Prediction of acute kidney injury using a combined model of inflammatory vascular endothelium biomarkers and ultrasound indices.

BACKGROUND: Acute kidney injury (AKI) is a common complication of sepsis, with the burden of long hospital admission. Early prediction of AKI is the most effective strategy for intervention and improvement of the outcomes. OBJECTIVE: In our study, we aimed to investigate the predictive performance of the combined model using ultrasound indices (grayscale and Doppler indieces), endothelium injury (E-selectin, VCAM-1, ICAM1, Angiopoietin 2, syndecan-1, and eNOS) as well as inflammatory biomarkers (TNF-a, and IL-1ß) to identify AKI. METHODS: Sixty albino rats were divided into control and lipopolysaccharide (LPS) groups. Renal ultrasound, biochemical and immunohistological variables were recorded 6 hrs, 24 hrs, and 48 hrs after AKI. RESULTS: Endothelium injury and inflammatory markers were found to be significantly increased early after AKI, and correlated significantly with kidney size reduction and renal resistance indices elevation. CONCLUSIONS: Using area under the curve (AUC), the combined model was analyzed based on ultrasound and biochemical variables and provided the highest predictive value for renal injury.

Low-intensity pulsed ultrasound (LIPUS) switched macrophage into M2 phenotype and mitigated necroptosis and increased HSP 70 in gentamicin-induced nephrotoxicity.

BACKGROUND AND AIM: Many attempts to control acute kidney injury (AKI) have failed due to a lack of understanding of its pathophysiological key components. Macrophages are a crucial determinant of AKI, which can be categorized functionally as M1 pro-inflammatory and M2 anti-inflammatory macrophages. Low-intensity pulsed ultrasound (LIPUS) is currently being investigated as an immune modulator. The present study aimed to explore the potential effects of LIPUS on the polarization of renal macrophages, as well as the possible interplay between macrophage polarization and necroptosis in gentamicin-induced acute kidney injury. METHOD: All rats were randomly allocated into one of four groups: control, LIPUS-treated control, gentamicin acute kidney (GM-AKI), and LIPUS-treated GM-AKI. Renal functions, macrophage polarization, necroptosis, and heat shock protein-70 (HSP70) were analyzed using real-time reverse-transcriptase-polymerase chain reaction (rT-PCR), Western Blot, Enzyme-linked immunosorbent assay (ELISA) as well as immunohistological analysis. RESULTS: we found that LIPUS markedly inhibited the expressions of M1 macrophage-related genes and promoted significantly the expression of M2 macrophages related genes. This was accompanied by an inhibition of necroptosis and a marked reduction of HSP-70, resulting in a reversal of gentamicin-induced renal alteration. CONCLUSION: Functional switching of macrophage responses from M1 into M2 seems to be a potential approach to ameliorate necroptosis as well as HSP-70 by low pulsed ultrasound waves in GM-AKI.

Iron dyshomeostasis and time-course changes in iron-uptake systems and ferritin level in relation to pro-inflammatory microglia polarization in sepsis-induced encephalopathy.

Encephalopathy is a frequent and lethal consequence of sepsis. Recently, a growing body of evidence has provided important insights into the role of iron dyshomeostasis in the context of inflammation. The molecular mechanisms underlying iron dyshomeostasis and its relationship with macrophage phenotypes are largely unknown. Here, we aimed to characterize the changes in iron-transporter and storage proteins and the microglia phenotype that occur during the course of sepsis, as well as their relationship with sepsis-induced encephalopathy. We used a cecal ligation and puncture (CLP) murine model that closely resembles sepsis-induced encephalopathy. Rats were subjected to CLP or sham laparotomy, then were neurologically assessed at 6 h, 24 h, and 3 days after sepsis induction. The serum and brain were collected for subsequent biochemical, histological, and immunohistochemical assessment. Here, an iron excess was observed at time points that followed the pro-inflammatory macrophage polarization in CLP-induced encephalopathy. Our results revealed that the upregulation of non-transferrin-bound iron uptake (NTBI) and ferritin reduction appeared to be partially responsible for the excess free iron detected within the brain tissues. We further demonstrated that the microglia were shifted toward the pro-inflammatory phenotype, leading to persistent neuro-inflammation and neuronal damage after CLP. Taken together, these findings led us to conclude that sepsis increased the susceptibility of the brain to the iron burden via the upregulation of NTBI and the reduction of ferritin, which was concomitantly and correlatively associated with dominance of pro-inflammatory microglia and could explain the neurological dysfunction observed during sepsis.

