High matrix metalloproteinase-9 expression induces angiogenesis and basement membrane degradation in stroke-prone spontaneously hypertensive rats after cerebral infarction

Basement membrane degradation and blood-brain barrier damage appear after cerebral infarc- tion, severely impacting neuronal and brain functioning; however, the underlying pathogenetic mechanisms remain poorly understood. In this study, we induced cerebral infarction in stroke- prone spontaneously hypertensive rats by intragastric administration of high-sodium water （1.3% NaC1） for 7 consecutive weeks. Immunohistochemical and immunofluorescence assays demonstrated that, compared with the non-infarcted contralateral hemisphere, stroke-prone spontaneously hypertensive rats on normal sodium intake and Wistar-Kyoto rats, matrix metalloproteinase-9 expression, the number of blood vessels with discontinuous collagen IV expression and microvessel density were significantly higher, and the number of continuous collagen IV-positive blood vessels was lower in the infarct border zones of stroke-prone sponta- neously hypertensive rats given high-sodium water. Linear correlation analysis showed matrix metalloproteinase-9 expression was positively correlated with the number of discontinuously collagen IV-labeled blood vessels and microvessel density in cerebral infarcts of stroke-prone spontaneously hypertensive rats. These results suggest that matrix metalloproteinase-9 upregula- tion is associated with increased regional angiogenesis and degradation of collagen IV, the major component of the basal lamina, in stroke-prone spontaneously hypertensive rats with high-sodi- um water-induced focal cerebral infarction.

Dancing to a somewhat different rhythm: Cell migration along thenatural basement membrane

Much of our understanding of the events which underlie cell migration has been derived from studies of cells intissue culture. One of the components that mediates this process is the dynamic actin-based microfilament system that canreorganize itself into so-called stress fibers that are considered essential components for cell motility. In contrast, relativelyfew studies have investigated cell movement along an extracellular matrix (ECM) which is known to influence both cellularorganization and behavior. This opinion/viewpoint article briefly reviews cell migration during corneal endothelial woundrepair along the tissue’s natural basement membrane, Descemet’s membrane. Because the tissue exists as a cell monolayer itaffords one an opportunity to readily explore the effect of cell/matrix influences on cell motility. As such, cell movementalong this substrate differs somewhat from that found in vitro and migrating endothelial cells also demonstrate an abilityto move along the ECM without the benefit of having an organized actin cytoskeleton.

Diabetes-related intestinal region-specific thickening of ganglionic basement membrane and regionally decreased matrix metalloproteinase 9 expression in myenteric ganglia

BACKGROUND The importance of the neuronal microenvironment has been recently highlighted in gut region-specific diabetic enteric neuropathy. Regionally distinct thickening of endothelial basement membrane(BM) of intestinal capillaries supplying the myenteric ganglia coincide with neuronal damage in different intestinal segments. Accelerated synthesis of matrix molecules and reduced degradation of matrix components may also contribute to the imbalance of extracellular matrix dynamics resulting in BM thickening. Among the matrix degrading proteinases, matrix metalloproteinase 9(MMP9) and its tissue inhibitor(TIMP1) are essential in regulating extracellular matrix remodelling.AIM To evaluate the intestinal segment-specific effects of diabetes and insulin replacement on ganglionic BM thickness, MMP9 and TIMP1 expression.METHODS Ten weeks after the onset of hyperglycaemia gut segments were taken from the duodenum and ileum of streptozotocin-induced diabetic, insulin-treated diabetic and sex-and age-matched control rats. The thickness of BM surrounding myenteric ganglia was measured by electron microscopic morphometry. Wholemount preparations of myenteric plexus were prepared from the different gut regions for MMP9/TIMP1 double-labelling fluorescent immunohistochemistry. Post-embedding immunogold electron microscopy was applied on ultrathin sections to evaluate the MMP9 and TIMP1 expression in myenteric ganglia and their microenvironment from different gut segments and conditions. The MMP9 and TIMP1 messenger ribonucleic acid(m RNA) level was measured by quantitative polymerase chain reaction.RESULTS Ten weeks after the onset of hyperglycaemia, the ganglionic BM was significantly thickened in the diabetic ileum, while it remained intact in the duodenum. The immediate insulin treatment prevented the diabetes-related thickening of the BM surrounding the ileal myenteric ganglia. Quantification of particle density showed an increasing tendency for MMP9 and a decreasing tendency for TIMP1 from the proximal to the distal small intestine under control conditions. In the diabetic ileum, the number of MMP9-indicating gold particles decreased in myenteric ganglia, endothelial cells of capillaries and intestinal smooth muscle cells, however, it remained unchanged in all duodenal compartments. The MMP9/TIMP1 ratio was also decreased in ileal ganglia only. However, a marked segment-specific induction was revealed in MMP9 and TIMP1 at the m RNA levels.CONCLUSION These findings support that the regional decrease in MMP9 expression in myenteric ganglia and their microenvironment may contribute to extracellular matrix accumulation, resulting in a region-specific thickening of ganglionic BM.

