Characterization of SIPs-type aquaporins and their roles in response to environmental cues in rice (Oryza sativa L.).

BACKGROUND: Aquaporins (AQPs) facilitate water diffusion across biological membranes and are involved in all phases of growth and development. Small and basic intrinsic proteins (SIPs) belong to the fourth subfamily of the plant AQPs. Although SIPs are widely present in higher plants, reports on SIPs are limited. Rice is one of the major food crops in the world, and water use is an important factor affecting rice growth and development; therefore, this study aimed to provide information relevant to the function and environmental response of the rice SIP gene family. RESULTS: The rice (Oryza sativa L. japonica) genome encodes two SIP-like genes, OsSIP1 and OsSIP2, whose products are predominantly located in the endoplasmic reticulum (ER) membrane but transient localization to the plasma membrane is not excluded. Heterologous expression in a yeast aquaglyceroporin-mutant fps1Δ showed that both OsSIP1 and OsSIP2 made the cell more sensitive to KCl, sorbitol and H2O2, indicating facilitated permeation of water and hydrogen peroxide. In addition, the yeast cells expressing OsSIP2 were unable to efflux the toxic methylamine taken up by the endogenous MEP permeases, but OsSIP1 showed subtle permeability to methylamine, suggesting that OsSIP1 may have a wider conducting pore than OsSIP2. Expression profiling in different rice tissues or organs revealed that OsSIP1 was expressed in all tissues tested, whereas OsSIP2 was preferentially expressed in anthers and weakly expressed in other tissues. Consistent with this, histochemical staining of tissues expressing the promoter-ß-glucuronidase fusion genes revealed their tissue-specific expression profile. In rice seedlings, both OsSIPs were upregulated to varied levels under different stress conditions, including osmotic shock, high salinity, unfavorable temperature, redox challenge and pathogen attack, as well as by hormonal treatments such as GA, ABA, MeJA, SA. However, a reduced expression of both OsSIPs was observed under dehydration treatment. CONCLUSIONS: Our results suggest that SIP-like aquaporins are not restricted to the ER membrane and are likely to be involved in unique membrane functions in substrate transport, growth and development, and environmental response.

H2O2 as a Feedback Signal on Dual-Located WHIRLY1 Associates with Leaf Senescence in Arabidopsis.

Leaf senescence, either as a natural stage of development or as an induced process under stress conditions, incorporates multiple intricate signaling pathways. At the cellular level, retrograde signals have been considered as important players during the initiation and progression of senescence in both animals and plants. The plant-specific single-strand DNA-binding protein WHIRLY1 (WHY1), a repressor of leaf natural senescence, is dually located in both nucleus and plastids. Despite many years of studies, the myth about its dual location and the underlying functional implications remain elusive. Here, we provide further evidence in Arabidopsis showing that alteration in WHY1 allocation between the nucleus and chloroplast causes perturbation in H2O2 homeostasis, resulting in adverse plant senescence phenotypes. The knockout of WHY1 increased H2O2 content at 37 days post-germination, coincident with an early leaf senescence phenotype, which can be rescued by ectopic expression of the nuclear isoform (nWHY1), but not by the plastid isoform (pWHY1). Instead, accumulated pWHY1 greatly provoked H2O2 in cells. On the other hand, exogenous H2O2 treatment induced a substantial plastid accumulation of WHY1 proteins and at the same time reduced the nuclear isoforms. This H2O2-induced loss of nucleus WHY1 isoform was accompanied by enhanced enrichments of histone H3 lysine 9 acetylation (H3K9ac) and recruitment of RNA polymerase II (RNAP II) globally, and specifically at the promoter of the senescence-related transcription factor WRKY53, which in turn activated WRKY53 transcription and led to a senescence phenotype. Thus, the distribution of WHY1 organelle isoforms and the feedback of H2O2 intervene in a circularly integrated regulatory network during plant senescence in Arabidopsis.