Carnitine, apelin and resveratrol regulate mitochondrial quality control (QC) related proteins and ameliorate acute kidney injury: role of hydrogen peroxide.

Mitochondrial impairment is recognised as a prominent feature in kidney diseases. Therefore, we investigated whether the effects of resveratrol, L-carnitine, and apelin in the acute kidney injury model were associated with modulation of mitochondrial quality control (QC) related proteins, intra-renal renin-angiotensin (RAS) activity, adenosine triphosphate (ATP) and Na+-K+ ATPase gene expression. Rats were randomly assigned to 7 groups: Distilled water injected control group, DMSO injected control group, distilled water injected lipopolysaccharide (LPS) group, DMSO injected LPS group, resveratrol injected LPS group, L-carnitine injected LPS group and apelin 13 injected LPS group. We observed that resveratrol, L-carnitine, and apelin treatments altered mitochondrial (QC) related protein levels (Pink1, Parkin, BNIP-3, Drp1, and PGC1α), decreased intra-renal RAS parameters, increased ATP level and upregulated Na+-K+ ATPase gene expression in renal tissue. Our results provide new insight into the role of mitochondrial quality control and how different antioxidants exert beneficial effects on acute kidney injury.

Melatonin-Pretreated Mesenchymal Stem Cells Improved Cognition in a Diabetic Murine Model.

Diabetes mellitus (DM) is a multisystem endocrine disorder affecting the brain. Mesenchymal stem cells (MSCs) pretreated with Melatonin have been shown to increase the potency of MSCs. This work aimed to compare Melatonin, stem cells, and stem cells pretreated with Melatonin on the cognitive functions and markers of synaptic plasticity in an animal model of type I diabetes mellitus (TIDM). Thirty-six rats represented the animal model; six rats for isolation of MSCs and 30 rats were divided into five groups: control, TIDM, TIDM + Melatonin, TIDM + Stem cells, and TIDM + Stem ex vivo Melatonin. Functional assessment was performed with Y-maze, forced swimming test and novel object recognition. Histological and biochemical evaluation of hippocampal Neuroligin 1, Sortilin, Brain-Derived Neurotrophic Factor (BDNF), inducible nitric oxide synthase (iNOS), toll-like receptor 2 (TLR2), Tumor necrosis factor-alpha (TNF-α), and Growth Associated Protein 43 (GAP43). The TIDM group showed a significant decrease of hippocampal Neuroligin, Sortilin, and BDNF and a significant increase in iNOS, TNF-α, TLR2, and GAP43. Melatonin or stem cells groups showed improvement compared to the diabetic group but not compared to the control group. TIDM + Stem ex vivo Melatonin group showed a significant improvement, and some values were restored to normal. Ex vivo melatonin-treated stem cells had improved spatial working and object recognition memory and depression, with positive effects on glucose homeostasis, inflammatory markers levels and synaptic plasticity markers expression.

IκB kinase inhibition remodeled connexins, pannexin-1, and excitatory amino-acid transporters expressions to promote neuroprotection of galantamine and morphine.

Inflammatory pathway and disruption in glutamate homeostasis join at the level of the glia, resulting in various neurological disorders. In vitro studies have provided evidence that membrane proteins connexions (Cxs) are involved in glutamate release, meanwhile, excitatory amino-acid transporters (EAATs) are crucial for glutamate reuptake (clearance). Moreover, pannexin-1 (Panx-1) activation is more detrimental to neurons. Their expression patterns during inflammation and the impacts of IκB kinase (IKK) inhibition, morphine, and galantamine on the inflammatory-associated glutamate imbalance remain elusive. To investigate this, rats were injected with saline or lipopolysaccharide. Thereafter, vehicles, morphine, galantamine, and BAY-117082 were administered in different groups of animals. Subsequently, electroencephalography, enzyme-linked immunosorbent assay, western blot, and histopathological examinations were carried out and various indicators of inflammation and glutamate level were determined. Parallel analysis of Cxs, Panx-1, and EAAts in the brain was performed. Our findings strengthen the concept that unregulated expressions of Cxs, Panx-1, and EAATs contribute to glutamate accumulation and neuronal cell loss. Nuclear factor-kB (NF-κB) pathway can significantly contribute to glutamate homeostasis via modulating Cxs, Panx-1, and EAATs expressions. BAY-117082, via inhibition of IkK, promoted the anti-inflammatory effects of morphine as well as galantamine. We concluded that NF-κB is an important component of reshaping the expressions of Cxs, panx-1, and EAATs and the development of glutamate-induced neuronal degeneration.