Anti-glomerular basement membrane disease with IgA nephropathy: A case report

BACKGROUND Anti-glomerular basement membrane(GBM)disease is a rare autoimmune disease manifesting as acute progressive nephritis syndrome with or without varying degrees of pulmonary hemorrhage.Anti-GBM disease coexisting with Immunoglobulin A(IgA)nephropathy is rarer and has different clinical manifestations and prognoses than simple anti-GBM disease.We describe a case of coexistence of these two diseases.CASE SUMMARY A 49-year-old man with hematuria and proteinuria accompanied by a slight elevation of serum creatinine was admitted to our hospital.The pathological results of renal biopsy and the elevated serum anti-GBM antibody titer supported a diagnosis of anti-GBM disease combined with IgA nephropathy.After treatment with corticosteroids and cyclophosphamide,the patient's serum creatinine was relatively stable,and the hematuria and proteinuria moderately improved in the subsequent six months.CONCLUSION Anti-GBM disease coexisting with IgA nephropathy is rare.The clinical manifestations and prognosis are better than those of simple anti-GBM disease.In this case,the patient's condition was improved and his renal function remained relatively stable with corticosteroid and cyclophosphamide treatment.New detection methods to identify whether the crescents in this case were derived from anti-GBM disease or IgA nephropathy are worthy of further exploration.

A biomimetic basementmembrane consisted of hybrid aligned nanofibers andmicrofibers with immobilized collagen IV and laminin for rapid endothelialization

Rapid formation of a continuous endothelial cell(EC)monolayer with healthy endothelium function on the luminal surface of vascular implants is imperative to improve the longtime patency of small-diameter vascular implants.In the present study,we combined the contact guidance effects of aligned nanofibers,which enhance EC adhesion and proliferation because of its similar fiber scale with native vascular basement membranes,and aligned microfibers,which could induce EC elongation effectively and allow ECs infiltration.It was followed by successive immobilization of collagen IV and laminin to fabricate a biomimetic basement membrane(BBM)with structural and compositional biomimicry.The hemolysis assay and platelet adhesion results showed that the BBM exhibited excellent hemocompatibility.Meanwhile,the adhered human umbilical vein endothelial cells(HUVECs)onto theBBMaligned along the orientation of the microfibers with an elongated morphology,and the data demonstrated that the BBM showed favorable effects on EC attachment,proliferation,and viability.The oriented EC monolayer formed on the BBM exhibited improved antithrombotic capability as indicated by higher production of nitric oxide and prostacyclin(PGI2).Furthermore,fluorescence images indicated that HUVECs could infiltrate into the BBM,implying theBBM’s ability to enhance transmural endothelialization.Hence,theBBMpossessed the properties to regulate ECbehaviors and allow transmural ingrowth,demonstrating the potential to be applied as the luminal surface of small-diameter vascular implants for rapid endothelialization.

