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Apoptotic cell administration is detrimental in murine renal ischaemia reperfusion injury.

Hesketh EE, Kluth DC, Hughes J - J Inflamm (Lond) (2014)

Bottom Line: The administration of apoptotic cells (ACs) has been shown to reduce inflammation in various organs including the liver and kidney.Early AC administration prior to severe IRI had no influence on plasma creatinine or ATN severity.These data suggest that AC-derived protection is not translationally relevant for patients with acute kidney injury induced by ischaemic injury.

View Article: PubMed Central - PubMed

Affiliation: MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ UK.

ABSTRACT

Background: Acute kidney injury induced by renal ischaemia reperfusion injury (IRI) is characterised by renal failure, acute tubular necrosis (ATN), inflammation and microvascular congestion. The administration of apoptotic cells (ACs) has been shown to reduce inflammation in various organs including the liver and kidney. This study explored whether AC administration prior to the induction of renal IRI was protective.

Findings: Renal IRI was induced in Balb/c mice by clamping the renal blood vessels for either 20, 24 or 25 minutes to induce mild, moderate or severe kidney dysfunction respectively. Renal function and injury was determined 24 hours following IRI by measurement of plasma creatinine and ATN scoring respectively. ACs were generated from Balb/c thymocytes and classified as either predominantly early or late apoptotic by Annexin-V and propidium iodide staining. Early AC administration prior to severe IRI had no influence on plasma creatinine or ATN severity. In contrast, administration of early or late ACs significantly worsened renal function in mice with mild or moderate renal IRI, respectively, compared to PBS treated controls, though ATN scores were comparable. Despite ACs exerting pro-coagulant effects, the worsening of renal function was not secondary to increased microvascular congestion, inferred by fibrin and platelet (CD41) deposition, or inflammation, assessed by neutrophil infiltration.

Conclusions: Despite the AC-derived protection demonstrated in other organs, ACs do not protect mice from renal IRI. ACs may in fact further impair renal function depending on injury severity. These data suggest that AC-derived protection is not translationally relevant for patients with acute kidney injury induced by ischaemic injury.

No MeSH data available.


Related in: MedlinePlus

Microvascular congestion remained unaffected following AC administration. Renal IRI was induced in 8-week old male Balb/c mice by a right nephrectomy and ischaemia induced by occluding the left renal pedicle for 20 (mild ischaemia), 24 (moderate) or 25 mins (severe). Sham mice underwent a laparotomy only. Either PBS or 20×106 early or late ACs were administered 24 hr prior to renal IRI. Mice were sacrificed 24 hr following IRI. A & C) Representative images of the outer stripe of the outer medulla in non-injured and ischaemic kidney sections following platelet (CD41) immunohistochemistry (A) and fibrin immunofluorescence (C) staining. In ischaemic kidneys microvascular congestion was observed as indicated by platelet and fibrin deposition. (CD41 - Magnification: ×200 & Scale Bar: 50 μM; Fibrin - Magnification: ×400 & Scale Bar: 25 μM) B & D) Scoring of platelet (B) and fibrin (D) staining (expressed as platelet/fibrin+ area) demonstrates that microvascular congestion remained similar between PBS and AC treated mice with severe, moderate and mild ischaemic injury. Grey circle symbol = Non-injured kidney Grey square symbol = Ischaemic kidney. Data expressed as mean ± SEM and analysed by two-way ANOVA. ns = non-significant. Sham (n = 4), PBS (n = 7–8), AC (n = 8).
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Fig4: Microvascular congestion remained unaffected following AC administration. Renal IRI was induced in 8-week old male Balb/c mice by a right nephrectomy and ischaemia induced by occluding the left renal pedicle for 20 (mild ischaemia), 24 (moderate) or 25 mins (severe). Sham mice underwent a laparotomy only. Either PBS or 20×106 early or late ACs were administered 24 hr prior to renal IRI. Mice were sacrificed 24 hr following IRI. A & C) Representative images of the outer stripe of the outer medulla in non-injured and ischaemic kidney sections following platelet (CD41) immunohistochemistry (A) and fibrin immunofluorescence (C) staining. In ischaemic kidneys microvascular congestion was observed as indicated by platelet and fibrin deposition. (CD41 - Magnification: ×200 & Scale Bar: 50 μM; Fibrin - Magnification: ×400 & Scale Bar: 25 μM) B & D) Scoring of platelet (B) and fibrin (D) staining (expressed as platelet/fibrin+ area) demonstrates that microvascular congestion remained similar between PBS and AC treated mice with severe, moderate and mild ischaemic injury. Grey circle symbol = Non-injured kidney Grey square symbol = Ischaemic kidney. Data expressed as mean ± SEM and analysed by two-way ANOVA. ns = non-significant. Sham (n = 4), PBS (n = 7–8), AC (n = 8).

Mentions: The finding of unexpectedly worse renal function without an increased ATN score in AC treated mice suggested that ACs might have detrimentally reduced renal microvascular flow. The coagulation cascade is activated following ischaemic injury [17] and the microvasculature becomes congested with erythrocytes and platelet/fibrin aggregates which aggravates tissue hypoxia and limits the perfusion of residual viable and potentially functional nephrons [1,18]. ACs expressing PS are pro-coagulant and might therefore contribute to this pro-coagulant milieu [19]. To investigate this CD41+ platelets and fibrin were selected as markers of microvascular congestion and their deposition assessed by IHC and IF, respectively. CD41+ platelets and fibrin deposition was observed in the OSOM of PBS and AC treated ischaemic kidneys (Figure 4A & C), but no significant differences between AC treated and control mice were found following quantification (Figure 4B & D).Figure 4


Apoptotic cell administration is detrimental in murine renal ischaemia reperfusion injury.

