Platelets Play an Integral Role in Body Heat Production and Maintenance: A Newly Proposed Function

In platelets, most of the ADP is stored in dense granules and released into extracellular space through exocytosis as a signaling molecule upon platelet activation. Glycolysis and the TCA cycle consume considerable amounts of ADP;however, limiting quantities of available ADP to make ATP through OXPHOS result in failure of ATP production and release of energy as heat into the surroundings. Thus, body heat may be a potential product of circulating platelets. Furthermore, the incomplete OXPHOS process causes the production of ROS that leads to earlier platelet death resulting in shorter life span. In the future, this new function may have a wide variety of clinical applications.

Effects of platelets on characteristics of lymphocytes cultured in vitro and optimization of adoptive immunotherapy

T lymphocytes,the main participants of cellular immunity,can express a variety of surface molecules and form different lymphocyte subsets under the induction of different factors to play the functions of immune regulation and immune killing.Studies have shown that platelets play a crucial role in maintaining the stable differentiation of lymphocytes and the balance in immunomodulation.Therefore,it is necessary to study the effect of platelets on lymphocytes in vitro to better understand the role of platelets in the immune system and broaden the application of adoptive immunotherapy.Methods:Cell counting and microscopic observation were used to detect the effect of activated platelets on lymphocyte proliferation in vitro;Flow cytometry was used to detect whether changes in platelet activity affect the proportion of lymphocyte subpopulations in vitro,and to detect differences in the expression of granzyme B;lactate dehydrogenase assay(LDH)was used to determine the difference in lymphocyte killing activity caused by platelet activity in vitro.Results:This was the first to promote lymphocyte proliferation through the expression or release of certain molecules in vitro,demonstrating that platelet activation is one of the key factors.Secondly,activated platelets or inactivated platelets promoted lymphocyte subset differentiation by enhancing the proportion of CD3+CD8+T lymphocytes(CTL cells)but had a slight effect on the proportion of CD3+CD4+T(Th cells)and CD4+CD25+T lymphocytes(Treg cells).Then,it was found that either activated platelets or inactivated platelets down-regulated the proportion of natural killer(NK)T lymphocytes,while activated platelets significantly enhance the proportion of NK lymphocytes.Therefore,by further detecting the killing activity of PBMCs treated with platelets,it was found that activated platelets promoted the extensive anti-tumor activity of lymphocytes and significantly increased the expression of granzyme B.Conclusion:Our results suggest that activated platelets promote lymphocyte proliferation,optimize lymphocyte subpopulation ratio,and promote cytotoxic effect of lymphocytes in vitro,which may provide a new strategy for optimizing the adoptive immunotherapy culture system and improving its efficacy.

Association between the early high level of serum tacrolimus and recurrence of hepatocellular carcinoma in ABO-incompatible liver transplantation

BACKGROUND Clinical factors predicting graft survival(GS)after ABO-incompatible(ABOi)liver transplantation(LT),and differences between recipients with and without hepatocellular carcinoma(HCC)are unclear.AIM To analyze the impact of serial serum tacrolimus trough concentration in recipients with or without(HCC)in ABOi living-donor liver transplantation(LDLT).METHODS We analyzed a historical cohort of 89 recipients who underwent ABOi LDLT,including 47 patients with HCC.RESULTS The 1-,3-,5-,and 10-year GS rates were 85.9%,73.3%,71.4%,and 71.4%,respectively,and there were no significant differences between HCC and non-HCC recipients.In multivariate Coxregression analyses,tacrolimus trough concentrations below 5.4 ng/mL at 24 wk post-LT,in addition to the antibody-mediated rejection(AMR)were associated with poor-graft outcomes.In HCC patients,AMR[hazard ratio(HR)=63.20,P<0.01]and HCC recurrence(HR=20.72,P=0.01)were significantly associated with poor graft outcomes.HCCs outside Milan criteria,and tacrolimus concentrations at 4 wk post-LT>7.3 ng/mL were significant predictive factors for HCC recurrence.After propensity score matching,patients with high tacrolimus concentrations at 4 wk had significantly poor recurrence-free survival.CONCLUSION Elevated tacrolimus levels at 4 wk after ABOi LDLT have been found to correlate with HCC recurrence.Therefore,careful monitoring and control of tacrolimus levels are imperative in ABOi LT recipients with HCC.