Analysis of clinical features and prognosis of anti-glomerular basement membrane antibody positive patients with anti-neutrophil cytoplasmic antibodies

Objective To investigate the characteristics and outcome of glomerulonephritis in patients with both antineutrophil cytoplasmic antibody and anti-glomerular basement membrane antibody.Methods The sera of 23 antiGBM glomerulonephritis patients were collected and were tested for ANCA respectively.Characteristics and outcome of patients with coexisting anti-GBM antibody

The importance of laminin at the blood-brain barrier

The blood-brain barrier is a unique property of central nervous system blood vessels that protects sensitive central nervous system cells from potentially harmful blood components.The mechanistic basis of this barrier is found at multiple levels,including the adherens and tight junction proteins that tightly bind adjacent endothelial cells and the influence of neighboring pericytes,microglia,and astrocyte endfeet.In addition,extracellular matrix components of the vascular basement membrane play a critical role in establishing and maintaining blood-brain barrier integrity,not only by providing an adhesive substrate for blood-brain barrier cells to adhere to,but also by providing guidance cues that strongly influence vascular cell behavior.The extracellular matrix protein laminin is one of the most abundant components of the basement membrane,and several lines of evidence suggest that it plays a key role in directing blood-brain barrier behavior.In this review,we describe the basic structure of laminin and its receptors,the expression patterns of these molecules in central nervous system blood vessels and how they are altered in disease states,and most importantly,how genetic deletion of different laminin isoforms or their receptors reveals the contribution of these molecules to blood-brain barrier function and integrity.Finally,we discuss some of the important unanswered questions in the field and provide a“to-do”list of some of the critical outstanding experiments.

Upregulation of histone H3 caused by CRYAA may contribute to the development of age-related cataract

Objective:Age-relate cataract(ARC)is a disease of the eyes with no effective drugs to prevent or treat patients.The aim of the present study is to determine whether histone H3,αA-crystallin(CRYAA),β-galactosidase(GLB1),and p53 are involved in the pathogenesis of ARC.Methods:A total of 99 anterior lens capsules(ALCs)of patients with ARC of various nuclear grades,ultraviolet models of ALCs,and two human lens epithelial cell lines(FHL-124 and SRA01/04)were used,and the expression of histone H3,CRYAA,GLB1,and p53 were detected by immunoblotting and reverse transcription and real time-quantitative polymerase chain reaction.The association between CRYAA with histone H3,GLB1,and p53 was assessed in FHL-124 and SRA01/04 cells following CRYAA overexpression.Results:Histone H3 and p53 in ALCs of patients with ARC were up-regulated in a grade-dependent manner,and the expression of CRYAA showed a positive association with histone H3,p53,and GLB1.In UV models of ALCs and human lens epithelial cell lines,the expression levels of histone H3,cell apoptosis factors(Bax/Bcl-2,cleaved caspase-3),and inflammation factors(interleukin-6,tumor necrosis factor-α)were all up-regulated.Furthermore,transfection of CRYAA in FHL-124 cells induced overexpression of histone H3.Conclusion:CRYAA-mediated upregulation of histone H3 may be involved in the pathogenesis of ARC.p53 may also have a role in ARC development,but not via the CRYAA-histone H3 axis.The results of the present study may assist in improving our understanding of the pathogenesis of ARC and in identifying potential targets for treatment.

