Expression of connexin 40 and connexin 45 in renal tissue of rats with chronic renal failure and effect of treatment with Astragalus polysaccharide and stachydrine combination

AIM：To explore the expression of connexin 40 (Cx40) and connexin 45 (Cx45) in chronic renal failure rats, and to investigate the effect of an Astragalus polysaccharide and stachydrine combination on the expressions of the 2 proteins, and the treatment effect of the combination on chronic renal failure. METHODS：Wistar rats were randomly divided into 4 groups:control group (6 rats), chronic renal failure model group (8 rats), low-dose Astragalus polysaccharide (200 mg·kg-1·d-1) and stachydrine (2.5 mg·kg-1·d-1) combination group (8 rats), and high-dose Astragalus polysaccharide (400 mg·kg-1·d-1) and stachydrine (5 mg·kg-1·d-1) combination group (8 rats). The rat model of chronic renal failure was induced by adenine (200 mg·kg-1·d-1) gavage. After 7-week administration, the expression of Cx40 and Cx45 in the renal tissue was determined by immunohistochemical staining. The renal function, electrolyte levels, and pathological changes of the kidneys were also analyzed. RESULTS：The expression of Cx40 and Cx45 was increased in the renal tissue of chronic renal failure rats. The combination of Astragalus polysaccharide and stachydrine reduced the kidney weight and index, attenuated the pathological renal damage in the model rats, decreased the expression of Cx40 and Cx45, maintained the stability of serum electrolytes, and decreased the levels of serum creatinine and blood urea nitrogen. CONCLUSION:Chronic renal failure caused the increase in the expression of Cx40 and Cx45 in the rat renal tissue. The combination of Astragalus polysaccharide and stachydrine reduces the expression of Cx40 and Cx45 in the renal tissue, and improves the renal function, thus playing a role in protecting the kidneys.     

Relationship between precore/basal core promoter mutations of hepatitis B virus and therapeutic effect of peginterferon α-2b,and changes of mutations before and after treatment

AIM:To investigate the relationship between therapeutic effect of peginterferon α-2b (Peg-IFNα-2b) and precore (PC) region G1896A and basal core promoter (BCP) region A1762T/G1764A mutations of hepatitis B virus (HBV), and the changes of the mutations before and after treatment. METHODS:The patients with HBeAg-positive chronic hepatitis B (CHB) (n=69) were treated with Peg-IFNα-2b for 48 weeks and followed up for 24 weeks. The PC and BCP sequences at baseline and the 72th week were determined using polymerase chain reaction (PCR) and direct sequencing. Serum HBsAg, HBeAg, alanine aminotransferase (ALT) and HBV DNA was quantified in the samples taken at baseline (week 0), during the treatment period (weeks 4, 8, 12, 24, 36 and 48), and during follow-up (weeks 60 and 72). RESULTS:Within the total cohort, wild-type (WT) virus was detectable in only 14 patients (20.29%), and mutants were detected in 55 patients (79.71%). The serum HBeAg level in the patients with mutant virus was significantly lower than that in the patients with WT virus (P=0.024). The proportion of WT, PC mutant, BCP mutant and PC+BCP mutant was significantly changed at baseline and week 72 (P=0.004). No significant difference of HBeAg seroconversion and combined response between patients with WT virus or mutants (PC, BCP and PC+BCP) was observed. CONCLUSION:PC and BCP mutations have no effect on the response of HBeAg-positive CHB patients to Peg-IFNα-2b. The proportion of each mutation was significantly changed before and after treatment.     