Evaluation of the diagnostic value of total bile acids/platelets in HBV related liver fibrosis

Objective:Explore the diagnostic value of total bile acids/platelets in HBV related liver fibrosis.Methods:160 patients with chronic HBV infection admitted to the Infection Department of the First Affiliated Hospital of Hainan Medical College from February 2021 to December 2022 were selected.They were divided into two groups based on the degree of liver fibrosis detected by liver biopsy:significant liver fibrosis group and non-significant liver fibrosis group.The total bile acid/blood platelet levels and their correlation with liver fibrosis in the two groups were compared and observed,and the efficacy of other non-invasive liver fibrosis diagnostic models was evaluated.Results:(1)Compared with the non-significant liver fibrosis group,the significant liver fibrosis group showed an increase in total bile acid levels,a decrease in platelet levels,and a significant increase in total bile acid/platelet levels(P<0.05).(2)Platelets decrease with the increase of liver fibrosis degree,total bile acids increase with the increase of liver fibrosis degree,and total bile acids/platelets increase with the increase of liver fibrosis degree.(3)The area under the curve(AUC)of total bile acid/platelet,APRI,FIB-4,and elastography in diagnosing the degree of liver fibrosis were 0.69,0.57,0.56,and 0.68,respectively.Conclusions:The diagnostic efficacy of total bile acids/platelets in diagnosing HBV related liver fibrosis is no less than that of other liver fibrosis diagnostic methods,and it is non-invasive,simple,and convenient,which is worthy of further clinical promotion and validation.

Chemokine platelet factor 4 accelerates peripheral nerve regeneration by regulating Schwann cell activation and axon elongation

Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and found that expression of platelet factor 4 was markedly up-regulated after sciatic nerve injury.Platelet factor is an important molecule in cell apoptosis,diffe rentiation,survival,and proliferation.Further,polymerase chain reaction and immunohistochemical staining confirmed the change in platelet factor 4 in the sciatic nerve at different time points after injury.Enzyme-linked immunosorbent assay confirmed that platelet factor 4 was secreted by Schwann cells.We also found that silencing platelet factor 4 decreased the proliferation and migration of primary cultured Schwann cells,while exogenously applied platelet factor 4 stimulated Schwann cell prolife ration and migration and neuronal axon growth.Furthermore,knocking out platelet factor 4 inhibited the prolife ration of Schwann cells in injured rat sciatic nerve.These findings suggest that Schwann cell-secreted platelet factor 4 may facilitate peripheral nerve repair and regeneration by regulating Schwann cell activation and axon growth.Thus,platelet factor 4 may be a potential therapeutic target for traumatic peripheral nerve injury.

Clinical significance of platelet mononuclear cell aggregates in patients with sepsis and acute respiratory distress syndrome

BACKGROUND The diagnosis of sepsis combined with acute respiratory distress syndrome(ARDS)has increased owing to the enhanced awareness among medical profes-sionals and the continuous development of modern medical technologies,while early diagnosis of ARDS still lacks specific biomarkers.One of the main patho-genic mechanisms of sepsis-associated ARDS involves the actions of various pathological injuries and inflammatory factors,such as platelet and white blood cells activation,leading to an increase of surface adhesion molecules.These adhesion molecules further form platelet-white blood cell aggregates,including platelet-mononuclear cell aggregates(PMAs).PMAs has been identified as one of the markers of platelet activation,here we hypothesize that PMAs might play a potential biomarker for the early diagnosis of this complication.METHODS We selected 72 hospitalized patients diagnosed with sepsis as the study population between March 2019 and March 2022.Among them,30 patients with sepsis and ARDS formed the study group,while 42 sepsis patients without ARDS comprised the control group.After diagnosis,venous blood samples were imme-diately collected from all patients.Flow cytometry was employed to analyze the expression of PMAs,platelet neutrophil aggregates(PNAs),and platelet aggregates(PLyAs)in the serum.Additionally,the Acute Physiology and Chronic Health Evaluation(APACHE)II score was calculated for each patient,and receiver operating characteristic curves were generated to assess diagnostic value.RESULTS The study found that the levels of PNAs and PLyAs in the serum of the study group were higher than those in the control group,but the difference was not statistically significant(P>0.05).However,the expression of PMAs in the serum of the study group was significantly upregulated(P<0.05)and positively correlated with the APACHE II score(r=0.671,P<0.05).When using PMAs as a diagnostic indicator,the area under the curve value was 0.957,indicating a high diagnostic value(P<0.05).Furthermore,the optimal cutoff value was 8.418%,with a diagnostic sensitivity of 0.819 and specificity of 0.947.CONCLUSION In summary,the serum levels of PMAs significantly increase in patients with sepsis and ARDS.Therefore,serum PMAs have the potential to become a new biomarker for clinically diagnosing sepsis complicated by ARDS.