Goodpasture syndrome and hemorrhage after renal biopsy: A case report

BACKGROUND Goodpasture syndrome(GS) is a rare disease, the morbidity of which is estimated to be 0.5-0.8 per million per year. Hemorrhage is the most serious complication in renal biopsy. Despite the fact that both GS and hemorrhage after renal biopsy are rare, it has not been reported that they are likely to occur in the same patient.CASE SUMMARY A 30-year-old man with diffuse pulmonary hemorrhage and rapid progressive renal function caused by anti-glomerular basement membrane disease presented atypical symptoms without hemoptysis, accompanied by life-threatening hypoxemia. Plasmapheresis was performed, and glucocorticoids and cyclophosphamide were administered. The patient started to show signs of improvement. Percutaneous renal biopsy is an appropriate diagnostic measure that is commonly safe, but this patient experienced hemorrhage after operation,thus necessitating embolization of the renal artery to stop the bleeding. The patient’s condition was improved, and the serum anti-glomerular basement membrane antibody level was 106 AU/m L(normal range: < 24 AU/m L) and slowly decreased. His discharge medications were oral daily prednisone(30 mg)and continued maintenance hemodialysis.CONCLUSION GS is a rare organ-specific autoimmune disease that is invariably ubiquitous in the lung and kidney areas. Renal biopsy is the appropriate procedure for the treatment of GS disease, although it is an invasive measure.

Production and Characterization of Recombinant Rat Non-Collagen Domain of α3 Chain of Type IV Collagen α3 (IV) NC1 Antigen

The glomerulonephritis disease is characterized by inflammation of glomeruli or small blood vessels in the kidney that causes kidney diseases. The reason of glomerulonephritis disease is to deposit the anti-GBM auto antibody in the glomerular basement membrane. The type IV collagen is the main component of glomerular basement membrane that has α3 chain of type (IV) collagen of non-collagenous domain which contains N-terminal 7S domain, a triple helical collagenous domain and C-terminal non-collagenous glomerular domain (NC1). The amino terminal of α3 (IV) NC1 that induces the Experimental Autoimmuno Glomerulonephritis (EAG) in rat model has been identified. The recombinant rat α3 (IV) NC1 antigen has nine amino acid spans that are consistent with antibody or T cell epitope that induces in EAG. The research is carried out on the recombinant rat α3 (IV) NC1 production, purification, quantification, and characterization. The circulation of anti-GBM antibody in glomerular basement membrane can be measured by the ELISA assay. In addition, the recombinant rat antigen is secreted in HEK293 cell supernatant that is purified by Anti-FLAG M2 monoclonal IgG antibody affinity column and characterized and quantified by SDS-PAGE gel electrophoresis and Western blotting techniques.

Comparison of the Histological Morphology between Normal Skin and Scar Tissue

Skin wound healing is a complex event, and interrupted wound healing process could lead to scar formation. The aim of this study was to examine the morphological changes of scar tissue. Pathological staining（HE staining, Masson＇s trichrome staining, methenamine silver staining） was used to evaluate the morphological changes of regenerating epidermis in normal skin and scar tissue, and immunofluorescence staining to detect the expression of collagen Ⅳ, a component of basement membrane（BM）, and the expression of integrinβ4, a receptor for BM laminins. Additionally, the expression of CK14, CK5, and CK10 was measured to evaluate the proliferation and differentiation of keratinocytes in normal skin and scar tissue. The results showed that the structure of the skin was histologically changed in scar tissue. Collagen Ⅳ, expressed under the epidermis of normal skin, was reduced distinctly in scar tissue. Integrinβ4, expressed in the basal layer of normal skin, was found absent in the basal layer of scar tissue. Additionally, it was found that keratinocytes in scarring epidermis were more proliferative than in normal skin. These results indicate that during the skin wound healing, altered formation of BM may affect the proliferation of keratinocytes, reepithelial and tissue remodeling, and then result in scar formation. Thus, remodeling BM structure during wound repair may be beneficial for improving healing in cutaneous wounds during clinical practice.

