Endoscopic ultrasound-guided tissue acquisition for the diagnosis of focal liver lesion

In patients with liver tumors,the histopathology examination can assist in diagnosis,staging,prognosis,and therapeutic management strategy.Endoscopic ultrasound(EUS)-guided tissue acquisition using fine needle aspiration(FNA)or more newly fine needle biopsy(FNB)is a well-developed technique in order to evaluate and differentiate the liver masses.The goal of the EUS-FNA or EUS-FNB is to provide an accurate sample for a histopathology examination.Therefore,malignant tumors such as hepatocarcinoma,cholangiocarcinoma and liver metastasis or benign tumors such as liver adenoma,focal hyperplastic nodular tumors and cystic lesions can be accurately diagnosed using EUS-guided tissue acquisition.EUS-FNB using 19 or 22 Ga needle provide longer samples and a higher diagnostic accuracy in patients with liver masses when compared with EUS-FNA.Few data are available on the diagnostic accuracy of EUS-FNB when compared with percutaneously,ultrasound,computer tomography or transjugulary-guided liver biopsies.This review will discuss the EUS-guided tissue acquisition options in patients with liver tumors and its efficacy and safety in providing accurate samples.The results of the last studies comparing EUS-guided liver biopsy with other conventional techniques are presented.The EUS-guided tissue acquisition using FNB can be a suitable technique in suspected liver lesions in order to provide an accurate histopathology diagnosis,especially for those who require endoscopy.

Diagnostic value of tissue plasminogen activator-inhibitor complex in sepsis-induced liver injury:A single-center retrospective casecontrol study

BACKGROUND Sepsis often causes severe liver injury and leads to poor patient outcomes.Early detection of sepsis-induced liver injury(SILI)and early treatment are key to improving outcomes.AIM To investigate the clinical characteristics of SILI patients and analyze the associated risk factors,to identify potential sensitive biomarkers.METHODS Retrospective analysis of clinical data from 546 patients with sepsis treated in the intensive care unit of the 908th Hospital of Chinese People’s Liberation Army Joint Logistic Support Force between May 2018 and December 2022.The patients were divided into the sepsis group(n=373)and SILI group(n=173)based on the presence of acute liver injury within 2 hours of admission.We used the random forest algorithm to analyze risk factors and assessed potential diagnostic markers of SILI using the area under the receiver operating characteristic curve,Kaplan-Meier survival curves,subgroup analysis and correlation analysis.RESULTS Compared with the sepsis group,tissue plasminogen activator-inhibitor complex(t-PAIC)levels in serum were significantly higher in the SILI group(P<0.05).Random forest results showed that t-PAIC was an independent risk factor for SILI,with an area under the receiver operating characteristic curve of 0.862(95%confidence interval:0.832-0.892).Based on the optimal cut-off value of 11.9 ng/mL,patients at or above this threshold had significantly higher levels of lactate and Acute Physiology and Chronic Health Evaluation II score.The survival rate of these patients was also significantly worse(hazard ratio=2.2,95%confidence interval:1.584-3.119,P<0.001).Spearman’s correlation coefficients were 0.42 between t-PAIC and lactate,and 0.41 between t-PAIC and aspartate transaminase.Subgroup analysis showed significant differences in t-PAIC levels between patients with different severity of liver dysfunction.CONCLUSION T-PAIC can serve as a diagnostic indicator for SILI,with its elevation correlated with the severity of SILI.

Insulin resistance and adipose tissue interactions as the cornerstone of metabolic(dysfunction)-associated fatty liver disease pathogenesis

