Spatial transcriptomics reveals the transcriptomic signatures in a mouse model of pediatric metabolic dysfunction-associated steatohepatitis.

Metabolic dysfunction-associated steatohepatitis (MASH) is considered the progressive form of metabolic dysfunction-associated steatotic liver disease (MASLD), which is the leading cause of chronic liver disease in children. However, the pathogenesis of pediatric MASH remains poorly understood due to the lack of animal models. In this study, we developed a mouse model of pediatric MASH and characterized the hepatic transcriptomic profile using spatial transcriptomics (ST) technology. C57BL/6J mice were fed a western diet (WD) along with weekly injections of carbon tetrachloride (CCl4) from 3 weeks old to 8 weeks old. After 5 weeks of feeding, WD+CCl4-treated mice showed significant liver injury without the development of insulin resistance. Histologically, WD+CCl4 induced key features of type 2 MASH, the most common type observed in children, characterized by liver steatosis, portal inflammation, and portal fibrosis. Through ST analysis of liver tissues, we identified that cluster 0 in the mouse from the WD+CCl4 group was enriched in pathways associated with lipid metabolism. Further investigation revealed that cytochrome p450 2E1 (CYP2E1) was the top marker gene of cluster 0, and its expression was increased in the periportal area of mice from the WD+CCl4 group. These findings suggest that our mouse model of pediatric MASH mirrors the histological features of human MASH, and the upregulation of CYP2E1 may be linked to the disease pathogenesis.

Targeted metabolomics unravels altered phenylalanine levels in piglets receiving total parenteral nutrition.

Parenteral nutrition, received by many patients with intestinal failure, can induce hepatobiliary complications, which is termed as parenteral nutrition-associated liver disease (PNALD). The spectrum of PNALD ranges from cholestasis and steatosis to fibrosis and cirrhosis. Although many factors contribute to the pathogenesis of PNALD, the underlying mechanisms remain unclear. In this study, we performed targeted metabolomics to characterize the metabolomic profile in neonatal piglets receiving total parenteral nutrition (TPN) or enteral nutrition (EN) for 1 or 2 weeks. Overall, the metabolomic signature of TPN groups differed from EN groups at both time points. Among the 20 acylcarnitines identified, a majority of them were significantly reduced in TPN groups. KEGG pathway analysis showed that phenylalanine metabolism-associated pathways were dysregulated accompanied by more progressive liver steatosis associated with TPN. Next, we evaluated phenylalanine catabolism and its association with fatty acid oxidation in piglets and rats with PNALD. We showed that the hepatic expression of phenylalanine-degrading enzyme phenylalanine hydroxylase (PAH) was reduced and systemic phenylalanine levels were increased in both animal models of PNALD. Moreover, carnitine palmitoyltransferase 1A, a central regulator of fatty acid oxidation, was downregulated and its expression was negatively correlated with phenylalanine levels in TPN-fed animals. To explore the effects of phenylalanine accumulation on lipid metabolism, we treated HepG2 cells with phenylalanine co-cultured with sodium palmitate or soybean oil emulsion to induce lipid accumulation. We found that phenylalanine treatment exacerbated lipid accumulation by inhibiting fatty acid oxidation without affecting fatty acid synthesis. In summary, our findings establish a pathogenic role of increased phenylalanine levels in driving liver steatosis, linking dysregulation of phenylalanine catabolism with lipid accumulation in the context of PNALD.

Photocatalytic degradation-based ambient mass spectrometry imaging for enhancing detection coverage of poorly-ionizable lipidomes.

Localization of lipidomes and tracking their spatial changes in tissues by mass spectrometry imaging (MSI) plays an important role in unveiling the mechanisms of living processes, diseases and therapeutic treatments. However, it is always challenging to achieve direct MSI of poorly-ionizable lipids, such as glycolipids and glycerolipids, due to the strong ion suppression and isobaric peaks interference from high-abundance phosphatidylcholines (PCs) in tissues. Here we developed a photocatalytic degradation-based ambient liquid extraction MSI method to largely enhance the detection coverage of poorly-ionizable lipids by rapid online removal of PCs in MSI. Phospholipids were found to be selectively photodegraded on TiO2 surface in acidic conditions in the presence of water under UV irradiation, while other poorly-ionizable lipids remained. Sulfate ion could largely improve the degradation efficiencies. Anatase nanoparticles-embedded TiO2 monolith was in-situ synthesized in the capillary of ambient liquid extraction system, and rapid online photodegradation of PCs was achieved during MSI with efficiency >80 %, largely reducing ion suppression. The pathway analysis showed that PC was oxidatively degraded starting from hydroxylation of C=C bonds. With intense UV irradiation, PCs were completely degraded into small molecules<200 Da without interference on the detection of endogenous lipids. With the new MSI method, detection coverage to cerebrosides, ceramides and diglycerides was enhanced by 2-9 times comparing with traditional MSI. Clearer localizations were observed for poorly-ionizable lipids via the new method than traditional method. Thus, this work provided a complementary MSI method for traditional MSI to address the issues on direct imaging of poorly ionizable lipids in ambient conditions.