[Clinical implication of urinary protein markers in diabetic nephropathy and interventional effects of Chinese herbal medicine].

In clinic, some urinary protein makers can dynamically and noninvasively reflect the degree of renal tubular injury in patients with diabetic nephropathy (DN). These urinary biomarkers of tubular damage are broadly divided into two categories. One is newfound, including kidney injury molecule-1 (Kim-1), neutrophil getatinase-associated lipocalin (NGAL), liver-type fatty acid-binding protein (L-FABP) and cystatin C (CysC); the other one is classical, including beta2 microglobulin (beta2-MG), retinal binding protein (RBP) and N-acetyl-beta-D-glucosaminidase (NAG). It is reported that, the increases in urinary protein markers are not only closely related to the damage of tubular epithelial cells in DN patients, but also can be ameliorated by the treatment with Chinese herbal compound preparations or Chinese herbal medicine. Recently, although urinary proteomics are used in the protein separation and identification, the traditional associated detection of urinary protein markers is more practical in clinic. At present, it is possible that the associated detection of urinary biomarkers of glomerular and tubular damages may be a feasible measure to reveal the clinical significance of urinary protein markers in DN patients and the interventional effects of Chinese herbal medicine.

Ureic clearance granule, alleviates renal dysfunction and tubulointerstitial fibrosis by promoting extracellular matrix degradation in renal failure rats, compared with enalapril.

ETHNOPHARMACOLOGICAL RELEVANCE: Chinese herbal compound prescription has a unique therapeutic action on chronic kidney disease (CKD) in China. In clinics, Uremic Clearance Granules (UCG), a compounded Chinese patent medicine, has been frequently used to treat chronic renal failure (CRF) patients for nearly 30 years, however, the deep therapeutic mechanisms involved in vivo remain a challenge. This study aims to demonstrate the effects and mechanisms of UCG on renal dysfunction and tubulointerstitial fibrosis by regulating extracellular matrix (ECM) degradation and transforming growth factor (TGF)-beta1/Smad signaling activity in vivo, compared with enalapril. MATERIALS AND METHODS: Twenty-six rats were randomly divided into 4 groups, a sham-operated group (Sham group), a vehicle-intervened group (Vehicle group), a UCG-treated group (UCG group) (5g/kg/day) and an enalapril-treated group (Enalapril group) (20mg/kg/day). The rats with renal failure were induced by adenine (150 mg/kg/day) and unilateral ureteral obstruction (UUO), and killed on day 35 after the administration. Proteinuria, urinary N-acetyl-beta-D-glucosaminidase (UNAG), blood biochemical parameters, renal morphological changes, collagen type IV (CIV), matrix metalloproteinase (MMP)-2, MMP-9 and tissue inhibitors of metalloproteinase (TIMP)-1, as well as the key molecular protein expressions in TGF-beta1/Smad signaling pathway were observed, respectively. RESULTS: Adenine administration and UUO induced severe renal damages, as indicated by renal dysfunction, proteinuria and the marked histopathological injuries in the tubules and interstitium, which were associated with MMP-2/TIMP-1 imbalance and TGF-beta1/Smad signaling activity, as shown by up-regulation of the protein expressions of TGF-beta1, TGF-beta receptor type I (RI), TGF-beta receptor type II (RII), Smad2/3, phosphorylated-Smad2/3 (p-Smad2/3) and Smad4, as well as down-regulation of the protein expression of Smad7 in the kidney. UCG treatment, however, significantly not only attenuated renal dysfunction and tubulointerstitial fibrosis, but also improved the protein expressions of MMP-2, TIMP-1, TGF-beta1, TGF-beta RI, p-Smad2/3, Smad4 and Smad7 in the kidney. Besides, the effects of UCG were stronger than those of enalapril partly. CONCLUSION: UCG similar to enalapril, is renoprotective via ameliorating renal dysfunction and tubulointerstitial fibrosis in the renal failure model. The potential mechanisms by which UCG exerts its therapeutical effects in vivo are through promoting ECM degradation and regulating MMP-2/TIMP-1 balance or signaling molecular activity in TGF-beta1/Smad pathway in the kidney. These findings suggest that UCG treatment is undoubtedly useful in preventing the progression of CRF.