The relationship between metabolic derangements and fatty liver development are undeniable,since more than 75% of patients with type 2 diabetes mellitus present with fatty liver.There is also significant epidemiological association between insulin resistance(IR)and metabolic(dysfunction)-associated fatty liver disease(MAFLD).For little more than 2 years,the nomenclature of fatty liver of non-alcoholic origin has been intended to change to MAFLD by multiple groups.While a myriad of reasons for which MAFLD is thought to be of metabolic origin could be exposed,the bottom line relies on the role of IR as an initiator and perpetuator of this disease.There is a reciprocal role in MAFLD development and IR as well as serum glucose concentrations,where increased circulating glucose and insulin result in increased de novo lipogenesis by sterol regulatory elementbinding protein-1c induced lipogenic enzyme stimulation;therefore,increased endogenous production of triglycerides.The same effect is achieved through impaired suppression of adipose tissue(AT)lipolysis in insulin-resistant states,increasing fatty acid influx into the liver.The complementary reciprocal situation occurs when liver steatosis alters hepatokine secretion,modifying fatty acid metabolism as well as IR in a variety of tissues,including skeletal muscle,AT,and the liver.The aim of this review is to discuss the importance of IR and AT interactions in metabolic altered states as perhaps the most important factor in MAFLD pathogenesis.

Liver transplantation as an alternative for the treatment of neuroendocrine liver metastasis: Appraisal of the current evidence

Background:Liver transplantation(LT)for neuroendocrine liver metastases(NELM)is still in debate.Studies comparing LT with liver resection(LR)for NELM are scarce,as patient selection is heterogeneous and experience is limited.The goal of this review was to provide a critical analysis of the evidence on LT versus LR in the treatment of NELM.Data sources:A scoping literature search on LT and LR for NELM was performed with PubMed,including English articles up to March 2023.Results:International guidelines recommend LR for NELM in resectable,well-differentiated tumors in the absence of extrahepatic metastatic disease with superior results of LR compared to systemic or liver-directed therapies.Advanced liver surgery has extended resectability criteria whilst entailing increased perioperative risk and short disease-free survival.In highly selected patients(based on the Milan criteria)with unresectable NELM,oncologic results of LT are promising.Prognostic factors include tumor biology(G1/G2)and burden,waiting time for LT,patient age and extrahepatic spread.Based on low-level evi-dence,LT for low-grade NELM within the Milan criteria resulted in improved disease-free survival and overall survival compared to LR.The benefits of LT were lost in patients beyond the Milan NELM-criteria.Conclusions:With adherence to strict selection criteria especially tumor biology,LT for NELM is becoming a valuable option providing oncologic benefits compared to LR.Recent evidence suggests even stricter selection criteria with regard to tumor biology.

Selective internal radiation therapy segmentectomy:A new minimally invasive curative option for primary liver malignancies?

Transarterial radioembolization or selective internal radiation therapy(SIRT)has emerged as a minimally invasive approach for the treatment of tumors.This percutaneous technique involves the local,intra-arterial delivery of radioactive microspheres directly into the tumor.Historically employed as a palliative measure for liver malignancies,SIRT has gained traction over the past decade as a potential curative option,mirroring the increasing role of radiation segmentectomy.The latest update of the BCLC hepatocellular carcinoma guidelines recognizes SIRT as an effective treatment modality comparable to other local ablative methods,particularly well-suited for patients where surgical resection or ablation is not feasible.Radiation segmentectomy is a more selective approach,aiming to deliver high-dose radiation to one to three specific hepatic segments,while minimizing damage to surrounding healthy tissue.Future research efforts in radiation segmentectomy should prioritize optimizing radiation dosimetry and refining the technique for super-selective administration of radiospheres within the designated hepatic segments.

Current status of yttrium-90 microspheres radioembolization in primary and metastatic liver cancer

Liver malignancy,including primary liver cancer and metastatic liver cancer has become one of the most common causes of cancer-related death worldwide due to the high malignant degree and limited systematic treatment strategy.Radioembolization with yttrium-90(^(90)Y)-loaded microspheres is a relatively novel technology that has made significant progress in the local treatment of liver malignancy.The different steps in the extensive work-up of radioembolization for patients with an indication for treatment with^(90)Y microspheres,from patient selection to follow up,both technically and clinically,are discussed in this paper.It describes the application and development of^(90)Y microspheres in the treatment of liver cancer.

