Time course of rat kidney cell proliferation and influence of endogenous inhibitors

1993 ◽  
Vol 115 (5) ◽  
pp. 575-577
Author(s):  
E. A. Shentseva ◽  
M. Ya. Shevtsova ◽  
A. B. Malyshev ◽  
V. N. Nikitin
1988 ◽  
Vol 117 (4_Suppl) ◽  
pp. S1
Author(s):  
H.-G. SCHNEIDER ◽  
F. RAUE ◽  
J. SCHROTH ◽  
H. SCHERÜBL ◽  
R. ZIEGLER

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Michael McGregor ◽  
Shabana Din ◽  
Natalie Gude ◽  
Mark A Sussman

Rationale Cardiac stem cells (CSC) regulate cardiomyogenesis and support regenerative processes in the heart, but aging adversely affects stem cell repair capacity. Aging is a primary cause of impaired cardiac function characterized by accumulation of senescent cells. CSC senescence is associated with permanent growth arrest that decreases survival signaling and cellular replacement, inevitably diminishing the capacity of the heart to maintain tissue homeostasis. Therefore, promoting CSC growth may improve cardiac performance with age. Pim-1 kinase exhibits protective and proliferative effects in the myocardium but the role of Pim-1 in cardiac aging has not been thoroughly studied. Objective Demonstrate that Pim-1 promotes stem cell growth in the aged myocardium correlating with increased expression of centromere protein A (CENP-A), a kinetochore-associated protein known to support cell proliferation in numerous species and cell types. Methods & Results CENP-A expression levels were evaluated from murine myocardial tissue samples ranging in age from 11 days post coitum to 4 months of age with analysis by immunoblot as well as quantitative PCR. CENP-A expression was colocalized with c-kit as a marker of CSC by immunohistochemical labeling, revealing a decline in CENP-A expression over the time course of postnatal myocardial maturation. The impact of Pim-1 upon CENP-A level was assessed by comparative analysis of non-transgenic mice versus genetically modified transgenic mouse lines expressing either Pim-1 (wild type) or a dominant negative functionally dead Pim-1 mutant. Pim-1 overexpression increases persistence of CENP-A in CSCs with age, as well as the prevalence of cycling CSCs as marked by phosph-H3 expression, while the functionally dead mutant accelerates CENP-A diminution and decreases CSC proliferation. Conclusion CENP-A decline in c-kit positive cells with age provides intriguing evidence of a potential mechanism for the diminished capacity of CSCs to maintain tissue homeostasis. Pim-1 mitigates CENP-A diminution, demonstrating the promising potential of Pim-1 to promote cardiac growth and repair with age.


2005 ◽  
Vol 288 (6) ◽  
pp. L1179-L1192 ◽  
Author(s):  
K. Ulrich ◽  
M. Stern ◽  
M. E. Goddard ◽  
J. Williams ◽  
J. Zhu ◽  
...  

Alveolar type II (ATII) cell proliferation and differentiation are important mechanisms in repair following injury to the alveolar epithelium. KGF is a potent ATII cell mitogen, which has been demonstrated to be protective in a number of animal models of lung injury. We have assessed the effect of recombinant human KGF (rhKGF) and liposome-mediated KGF gene delivery in vivo and evaluated the potential of KGF as a therapy for acute lung injury in mice. rhKGF was administered intratracheally in male BALB/c mice to assess dose response and time course of proliferation. SP-B immunohistochemistry demonstrated significant increases in ATII cell numbers at all rhKGF doses compared with control animals and peaked 2 days following administration of 10 mg/kg rhKGF. Protein therapy in general is very expensive, and gene therapy has been suggested as a cheaper alternative for many protein replacement therapies. We evaluated the effect of topical and systemic liposome-mediated KGF-gene delivery on ATII cell proliferation. SP-B immunohistochemistry showed only modest increases in ATII cell numbers following gene delivery, and these approaches were therefore not believed to be capable of reaching therapeutic levels. The effect of rhKGF was evaluated in a murine model of OA-induced lung injury. This model was found to be associated with significant alveolar damage leading to severe impairment of gas exchange and lung compliance. Pretreatment with rhKGF 2 days before intravenous OA challenge resulted in significant improvements in Po2, Pco2, and lung compliance. This study suggests the feasibility of KGF as a therapy for acute lung injury.


1992 ◽  
Vol 102 (1) ◽  
pp. 71-78 ◽  
Author(s):  
SANDRA CITTERIO ◽  
SERGIO SGORBATI ◽  
MARISA LEVI ◽  
BRUNO MARIA COLOMBO ◽  
ELIO SPARVOLI

The identification of cell proliferation markers has been shown to be a useful tool with which to study basic mechanisms of cell cycle progression. The use of immunofluorescence techniques revealed the presence of the proliferating cell nuclear antigen (PCNA) in pea tissue, where we observed a high PCNA expression in proliferating cells of the root meristem compared to noncycling cells of the differentiated leaf. The presence of PCNA was monitored also during the time-course of seed germination, before, during and after the cell cycle resumption of the embryo cells. PCNA is present in embryo cells not only during and after resumption of the cell cycle but also before, when cells have not yet begun replicating their genome. A bivariate flow cytometric analysis of DNA and nuclear protein content was used to localize precisely the cells of the examined pea tissues in different cell cycle phase subcompartments. A high correlation was found between the degree of cell proliferation and the protein content of G1 nuclei, on the one hand, and the percentage of PCNA positive cells on the other.


1995 ◽  
Vol 97 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Patricia C. Phelps ◽  
Carolyn J.M. Best ◽  
Irene K. Berezesky ◽  
Ronald L. Merriman ◽  
Lee R. Tanzer ◽  
...  

1979 ◽  
Vol 236 (1) ◽  
pp. F9-F13
Author(s):  
C. S. Lo ◽  
T. N. Lo

Experiments were carried out to compare temporal changes in glomerular filtration rate (GFR), filtered Na+ load, and renal cortical (Na+ + K+)-adenosine triphosphatase (Na-K-ATPase) activity in the hypothyroid rat after administration of a single dose of triiodothyronine (T3) (50 microgram/100 g body wt). The cortex showed an increase in Na-K-ATPase at 24 h and progressive increases to a peak of 62% at 48 h. GFR and filtered Na+ load showed no changes at 24 and 48 h. At 72h, however, significant increases of 62 and 63% (per rat) were observed in GFR and filtered Na+ load, respectively. The results show that the early increase in Na-K-ATPase activity upon T3 treatment precedes the increases in GFR and filtered Na+ load, suggesting a direct effect of T3 on the regulation of Na-K-ATPase activity in the hypothyroid rat kidney cortex, rather than a secondary response to a primary increase in filtered Na+ load as proposed previously.


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