Low-dose of multi-glycoside of Tripterygium wilfordii Hook. f., a natural regulator of TGF-ß1/Smad signaling activity improves adriamycin-induced glomerulosclerosis in vivo.

ETHNOPHARMACOLOGICAL RELEVANCE: Transforming growth factor (TGF)-ß1/Smad signaling pathway plays a critical role in the prolonged glomerulosclerosis (GS), which is an important determinant during the progression in chronic kidney disease (CKD). For recent 30 years, multi-glycoside of Tripterygium wilfordii Hook. f. (GTW), an extract from Chinese herbal medicine has been proved clinically effective in improving GS in CKD in China. However, therapeutic mechanisms involved in vivo are still unclear. In this study, we aimed to explain the dose-effects and molecular mechanisms of GTW on GS by regulating TGF-ß1/Smad signaling activity in adriamycin (ADR)-induced nephropathy (ADRN). MATERIALS AND METHODS: Rats with ADRN, created by unilateral nephrectomy and twice adriamycin injections (ADR, 4 mg/kg and 2 mg/kg) within 4 weeks, were divided into four groups, the Sham group, the Vehicle group, the low-dose GTW-treated group, and the high-dose GTW-treated group, and that, sacrificed at the end of the 6th week after administration. Proteinuria, blood biochemical parameters, glomerulosclerotic morphological makers, podocyte shape, and nephrin expression were examined, respectively. Protein expressions of key signaling molecules in TGF-ß1/Smad pathway, such as TGF-ß1, Smad3, phosphorylated-Smad2/3 (p-Smad2/3), and Smad7, were also evaluated individually. RESULTS: The results indicated that the characterizations of ADRN involved the typical prolonged GS, a small amount of abnormal proteinuria, and the failing renal function; TGF-ß1/Smad signaling molecules, especially Smad3, p-Smad2/3, and Smad7 were activated in vivo, accompanied by the exasperation of glomerulosclerotic lesion; GTW at high-dose (100 mg/kg) and low-dose (50 mg/kg) could slightly ameliorate the prolonged GS and nephrin expression, furthermore, the anti-proliferative action of GTW at high-dose was superior to that at low-dose, but caused the significant liver injury; in ADRN model rats, protein expressions of TGF-ß1, p-Smad2/3, and Smad7 in the kidneys could be regulated with the treatment of GTW at low-dose. CONCLUSION: This study farther demonstrated that the low-dose of GTW, as a natural regulator in vivo, could effectively and safely ameliorate the prolonged GS in FSGS model, via the potential molecular mechanisms involving the reduction of ECM components and the suppression of TGF-ß1 over-expression, as well as the bidirectional regulation of TGF-ß1/Smad signaling activity.

[Regulative mechanisms of oxidative stress in kidney in diabetic nephropathy and interventional effects of Chinese herbal medicine].

In the development of diabetic nephropathy (DN), reactive oxygen specie (ROS) over much in vivo leads to oxidative stress(OS)-related renal injuries, which are characterized by the structural and functional changes in glomerular and renal tubular cells in morphology. The regulative approaches of OS involve the several signaling pathways, in which, both p38 mitogen-activated protein kinase (MAPK) signaling pathway and adenosine monophosphate-activated protein kinase (AMPK) signaling pathway play the important roles as the target of anti-oxidants. The interventional actions of Chinese herbal compound prescriptions and the extracts of single Chinese herbal medicine (CHM) on OS in the kidney in DN include regulating the balance between ROS and antioxidants, reducing the production of AGEs, inhibiting the expression of growth factors and intervening the activity of signaling pathways.

[Recognition of experimental animal model with kidney disease].