Role of central PGE2 on sympathetic excitation in chronic heart failure

AIM: To observe the effect of central prostaglandin E₂ (PGE₂) on sympathetic activation in chronic heart failure (CHF) and to explore the underlying mechanism. METHODS: Male SD rats were subjected to coronary artery ligation to induce heart failure (HF), and the intracerebroventricular infusion was performed by osmotic pump continuously. The rats in sham group and HF group were given artificial cerebrospinal fluid (0.25 μL/h). The rats in HF plus treatment group was given celecoxib (CLB; 20 mg/h). After 4 weeks, the levels of PGE₂ in cerebrospinal fluid (CSF), the sympathetic nerve excitability and cardiac function were measured, and the changes of corticotropin-hormone releasing hormone (CRH)-containing neurons activation and neurotransmitter contents in the hypothalamic paraventricular nucleus (PVN) were also determined. RESULTS: Compared with the sham-operated rats, the HF rats had raised level of PGE₂ in CSF, up-regulated renal sympathetic nerve activity and plasma norepinephrine, increased left ventricular end diastolic pressure, lung-to-body weight and right ventricular-to-body weight ratios, and decreased maximal increase and decreased rate of left ventricular pressure (P<0.05). In addition, the number of CRH positive neurons in PVN and the level of plasma adrenocorticotropic hormone were higher in HF rats than those in sham-operated rats (P<0.05). After administration of CLB into the lateral ventricle of HF rats, the contents of PGE₂ in CSF were significantly reduced, the number of activation CRH neurons in PVN was decreased, the excitability of sympathetic nerves was down-regulated and cardiac function was improved (P<0.05). Compared with the sham-operated rats, the content of glutamic acid in PVN of HF rats was increased, the content of γ-aminobutyric acid and the number of glutamate decarboxylase 67-positive neurons were decreased (P<0.05). After the CLB was given, the above indexes were reversed (P<0.05). CONCLUSION: These findings indicate that in CHF, the increased central PGE₂ may activate CRH-containing PVN neurons and contribute to the augmented sympathetic drive possibly by modulating the neurotransmitters within the PVN.     

Electroacupuncture improves spatial learning and memory ability of rats with chronic cerebral hypoperfusion and signal regulation of hippocampal IL-6/JAK2/STAT3

AIM:To observe the effect of electroacupuncture (EA) on the inflammatory response and hippocampal JAK2/STAT3 signaling pathway in the rats with chronic cerebral hypoperfusion (CCH), and to explore the mechanism of EA attenuating the spatial learning and memory impairment induced by CCH. METHODS:Adult male Sprague-Dawley rats were randomly divided into sham group, model group and EA group (n=10). Modified permanent bilateral common carotid artery occlusion was used to establish animal model. The rats in EA group were stimulated at "Baihui" and "Dazhui" acupoints by 2/15 Hz frequency (30 min/d for 4 weeks), while the rats in the other 2 groups received balanced treatment. The spatial learning and memory ability and regional cerebral blood flow (rCBF) were detected by the methods of Morris water maze and laser Doppler flowmetry. The concentrations of interleukin (IL)-6 and IL-1β, the mRNA expression of JAK2 and STAT3, and the phosphorylated JAK2 and STAT3 protein levels in the hippocampus were determined by ELISA, RT-PCR and Western blot. The pathological changes of the hippocampus were observed with HE staining. RESULTS:In EA group, the rCBF, the average escape latency at every time point, and the original platform quadrant residence time were better than those in model group (P<0.01 or P<0.05). The level of IL-1β in EA group was significantly lower than that in model group (P<0.05), and the level of IL-6 was significantly increased (P<0.05). The mRNA expression of JAK2 and STAT3, and the protein levels of p-JAK2 and p-STAT3 in EA group were significantly higher than those in model group (P<0.05). The impairment of nerve cells in the hippocampal CA1 region was reduced. CONCLUSION:Electroacupuncture inhibits inflammatory response, and alleviates the hippocampal damage and the cognitive disorder by regulating IL-6/JAK2/STAT3 signaling pathways.     