Metabolic liver disease of obesity and role of adipose tissue in the pathogenesis of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease （NAFLD） is an increasingly recognized cause of liver-related morbidity and mortality. It can develop secondary to numerous causes but a great majority of NAFLD cases occur in patients who are obese or present with other components of metabolic syndrome （hypertension, dyslipidemia, diabetes）. This is called primary NAFLD and insulin resistance plays a key role in its pathogenesis. Obesity is characterized by expanded adipose tissue, which is under a state of chronic inflammation. This disturbs the normal storage and endocrine functions of adipose tissue. In obesity, the secretome （adipokines, oytokines, free fatty acids and other lipid moieties） of fatty tissue is amplified, which through its autocrine, paracrine actions in fat tissue and systemic effects especially in the liver leads to an altered metabolic state with insulin resistance （IR）. IR leads to hyperglycemia and reactive hyperinsulinemia, which stimulates lipid-accumulating processes and impairs hepatic lipid metabolism. IR enhances free fatty acid delivery to liver from the adipose tissue storage due to uninhibited lipolysis. These changes result in hepatic abnormal fat accumulation, which may initiate the hepatic IR and further aggravate the altered metabolic state of whole body. Hepatic steatosis can also be explained by the fact that there is enhanced dietary fat delivery and physical inactivity. IR and NAFLD are also seen in various lipodystrophic states in contrary to popular belief that these problems only occur due to excessive adiposity in obesity. Hence, altered physiology of adipose tissue is central to development of IR, metabolic syndrome and NAFLD.

Immunohistochemical assessment of angiogenesis in hepatocellular carcinoma and surrounding cirrhotic liver tissues

AIM: To investigate whether vascular endothelial growth factor (VEGF) was over-expressed in hepatocellular carcinoma (HCC) or in surrounding cirrhotic liver tissues.METHODS: Immunohistochemistry was performed to investigate the expression of VEGF proteins in HCC tissues from 105 consecutive patients undergoing curative resection for HCC. The immunostaining results and related clinicopathologic materials were analyzed with statistical methods. Kaplan-Meier method was used to calculate survival curves, and Log-rank test was performed to compare differences in survival rates of the patients with positive HCC staining and negative VEGF.RESULTS: VEGF-positive expression was found in 72 of105 HCC patients (68.6%). Capsular infiltration (P= 0.005),vascular invasion (P = 0.035) and intrahepatic metastasis(P=0.008) were observed more frequently in patients with VEGF-positive expression than in those with VEGFnegative expression. Kaplan-Meier curves showed that VEGF-positive expression was associated with a shorter overall survival (P = 0.014). VEGF-positive expression was found in 47 of tissues 68 HCC (69.1%), and VEGF-positive expression was found in 54 of 68 surrounding cirrhotic liver tissues (79.4%). VEGF-positive expression was significantly higher in surrounding cirrhotic liver tissues than in HCC (P= 0.017).CONCLUSION: VEGF may play an important role in the angiogenesis and prognosis of HCC, as well as in the angiogenesis of liver cirrhosis.

Relationship between adipose tissue dysfunction, vitamin D deficiency and the pathogenesis of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD)is the most common chronic liver disease worldwide.Its pathogenesis is complex and not yet fully understood.Over the years many studies have proposed various pathophysiological hypotheses,among which the currently most widely accepted is the"multiple parallel hits"theory.According to this model,lipid accumulation in the hepatocytes and insulin resistance increase the vulnerability of the liver to many factors that act in a coordinated and cooperative manner to promote hepatic injury,inflammation and fibrosis.Among these factors,adipose tissue dysfunction and subsequent chronic low grade inflammation play a crucial role.Recent studies have shown that vitamin D exerts an immune-regulating action on adipose tissue,and the growing wealth of epidemiological data is demonstrating that hypovitaminosis D is associated with both obesity and NAFLD.Furthermore,given the strong association between these conditions,current findings suggest that vitamin D may be involved in the relationship between adipose tissue dysfunction and NAFLD.The purpose of this review is to provide an overview of recent advances in the pathogenesis of NAFLD in relation to adipose tissue dysfunction,and in the pathophysiology linking vitamin D deficiency with NAFLD and adiposity,together with an overview of the evidence available on the clinical utility of vitamin D supplementation in cases of NAFLD.

mPGES-1 expression in non-cancerous liver tissue impacts on postoperative recurrence of HCC