Animal models with kidney disease are generally divided into two types. One belongs to the models which imitate human kidney disease by the artificial operations, such as anti-glomerular basement membrane antibody nephritis, Heymann nephritis, anti-Thyl. 1 antibody nephritis, BSA nephritis and puromycin nephropathy. The other one pertains to the models which make themselves kidney disease, and appear the pathological characteristics naturally as like as human, such as HIGA mice with IgA nephropathy and NZB/WF1 and MRL/1pr mice with lupus nephritis. In addition,the transgenic animal models with kidney disease can also be established by the modern molecular biologic techniques including gene knockout and siRNA transfection. As for the studies related with kidney disease in pharmacodynamics and pharmacology of Chinese herbal medicine (CHM), it is important to understand deeply the features of each animal model with kidney disease, and select accurately the proper models according to the different experimental objectives, and then, build the special models provided with the combination of disease with syndrome in traditional Chinese medicine (TCM). Therefore,it is the developmental direction for the further study to establish animal models with kidney disease, which should possess the characteristics of syndrome in TCM.

[Effects and mechanisms of multi-glycoside of Tripterygium wilfordii improving glomerular inflammatory injury by regulating p38MAPK signaling activation in diabetic nephropathy rats].

OBJECTIVE: To explore the effects and mechanisms of multi-glycoside of Tripterygium wilfordii (GTW) on improving glomerular inflammatory lesion in rats with diabetic nephropathy (DN). METHOD: DN model was induced by unilateral nephrectomy and intraperitoneal injection of STZ (35 mg x kg(-1)) twice. The rats were randomly divided into 3 groups, the sham-operated group (Sham group, n = 5), the vehicle-given group (Vehicle group, n = 5 ) and GTW-treated group (GTW group, n = 5). After the model was successfully established, the rats in GTW group were daily oral administrated with GTW suspension (50 mg x kg(-1) x d(-1)), meanwhile, the rats in Vehicle group were daily oral administrated with distilled water (2 mL) for 8 weeks. From the beginning of the administration, all rats were killed 8 weeks later. Blood and renal tissues were collected,and then UAlb, renal function, glomerular morphology characteristics and glomerular macrophages (ED1 + cells) infiltration, as well as the protein expressions of inflammatory cytokines including tumor necrosis factor(TNF)-α and interleukin(IL)-lß, and the key molecules in p38MAPK signaling pathway including p38 mitogenactivated protein kinase (MAPK), phosphorylated p38 (p-p38MAPK) and transforming growth factor(TGF)-ß1 were investigated respectively. RESULT: GTW not only ameliorated the general state of health and body weight,but also attenuated UAlb, glomerulosclerosis, the infiltration of glomerular ED1 + cells and the protein expressions of TNF-α, IL-1ß, p-p38MAPK and TGF-ß1 in the kidney in DN model rats. CONCLUSION: By means of DN model rats, we demonstrated that GTW has the protective effect on renal inflammatory damage in vivo via inhibiting inflammatory cells infiltration and inflammatory cytokines expression. Furthermore, GTW could improve renal inflammatory lesion through down-regulating the expressions of the key signaling molecules in p38MAPK pathway such as p-p38MAPK and TGF-ß1 ,and inhibiting the activation of p38MAPK signaling in the kidney.

[Effects and mechanisms of huangkui capsule ameliorating renal fibrosis in diabetic nephropathy rats via inhibiting oxidative stress and p38MAPK signaling pathway activity in kidney].