Effects of sodium hydrosulfide on cardiac function and activity of renin-angiotensin-aldosterone system in rats with chronic heart failure

AIM: To investigate the effect of sodium hydrosulfide (NaHS) on cardiac function and activity of renin-angiotensin (Ang)-aldosterone (ALD) system (RAAS) in the rats with chronic heart failure (CHF).METHODS: The CHF rat model was established by abdominal aortic coarctation. SD rats were randomly divided into sham operation group, model group, low dose of NaHS group and high dose of NaHS group (n=6). The left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD) and left ventricular ejection fraction (LVEF) were measured before and after treatment by echocardiography in each group. The levels of renin, AngⅡ and ALD in the plasma were measured by ELISA. The expression of angiotensin-converting enzyme (ACE) and angiotensin Ⅱ type 1 receptor (AT1R) at mRNA and protein levels in the myocardium tissues was determined by qPCR and Western blot, respectively.RESULTS: After treatment with NaHS, compared with model group and before treatment, LVEDD and LVESD in low dose of NaHS group and high dose of NaHS group were decreased significantly, while LVEF was increased significantly (P<0.05). Compared with low dose of NaHS group, LVEDD and LVESD were decreased, while LVEF was increased in high dose of NaHS group (P<0.05). Compared with sham operation group, the levels of renin, AngⅡ and ALD in the plasma of model group were significantly increased (P<0.05), and the expression of ACE and AT1R at mRNA and protein levels in the myocardium tissues of model group were significantly increased (P<0.05). Compared with model group, the plasma levels of renin, AngⅡ and ALD in low dose of NaHS group and high dose of NaHS group were significantly decreased (P<0.05), and the myocardial expression of ACE and AT1R at mRNA and protein levels was significantly down-regulated (P<0.05). The plasma levels of renin, AngⅡ and ALD, and the myocardial expression of ACE and AT1R at mRNA and protein levels in high dose of NaHS group were significantly lower than those in low dose of NaHS group (P<0.05).CONCLUSION: NaHS inhibits the activation of RAAS, thus improving the cardiac function of CHF rats, and the effect of high-dose NaHS is better than that of low-dose NaHS.     

Advances of phosphatase of regenerating liver-3 in hematological malignancies

In recent years,accumulating evidence shows that phosphatase of regenerating liver-3(PRL-3) is closely implicated in tumor progression,especially in the stages of invasion and metastasis of various solid tumors,including colorectal cancer,gastric cancer and breast cancer.However,the study of PRL-3 in hematological malignancies is relatively lagged, but there are some advances in leukemia and myeloma,in which PRL-3 up-regulation is tightly associated with poor prognosis,while the underlying mechanism of signal transduction is gradually explored.In this review,we summarized the recent advances of PRL-3 in hematological malignancies such as acute myeloid leukemia,multiple myeloma and chronic myeloid leukemia,as well as the molecular mechanism of PRL-3 in pathogenesis.     

Acute monoblastic leukemia in a FeLV-positive cat

A 1.6-year-old male domestic short hair cat was brought to the Veterinary Medical Teaching Hospital, Kasetsart University, with signs of severe anemia, depression, and general lymph node enlargement. Complete blood count revealed leukocytosis and massive undifferentiated blasts. Testing for antibodies specific to feline leukemia virus (FeLV) was positive, and FeLV nucleic acid was confirmed by nested polymerase chain reaction. Base on cytochemistry and ultrastructure, the cat was diagnosed with acute monoblastic leukemia.     

Effects of N-acetylcysteine combined with azithromycin on oxidative stress in rats with chronic obstructive pulmonary disease

AIM: To investigate the effects of N-acetylcysteine (NAC) combined with azithromycin (AZI) on oxidative stress in the rats with chronic obstructive pulmonary disease (COPD). METHODS: Male Wistar rats (n=60) were randomly divided into control group, model group, AZI intervention group,NAC intervention group and AZI+NAC group. The COPD model was established by passive smoking and intratracheal instillation of lipopolysaccharide. Each day 30 min prior to smoking, intragastric administration with AZI, NAC or combination of the 2 drugs was given for AZI, NAC, and AZI+NAC groups, respectively. On the 31st day, all rats were killed following lung function test. Cell counts of bronchoalveolar lavage fluid (BALF) were performed, and the contents of interleukin-8 (IL-8), interleukin-17 (IL-17) and tumor necrosis factor alpha (TNF-α) in BALF were measured by ELISA. The histopathology of the lung tissues was observed under light microscope, and the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in the lung homogenate were measured. RESULTS: Compared with control group, the other 4 groups showed decreased pulmonary function, and inflammatory cell infiltration and alveolar destruction in histopathology. Compared with control group, the other groups showed higher white blood cells, monocyte-macrophages, neutrophils and lymphocytes in the BALF (P<0.05). Compared with model group, AZI group and NAC group, lower white blood cells, neutrophils and lymphocytes in the BALF were observed in AZI+NAC group (P<0.05). Compared with model group, IL-8, IL-17, TNF-α and MDA in AZI group, NAC group and AZI+NAC group significantly decreased (P<0.05), while SOD and GSH-Px significantly increased (P<0.05). Compared with AZI or NAC group, IL-8, IL-17, TNF-α and MDA in AZI+NAC group significantly decreased (P<0.05), while SOD and GSH-Px increased significantly (P<0.05). CONCLUSION: Both NAC and AZI attenuate the lung inflammation and oxidative damage in COPD model rats. Combined medication exerts preferable anti-oxidation effects, which might be more suitable for the treatment of COPD.     