Recent Progress in Ferroptosis Induced Tumor Cell Death by Anti-tumor Metallic complexes.

Metal complexes represented by platinum complexes play a very important role in cancer treatment due to their diverse chemical structures and anti-tumor activities. Recently, ferroptosis has emerged as a newly occurring cell death form in the anti-tumor process. It has been reported that metal complexes could inhibit the proliferation and metastasis of tumors and combat chemotherapy resistance by targeting ferroptosis. In this review, we briefly describe ferroptosis as a fundamental process for tumor suppression and triggering anti-tumor immune responses. We summarize recent developments on metal complexes that induce ferroptosis. Finally, we outline the prospects for the application of metal complexes to the treatment of tumors based on ferroptosis and the associated problems that need to be solved, and discussed other potential research directions of metal complexes.

Photocatalytic reactive liquid microjunction surface sampling-mass spectrometry for rapid and selective in-situ analysis of alpha-unsubstituted amine metabolites or drugs in brain tissue.

In in-situ mass spectrometry (MS), different on-tissue derivatization methods have been developed to enhance the signals of poorly ionizable primary amines. However, those chemical derivatization methods are laborious and time-consuming, and are usually limited to detection of high-abundance amino acids which suppress the reaction of low-abundance monoamine neurotransmitters and drugs. Herein, A rapid and selective photocatalytic derivatization technique for alpha-unsubstituted primary amine was developed with 5-hydroxyindole as derivatization reagent and TiO2 as photocatalyst, and was introduced into liquid microjunction surface sampling (LMJSS)-MS system as online derivatization. The results showed that the photocatalytic derivatization method largely enhanced the signals of primary amines by 5-300 fold, and were selective to alpha-unsubstituted primary amines. Thus, the suppression effects from high-abundance amino acids to the reaction of monoamine neurotransmitters and benzylamine drugs proved to be largely reduced in the new method (matrix effect>50%) comparing with those in chemical derivatization method (matrix effect<10%). In addition, the optimal pH of the derivatization reaction was measured to be 7, which indicates the mild and physiologically compatible reaction conditions. By in-situ synthesis of TiO2 monolith in the transfer capillary of the LMJSS-MS system, rapid on-line photocatalytic derivatization was achieved and completed in 5 s during the transfer of sampling extract from the flow-probe to the MS inlet. With the new photocatalytic reactive LMJSS-MS method, detection limits of three primary amines on glass slides were in the range of 0.031-0.17 ng/mm2 with acceptable linearity (r=0.9815-0.9998) and relatively high repeatability (relative standard deviations <22.1%). Finally, endogenous tyramine, serotonin, two dipeptides and one doped benzylamine drug were identified and in-situ analyzed in the mouse cerebrum by the new method with largely enhanced signals comparing with LMJSS-MS without online derivatization. The new method provides a more selective, rapid and automated way to analyze alpha-unsubstituted amine metabolites and drugs in-situ comparing with traditional methods.

Lactobacillus johnsonii Attenuates Liver Steatosis and Bile Acid Dysregulation in Parenteral Nutrition-Fed Rats.

Parenteral nutrition (PN), a vital therapy for patients with intestinal failure, can lead to the development of parenteral nutrition-associated liver disease (PNALD). In this study, we aimed to investigate the role of Lactobacillus johnsonii (L. johnsonii) in a rat model of PNALD. Total parenteral nutrition (TPN)-fed rats were used to assess the role of L. johnsonii in liver steatosis, bile acid metabolism, gut microbiota, and hepatocyte apoptosis. We observed a depletion of L. johnsonii that was negatively correlated with the accumulation of glycochenodeoxycholic acid (GCDCA), a known apoptosis inducer, in rats subjected to TPN. L. johnsonii attenuated TPN-induced liver steatosis by inhibiting fatty acid synthesis and promoting fatty acid oxidation. TPN resulted in a decrease in bile acid synthesis and biliary bile secretion, which were partially restored by L. johnsonii treatment. The gut microbial profile revealed depletion of pathogenic bacteria in L. johnsonii-treated rats. L. johnsonii treatment reduced both hepatic GCDCA levels and hepatocyte apoptosis compared with the TPN group. In vitro, L. johnsonii treatment inhibited GCDCA-induced hepatocyte apoptosis via its bile salt hydrolase (BSH) activity. Our findings suggest that L. johnsonii protects against liver steatosis, bile acid dysregulation, and hepatocyte apoptosis in TPN-fed rats.

Antinociceptive effects of IL-6R vs. glucocorticoid receptors during rat hind paw inflammatory pain.