OBJECTIVE: To demonstrate the effects and mechanisms of Huangkui capsule (HKC) on renal fibrosis in rats with diabetic nephropathy (DN). METHOD: Rats were randomly divided into 5 groups, the sham-operated group (Sham group, n = 5), the vehicle-given group (Vehicle group, n = 7), the low dose of HKC-treated group (L-HKC group, n = 7), the high dose of HKC-treated group (H-HKC group, n = 7) and the lipoic acid (LA)-treated group (LA group, n = 7). DN models were induced by intraperitoneal injection of streptozotocin (STZ,35 mg x kg(-1)) twice and unilateral nephrectomy. After models were successfully established, the rats in HKC and LA groups were daily administrated with HKC suspensions (0.75, 2 g x kg(-1)) or LA suspensions (60 mg x kg(-1)) respectively, and at the same time, the rats in Vehicle group were daily administrated with distilled water (2 mL) for 8 weeks. All rats were sacrificed at the end of week 8 to collect blood and renal tissues. UAlb, renal function, renal fibrotic morphologic characteristics, as well as oxidative stress (OS)-related markers, the protein expressions of the key signaling molecules in p38 mitogen-activated protein kinase (p38MAPK) signaling pathway, fibrogenic cytokines and inflammatory factors were examined respectively. RESULT: HKC, similar to LA, improved the general state of health, body weight, UAlb, BUN, UA and Alb in DN model rats. Of note, renal fibrosis was ameliorated in HKC groups,especially in H-HKC group which was better than that in LA group. In addition, HKC not only improved the main indexes of OS in the kidney like LA, but also down-regulated the protein expressions of phosphorylated-p38MAPK (p-p38MAPK), transforming growth factor (TGF)-ß1 and tumor necrosis factor(TNF)-α in the kidney, whereas, LA only decreased the protein expression of TNF-α in the kidney in DN model rats. CONCLUSION: HKC, similar to LA, has the actions of anti-OS in vivo. Moreover, HKC could attenuate renal fibrosis by suppressing the activation of p38MAPK signaling pathway and the protein expressions of fibrogenic cytokines and inflammatory factors in the kidney in DN model rats, which is different from LA.

[Regulative mechanism of renal inflammatory-related p38MAPK signaling pathway in diabetic nephropathy and interventional effects of Chinese herbal medicine].

It is reported, in the process of diabetic nephropathy (DN), inflammatory-related p38 mitogen-activated protein kinase (MAPK) signaling pathway has a close relationship with renal injury. On the one hand,many factors in the upstream including hyperglycemia, abnormal hemodynamics, oxidative stress, and pro-inflammatory cytokines could activate p38MAPK signaling pathway. On the other hand,the activated p38MAPK signaling pathway could lead to renal damage via activating inflammatory cells, inducing the expression of inflammatory mediators, and intervening cytokines production. CHM could intervene p38MAPK signaling pathway through multi-ways, including inhibiting inflammatory cytokines expression, regulating phosphorylated p38MAPK (p-p38MAPK) expression, and reducing fibrogenic factors expression.

Huangkui capsule, an extract from Abelmoschus manihot (L.) medic, ameliorates adriamycin-induced renal inflammation and glomerular injury via inhibiting p38MAPK signaling pathway activity in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Abelmoschus manihot (L.) medic (AM) is a natural medicinal plant used for the treatment of inflammatory diseases in China. Huangkui capsule (HKC), an extract from AM, has been proved clinically effective in improving renal inflammation and glomerular injury in chronic kidney disease (CKD). However, the dose-effects and the mechanisms involved in vivo are still unclear. AIM OF THE STUDY: This study was performed to examine the dose-effects of HKC on renal inflammation and glomerular lesion in adriamycin-induced nephropathy (ADRN), then to clarify the mechanisms in vivo of HKC by investigating its actions on modulating the activation of p38 mitogen-activated protein kinase (p38MAPK) signaling pathway. MATERIALS AND METHODS: The rats with chronic ADRN, created by the unilateral nephrectomy and twice adriamycin injections (ADR, 4 mg/kg and 2mg/kg) within 4 weeks, were divided into four groups, a Sham group, a Vehicle group, a high-dose HKC group, and a low-dose HKC group, and that, sacrificed at the end of the 4th week after the administration. The rat's general status, renal morphological appearance, proteinuria, blood biochemical parameters, glomerular morphological changes, podocyte shape, and macrophage (ED1(+) and ED3(+) cells) infiltration in glomeruli were examined, respectively. The protein expressions of inflammatory cytokines including tumor necrosis factor (TNF)-α and interleukin (IL)-2, as well as p38MAPK signaling molecules such as transforming growth factor (TGF)-ß1, p38MAPK, and phosphorylated-p38MAPK (p-p38MAPK), were also evaluated individually. RESULTS: HKC at high dose of 2g/kg/d not only significantly ameliorated the rat's general status, renal morphological appearance, proteinuria, albumin, and glomerulosclerosis, but also obviously reduced the infiltrated ED1(+) and ED3(+) macrophages in glomeruli and TNF-α protein expression in the kidney, in addition to these, evidently down-regulated TGF-ß1 and p-p38MAPK protein expressions in ADRN rats, but had no influence on podocyte shape and renal function. CONCLUSION: HKC could dose-dependently ameliorate renal inflammation and glomerular injury in ADRN rats, by way of reducing the infiltration and the activation of macrophages in glomeruli, and TNF-α protein expression in the kidney, as well as inhibiting p38MAPK signaling pathway activity via the down-regulation of p-p38MAPK and TGF-ß1 protein expressions in vivo.