Sialic acid in external membrane of C-type primary sensory neurons with peripheral nerve injury increases excitability of the neurons

AIM: To study the change of electrophysiological property of dorsal root ganglion (DRG) C-type primary sensory neurons with sialic acid on the membrane surface after rat sciatic nerve injury. METHODS: The operation to induce chronic constriction nerve injury (CCI) for establishing CCI pain model was performed in the rats, and normal rats served as controls. The thermal hyperalgesia behavior was observed to select CCI pain rats, and electrophysiological property of injured and normal C-type neurons was studied by intracellular recording. Ca²⁺ and neuraminidase (NA) were topically added on the extracellular membrane of C-type neurons to counteract or selectively remove the negatively charged sialic acid residues, and at the same time the change of electrophysiological property was observed. RESULTS: The rest potential (RP) of injured C-type neurons shifted to depolarizing direction. The incidence of evoked action potential (AP) was higher, and the rheobase to evoke AP was lower than the control. After topical application of Ca²⁺ and NA on injured C-type neurons, hyperpolarized RP and increased rheobase to evoke AP were observed, indicating the excitability of injured C-type neurons diminished. However, these treatments to normal neurons had no effect on electrophysiological property. CONCLUSION: Increased negative charge on the injured C-type neuron surface, carried by the sialic acid residues, contributes to the change of electrophysiological property.     

Suspected myelodysplastic/myeloproliferative neoplasm in a feline leukemia virus‐negative cat

A 10‐year‐old castrated Domestic Short‐Haired cat was presented to a primary care veterinarian for a wellness examination and laboratory examination for monitoring of diabetes mellitus. The CBC revealed marked thrombocytosis, leukopenia and macrocytic, normochromic anemia. The cat tested negative for FeLV and feline immunodeficiency virus, but was positive for Mycoplasma haemominutum by PCR. Hematologic abnormalities were not responsive to therapy, so a repeat CBC and a bone marrow aspiration for cytology were performed. Additional blood smear findings included anisocytosis with megaloblastic erythroid precursors, large platelets, eosinophilic myelocytes and metamyelocytes, and rare unidentified blasts. The bone marrow smear was highly cellular, and the cytologic pattern was consistent with myelodysplastic syndrome with an erythroid predominance. At that time, 15% blasts were present. The cat was treated with a vitamin K₂ analog, doxycycline, and prednisolone, but without a clinical response. Within 3 months, euthanasia was elected due to declining quality of life, and a necropsy was performed. Postmortem bone marrow smears were highly cellular and dominated by monomorphic blasts of unknown line of origin (52%), persistent marked erythroid and megakaryocytic dysplasia, and ineffective erythropoiesis and granulopoiesis. Immunohistochemical, immunocytochemical, and cytochemical stains resulted in a diagnosis of acute myeloid leukemia of unclassified type. Additional histologic findings included mixed hepatitis with trematode infestation and lymphoplasmacytic interstitial nephritis with fibrosis. The marked thrombocytosis with myelodysplastic syndrome and the FeLV‐negative status of this cat were unusual. The difficulty in classifying the myelodysplasia and subsequent leukemia highlights a need for further reporting and characterization of these types of disease.