BACKGROUND: The glucocorticoid receptor (GR) plays a role in inflammatory pain modulation. However, the specific role played by interleukin 6 receptor (IL-6R) in these processes remains elusive. The present study aimed to investigate the extent of inflammation induced by IL-6R and GR. METHODS: Male Wistar rats were treated with Freund's complete adjuvant to induce right hind paw inflammation. The levels of IL-6Rα and GR were evaluated in the spinal cord and dorsal root ganglion using Western blot and immunofluorescence assays. Subsequently, we examined the nociceptive behavioral changes following the binding of IL-6R with a GR agonist and/or antagonist, as well as the concentration levels of IL-6 and soluble IL-6R (sIL-6R) in the serum and cerebrospinal fluid. Moreover, the spinal levels of IL-6, IL-6Rα, gp130, JAK2, pJAK2, STAT3, pSTAT3, c-fos, GFAP, and Iba-1 were assessed following anti-IL-6R antibody, sgp130, and dexamethasone intrathecal administration. RESULTS: Right hind paw inflammation resulted in significant upregulation of IL-6Rα expression in spinal nociceptive neurons, astrocytes, and microglia cells, as well as increased of IL-6Rα and GR colocalization. Notably, anti-IL-6R or dexamethasone attenuated the nociceptive behavior in a dose-dependent manner. Isobologram analysis indicated the sub-additive effects with a concomitant decrease in the spinal levels of IL-6, pJAK2, pSTAT3, c-fos, GFAP, and Iba-1 and increase in the sIL-6R level. CONCLUSION: The enhanced mechanical sensitivity accompanying the increase of IL-6Rα and GR was attenuated by anti-IL-6R and dexamethasone application, and the sub-additive effects were regulated by the decreased activation of neurons and glial cells and modulated by IL-6/JAK2/STAT3 signaling pathway, which might be attributed to IL-6 induced trans-signaling.

Clear cell renal cell carcinoma: contrast-enhanced ultrasound features relation to tumor size.

OBJECTIVES: To analyze the contrast-enhanced ultrasound (CEUS) features of clear cell renal cell carcinoma (CCRCC) in relation to tumor size. MATERIALS AND METHODS: The CEUS appearance of 92 CCRCCs confirmed pathologically were retrospectively analyzed. Tumor size was stratified into six groups with a 1cm interval. For each lesion, the degree of enhancement, the homogeneity of enhancement and the presence of pseudocapsule sign were evaluated and compared with the pathologic findings. RESULTS: The tumors of groups I-VI were counted for 13, 26, 21, 11, 10 and 11, respectively. All the CCRCCs mainly showed a marked enhancement, and there was no statistically significance between the degree of enhancement and tumor size (P>0.05). However, both homogeneity of enhancement and frequency of pseudocapsule correlated well with the tumor size (P<0.01). Homogeneous enhancement was shown in 85%, 65%, 19%, 9%, 0% and 0% of the tumors in the six groups, respectively. In tumors < or =3cm the frequency (72%) of homogeneity was significantly higher than in tumors >3cm (9%; P<0.01). The detection rate of pseudocapsule sign in the six group was 23%, 62%, 71%, 64%, 50% and 0%, respectively. The frequency of pseudocapsule sign was significantly higher in tumors 2.1-5cm than <2cm and >5cm (66%, 23%, 24%, respectively; P<0.01). On the pathologic examinations, the mean MVD was significantly higher in marked enhancement tumors than slight enhancement tumors (46.0+/-15.9, 27.5+/-8.3, respectively; P<0.01). Any tumors with a heterogeneous enhancement pattern were accompanied by intratumoral necrosis or cysts on histologic specimen. A pseudocapsule was seen at pathology in all the 46 cases with perilesional enhancement and 4 of 46 tumors without perilesional enhancement at CEUS. CONCLUSION: CEUS features of CCRCCs vary with the size of the tumor, especially in the homogeneity of enhancement and the presence of pseudocapsule sign. CEUS is effective in demonstrating the sonographic visualization of tumoral characteristics.

Contrast-enhanced harmonic ultrasonography for the assessment of prostate cancer aggressiveness: a preliminary study.

OBJECTIVE: To determine whether contrast-enhanced harmonic ultrasonography can be used to predict the aggressiveness of prostate cancer. MATERIALS AND METHODS: Contrast-enhanced harmonic ultrasonography was performed in 103 patients suspected of prostate cancer before biopsy. Time intensity curves were reconstructed for systematic biopsy sites and sonographic abnormalities. The characteristics of the curves were described using hemodynamic indices including arrival time (AT), time-to-peak (TTP), and peak intensity (PI). The differences of hemodynamic indices between high-grade and low-grade cancer were analyzed and the correlations between the hemodynamic indices and biopsy Gleason score were studied. RESULTS: Prostate cancer was detected in 41 of 103 patients and there were significant differences in the hemodynamic indices between the biopsy sites of the non-malignant patients and prostate cancer lesions (p < 0.05). The prostate biopsies revealed 154 prostate cancer lesions, including 31 low-grade lesions and 123 high-grade lesions. The hemodynamic indices AT and TTP of high-grade tumors were significantly shorter than those of low-grade tumors (p = 0.001, 0.002). In addition, high-grade peripheral zone (PZ) tumors had higher PI than low-grade PZ tumors (p = 0.009). The PZ prostate cancer Gleason score correlated with PI, AT and TTP, with Spearman correlation coefficients of 0.223, -0.335, and -0.351, respectively (p = 0.013, < 0.001 and < 0.001). CONCLUSION: Contrast-enhanced ultrasound measurements of hemodynamic indices correlate with the prostate cancer Gleason score.