Molecular mechanisms by which iNOS uncoupling can induce cardiovascular dysfunction during sepsis: Role of posttranslational modifications (PTMs).

Human sepsis is the result of a multifaceted pathological process causing marked dysregulation of cardiovascular responses. A more sophisticated understanding of the pathogenesis of sepsis is certainly prerequisite. Evidence from studies provide further insight into the role of inducible nitric oxide synthase (iNOS) isoform. Results on inhibition of iNOS in sepsis models remain inconclusive. Concern has been devoted to improving our knowledge and understanding of the role of iNOS. The aim of this review is to define the role of iNOS in redox homeostasis disturbance, the detailed mechanisms linking iNOS and posttranslational modifications (PTMs) to cardiovascular dysfunctions, and their future implications in sepsis settings. Many questions related to the iNOS and PTMs still remain open, and much more work is needed on this.

22-oxacalcitriol prevents acute kidney injury via inhibition of apoptosis and enhancement of autophagy.

BACKGROUND: The pathophysiology of ischemic acute kidney injury (AKI) is thought to include a complex interplay between tubular cell damage and regeneration. Several lines of evidences suggest a potential renoprotective effect of vitamin D. In this study, we investigated the effect of 22-oxacalcitriol (OCT), a synthetic vitamin D analogue, on renal fate in a rat model of ischemia reperfusion injury (IRI) induced acute kidney injury (AKI). METHODS: 22-oxacalcitriol (OCT) was administered via intraperitoneal (IP) injection before ischemia, and continued after IRI that was performed through bilateral clamping of the renal pedicles. 96 h after reperfusion, rats were sacrificed for the evaluation of autophagy, apoptosis, and cell cycle arrest. Additionally, assessments of toll-like receptors (TLR), interferon gamma (IFN-g) and sodium-hydrogen exchanger-1 (NHE-1) were also performed to examine their relations to OCT-mediated cell response. RESULTS: Treatment with OCT-attenuated functional deterioration and histological damage in IRI induced AKI, and significantly decreased cell apoptosis and fibrosis. In comparison with IRI rats, OCT + IRI rats manifested a significant exacerbation of autophagy as well as reduced cell cycle arrest. Moreover, the administration of OCT decreased IRI-induced upregulation of TLR4, IFN-g and NHE-1. CONCLUSION: These results demonstrate that treatment with OCT has a renoprotective effect in ischemic AKI, possibly by suppressing cell loss. Changes in the expression of IFN-g and NHE-1 could partially link OCT to the cell survival-promoted effects.

Possible involvement of tetrahydrobiopterin in the disturbance of redox homeostasis in sepsis - Induced brain dysfunction.

BACKGROUND AND AIM: Tetrahydrobiopterin (BH4) is an essential co-factor that regulates nitric oxide (NO) and reactive oxygen species (ROS) production by nitric oxide synthases (NOS). In this study, we evaluated the effects of sepsis on BH4 level and redox status in the brain by using the rat model of sepsis-induced by cecal ligation and puncture (CLP) and examined whether BH4 and/or acetyl-L-carnitine (ALC) could prevent the neuronal apoptosis and neurological changes induced by sepsis. MATERIAL AND METHOD: Male albino rats were randomly and blindly divided into 8 groups: sham, sham + BH4, sham + ALC, sham +BH4+ ALC, CLP, CLP + BH4, CLP + ALC, and CLP+BH4+ ALC. We measured neurological indicators, brain levels of BH4, guanosine triphosphate cyclohydrolase (GTPCH), sepiapterin reductase (SR) and dihydropteridine reductase (DHPR) genes expression (Essential enzymes in BH4 biosynthesis and recycling pathways). We investigated also brain redox status and both endothelial and inducible NOS expressions. RESULTS: Brain of septic rats demonstrated a reduced BH4 bioavailability, downregulation of BH4 synthetic enzymes, increased production of hydrogen peroxide and impaired antioxidant enzymes activities. Treatments with BH4 and/or ALC increased BH4 level, upregulated BH4 synthetic enzymes expressions, and attenuated oxidative-induced neuronal apoptosis. CONCLUSION: Our results suggest that BH4 and/or ALC might protect the brain against oxidative stress induced neuronal apoptosis by restoring bioavailability of BH4 and upregulating of BH4 synthetic enzymes in the brain during sepsis.