Case of Refractory Thrombocytopenia in Pregnancy Associated with May-Heglin Anomaly after Repeated Platelet Transfusions

May-Heglin Anomaly is an autosomal dominant disorder characterized by macrothrombocytopenia with a platelet function that is usually preserved. Platelets play an essential role in hemostasis. During pregnancy, a woman is susceptible to complications, including postpartum hemorrhage. Monitoring patients’ hemostatic functions and observing the patient’s clinical picture to maintain patient safety is paramount, while avoiding unnecessary therapeutic measures. This case report presents a rare instance of May-Heglin Anomaly (MHA) in a 35-year-old pregnant patient, with refractory thrombocytopenia despite receiving multiple platelet transfusions. Initially referred to as gravida 5 para 4 with severe thrombocytopenia at 28 weeks gestation, throughout her pregnancy, she was closely monitored and received over 40 units of platelets, which failed to increase her platelet count significantly. She delivered a healthy baby via vaginal delivery at 38 weeks, with her platelet count still critically low. This report highlights the challenges of managing MHA in pregnancy, the inefficacy of standard thrombocytopenia treatments such as platelet transfusion in MHA patients, and the importance of tailored management strategies to ensure maternal and fetal safety.

Kelp Fucoidans Facilitate Vascular Recanalization via Inhibiting Excessive Activation of Platelet in Deep Venous Thrombosis Model of Mouse

This study was carried out explore the mechanism underlying the inhibition of platelet activation by kelp fucoidans in deep venous thrombosis(DVT)mouse.In the control and sham mice,the walls of deep vein were regular and smooth with intact intima,myometrium and adventitia.The blood vessel was wrapped with the tissue and there was no thrombosis in the lumen.In the DVT model,the wall was uneven with thicken intima,myometrium and adventitia.After treated with fucoidans LF1 and LF2,the thrombus was dissolved and the blood vessel was recanalized.Compared with the control group,the ROS content,ET-1 and VWF content and the expression of PKC-βand NF-κB in the model were significantly higher(P<0.05);these levels were significantly reduced following treatments with LF2 and LF1.Compared with H_(2)O_(2)treated-HUVECs,combined LF1 and LF2 treatment resulted in significant decrease in the expression of PKC-β,NF-κB,VWF and TM protein(P<0.05).It is clear that LF1 and LF2 reduces DVT-induced ET-1,VWF and TM expressions and production of ROS,thus inhibiting the activation of PKC-β/NF-κB signal pathway and the activation of coagulation system and ultimately reducing the formation of venous thrombus.

Aspirin suppresses hepatocellular carcinoma progression by inhibiting platelet activity

BACKGROUND Hepatocellular carcinoma(HCC)is the most common malignant liver disease in the world.Platelets(PLTs)are known to play a key role in the maintenance of liver homeostasis and the pathophysiological processes of a variety of liver diseases.Aspirin is the most classic antiplatelet agent.However,the molecular mechanism of platelet action and whether aspirin can affect HCC progression by inhibiting platelet activity need further study.AIM To explore the impact of the antiplatelet effect of aspirin on the development of HCC.METHODS Platelet-rich plasma,platelet plasma,pure platelet,and platelet lysate were prepared,and a coculture model of PLTs and HCC cells was established.CCK-8 analysis,apoptosis analysis,Transwell analysis,and real-time polymerase chain reaction(RT-PCR)were used to analyze the effects of PLTs on the growth,metastasis,and inflammatory microenvironment of HCC.RT-PCR and Western blot were used to detect the effects of platelet activation on tumor-related signaling pathways.Aspirin was used to block the activation and aggregation of PLTs both in vitro and in vivo,and the effect of PLTs on the progression of HCC RESULTS PLTs significantly promoted the growth,invasion,epithelial-mesenchymal transition,and formation of an inflammatory microenvironment in HCC cells.Activated PLTs promoted HCC progression by activating the mitogenactivated protein kinase/protein kinase B/signal transducer and activator of transcription three(MAPK/AKT/STAT3)signaling axis.Additionally,aspirin inhibited HCC progression in vitro and in vivo by inhibiting platelet activation.CONCLUSION PLTs play an important role in the pathogenesis of HCC,and aspirin can affect HCC progression by inhibiting platelet activity.These results suggest that antiplatelet therapy has promising application prospects in the treatment and combined treatment of HCC.

Inverse relationship between platelet Akt activity and hippocampal atrophy:A pilot case-control study in patients with diabetes mellitus

BACKGROUND Akt plays diverse roles in humans.It is involved in the pathogenesis of type 2 diabetes mellitus(T2DM),which is caused by insulin resistance.Akt also plays a vital role in human platelet activation.Furthermore,the hippocampus is closely associated with memory and learning,and a decrease in hippocampal volume is reportedly associated with an insulin-resistant phenotype in T2DM patients without dementia.AIM To investigate the relationship between Akt phosphorylation in unstimulated platelets and the hippocampal volume in T2DM patients.METHODS Platelet-rich plasma(PRP)was prepared from the venous blood of patients with T2DM or age-matched controls.The pellet lysate of the centrifuged PRP was subjected to western blotting to analyse the phosphorylation of Akt,p38 mitogen-activated protein(MAP)kinase and glyceraldehyde 3-phosphate dehydrogenase(GAPDH).Phosphorylation levels were quantified by densitometric analysis.Hippocampal volume was analysed using a voxel-based specific regional analysis system for Alzheimer’s disease on magnetic resonance imaging,which proposes the Z-score as a parameter that reflects hippocampal volume.RESULTS The levels of phosphorylated Akt corrected with phosphorylated p38 MAP kinase were inversely correlated with the Z-scores in the T2DM subjects,whereas the levels of phosphorylated Akt corrected with GAPDH were not.However,this relationship was not observed in the control patients.CONCLUSION These results suggest that an inverse relationship may exist between platelet Akt activation and hippocampal atrophy in T2DM patients.Our findings provide insight into the molecular mechanisms underlying T2DM hippocampal atrophy.

Platelet indices as predictors of poor glucoregulation in type 2 diabetes mellitus adults at Bishoftu General Hospital,Ethiopia

BACKGROUND Diabetes is a chronic metabolic syndrome that has become a global public health problem with significant morbidity and mortality.It is a pro-inflammatory and pro-thrombotic condition characterized by increased platelet activation and alterations in platelet indices.However,the use of platelet indices as predictors of poor glucoregulation has not been fully evaluated in this context,and evidence for their role as predictors of poor glycemic status in diabetic patients is limited.AIM To evaluate platelet indices and determine their prognostic significance in relation to inadequate glucoregulation among individuals diagnosed with type 2 diabetes at Bishoftu General Hospital in Ethiopia,from June 15 to August 12,2022.METHODS A comparative cross-sectional study was conducted in 261 participants including 174 individuals with type 2 diabetes mellitus(T2DM)and 87 non-diabetic controls.The systematic random sampling technique was used to select participants.Data were collected using structured questionnaires,physical measurements,checklists,and laboratory tests.Platelet parameters and fasting blood glucose levels were determined from blood samples using Sysmex-XN550 and CobasC311 analyzers,respectively.The hematology analyzer output was checked and participants were also screened for malaria parasites using a prepared blood smear.Collected data were entered into Epi-data version 3.1 and exported to SPSS version 25 for analysis.Theχ2 test,Mann-Whitney U test,Kruskal-Wallis test,post hoc test,Spearman correlation,and receiver operating characteristic curve were used for analysis.A P value<0.05 was considered statistically significant.RESULTS The results of our study indicate that diabetic patients have significantly higher levels of platelet distribution width(PDW),mean platelet volume(MPV),platelet large cell ratio(PLCR),and plateletcrit(PCT)compared to healthy individuals(P<0.001).Furthermore,these indices were found to be significantly elevated in individuals with poor glycemic control in T2DM compared to those with good glycemic control and healthy controls.We also observed significant correlations between these indices and various anthropometric and clinical variables.Our findings suggest that PDW,with a cut-off value of 15.75 fL and an area under the curve(AUC)of 0.803,MPV,with a cut-off value of 12.25 fL and an AUC of 0.774,PLCR,with a cut-off value of 36.3%and an AUC of 0.775,and PCT,with a cut-off value of 0.24%and an AUC of 0.761,can serve as predictors of poor glycemic control in patients with diabetes mellitus.CONCLUSION The observed correlation between diabetic patients and a significant increase in platelet indices has highlighted their potential as predictors of poor glycemic control in diabetes.Therefore,regular screening and profiling of platelet indices is recommended as part of the follow-up process for individuals with diabetes mellitus.

Intra-articular interventions in osteoarthritis:Navigating the landscape of hyaluronic acid,mesenchymal stem cells,and plateletrich plasma

Osteoarthritis(OA)poses a substantial burden on patients,leading to pain,functional decline,and reduced quality of life.While conventional treatments focus on symptom management,disease-modifying interventions are yet to be established.This review explores the efficacy of intra-articular interventions,particularly hyaluronic acid(HA),mesenchymal stem cells(MSCs),and platelet-rich plasma(PRP),in the context of OA management.HA injections,with diverse formulations like Hylan G-F20,sodium hyaluronate,and hyaluronan,present varying outcomes,necessitating a nuanced understanding of their effectiveness and timing.MSC therapy,derived from adipose tissue,umbilical cord,or bone marrow,shows promising results in clinical improvement,with adipose-derived MSCs demonstrating efficacy in maintaining benefits over 6 mo.Conversely,bone-marrow-derived MSCs show limited effectiveness,highlighting the need for sourcespecific considerations.PRP has emerged as a superior option for long-term pain reduction and quality of life improvement,with leukocyte-poor formulations and a critical platelet count of 10 billion demonstrating optimal results.This comprehensive analysis underscores the potential of intra-articular interventions in OA management,emphasizing the need for personalized and evidence-based approaches to enhance treatment efficacy and patient outcomes.

Red cell distribution width/platelet ratio estimates the 3-year risk of decompensation in Metabolic Dysfunction-Associated Steatotic Liver Disease-induced cirrhosis

BACKGROUND For compensated advanced chronic liver disease(cACLD)patients,the first decompensation represents a dramatically worsening prognostic event.Based on the first decompensation event(DE),the transition to decompensated advanced chronic liver disease(dACLD)can occur through two modalities referred to as acute decompensation(AD)and non-AD(NAD),respectively.Clinically Significant Portal Hypertension(CSPH)is considered the strongest predictor of decompensation in these patients.However,due to its invasiveness and costs,CSPH is almost never evaluated in clinical practice.Therefore,recognizing noninvasively predicting tools still have more appeal across healthcare systems.The red cell distribution width to platelet ratio(RPR)has been reported to be an indicator of hepatic fibrosis in Metabolic Dysfunction-Associated Steatotic Liver Disease(MASLD).However,its predictive role for the decompensation has never been explored.AIM In this observational study,we investigated the clinical usage of RPR in predicting DEs in MASLD-related cACLD patients.METHODS Fourty controls and 150 MASLD-cACLD patients were consecutively enrolled and followed up(FUP)semiannually for 3 years.At baseline,biochemical,clinical,and Liver Stiffness Measurement(LSM),Child-Pugh(CP),Model for End-Stage Liver Disease(MELD),aspartate aminotransferase/platelet count ratio index(APRI),Fibrosis-4(FIB-4),Albumin-Bilirubin(ALBI),ALBI-FIB-4,and RPR were collected.During FUP,DEs(timing and modaities)were recorded.CSPH was assessed at the baseline and on DE occurrence according to the available Clinical Practice Guidelines.RESULTS Of 150 MASLD-related cACLD patients,43(28.6%)progressed to dACLD at a median time of 28.9 months(29 NAD and 14 AD).Baseline RPR values were significantly higher in cACLD in comparison to controls,as well as MELD,CP,APRI,FIB-4,ALBI,ALBI-FIB-4,and LSM in dACLD-progressing compared to cACLD individuals[all P<0.0001,except for FIB-4(P:0.007)and ALBI(P:0.011)].Receiving operator curve analysis revealed RPR>0.472 and>0.894 as the best cut-offs in the prediction respectively of 3-year first DE,as well as its superiority compared to the other non-invasive tools examined.RPR(P:0.02)and the presence of baseline-CSPH(P:0.04)were significantly and independently associated with the DE.Patients presenting baseline-CSPH and RPR>0.472 showed higher risk of decompensation(P:0.0023).CONCLUSION Altogether these findings suggest the RPR as a valid and potentially applicable non-invasive tool in the prediction of timing and modalities of decompensation in MASLD-related cACLD patients.

Salivary C-reactive protein and mean platelet volume as possible diagnostic markers for late-onset neonatal pneumonia

BACKGROUND Neonatal sepsis,a formidable threat to newborns,is a leading cause of neonatal mortality,with late-onset sepsis manifesting after 72 hours post-birth being particularly concerning.Pneumonia,a prevalent sepsis presentation,poses a significant risk,especially during the neonatal phase when lung defenses are compromised.Accurate diagnosis of pneumonia is imperative for timely and effective interventions.Saliva,a minimally invasive diagnostic medium,holds great promise for evaluating infections,especially in infants.AIM To investigate the potential of serum C-reactive protein(CRP),salivary CRP(sCRP),and mean platelet volume(MPV)as diagnostic markers for late-onset neonatal pneumonia(LONP).METHODS Eighty full-term neonates were systematically examined,considering anthropometric measurements,clinical manifestations,radiology findings,and essential biomarkers,including serum CRP,sCRP,and MPV.RESULTS The study reveals noteworthy distinctions in serum CRP levels,MPV,and the serum CRP/MPV ratio between neonates with LONP and healthy controls.MPV exhibited a robust discriminatory ability[area under the curve(AUC)=0.87]with high sensitivity and specificity at a cutoff value of>8.8.Correlations between serum CRP,sCRP,and MPV were also identified.Notably,sCRP demonstrated excellent predictive value for serum CRP levels(AUC=0.89),underscoring its potential as a diagnostic tool.CONCLUSION This study underscores the diagnostic promise of salivary and serum biomarkers,specifically MPV and CRP,in identifying and predicting LONP among neonates.These findings advocate for further research to validate their clinical utility in larger neonatal cohorts.

Platelets in hemostasis and thrombosis:Novel mechanisms of fibrinogen-independent platelet aggregation and fibronectin-mediated protein wave of hemostasis

Platelets are small anucleate cells generated from megakaryocytes in the bone marrow. Although platelet genera- tion, maturation, and clearance are still not fully understood, significant progress has been made in the last 1-2 dec- ades. In blood circulation, platelets can quickly adhere and aggregate at sites of vascular injury, forming the platelet plug （i.e. the first wave of hemostasis）. Activated platelets can also provide negatively charged phosphatidylserine- rich membrane surface that enhances cell-based thrombin generation, which facilitates blood coagulation （i.e. the second wave of hemostasis）. Platelets therefore play central roles in hemostasis. However, the same process of hemostasis may also cause thrombosis and vessel occlusion, which are the most common mechanisms leading to heart attack and stroke following ruptured atherosclerotic lesions. In this review, we will introduce the classical mechanisms and newly discovered pathways of platelets in hemostasis and thrombosis, including fibrinogen-inde- pendent platelet aggregation and thrombosis, and the plasma fibronectin-mediated ＂protein wave＂ of hemostasis that precedes the classical first wave of hemostasis. Furthermore, we briefly discuss the roles of platelets in inflam- marion and atherosclerosis and the potential strategies to control atherothrombosis.

