Protein kinase C (PKC) is a large family of calcium- and phospholipid-dependent serine/threonine kinases that consists of at least 11 isozymes. Based on their structural characteristics and mode of activation, the PKC family is classified into three subfamilies: conventional or classic (cPKCs; α, βI, βII, and γ), novel or non-classic (nPKCs; δ, ε, η, and θ), and atypical (aPKCs; ζ, ι, and λ) (PKCλ is the mouse homolog of PKCι) PKC isozymes. PKC isozymes play important roles in proliferation, differentiation, survival, migration, invasion, apoptosis, and anticancer drug resistance in cancer cells. Several studies have shown a positive relationship between PKC isozymes and poor disease-free survival, poor survival following anticancer drug treatment, and increased recurrence. Furthermore, a higher level of PKC activation has been reported in cancer tissues compared to that in normal tissues. These data suggest that PKC isozymes represent potential diagnostic and prognostic biomarkers and therapeutic targets for cancer. This review summarizes the current knowledge and discusses the potential of PKC isozymes as biomarkers in the diagnosis, prognosis, and treatment of cancers.

Doxorubicin (DOX) induces dose-dependent cardiotoxicity via oxidative stress and abnormal mitochondrial function in the myocardium. Therefore, a noninvasive in vivo imaging procedure for monitoring the redox status of the heart may aid in monitoring diseases and developing treatments. However, an appropriate technique has yet to be developed. In this study, we demonstrate a technique for detecting and visualizing the redox status of the heart using in vivo dynamic nuclear polarization–magnetic resonance imaging (DNP–MRI) with 3-carbamoyl-PROXYL (CmP) as a molecular imaging probe. Male C57BL/6N mice were administered DOX (20 mg/kg) or saline. DNP–MRI clearly showed a slower DNP signal reduction in the DOX group than in the control group. Importantly, the difference in the DNP signal reduction rate between the two groups occurred earlier than that detected by physiological examination or clinical symptoms. In an in vitro experiment, KCN (an inhibitor of complex IV in the mitochondrial electron transport chain) and DOX inhibited the electron paramagnetic resonance change in H9c2 cardiomyocytes, suggesting that the redox metabolism of CmP in the myocardium is mitochondrion-dependent. Therefore, this molecular imaging technique has the potential to monitor the dynamics of redox metabolic changes in DOX-induced cardiomyopathy and facilitate an early diagnosis of this condition.

Background: Histidine-rich glycoprotein (HRG), a potential prognostic factor in sepsis, lacks clarity regarding its relevance in septic-induced shock, disseminated intravascular coagulation (DIC), and acute respiratory distress syndrome (ARDS) pathogenesis. This study investigated the association between HRG concentrations and these critical conditions. Methods: Blood samples were collected from 53 critically ill patients on days 1, 3, 5, and 7 after ICU admission at the Kyushu University Hospital. Daily clinical and laboratory data were recorded, and patient survival was assessed 28 days after ICU admission. Results: Serum HRG concentrations were significantly reduced on days 3, 5, and 7 in patients with septic shock and DIC but not in those with ARDS. While initial HRG levels on day one were not correlated with survival, nonsurvivors displayed decreased HRG levels, notably on days 3, 5, and 7 post-ICU admissions. The HRG levels remained stable in survivors. A progressive decrease was associated with higher mortality rates, particularly on days 5 and 7. On day 5, an HRG level with a cutoff of 25.5 μg/mL showed a sensitivity of 0.77 and a specificity of 0.75, indicating significantly lower survival rates (log-rank test, P < 0.05). Conclusion: HRG presents a potential intervention for critically ill sepsis patients, providing a novel strategy to enhance outcomes. Further research is needed to explore the therapeutic potential of HRG in sepsis management.

Phosphatidylserine (PS) and phosphatidylethanolamine (PE) act as an "eat-me" signal for phagocytes to engulf apoptotic cells. The aim of our study was to investigate the biodistribution of PS- or PE-containing liposomes. Three phospholipid liposomes (DOPC/DOPS, DOPC/DOPE, and DOPC/soybean PS) were intravenously injected and analyzed. DOPC/DOPS showed higher average radiant efficiency (intensity/area) in the lung, liver, kidney, and heart than DOPC/DOPE. The total and average radiant efficiency of DOPC/DOPS was higher than that of DOPC/soybean PS in the lung, liver, and kidney. These results suggest that the biodistribution of anionic phospholipid liposomes depends on their phospholipid composition.

Hepatic ischemia–reperfusion injury (IRI) is a critical clinical condition associated with liver transplantation and acute liver injury. This study investigated the role of sulfide quinone oxidoreductase (SQOR) and its downstream product, supersulfides, in hepatic IRI. C57BL/6NJ mice were subjected to 45 min of partial hepatic ischemia, followed by reperfusion lasting 4 h. Control of shRNA mediated knockdown of SQOR expressing adeno-associated viral vectors were administered 3 weeks prior to liver ischemia. In the shRNA-mediated knockdown of SQOR group, the hydro-trisulfide donor sodium trisulfide was administered daily for 1 week prior to the induction of liver ischemia. SQOR played a crucial protective role during hepatic IRI by facilitating electron transport to the mitochondrial respiratory chain and maintaining the oxidized and reduced nicotinamide adenine dinucleotide ratio. Administration of sodium trisulfide, exhibited protective effects against hepatic IRI. Sodium trisulfide restored the oxidized and reduced nicotinamide adenine dinucleotide ratio, reduced oxidative stress, and preserved the expression of key enzymes involved in the sulfide oxidation pathway. SQOR and supersulfides contribute to hepatic protection against IRI, likely through their potent antioxidative and redox-regulating functions, and highlight sodium trisulfide as a potential therapeutic agent.