Royal Jelly Extract Accelerates Keratinocyte Proliferation, and Upregulates Laminin α3 and Integrin β1 mRNA Expression, via Akt/mTOR/HIF-1α Pathway

Background: In the previous decade, various benefits and biological activities of royal jelly, applied in alternative and modern medicine, and cosmetics, have been reported. However, the effects of royal jelly extract (RJ) on keratinocytes have not been fully elucidated. Objective: The primary objectives of this study were to reveal the effects of RJ on keratinocytes and explore the underlying mechanism. Methods: HaCaT cells, an immortal human epidermis-derived keratinocyte cell line, were used in this study. Laminin α3 (LAMA3), integrin β1 (ITGB1), and hypoxia-inducible factor-1α (HIF-1α) mRNA expression levels were determined using real-time PCR. Cell proliferation rate was measured using a bromodeoxyuridine uptake assay. Results: RJ treatment upregulated LAMA3, ITGB1 and HIF-1α mRNA expression, and accelerated HaCaT cell proliferation. Akt and mTOR inhibitors suppressed the RJ-induced HIF-1α expression and cell proliferation. HIF-1α silencing abrogated RJ-induced LAMA3 and ITGB1 mRNA expression and cell proliferation, whereas LAMA3 silencing and antibody-mediated ITGB1 blockade did not affect the effects of RJ. Conclusion: RJ upregulates LAMA3 and ITGB1 mRNA expression levels by HIF-1α expression enhancement. In addition, RJ accelerates keratinocyte proliferation via Akt/mTOR/HIF-1α/NF-κB signaling pathway. These suggest that RJ is beneficial for anti-aging, as a skin care product ingredient.

Assessment of seminal plasma laminin in fertile and infertile men

Aim： To assess laminin levels in the seminal plasma of infertile and fertile men, and to analyze the correlation of laminin levels with sperm count, age, sperm motility and semen volume. Methods： One hundred and twenty-five recruited men were equally divided into five groups according to their sperm concentration and clinical examination： fertile normozoospermia, oligoasthenozoospermia, non-obstructive azoospermia （NOA）, obstructive azoospermia （OA） and congenital bilateral absent vas deferens （CBAVD）. The patients＇ medical history was investigated and patients underwent clinical examination, conventional semen analysis and estimation of seminal plasma laminin by radioimmunoassay. Results： Seminal plasma laminin levels of successive groups were： 2.82 ± 0.62, 2.49 ± 0.44, 1.77 ± 0.56, 1.72 ± 0.76, 1.35 ± 0.63 U/mL, respectively. The fertile normozoospermic group showed the highest concentration compared to all infertile groups with significant differences compared to azoospermic groups （P 〈 0.05）. Testicular contribution was estimated to be approximately one-third of the seminal laminin. Seminal plasma laminin demonstrated significant correlation with sperm concentration （r = 0.460, P 〈 0.001） and nonsignificant correlation with age （r = 0.021, P = 0.940）, sperm motility percentage （r = 0.142, P = 0.615） and semen volume （r = 0.035, P = 0.087）. Conelusion： Seminal plasma laminin is derived mostly from prostatic and testicular portions and minimally from the seminal vesicle and vas deferens. Estimating seminal laminin alone is not conclusive in diagnosing different cases of male infertility.

THE EOSINOPHILIC MATERIAL IN ADENOMATOID ODONTOGENICTUMOR ASSOCIATED WITH AMYLOID PROTEIN COMPONENT

Objective: To investigate the relation between eosinophilic materials and amyloid P (AP) component in adenomatoid odontogenic tumor (AOT). Methods: The expression of amyloid proteins and basement membrane proteins, including type IV collagen, laminin and heparin sulfate proteoglycan (HSPG), in AOT were analyzed by immunohistochemical method. Results: Most eosinophilic droplets among tumor cells and some epithelial cells showed positive stain for AP component. The immunoreactions of type IV collagen and laminin were only found in blood vessels of this tumor. The tumor cells and eosinophilic materials in duct-like structures were constantly unstained for both amyloid and basement membrane proteins. Present results suggest that the nature and composition of eosinophilic droplets may differ from the eosinophilic layer in ductlike structures. This study first demonstrated that the amyloid-like deposition in AOT is associated with AP component by immunohistochemical method. It supported that AP component may be epithelial origin since the AP immunolocalization was found in tumor cells.