AIM:To investigate whether microsomal prostaglandin E synthase-1 (mPGES-1) expression in hepatocellular carcinoma (HCC) and in non-cancerous liver affects HCC prognosis after hepatectomy. METHODS: The relationship between patient clinical prof iles, tumor factors, surgical determinants, and mPGES-1 expression and the recurrence-free survival rate were examined in 64 patients who underwent curative hepatectomy between March 2003 and December 2006. RESULTS: The scores for mPGES-1 expression were higher in well differentiated and moderately differentiated HCC tissues than in poorly differentiated HCC tissues (well differentiated, 5.1 ± 2.7; moderately differentiated, 5.1 ± 1.7; poorly differentiated, 3.0 ± 1.8). In noncancerous liver tissues, the mPGES-1 levels were higher in injured liver tissues than in normal tissues. Cirrhotic livers had higher mPGES-1 levels than livers with chronic hepatitis (normal livers, 3.3 ± 0.7; chronic hepatitic livers, 5.4 ± 1.9; cirrhotic livers, 6.4 ± 1.6). A univariate analysis revealed that the recurrence-free survival rate was signif icantly lower in patients with vascular invasion,a higher mPGES-1 level in non-cancerous liver tissue,a larger tumor diameter (≥5 cm), and a lower serum albumin level (≤3.7 g/dL). The mPGES-1 expression in HCC tissues did not correlate well with postoperative recurrence. A multivariate analysis demonstrated that the presence of vascular invasion and higher mPGES-1 levels were statistically significant independent predictors for early postoperative recurrence of HCC.CONCLUSION: Increased mPGES-1 expression in noncancerous liver tissues is closely associated with the early recurrence of HCC after curative resection.

VEGF in hepatocellular carcinoma and surrounding cirrhotic liver tissues

We read with a great interest the recent work of Deli and colleagues. in the World Journal of Gastroenterology reporting vascular endothelial growth factor （VEGF） expression in hepatocellular carcinoma （HCC） and cirrhotic liver tissues. This well-documented work shows that VEGF was significantly higher in surrounding cirrhotic liver tissues than in HCC. Authors assessed VEGF expression using immunohistochemistry. The immunohistochemical staining is an efficient tool to assess the percentage of cells stained positively for VEGF but is not really efficient to estimate their true VEGF content. Evaluation of the VEGF protein by an enzyme-linked immunosorbent assay 0ELISA） has been reported, by us and others, to be an efficient tool in order to assess tissue VEGF expression. We have, thus, tested whether the ELISA method might be an efficient tool in order to confirm data reporting higher amounts of VEGF in surrounding cirrhotic liver tissues than in HCC. Deli and colleagues. also correctly pointed out that basic fibroblast growth factor （bFGF） has been reported to act cooperatively on VEGF expression. We have, thus, also assessed bFGF tissue levels in order to search for a putative link between VEGF and bFGF levels in cirrhotic tissues.

Construction and characterization of a cDNA library from human liver tissue with chronic hepatitis B

Objective: To construct a cDNA library from human liver tissue with chronic hepatitis B and check its quality for investigating the expression level of liver tissue infected by hepatitis B virus. This will then be used to find the relevant genes and interesting proteins associated with the development of hepatitis B. Methods: The total RNA from liver tissue with chronic hepa- titis B was extracted and the mRNA was purified using TRIZOL method. Switching mechanism at 5′ end of the RNA transcript (SMART) technique and CDS III/3′ primer were used for first-strand cDNA synthesis. Long distance polymerase chain reaction (LD PCR) was then used to synthesize the double-strand cDNA that was then digested by Sfi I and fractionated by CHROMA SPIN-400 column. The longer than 0.4 kb cDNAs were collected and ligated to λTriplEx2 vector. Then λ phage packaging reaction and library amplification were performed. The qualities of both unamplified and amplified cDNA libraries were strictly checked by conventional titer determination. Fourteen plaques were randomly picked and tested using PCR with universal primers derived from the sequence flanking the vector. Results: The titers of unamplifed and amplified libraries were 1.94×106 pfu/ml and 1.49×109 pfu/ml respectively. The percentages of recombinants from both libraries were 98.15% in unamplified library and 98.76% in amplified library. The lengths of the inserts were 1.23 kb in average, 1?2 kb in 64.29%, and 0.5?1.0 kb in 35.71%. Conclusion: A high quality cDNA library from human liver tissue with chronic hepatitis B was successfully constructed.