Clinical relevance of early sublingual microcirculation monitoring in septic shock patients.

INTRODUCTION: Although microcirculation dysfunction plays unique role in septic shock, translation of microcirculation to clinical practices is limited by current semi-quantities analysis and unclear clinical relevance of microcirculation monitoring. Our aim was to critically evaluate the characteristic nature and relevant clinical important of microcirculation. EVIDENCE ACQUISITION: Pubmed (2000 to August 2015) were searched to identify observation, case-control, intervention and randomized clinical studies evaluating the relationship between microcirculation alterations and mortality, morbidity and drug responses. The STROBE and CONSORT Statement for assessment of the quality of included studies. EVIDENCE SYNTHESIS: We examined results from 17 observations, 4 randomized controlled trials and one case report published studies. This data set comprised of 637 patients. Early septic shock is associated with hypoperfusion and heterogeneous microcirculation that is associated with hyperlactemia and metabolic acidosis. The evidence on clinical relevance of microcirculation is less striking, mainly due to the limited number of studies and problems related to the methodological protocol of the studies and currently semi-quantitative analysis technique. In particular the baseline and time course of microcirculation alteration appears to be controversial. CONCLUSION: There is lack of evidences of clinical importance of early microcirculation monitoring and mechanism of microcirculation dysfunction in septic shock patients. This could be due to the methodological protocol of the studies and currently semi-quantitative analysis technique.

Preliminary clinical evaluation of automated analysis of the sublingual microcirculation in the assessment of patients with septic shock: Comparison of automated versus semi-automated software.

INTRODUCTION: The outcome of patients in septic shock has been shown to be related to changes within the microcirculation. Modern imaging technologies are available to generate high resolution video recordings of the microcirculation in humans. However, evaluation of the microcirculation is not yet implemented in the routine clinical monitoring of critically ill patients. This is mainly due to large amount of time and user interaction required by the current video analysis software. The aim of this study was to validate a newly developed automated method (CCTools®) for microcirculatory analysis of sublingual capillary perfusion in septic patients in comparison to standard semi-automated software (AVA3®). METHODS: 204 videos from 47 patients were recorded using incident dark field (IDF) imaging. Total vessel density (TVD), proportion of perfused vessels (PPV), perfused vessel density (PVD), microvascular flow index (MFI) and heterogeneity index (HI) were measured using AVA3® and CCTools®. RESULTS: Significant differences between the numeric results obtained by the two different software packages were observed. The values for TVD, PVD and MFI were statistically related though. CONCLUSION: The automated software technique successes to show septic shock induced microcirculation alterations in near real time. However, we found wide degrees of agreement between AVA3® and CCTools® values due to several technical factors that should be considered in the future studies.

Microcirculation research in community hospitals - challenges and chances.

Community hospitals provide ideal conditions for large clinical studies because of the high volume of unselected patients admitted every year. With regard to microcirculatory studies, there are still some feasibility problems which are not solved yet. First of all, the lack of reliable automated software to analyze microcirculatory images represents the most important issue. Secondly, hardware aspects still need improvements regarding portability and miniaturization. Finally, to conduct studies of the microcirculation in a community hospital is also always a funding issue. The cost of the measurement device is hereby only one factor. Main cost factor is the personnel.

The cellular selection between apoptosis and autophagy: roles of vitamin D, glucose and immune response in diabetic nephropathy.

BACKGROUND AND AIMS: Apoptosis, autophagy and cell cycle arrest are cellular responses to injury which are supposed to play fundamental roles in initiation and progression of diabetic nephropathy (DN). The aims of the present study is to shed light on the potential effects of vitamin D analog 22-oxacalcitriol (OCT) on different cell responses during DN, and the possible interplay between both glucose, immune system and vitamin D in determining the cell fate. METHOD: All rats were randomly allocated into one of three groups: control, vehicle-treated DN group and OCT-treated DN group. Eight weeks after induction of diabetes, the rats were killed. Fasting blood glucose levels, serum 25 (OH) D, renal functions, cytokines and gene expression of autophagy, apoptotic and cell cycle arrest markers were assessed. In addition, the histological assessment of renal architecture was done. RESULTS: OCT treatment remarkably improved the renal functions and albuminuria. The reductions in mesangial cell hypertrophy, extracellular matrix as well as cell loss were significantly associated with upregulation of pro-autophagy gene expressions and downregulation of both pro-apoptotic and G1-cell cycle arrest genes expression. The reno-protective effects of OCT treatment were associated with significant attenuation of the fasting blood glucose, serum IL-6, renal TLR-4 and IFN-g gene expression. CONCLUSION: Modulator effects of OCT on glucose and immune system play important roles in renal cell fate decision and chronic kidney disease progression.

