Hydronephrosis promotes expression of hypoxia-inducible factor 1 alpha.
BACKGROUND
Obstructive uropathy is argued to involve an ischemia-type tissue injury. Further, hypoxia-inducible factor 1 alpha (HIF-1 alpha) constitutes a nuclear transcription factor normally upregulated under hypoxic conditions. We hypothesized that HIF-1 alpha is expressed in the hydronephrotic renal pelvis, as a result of tissue hypoxia.


METHODS
Renal pelvis tissue specimens were obtained from 2 patient groups. Group 1 (controls, n = 10) consisted of patients who underwent nephrectomy due to nonobstructive renal malignancy. Group 2 (n = 18) consisted of patients who underwent open procedures due to intractable hydronephrosis, not amenable to conservative measures. HIF-1 alpha detection was conducted via immunohistochemical techniques, while histological alterations in both groups were also recorded.


RESULTS
Smooth muscle hypertrophy and urothelial hyperplasia were major findings in group 2. HIF-1 alpha-positive cells (fibroblasts and occasionally macrophages), mainly localized in the stroma, were also found to a greater extent in group 2 (p = 0.0066).


CONCLUSIONS
We conclude that HIF-1 alpha is mainly expressed in stroma fibroblasts of the hydronephrotic renal pelvis, implying the presence of significant tissue hypoxia at the dilated upper urinary tract.
Stravodimos
Konstantinos G
KG
1st Urology Department, Laiko General Hospital, Athens, Greece.
Koritsiadis
Georgios
G
Lazaris
Andreas C
AC
Agrogiannis
Georgios
G
Koutalellis
Georgios
G
Constantinides
Constantinos
C
Patsouris
Efstratios
E
Kapetanakis
Theodoros
T
Zervas
Anastasios
A
D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005347:Fibroblasts / Q000737:chemistry; D006801:Humans; D006869:Hydronephrosis / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D006965:Hyperplasia; D006984:Hypertrophy; D000860:Hypoxia / Q000378:metabolism* / Q000473:pathology; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000032:analysis*; D007150:Immunohistochemistry; D007682:Kidney Pelvis / Q000737:chemistry* / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009130:Muscle, Smooth / Q000737:chemistry; D009392:Nephrectomy; D011446:Prospective Studies; D017154:Stromal Cells / Q000737:chemistry* / Q000473:pathology; D015854:Up-Regulation; D019459:Urothelium / Q000737:chemistry
C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit