ABSTRACTDysfunction of the circadian clock has been implicated in the pathogenesis of various diseases, including metabolic disorders, inflammatory conditions, and cancer. While the significance of circadian rhythm in diabetic nephropathy is gaining attention, the specific alterations in circadian profiles in diabetic nephropathy remain unexplored. In the present study, we performed RNA sequencing on renal cortex samples collected every 4 h across the day from both control and diabetic mice. The rhythmicity of genes was identified using the JTK_CYCLE algorithm for each group. Genes that lost, acquired, or sustained rhythmicity in diabetic mice were denoted the circadian dysregulation gene set. Subsequent bioinformatic analyses focused on this gene set to investigate the circadian reprogramming in diabetic nephropathy. We observed significant circadian disruption in the kidney of diabetic mice, marked by both the gain and loss of rhythmicity, along with alterations in the phase and relative amplitude of genes that retained rhythmic expressions. Circadian disturbances, such as phase shifts and alterations in relative amplitude or mesor, were also noted in core clock genes. Furthermore, genes that lost rhythmicity in diabetic nephropathy were predominantly associated with protein homeostasis and glycolipid metabolism, whereas those that gained rhythmicity were mainly linked to gene regulation, fatty acid metabolism, and protein transport. The genes in the circadian dysregulation gene set that exhibit differential expression at least at one Zeitgeber time were most prominently enriched in the lipid metabolic process. WGCNA and correlation analysis revealed co‐expression networks involving core clock genes and PPAR signaling pathway with renal triglyceride levels. Our study reveals substantial circadian disruption in diabetic nephropathy, with significant impacts on protein homeostasis and glycolipid metabolism. Furthermore, our findings highlight the potential influence of circadian system dysregulation on the disorder of fatty acid metabolism in diabetic nephropathy.

Breast cancer (BC) is one of the most common cancers in women around the world, and utilizing a combined approach is a crucial strategy. Induction of cuproptosis in tumor cells is a novel antitumor approach, though its standalone efficacy remains unclear. In this study, we prepared a novel liposome loaded with the photosensitizer indocyanine Green (ICG) and the cuproptosis inducer elesclomol-Cu (ES-Cu) to examine the synergistic effects of photodynamic-cuproptosis treatment on BC. The cuproptosis inducer ES-Cu and the photosensitizer ICG were encapsulated in nanoliposomes with a membrane hydration approach and then validated invitro and invivo. JC-1, MDA, GSH, and other cuproptosis-related indicators were used to confirm the ability of PDT to enhance ES-Cu-induced cuproptosis in MCF-7 breast cancer cells. For confirming the cytotoxic impact of PDT in conjunction with the cuproptosis inducer, tests for CCK-8 and cell death staining were performed. The drugs were administered to animals via tail vein injection to observe their tumor inhibition effects invivo. Their safety was assessed by monitoring changes in body weight. The average particle size of liposomes loaded with ES-Cu and ICG was 208.3 ± 1.07 nm, exhibiting a consistent nanospherical morphology. ICG produced cytotoxic reactive oxygen species (ROS) that enhanced ES-Cu-induced cell cupping under NIR laser irradiation. The therapeutic effect of the synergistic treatment combining PDT and cuproptosis was validated in both invitro and invivo experiments. This investigation proved that PDT markedly augments the ES-Cu-induced cuproptosis in breast cancer cells, demonstrating a synergistic therapeutic effect. This synergistic effect presents a novel therapy approach for BC with substantial practical application potential.

ABSTRACTMyocardial infarction remains one of the leading causes of mortality. Reperfusion of the infarcted myocardium restores blood flow and reduces primary ischemic injury. However, despite its protective function, reperfusion is also associated with several deleterious outcomes that can result in ischemia–reperfusion (I/R) injury to cardiac tissue. Although negative outcomes such as reactive oxygen species generation are strongly associated with I/R injury, cardiac energy metabolism is also greatly disrupted. Furthermore, previous studies have shown that the restoration of normal fuel oxidation in the myocardium regulates the extent of contractile recovery. A better understanding of the pathophysiological mechanisms underlying I/R injury may allow us to develop new treatments that limit the negative aspects of the process. In this study, we examined the role played by GCN5L1, a protein implicated in the regulation of energy metabolism, in I/R injury. We demonstrate that cardiac‐specific loss of GCN5L1 promotes the inhibitory phosphorylation of pyruvate dehydrogenase in vitro and in vivo, a process likely to inhibit glucose oxidation, and that this corresponds to increased myocardial damage following ischemia–reperfusion (I/R) injury.

ABSTRACTInterest in the endogenous role of methane has grown rapidly over the past decade, driven both by its relevance for disease detection (including intestinal methanogen overgrowth) as well as discoveries that raise the possibility of endogenous sources of methane and suggestive evidence of methane effects relevant to physiology. This review explores both established and emerging origins of breath methane, its physiological relevance, and the evolving landscape of detection methods. We aim to summarize current understanding and provide a platform to outline key directions for future research. Evidence supports the existence of non‐microbial, endogenous methane production pathways and potential biological effects beyond the gut. However, the concentrations generated via these pathways and the levels required to elicit physiological responses remain under investigation. Recent technological advances have enabled more accessible and longitudinal breath methane monitoring, opening new avenues for research and clinical application.