Ectopic liver tissue (choristoma) on the gallbladder: Acomprehensive literature review

BACKGROUND Liver tissue situated outside the liver with a hepatic connection is usually calledan accessory liver, and that without a connection to the mother liver, is calledectopic liver tissue.AIM To identify studies in the literature on ectopic liver tissue located on thegallbladder surface or mesentery.METHODS We present two patients and review published articles on ectopic liver tissuelocated on the gallbladder surface accessed via PubMed, MEDLINE, GoogleScholar, and Google databases. Keywords used included accessory liver lobe,aberrant liver tissue, ectopic liver tissue, ectopic liver nodule, heterotopic livertissue, hepatic choristoma, heterotopic liver tissue on the gallbladder, and ectopicliver tissue on the gallbladder. The search included articles published before June2020 with no language restriction. Letters to the editor, case reports, reviewarticles, original articles, and meeting presentations were included in the search.Articles or abstracts containing adequate information on age, sex, history of liverdisease, preliminary diagnosis, radiologic tools, lesion size, surgical indication,surgical procedure, and histopathological features of ectopic liver tissue wereincluded in the study.RESULTS A total of 72 articles involving 91 cases of ectopic liver tissue located on the gallbladder surface or mesentery were analyzed. Of these 91 patients, 62 werefemale and 25 were male (no gender available for 4 patients), and the age rangewas 5 d to 91 years. Forty-nine patients underwent surgery for chroniccholecystitis or cholelithiasis, and 14 patients underwent surgery for acutecholecystitis. The remaining 28 patients underwent laparotomy for other reasons.Cholecystectomy was laparoscopic in 69 patients and open in 11 patients. Theremaining 19 patients underwent various other surgical procedures such asautopsy, liver transplantation, living donor hepatectomy, Whipple procedure, andliver segment V resection. Histopathologically, hepatocellular carcinoma wasdetected in the ectopic liver tissue of one patient.CONCLUSION Ectopic liver tissue is a rare developmental anomaly which is usually detectedincidentally. Although most studies suggest that ectopic liver located outside thegallbladder has a high risk of hepatocellular carcinoma, this is not reflected instatistical analysis.

Ultrasonic characterization of porcine liver tissue at frequency between 25 to 55 MHz

AIM： To study the relation between acoustic parameters and histological structure of biological tissue and to provide the basis for high-resolution image of biological tissues and quantitative ultrasonic diagnosis of liver disease. METHODS： Ultrasonic imaging and tissue characterization of four normal porcine liver and five cirrhotic liver tissue samples were performed using a high frequency imaging system. RESULTS： The acoustic parameters of cirrhotic liver tissue were larger than those of normal liver tissue. The sound velocity was 1577 m/s in normal liver tissue and 1631 m/s in cirrhotic liver tissue. At 35 MHz, the attenuation coefficient was 3.0 dB/mm in normal liver tissue and 4.1 dB/mm in cirrhotic liver tissue. The backscatter coefficient was 0.00431 dB/Srmm in cirrhotic liver tissue and 0.00303 dB/Srmm in normal liver tissue. The backscatter coefficient increased with the frequency. The high frequency images coincided with their histological features. CONCLUSION： The acoustic parameters, especially the sound backscatter coefficient, are sensitive to the changes of liver tissues and can be used to differentiate between the normal and pathological liver tissues. High frequency image system is a useful device for highresolution image and tissue characterization.