Albumin Modulates the Production of Matrix Metalloproteinases-2 and -9 in Podocytes

To investigate the effects of albumin on the production of matrix metalloproteinases-2 （MMP-2） and matrix metalloproteinases-9 （MMP-9）in podocytes. Podocytes were treated with bovine serum albumin （BSA） at the concentration of 0.1, 0.5, 1, 2 g/L, respectively. Conditioned media were harvested 12, 24, 48 and 72 h after the treatment. The expression of MMP-2 and MMP-9 was assayed by gelatin zymography, RT-PCR and Western blotting analysis. Our results showed that in comparison with the control group, BSA increased the expression of MMP-2 and MMP-9 mRNA and protein in a doseand time-dependent manner （P〈0.05）. Meanwhile, the enzymatic activities of MMP-2 and MMP-9 in the culture supernatants of podocytes were also increased （P〈0.05）. It is concluded that albumin up-regulated the expression of MMP-2 and MMP-9 at gene and protein levels in a time-and dose-dependent manner.

"Triple-positive" renal limited vasculitis presenting with rapidly progressive glomerulonephritis: A case report

Rationale:Coexistence of anti-glomerular basement membrane(anti-GBM)disease with anti-neutrophil cytoplasmic antibody(ANCA)in a case of glomerulonephritis is often identified as a"double-positive"disease.Interestingly,the majority of"double positive"ANCA is myeloperoxidase(MPO)-ANCA and some of the MPO-ANCA positive cases showed intrarenal arteritis,suggesting an ANCA-associated kidney lesion.Proteinase 3-ANCA positive diseases are also rarely reported.Patients positive for all three antibodies,i.e.,triple-positive patients,are extremely rare.Patient's Concern:A 53 year-old female presented with anasarca and oliguria of 2 months'duration.Diagnosis:Pauci-immune type renal limited crescentic glomerulonephritis positive for MPO-ANCA,proteinase 3-ANCA,and anti-GBM antibody(triple-positive).Interventions:Intravenous high dose cyclophosphamide,oral azathioprine,intravenous methylprednisolone,and plasma exchange as per British Health Professionals in Rheumatology Guidelines.Outcomes:After one-month follow-up,anasarca and proteinuria were lessened,serum creatinine was normalized,titers of MPO-ANCA levels were decreased,and anti-GBM antibody levels were normalized.Lessons:Triple-positive renal limited vasculitis is rare and response to combined immunosuppressive therapy and plasma exchange can contribute to successful remission.

Triple hit to the kidney-dual pathological crescentic glomerulonephritis and diffuse proliferative immune complexmediated glomerulonephritis: A case report

BACKGROUND Anti-glomerular basement membrane(GBM)disease is a rare rapidly progressive glomerulonephritis,frequently associated with alveolar hemorrhage in the lungs and involving the kidney by crescentic glomerulonephritis.It has been described in association with other glomerulonephritides[such as anti-neutrophilic antibody(ANCA)-glomerulonephritis,membranous nephropathy,and immunoglobulin(Ig)A nephropathy].CASE SUMMARY Herein we present an unusual case of concurrent anti-GBM disease,ANCAassociated crescentic glomerulonephritis and diffuse proliferative immune complex mediated glomerulonephritis with predominant staining for IgA and C3 by immunofluorescence.The patient is a 46-year-old Caucasian male who presented to the emergency department with acute onset of flank pain and was found to have high serum creatinine levels of 15 mg/dL,proteinuria,and hematuria.He rapidly deteriorated and became anuric.He was found to have high anti-GBM antibodies titers(151 units)and high anti-neutrophil cytoplasmic-ANCA.Despite prompt and early treatment,the patient’s condition worsened,and he succumbed to his illness.CONCLUSION Our case emphasizes the importance of a renal biopsy in anti-GBM disease,even in the presence of positive serum anti-GBM antibodies,to identify other potential causes of rapidly progressive glomerulonephritis.The challenge in treating such cases lies in the different therapy modalities.

