAPK and oncogenesis of breast cancer.

METHODS

Immunohistochemical technique was used to detect the expression of p-MAPK and c-fos and c-jun proteins in 68 cases of breast cancers, 42 cases of pericarcinomatous tissues and 7 cases of normal breast tissues.

RESULTS

Positive stainings of p-MAPK, c-fos, and c-jun were localized in cancer cell nuclei. The positive rates of p-MAPK, c-fos, and c-jun were 86.8% (59/68), 82.4% (56/68), and 77.9% (53/68), respectively, which were much higher than that in pericarcinomatous tissues (P < 0.01). Of some cases, p-MAPK positive staining was also found in the nuclei of the fibroblastic and angioendothelial cells of cancer stroma.

CONCLUSION

Activated or overexpressive MAPK activates the immediately-early oncogenes(c-fos, c-jun), which might play an important role in carcinogenesis of breast cancer and be an early event of oncogenesis of breast cancer.

Effect of phosphorylation of MAPK and Stat3 and expression of c-fos and c-jun proteins on hepatocarcinogenesis and their clinical significance

AIM: To study the effect of phosphorylation of MAPK and Stat3 and the expression of c-fos and c-jun proteins on hepatocellular carcinogenesis and their clinical significance.

METHODS: SP immunohistochemistry was used to detect the expression of p42/44^MAPK, p-Stat3, ca2fos and c-jun proteins in 55 hepatocellular carcinomas (HCC) and their surrounding liver tissues.

RESULTS: The positive rates and expression levels of p42/44^MAPK, p-Stat3, c-fos and c-jun proteins in HCCs were significantly higher than those in pericarcinomatous liver tissues (PCLT). A positive correlation was observed between the expression of p42/44^MAPK and c-fos proteins, and between pa2Stat3 and c-jun, but there was no significant correlation between p42/44^MAPK and p-Stat3 in HCCs and their surrounding liver tissues.

CONCLUSION: The abnormalities of Ras/Raf/MAPK and JAKs/Stat3 cascade reaction may contribute to malignant transformation of hepatocytes.Hepatocytes which are positive for p42/44^MAPK, c-fos or c-jun proteins may be potential malignant pre-cancerous cells. Activation of MAPK and Stat3 proteins may be an early event in hepatocellular carcinogenesis.

[Relationship between vascular endothelial growth factor expression and microvessel density in hepatocellular carcinomas and their surrounding liver tissue]

The relationship between vascular endothelial growth factor (VEGF) expression and microvessel density was studied with immunohistochemical method in hepatocellular carcinoma (HCC) and pericarcinomatous liver tissue. The positive rate of VEGF in HCCs was significantly lower than in surrounding liver tissues (66.7% vs. 85.4%, P < 0.05). There was no significant difference between HCC and pericarcinomatous liver tissue on expressive intensity of VEGF. The positive signal of VEGF was mainly localized in cytoplasma of cancer cells, pericarcinomatous hepatocytes, and vascular endothelial cells. The microvessel density in HCC was higher than in pericarcinomatous liver tissue and closely correlated to differentiated degree of cancer cells (rs = 0.5870; rs = 0.8235). The poorer cancer cell differentiation, the higher microvessel density. The results suggest that VEGF may not be the sole factor that stimulates angiogenesis in HCC genesis and development. To detect microvessel density in judging prognosis and biological behavior of HCC is more important than that of VEGF.

[The expression of p42/p44MAPK and cyclin D1 protein and their relationship in Hodgkin's disease]

The expressions of p42/44 mitogen-activated protein kinase(p42/p44MAPK) and cyclin D1 protein were detected by SP immunohistochemical technique in 40 cases of Hodgkin's disease(HD) and 13 cases of reactive hyperplasia(RH). The results showed that p42/p44MAPK and cyclin D1 protein were both overexpressed in RS/H cells of HD(positive rates were 72.5% and 70% respectively), and their positive rates were positively correlated(P < 0.01). The data suggest that MAPK cascades signal transduction may play an important role in genesis of HD. MAPK may induce overexpression of cyclin D1 protein and result in persistent proliferation and progression of RS/H cells.

[An improved deresining method for semithin sections embedded-epoxy resin]

Deresining must be performed for HE, specific histochemical staining and immunohistochemical detection on semithin-sections embedded-epoxy resin. The deresining process in general methods had to take 24 hours, and the semithin-sections were easily separated from slides. An improved method was introduced in this paper, by which deresining time was only 5 minutes, and it could also avoid the separation of semithin-sections from the slides. The staining result was very good, and the resolving power of images was high.