Polyethylene glycol crosslinked decellularized single liver lobe scaffolds with vascular endothelial growth factor promotes angiogenesis in vivo

Background: Improving the mechanical properties and angiogenesis of acellular scaffolds before transplantation is an important challenge facing the development of acellular liver grafts. The present study aimed to evaluate the cytotoxicity and angiogenesis of polyethylene glycol(PEG) crosslinked decellularized single liver lobe scaffolds(DLSs), and establish its suitability as a graft for long-term liver tissue engineering. Methods: Using mercaptoacrylate produced by the Michael addition reaction, DLSs were first modified using N-succinimidyl S-acetylthioacetate(SATA), followed by cross-linking with PEG as well as vascular endothelial growth factor(VEGF). The optimal concentration of agents and time of the individual steps were identified in this procedure through biomechanical testing and morphological analysis. Subsequently, human umbilical vein endothelial cells(HUVECs) were seeded on the PEG crosslinked scaffolds to detect the proliferation and viability of cells. The scaffolds were then transplanted into the subcutaneous tissue of Sprague-Dawley rats to evaluate angiogenesis. In addition, the average number of blood vessels was evaluated in the grafts with or without PEG at days 7, 14, and 21 after implantation. Results: The PEG crosslinked DLS maintained their three-dimensional structure and were more translucent after decellularization than native DLS, which presented a denser and more porous network structure. The results for Young’s modulus proved that the mechanical properties of 0.5 PEG crosslinked DLS were the best and close to that of native livers. The PEG-VEGF-DLS could better promote cell proliferation and differentiation of HUVECs compared with the groups without PEG cross-linking. Importantly, the average density of blood vessels was higher in the PEG-VEGF-DLS than that in other groups at days 7, 14, and 21 after implantation in vivo. Conclusions: The PEG crosslinked DLS with VEGF could improve the biomechanical properties of native DLS, and most importantly, their lack of cytotoxicity provides a new route to promote the proliferation of cells in vitro and angiogenesis in vivo in liver tissue engineering.

Effects of regenerated tissue extracts after liver injury on the proliferation,differentiation,migration and invasion of SK-HEP1 cells

Objective: To study the effects of regenerated tissue extracts after liver injury on the proliferation, differentiation, migration and invasion of SK-HEP1 cells. Methods: Regenerated tissue extracts after liver injury were used to induce SK-HEP1 cells after enrichment, their effects on the proliferation, differentiation, migration and invasion of SK-HEPI cells were observed through in vitro cell culture, MTT, flow cytometry and transwell assays. Results:In response to the action of regenerated tissue extracts after liver injury, SK-HEP1 cells were blocked in G_0/G_1 phase, their growth rate was distinctly reduced. The number of SK-HEP1^(-fj)colonies decreased. The migration ability of SK-HEPI cells showed a decreased trend on day7 and day 11 after induction. SK-HEPl's invasion ability clearly decreased on days 7 and11 after induction, especially on day 7. Conclusions: To a certain extent, regenerated tissue extracts after liver injury can inhibit the proliferation, differentiation, migration and invasion of hepatoma cells, showing an important potential of being a differentiating agent for the treatment of liver cancer.

A NEW METHOD OF ISOLATING KUPFFER CELLS FROM BIOPSY TISSUE OF RAT LIVER

The isolation of a high yield and purity of Kupffer cells has been reported in detail.1 This paper reports into the research about isolation Kupffer cells from biopsy tissue of liver. This method includes 5 important steps: (1) take fresh liver tissue, and mince with scissors. (2) spin at low speed to wash off red blood cells. (3) digest in collagenase for suitable time. (4) isolate Kupffer cells on a percoll density gradient. (5) cell charaterization was observed by N.S.E stain and peroxidatic activity with lumino-meter measurement and phagocytosis with latex beads.2.3

Matrix Metalloproteinases and Their Tissue Inhibitors in Patients with Nonalcoholic Fatty Liver Disease