Human platelets inhibit liver fibrosis in severe combined immunodeficiency mice

AIM:To investigate the role of human platelets in liver fibrosis.METHODS:Severe combined immunodeficiency(SCID)mice were administered CCl4and either phosphate-buffered saline(PBS group)or human platelet transfusions(hPLT group).Concentrations of hepatocyte growth factor(HGF),matrix metallopeptidases(MMP)-9,and transforming growth factor-β(TGF-β)in the liver tissue were compared between the PBS and the hPLT groups by enzyme-linked immunosorbent assay(ELISA)and Western blotting.The effects of a human platelet transfusion on liver fibrosis included the fibrotic area,hydroxyproline content,and-smooth muscle actin(α-SMA)expression,which were evaluated by picrosirius red staining,ELISA,and immunohistochemical staining using an anti-mouse-SMA antibody,respectively.Phosphorylations of mesenchymal-epithelial transition factor(Met)and SMAD3,downstream signals of HGF and TGF-β,were compared between the two groups by Western blotting and were quantified using densitometry.Hepatocyte apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling.Furthermore,the accumulation of human platelets in the liver 2 h after platelet transfusion was compared between normal and fibrotic livers by immunohistochemical staining using an anti-human CD41 antibody.RESULTS:The fibrotic area and hydroxyproline content in the liver were both significantly lower in the hPLT group when compared to the PBS group(fibrotic area,1.7%±0.6%vs 2.5%±0.6%,P=0.03;hydroxyproline content,121±26 ng/g liver vs 156±47 ng/g liver,P=0.04).There was less α-smooth muscle actin staining in the hPLT group than in the PBS group(0.5%±0.1%vs 0.8%±0.3%,P=0.02).Hepatic expression levels of mouse HGF and MMP-9were significantly higher in the hPLT group than in the PBS group(HGF,109±13 ng/g liver vs 88±22 ng/g liver,P=0.03;MMP-9,113%±7%/GAPDH vs 92%±11%/GAPDH,P=0.04).In contrast,the concentration of mouse TGF-β in the liver tissue was significantly lower in the hPLT group than in the PBS group(22±5ng/g liver vs 39±6 ng/g liver,P=0.02).Phosphorylation of Met was more prevalent in the hPLT group than in the PBS group(37%±4%/GAPDH vs 20%±8%/GAPDH,P=0.03).Phosphorylation of SMAD3was weaker in the hPLT group than in the PBS group(60%±12%/GAPDH vs 84%±12%/GAPDH,P=0.1),although this difference was not significant.Furthermore,a lower rate of hepatocyte apoptosis was observed in the hPLT group than in the PBS group(5.9%±1.7%vs 2.9%±2.1%,P=0.02).Significant human platelet accumulation was observed in the fibrotic liver tissues,whereas few platelets accumulated in the normal liver.CONCLUSION:Human platelets inhibit liver fibrosis in SCID mice.Increased concentration of HGF in the liver suppresses hepatic stellate cell activation,induces MMPs,and inhibits hepatocyte apoptosis.

Multipotent role of platelets in inflammatory bowel diseases:A clinical approach

There is evidence that inflammatory bowel diseases (IBD) combine both inflammation and coagulation in their pathogenesis and clinical manifestations. Although platelets (PLT) are well known for their role in hemostasis, there are a rising number of studies supporting their considerable role as inflammatory amplifiers in chronic inflammatory conditions. IBD are associated with several alterations of PLT, including number, shape, and function, and these abnormalities are mainly attributed to the highly activated state of circulating PLT in IBD patients. When PLT activate, they increase in size, release a great variety of bio-active inflammatory and procoagulant molecules/particles, and express a variety of inflammatory receptors. These inflammatory products may represent a part of the missing link between coagulation and inflammation, and can be considered as possible IBD pathogenesis instigators. In clinical practice, thrombocytosis is associated both with disease activity and iron deficiency anemia. Controlling inflammation and iron replacement in anemic patients usually leads to a normalization of PLT count. The aim of this review is to update the role of PLT in IBD and present recent data revealing the possible therapeutic implications of anti-PLT agents in future IBD remedies.

Influence of Kupffer cells and platelets on ischemia-reperfusion injury in mild steatotic liver