Nidogen:A matrix protein with potential roles in musculoskeletal tissue regeneration

Basement membrane proteins are known to guide cell structures,differentiation,and tissue repair.Although there is a wealth of knowledge on the functions of laminins,per-lecan,and type IV collagen in maintaining tissue homeostasis,not much is known about nidogen.As a key molecule in the basement membrane,nidogen contributes to the formation of a delicate microenvironment that proves necessary for stem cell lineage-specific differentiation.In this review,the expression of nidogen is delineated at both cellular and tissue levels from embryonic to adult stages of development;the effect of nidogens is also summarized in the context of musculoskeletal development and regeneration,including but not limited to adipogenesis,angiogenesis,chondrogenesis,myogenesis,and neurogenesis.Furthermore,potential mechanisms underlying the role of nidogens in stem cell-based tissue regeneration are also discussed.This concise review is expected to facilitate our existing understanding and utilization of nidogen in tissue engineering and regeneration.

Type IV collagen α5 chain promotes luminal breast cancer progression through c-Myc-driven glycolysis

Cancer cell metabolism reprogramming is one of the hallmarks of cancer.Cancer cells preferentially utilize aerobic glycolysis,which is regulated by activated oncogenes and the tumor microenvironment.Extracellular matrix(ECM)in the tumor microenvironment,including the basement membranes(BMs),is dynamically remodeled.However,whether and how ECM regulates tumor glycolysis is largely unknown.We show that type IV collagens,components of BMs essential for the tissue integrity and proper function,are differentially expressed in breast cancer subtypes thatα5 chain(α5(IV))is preferentially expressed in the luminal-type breast cancer and is regulated by estrogen receptor-α.α5(IV)is indispensable for luminal breast cancer development.Ablation ofα5(IV)significantly reduces the growth of luminal-type breast cancer cells and impedes the development of luminal-type breast cancer.Impaired cell growth and tumor development capability ofα5(IV)-ablated luminal breast cancer cells is attributed to the reduced expression of glucose transporter and glycolytic enzymes and impaired glycolysis in luminal breast cancer cells.Non-integrin collagen receptor discoidin domain receptor-1(DDR1)expression and p38 mitogen-activated protein kinase activation are attenuated inα5(IV)-ablated luminal breast cancer cells,resulting in reduced c-Myc oncogene expression and phosphorylation.Ectopic expression of constitutively active DDR1 or c-Myc restores the expression of glucose transporter and glycolytic enzymes,and thereafter restores aerobic glycolysis,cell proliferation,and tumor growth of luminal breast cancer.Thus,type IV collagenα5 chain is a luminal-type breast cancer-specific microenvironmental regulator modulating cancer cell metabolism.

Advanced glycosylation end products, protein kinase C and renal alterations in diabetic rats

To study the relationship between advanced glycosylation end products (AGE) and protein kinase C (PKC), and their effects on renal alteration in diabetic rats Methods Insulin or aminoguanidine was administered to diabetic rats Blood glucose, hemoglobin A 1C (HbA 1C ), glomerular tissue extracts AGE (GTE AGE), PKC, glomerular basement membrane thickness (GBMT) and urine protein/creatinine (Pr/Cr) ratio in diabetic rats were measured and analysed Results Levels of blood glucose, HbA 1C and AGE, PKC activity, the Pr/Cr ratio and GBMT were all significantly increased ( P values all less than 0 01) in diabetic rats Insulin could decrease the formation of HbA 1C and AGE, and improve PKC activity Aminoguanidine had no influence on PKC activity ( P >0 05) although it decreased the formation of AGE Both drugs could delay the increase of urine Pr/Cr ratio and GBMT ( P <0 05 or P <0 01) Conclusions Chronic hyperglycemia may lead to an increase of PKC activity HbA 1C and AGE may not directly contribute to alterations of PKC activity, but the increase of PKC activity could promote the action of AGE on GBM thickening It is important to inhibit the formation of AGE and reduce the PKC activity so as to prevent or delay the development of diabetic nephropathy