The objective of the study is to assess the role of MMP-9, TIMP-1 ＆ 2 as non-invasive markers of liver fibrosis in the NAFLD. The 99 patients with NAFLD and different stages of fibrosis were examined. We assessed of anthropometric indicators, biochemical analysis of blood, abdominal ultrasonic studies, the levels of MMP-9, TIMP-1 ＆ 2. According of results of elastometry, patients were divided into five groups： n = 27, n = 22, n = 23, n = 14, n = 13, respectively, depending on the stage of fibrosis （0-4）. Between the groups in physical examination, no significant differences in BMI and W/H were found. 64.6% of patients had abdominal obesity （BMI： 31.5 （29.1-33.9）, W/H： 1.02 （1.01-1.05））. Obesity and abdominal obesity （BMland W/H） had a significant positive relationship of moderate streight （rs = 0.257, p 〈 0.04 and rs = 0.301, p 〈 0.02, respectively）, with the stage of liver fibrosis. The groups were significant differences in the level of glucose, total bilirubin （p 〈 0.04, p 〈 0.03, respectively）. No significant differences in the level of liver function tests （ALT and AST） in the study groups were found. Significant differences were found in level of TIMP-2 （p 〈 0.04）. TIMP-2 had a significant positive correlation with the severity of fibrosis in the hepatic tissue （rs = 0.349, p 〈 0.004）. TIMP-2 may be considered as a potential non-invasive marker for the diagnosis of liver fibrosis in patients with NAFLD.

COVID-19 and liver injury in individuals with obesity

Coronavirus disease 2019 is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 that manifests as a variety of clinical manifestations,including liver damage commonly detected by a hepatocellular pattern from liver function tests.Liver injury is associated with a worse prognosis overall.Conditions associated with the severity of the disease include obesity and cardiometabolic comorbidities,which are also associated with nonalcoholic fatty liver disease(NAFLD).The presence of NAFLD,similarly to obesity,is associated with an unfavourable impact on the coronavirus disease 2019 outcome.Individuals with these conditions could present with liver damage and elevated liver function tests due to direct viral cytotoxicity,systemic inflammation,ischemic or hypoxic liver damage or drug side effects.However,liver damage in the setting of NAFLD could also be attributed to a pre-existing chronic low-grade inflammation associated with surplus and dysfunctional adipose tissue in these individuals.Here we investigate the hypothesis that a pre-existing inflammatory status is exacerbated after severe acute respiratory syndrome coronavirus 2 infection,which embodies a second hit to the underestimated liver damage.

Immunomodulatory effects of mesenchymal stem cells derived from adipose tissues in a rat orthotopic liver transplantation model

BACKGROUND: Acute rejection after liver transplantation is usually treated with large doses of immunosuppressants with severe toxic and side-effects, so it is imperative to find a safe and effective method for preventing and treating rejection. This study was designed to confirm the immunomodulatory effects of rat mesenchymal stem cells (MSCs) in vitro and investigate the tolerogenic features in a rat model of allogeneic liver transplantation. METHODS: MSCs were isolated from adipose tissue of Sprague-Dawley (SD) rats and cultured. In vitro, MSCs were added into a mixed lymphocyte culture (MLC) system to study the inhibitory effects of MSCs on the proliferation of T lymphocytes in Wistar rats. By using SD and Wistar rats as liver donors and recipients, an orthotopic liver transplantation model was established and the rats were divided into a MSC-treated group and a blank control group. On postoperative day 7, all rats were sacrificed, and the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), interleukin-2 (IL-2) and interleukin-10 (IL-10) were measured. The pathological changes of liver tissue and apoptosis of hepatocytes were also assessed. RESULTS: In in vitro MLC, T lymphocyte proliferation in Wistar rats was significantly inhibited by 48.44%. In the MSC-treated group, the levels of ALT, AST, TBIL, IL-2 and IL-10 were 134.2 +/- 45.0 U/L, 162.5 +/- 30.5 U/L, 30.6 +/- 5.4 mu mol/L, 187.35 +/- 18.26 mu g/L and 193.95 +/- 37.62 mu g/L, and those in the blank control group were 355.6 +/- 54.3 U/L, 296.4 +/- 71.2 U/L, 145.7 +/- 28.6 +/- mol/L, 295.73 +/- 57.15 mu g/L and 75.12 +/- 11.23 mu g/L, respectively, with statistically significant differences (P<0.05). Pathological examination revealed that the rejection in the MSC-treated group was clearly alleviated compared with that in the blank control group. TUNEL indicated that the apoptosis of hepatocytes in the MSC-treated group was milder than that in the blank control group (P<0.05). CONCLUSION: Adipose-derived MSCs clearly inhibit recipient-derived T lymphocyte proliferation in MLC and significantly alleviate acute rejection following orthotopic liver transplantation in rats.