Hesketh EE, Kluth DC, Hughes J - J Inflamm (Lond) (2014)

Microvascular congestion remained unaffected following AC administration. Renal IRI was induced in 8-week old male Balb/c mice by a right nephrectomy and ischaemia induced by occluding the left renal pedicle for 20 (mild ischaemia), 24 (moderate) or 25 mins (severe). Sham mice underwent a laparotomy only. Either PBS or 20×106 early or late ACs were administered 24 hr prior to renal IRI. Mice were sacrificed 24 hr following IRI. A & C) Representative images of the outer stripe of the outer medulla in non-injured and ischaemic kidney sections following platelet (CD41) immunohistochemistry (A) and fibrin immunofluorescence (C) staining. In ischaemic kidneys microvascular congestion was observed as indicated by platelet and fibrin deposition. (CD41 - Magnification: ×200 & Scale Bar: 50 μM; Fibrin - Magnification: ×400 & Scale Bar: 25 μM) B & D) Scoring of platelet (B) and fibrin (D) staining (expressed as platelet/fibrin+ area) demonstrates that microvascular congestion remained similar between PBS and AC treated mice with severe, moderate and mild ischaemic injury. Grey circle symbol = Non-injured kidney Grey square symbol = Ischaemic kidney. Data expressed as mean ± SEM and analysed by two-way ANOVA. ns = non-significant. Sham (n = 4), PBS (n = 7–8), AC (n = 8).
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Fig4: Microvascular congestion remained unaffected following AC administration. Renal IRI was induced in 8-week old male Balb/c mice by a right nephrectomy and ischaemia induced by occluding the left renal pedicle for 20 (mild ischaemia), 24 (moderate) or 25 mins (severe). Sham mice underwent a laparotomy only. Either PBS or 20×106 early or late ACs were administered 24 hr prior to renal IRI. Mice were sacrificed 24 hr following IRI. A & C) Representative images of the outer stripe of the outer medulla in non-injured and ischaemic kidney sections following platelet (CD41) immunohistochemistry (A) and fibrin immunofluorescence (C) staining. In ischaemic kidneys microvascular congestion was observed as indicated by platelet and fibrin deposition. (CD41 - Magnification: ×200 & Scale Bar: 50 μM; Fibrin - Magnification: ×400 & Scale Bar: 25 μM) B & D) Scoring of platelet (B) and fibrin (D) staining (expressed as platelet/fibrin+ area) demonstrates that microvascular congestion remained similar between PBS and AC treated mice with severe, moderate and mild ischaemic injury. Grey circle symbol = Non-injured kidney Grey square symbol = Ischaemic kidney. Data expressed as mean ± SEM and analysed by two-way ANOVA. ns = non-significant. Sham (n = 4), PBS (n = 7–8), AC (n = 8).
Mentions: The finding of unexpectedly worse renal function without an increased ATN score in AC treated mice suggested that ACs might have detrimentally reduced renal microvascular flow. The coagulation cascade is activated following ischaemic injury [17] and the microvasculature becomes congested with erythrocytes and platelet/fibrin aggregates which aggravates tissue hypoxia and limits the perfusion of residual viable and potentially functional nephrons [1,18]. ACs expressing PS are pro-coagulant and might therefore contribute to this pro-coagulant milieu [19]. To investigate this CD41+ platelets and fibrin were selected as markers of microvascular congestion and their deposition assessed by IHC and IF, respectively. CD41+ platelets and fibrin deposition was observed in the OSOM of PBS and AC treated ischaemic kidneys (Figure 4A & C), but no significant differences between AC treated and control mice were found following quantification (Figure 4B & D).Figure 4

Bottom Line: The administration of apoptotic cells (ACs) has been shown to reduce inflammation in various organs including the liver and kidney.Early AC administration prior to severe IRI had no influence on plasma creatinine or ATN severity.These data suggest that AC-derived protection is not translationally relevant for patients with acute kidney injury induced by ischaemic injury.

View Article: PubMed Central - PubMed

Affiliation: MRC Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ UK.

ABSTRACT

Background: Acute kidney injury induced by renal ischaemia reperfusion injury (IRI) is characterised by renal failure, acute tubular necrosis (ATN), inflammation and microvascular congestion. The administration of apoptotic cells (ACs) has been shown to reduce inflammation in various organs including the liver and kidney. This study explored whether AC administration prior to the induction of renal IRI was protective.

Findings: Renal IRI was induced in Balb/c mice by clamping the renal blood vessels for either 20, 24 or 25 minutes to induce mild, moderate or severe kidney dysfunction respectively. Renal function and injury was determined 24 hours following IRI by measurement of plasma creatinine and ATN scoring respectively. ACs were generated from Balb/c thymocytes and classified as either predominantly early or late apoptotic by Annexin-V and propidium iodide staining. Early AC administration prior to severe IRI had no influence on plasma creatinine or ATN severity. In contrast, administration of early or late ACs significantly worsened renal function in mice with mild or moderate renal IRI, respectively, compared to PBS treated controls, though ATN scores were comparable. Despite ACs exerting pro-coagulant effects, the worsening of renal function was not secondary to increased microvascular congestion, inferred by fibrin and platelet (CD41) deposition, or inflammation, assessed by neutrophil infiltration.

Conclusions: Despite the AC-derived protection demonstrated in other organs, ACs do not protect mice from renal IRI. ACs may in fact further impair renal function depending on injury severity. These data suggest that AC-derived protection is not translationally relevant for patients with acute kidney injury induced by ischaemic injury.

No MeSH data available.


Related in: MedlinePlus