Tetrahydrobiopterin improves microcirculation in experimental sepsis.

BACKGROUND: Tetrahydrobiopterin (BH4), an endogenous nucleic acid derivative, acts as an important cofactor for several enzymes found within the vascular endothelium, which is deranged in sepsis. OBJECTIVE: We hypothesized that BH4 would improve capillary density and decrease inflammation within the intestinal microcirculation of septic rats. METHODS: We conducted a randomized, controlled trial using two previously validated models of sepsis in rats: 1) A fecal peritonitis model using a stent perforating the ascending colon, and 2) An endotoxemia model using lipopolysaccharide (LPS) toxin from E. coli. Experimental groups receiving BH4 (60 mg/kg) were compared to otherwise healthy controls and to untreated groups with sepsis-like physiology. RESULTS: BH4 decreased leukocyte-endothelial adhesion by 55% and 58% (P < 0.05) in the peritonitis model and endotoxemia models, respectively. In the endotoxemia model but not the peritonitis model, BH4 improved functional capillary density in capillary beds within the intestine (141.3 vs. 106.7 mm/cm2, p < 0.05). Macrohemodynamic parameters were no different between placebo treatment and BH4-treated groups. CONCLUSIONS: This study demonstrates that BH4 improves capillary density and inflammation in two separate models of sepsis. BH4 may represent a novel adjunct in the treatment of sepsis and septic shock in clinical practice. Further dose-finding studies and clinical trials are warranted.

Effects of haemoglobin levels on the sublingual microcirculation in pregnant women.

Anemia in pregnant women is associated with increased maternal and perinatal mortality and represents an important economic burden in many developing countries. Our goal was to evaluate the impact of anemia on the capillary network during pregnancy. Therefore, we compared microcirculatory parameters of anemic pregnant study participants to that of non-anemic pregnant women employing sublingual microcirculation video imaging technology and novel automated video analysis software.Non-anemic (n = 7) and anemic (n = 44) pregnant women were enrolled in the study at second and third trimesters. Video imaging was applied to the sublingual mucosal surface in five visual fields. The resultant videos were analyzed automatically, avoiding observer bias. Total vessel density (TVD), perfused vessel density (PVD) and proportion of perfused vessels (PPV) were calculated by the software. Both, mean TVD and PVD were significantly increased in the anemic pregnant group, while the PPV was not significantly different. Significant negative correlations were observed between haemoglobin (Hb) levels and both, TVD and PVD. Haemoglobin level seems to play an important determinant role in restructuring the capillary network. An effect that could compensate the impaired tissue oxygen delivery associated with anemia during pregnancy.

Study of the effects of cyclooxygenase-2 inhibitor on the promotion of hepatic tumorigenesis in rats fed a high fat diet.

BACKGROUND/OBJECTIVE: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. The highest prevalence of hepatitis is an important risk factor contributing to development of HCCs. However, an increasing number of cases are associated metabolic disease and steatohepatitis. Inflammation associated with many liver disease, seems to be a necessary pre-requisite for successful tumor initiation. Mechanisms that link high fat diet and inflammation initial stage of HCC are not completely understood. The present work was designed to investigate the effect of fat, through modulation of the insulin-like growth factors I and II (IGF-I and IGF-II), on the promotion of hepatocellular carcinoma, and the role of cyclooxygenase 2 (COX-2). METHODS: two main groups of rats were used: control and HCC groups. The HCC group was further sub-divide in to two subgroups, HCC fed with standard diet and HCC fed with high fat diet. The effects of celecoxib were also investigated in HCC fed with high fat diet. RESULTS: We found that high fat diet was associated with significant increases in COX2 and interleukin 6 (IL6) with significant promotion of HCC progression. The significant increase in IGF could contribute partially to the observed effects of high fat diet. In addition, celecoxib was found to significantly reduce HCC progression. CONCLUSIONS: We conclude that COX2 could play central role in high prevalence of HCC observed with high fat diet. Several triggering factors such as IGF and IL6, together with the direct modulation of fat metabolism could open several novel preventive strategies of celecoxib treatment, and could be useful biomarkers for assessment of its pharmacological effects.