AIM: To investigate the effect of mild steatotic liver on ischemia-reperfusion injury by focusing on Kupffer cells (KCs) and platelets. METHODS: Wistar rats were divided into a normal liver group (N group) and a mild steatotic liver group (S group) induced by feeding a choline-deficient diet for 2 wk. Both groups were subjected to 20 min of warm ischemia followed by 120 min of reperfusion. The number of labeled KCs and platelets in sinusoids and the blood perfusion in sinusoids were observed by intravital microscopy (IVM), which was performed at 30, 60 and 120 min after reperfusion. To evaluate serum alanine aminotransferase as a marker of liver deterioration, blood samples were taken at the same time as IVM.RESULTS: In the S group, the number of platelets adhering to KCs decreased significantly compared with the N group (120 after reperfusion; 2.9±1.1 cells/acinus vs 4.8±1.2 cells/acinus, P<0.01). The number of KCs in sinusoids was significantly less in the S group than in the N group throughout the observation periods (before ischemia, 19.6±3.3 cells/acinus vs 28.2±4.1 cells/acinus, P<0.01 and 120 min after reperfusion, 29.0±4.3 cells/acinus vs 40.2±3.3 cells/acinus, P<0.01). The blood perfusion of sinusoids 120 min after reperfusion was maintained in the S group more than in the N group. Furthermore, elevation of serum alanine aminotransferase was lower in the S group than in the N group 120 min after reperfusion (99.7±19.8 IU/L vs 166.3±61.1 IU/L, P=0.041), and histological impairment of hepatocyte structure was prevented in the S group. CONCLUSION: Ischemia-reperfusion injury in mild steatotic liver was attenuated compared with normal liver due to the decreased number of KCs and the reduction of the KC-platelet interaction.

Platelets and depression in cardiovascular disease:A brief review of the current literature

Major depression is an independent risk factor for cardiovascular mortality and morbidity. The exact mechanisms linking depression and increased cardiovascular risk remain poorly understood. Several mechanisms have been proposed including increased platelet reactivity. This review focuses on the current literature that examines the platelet hypothesis of depression. To date studies show increased serotonin response, increased platelet serotonin receptor density, decreased serotonin transporter binding, and decreased platelet serotonin levels in individuals with depression. However other studies have shown no change in serotonin uptake. In addition to platelet serotonin specific pathways, other platelet pathways that have shown significant changes in depressed individuals include blunting of the platelet adenosine response, increased platelet thrombin response, increased glycoprotein Ⅰb expression, increased P-selectin, β thromboglobulin, and platelet factor four, as well as decreased platelet brain derived neurotrophic factor. However there are other studies that show conflicting evidence of increased platelet activation as measured by integrin receptor α2b β3. Other conflictingdata include α adrenergic density and platelet response to augmented serotonin. The direction of future research in platelet functional changes in depression and coronary artery disease should continue to focus on serotonin specific pathways with emphasis on potential mechanisms of specific pathway changes.

Risk factor for ischemic-type biliary lesion after ABO-incompatible living donor liver transplantation

AIM: To evaluate the risk factors for ischemic-type biliary lesion(ITBL) after ABO-incompatible(ABO-I) adult living donor liver transplantation(ALDLT).METHODS: Among 141 ALDLTs performed in our hospital between 2008 and 2014, 27(19%) were ABO-I ALDLT and 114 were ABO-identical/compatible ALDLT. In this study, we extensively analyzed the clinico-pathological data of the 27 ABO-I recipients to determine the risk factors for ITBL after ABO-I ALDLT. All ABO-I ALDLT recipients underwent an identical B-cell depletion protocol with preoperative rituximab, plasma exchange(PE), and operative splenectomy. The median follow-up period after transplantation was 26 mo. The clinical outcomes of the 27 ABO-I ALDLT recipients were compared with those of 114 ABO-identical/compatible ALDLT recipients.RESULTS: ITBL occurred in four recipients(14.8%) between 45 and 112 d after ABO-I ALDLT. The overall survival rates were not different between ABO-I ALDLT and ABO-identical/compatible ALDLT(P = 0.303). Among the ABO-I ALDLT recipients, there was no difference between patients with ITBL and those without ITBL in terms of B-cell and T-cell count, serum isoagglutinin titers, number of PEs, operative time and transfusion, use of graft infusion therapy, or number of remnant B-cell follicles and plasma cells in the spleen. However, the perioperative NK cell counts in the blood of patients with ITBL were significantly higher than those in the patients without ITBL(P < 0.05). Preoperative NK cell count > 150/μL and postoperative NK cell count > 120/μL were associated with greater relative risks(RR) for development of ITBL(RR = 20 and 14.3, respectively, P < 0.05). CONCLUSION: High NK cell counts in a transplant recipient's blood are associated with ITBL after ABO-I ALDLT. Further research is needed to elucidate the molecular mechanism of NK cell involvement in the development of ITBL.