ABSTRACTAxon guidance proteins have been found to play a regenerative role in the peripheral nervous system and the cornea. Netrin‐4 is a member of the Netrins family of axon guidance proteins implicated in diabetic retinopathy and corneal hemangiogenesis. However, its effects on corneal nerve and epithelium repair are not well understood. We performed in vitro and in vivo studies to assess the effects of Netrin‐4 in corneal wound healing. We found that Netrin‐4 induced extensive neurite growth and branching in trigeminal ganglia neurons and accelerated the scratch closure of corneal epithelial cells. In vivo, the dual action of Netrin‐4 enhanced corneal epithelium healing and nerve regeneration in mice subjected to corneal epithelium debridement. Inhibition studies demonstrate that Netrin‐4‐induced neuronal growth may be mediated by interaction with Neogenin or α6β1 Integrin receptors. In conclusion, our data demonstrate that Netrin‐4 has trophic and neuroregenerative effects in the cornea and could be a suitable therapeutic target to treat corneal injury.

ABSTRACTStem cell‐based models of embryogenesis have exploded in popularity, resulting in protocols with overlapping use of some reagents and differential use of others. As such, the precise contributions of individual signaling molecules, such as Chiron and BMP4, applied to whole or part of aggregates, and matrices, such as Matrigel, to the development of these models are unknown. Furthermore, the use of these different methods, signaling molecules, and matrices has yet to be directly compared under the same conditions. In this paper, we used a mouse embryonic stem cell aggregate model to compare the use of Chiron and BMP4 signaling as pulses (applied to the whole aggregate) or signaling centers (applied to part of the aggregate) and embedded them in low‐percentage Matrigel. Each factor had different effects on morphology, Brachyury protein expression, and lineage commitment, with signaling centers having different effects to pulses. BMP4 as a pulse was shown to drive neural differentiation, while signaling centers resulted in better recapitulation of aspects of anterior–posterior axis formation, with polarization of Brachyury protein and expression of anterior and posterior genes observed. This further elucidates the contributions of Chiron and BMP4 to aggregate development to better inform decisions around experimental conditions for in vitro models of embryonic development.

Physiology is closely synchronized to daily and seasonal light/dark cycles. Humans artificially extend daylight and experience irregular light schedules, resulting in dysregulation of metabolism and body mass. In rodents, winter-like conditions (cold and short photoperiod) can alter energy balance and adipose tissue mass. To determine if photoperiod alone, independent of temperature, is a strong enough signal to regulate adiposity, we compared the effects of long and short photoperiod at thermoneutrality on adiposity and WAT gene expression in photoperiod-sensitive, F1 generation wild-derived adult male white-footed mice (Peromyscus leucopus). Mice were housed in long-day (16:8 light:dark) or short-day (8:16 light:dark) photoperiod conditions at thermoneutrality (27°C) for 4 weeks with the extended light being provided through artificial lighting. Photoperiod did not impact body weight or calorie consumption. However, mice housed in long photoperiod with extended artificial light selectively developed greater visceral WAT mass without changing subcutaneous WAT or interscapular BAT mass. This was accompanied by a decrease in Adrβ3 and Ucp1 mRNA expression in visceral WAT with no change in Pgc1a, Lpl, or Hsl. Expression of Per1, Per2, and Nr1d1 mRNA in visceral WAT differed between long and short photoperiods over time when aligned to circadian time but not onset of darkness, indicating alterations in clock gene expression with photoperiod. These findings suggest that extended photoperiod through artificial light can promote visceral fat accumulation alone, independent of temperature, supporting that artificial light may play a role in obesity.

Satisfactory outcomes after acute tendon injuries are hampered by a fibrotic healing response. As such, modulation of extracellular matrix deposition and remodeling represents an important intervention point to improve healing. During fibrosis, matrix is deposited and remodeled by activated fibroblasts and/or myofibroblasts. Recent work has demonstrated that Ogerin, a positive allosteric modulator of the orphan proton-sensing GPCR, GPR68, can modulate fibroblast ↔ myofibroblast dynamics in multiple fibroblast populations, including blunting myofibroblast differentiation and facilitating reversion of mature myofibroblasts to a basal fibroblast state invitro. In the present study, we tested the ability of Ogerin to modulate tendon fibroblast ↔ myofibroblast behavior invitro and invivo. Consistent with prior work, Ogerin can both blunt TGF-β induced tenocyte → myofibroblast differentiation and partially revert mature myofibroblasts to a basal tenocyte state. However, Ogerin treatment from days 8-12 after tendon repair surgery did not inhibit myofibroblast differentiation, and Ogerin treatment from post-operative days 24-28 did not induce myofibroblast reversion. Moreover, while we expected Ogerin treatment from days 8-12 to impair healing due to blunted extracellular matrix formation, Ogerin treatment improved tendon mechanical properties and altered cell transcriptional profiles and communication patterns in a way that suggests accelerated remodeling and resolution of the repair response, identifying Ogerin as a novel therapeutic approach to improve the tendon healing process.