Evaluation of the effects of Eserine and JWH-133 on brain dysfunction associated with experimental endotoxemia.

UNLABELLED: Sepsis is associated with neuronal damage and cognitive impairment, with the participation of pro-inflammatory cytokines and oxidative-nitrous stress. It is known that activated microglia plays a vital role in neuro-inflammation and neuro-degeneration. Thus, the objective of this study was to evaluate therapeutic roles of two microglia regulating agents, JWH-133 and Eserine, on the neuroinflammatory associated brain dysfunctions. To achieve our aim, we used control rats or submitted rats to lipopolysaccharide (LPS) challenge. 30 min after LPS challenge, the animals received either saline, Eserine, JWH-133 or Eserine+JWH-133. After 24h, animals were submitted to the habituation to T maze, Rotarod and activity cage tests. The rats were killed after and were evaluated for central and peripheral inflammatory and oxidative parameters. We observed that the use of Eserine, JWH-133 or Eserine + JWH-133 reverted the increases in the inflammatory markers [interleukin 6 (IL6), vascular cell adhesion molecule 1(VCAM-1) and Eselectin] and oxidative-nitrous stress MDM, and that the anti-inflammatory, antioxidant properties of both JWH-133 and Eserine successfully improve the LPS induced brain dysfunction. CONCLUSIONS: The results observed in this study reinforce the role of microglia activation regulating agents, in particular, JWH-133 and Eserine, in the brain dysfunction associated with endotoxemia.

Evaluation of multi-neuroprotective effects of erythropoietin using cisplatin induced peripheral neurotoxicity model.

Cisplatin (CDDP) is severely neurotoxic anti-neoplastic drug that causes peripheral neuropathies with clinical signs known as chemotherapy-induced peripheral neurotoxicity. The ameliorating effects of erythropoeitin on cisplatin-induced neuropathy, which seem to be mediated by enhancing the cell resistance to side effects of cisplatin rather than by influencing the formation or repair rates of cisplatin-induced cross-links in the nuclear DNA, had been previously reported. The main objective of our study is to investigate the roles of nitro-oxidative stress, nuclear factor kappa B (NFκB) gene expressions and TNF levels on the previous reported erythropoietin anti-apoptotic neuroprotective effects during cisplatin induced neurotoxicity. The present study compared the effects of erythropoietin (50 µg/kg/d thrice weekly) on cisplatin (2mg/kg/d i.p. twice weekly for 4 weeks) induced neurophysiologic changes and the associated changes in the inflammatory mediators (TNF alpha and NFKB), oxidative stress (malondialdehyde (MDA), superoxide dismutases (SOD) and glutathione) and gene expression of both neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS). In addition, sciatic nerve pro-apoptotic and anti-apoptotic indicators (Bcl, Bax, Caspase 3) were measured. We found that concomitant administration of erythropoietin significantly reversed the cisplatin induced nitro-oxidative stress - with significant increases in sciatic nerve glutathione and superoxide dismutase antioxidant enzyme levels and a significant decrease in iNOS gene expression. We conclude that erythropoietin anti-apoptotic neuro-protective effects could partially contribute to observed antioxidant effects of erthropoietin.

New directions for sepsis and septic shock research.

BACKGROUND: Septic shock is a frequent complication in intensive care unit that can result in multiple organ failure and death. In addition, recent data suggested that severe sepsis and septic shock represent an economic burden. Therefore, septic shock is an important public health problem. METHOD: In this review, we will focus on the recent evidences concerning the stages of septic shock, the complex macrocirculation and microcirculation relationship, and the importance of those evidences for future resuscitation goals and therapeutic strategies during late septic shock. RESULT: Recently, two stages of septic shock are suggested. In early stage, hypovolemia is the main contributing factor. During this stage, macrocirculatory and microcirculatory changes run parallel, and fluid resuscitation seems to be effective in restoring the hemodynamic parameters. Late stage of septic shock is characterized by complex microcirculation and macrocirculation relationship. CONCLUSIONS: Although early goal-directed therapy is a stepwise approach in the treatment of septic shock, tissue perfusion remains an important factor that contributes to septic shock outcome. Because appropriate monitoring of tissue perfusion is a matter of debt, the ideal therapeutic strategy remains a controversial issue that needs further investigations.