[Characteristic of urinary protein spectrum in patients with stage III diabetic nephropathy and its regression analysis with traditional Chinese medicine symptom].

To analyze the characteristic of urinary protein spectrum in patients with stage III diabetic nephropathy (DN) and its compliance with traditional Chinese medicine (TCM)symptom, for the sake of providing a basis for clarifying the rules of TCM syndrome differentiation in DN. Adopting the traditional epidemiological retrospective method, thirty-eight TCM syndromes and urinary protein with medium or low molecular weight, as well as urinary enzyme, including 24 h urinary protein (Upro), urinary albumin( UAlb), urinary retinal binding protein( URBP), urinary cystatin C (UCysC), urinary N-acetyl-beta-D-glucosaminidase (UNAG), were collected from 108 patients with stage III DN, and a multiple factor regression analysis between them was conducted. As the results, the levels of Upro, UAlb, URBP, UCysC, and UNAG were increased in 108 patients with stage III DN. Qi-Yin deficiency type was the major type. The level of UAlb in patients with Qi-Yin deficiency type was significantly higher than those without Qi-Yin deficiency type (P < 0.05). The elevation of Upro with the factors as swift digestion with rapid hungering, lassitude and lack of strength, weakness of waist and knees was complied, the elevation of UA1b with the factors as dry mouth with desire to drink, the elevation of URBP with the factors as numbness of extremities, shortness of breath, the elevation of UCysC with the factors as clear urine in large amounts, and the elevation of UNAG with the factors as frequent micturition, were complied respectively. In conclusion, for 108 stage III DN patients. The increase in urinary protein spectrum including UAlb, URBP, UCysC, and UNAG is the major characteristic. Shen and Pi are the major organs related to the appearance of urinary protein; Pi-Shen deficiency is the basic pathogenesis. The level of UAlb is taken as one of the objective syndrome factors for Qi-Yin deficiency type. The levels of UNAG and UCysC are possibly the objective syndrome factors for Shen-Qi deficiency type.

[Overview research of uremic ulearance granule treating chronic renal failure].

The effective bioactivity compositions of uremic clearance granul (UCG) include isoflavonoids, emodin, astragaloside, paeoniflorin, salvianolic acid A, and so on. The effects of UCG treating chronic renal failure (CRF) in clinical pharmacodynamics mainly refer to improve renal function and the complications of CRF. The mechanisms involved in vivo basically include depressing transforming growth factor (TGF)-beta1 over-expression, lessening podocyte injury,inhibiting tubular epithelial myofibroblast transdifferentiation, ameliorating microinflammation status, retarding oxidative stress, and alleviating insulin resistance.