Cathepsin inhibitors nitroxoline and its derivatives inhibit SARS-CoV-2 infection

Compensational role between cathepsins

Cathepsins, a family of lysosomal peptidases, play a crucial role in maintaining cellular homeostasis by regulating protein turnover and degradation as well as many specific regulatory actions that are important for proper cell function and human health. Alterations in the activity and expression of cathepsins have been observed in many diseases such as cancer, inflammation, neurodegenerative disorders, bone remodelling-related conditions and others. These changes are not exclusively harmful, but rather appear to be a compensatory response on the lack of one cathepsin in order to maintain tissue integrity. The upregulation of specific cathepsins in response to the inhibition or dysfunction of other cathepsins suggests a fine-tuned system of proteolytic balance and understanding the compensatory role of cathepsins may improve therapeutic potential of cathepsin's inhibitors. Selectively targeting one cathepsin or modulating their activity could offer new treatment strategies for a number of diseases. This review emphasises the need for comprehensive research into cathepsin biology in the context of disease. The identification of the specific cathepsins involved in compensatory responses, the elucidation of the underlying molecular mechanisms and the development of targeted interventions could lead to innovative therapeutic approaches.

Peptidomimetics as potent dual SARS-CoV-2 cathepsin-L and main protease inhibitors: In silico design, synthesis and pharmacological characterization

In this paper we present the design, synthesis, and biological evaluation of a new series of peptidomimetics acting as potent anti-SARS-CoV-2 agents. Starting from our previously described Main Protease (MPro) and Papain Like Protease (PLPro) dual inhibitor, CV11, here we disclose its high inhibitory activity against cathepsin L (CTSL) (IC50 = 19.80 ± 4.44 nM), an emerging target in SARS-CoV-2 infection machinery. An in silico design, inspired by the structure of CV11, led to the development of a library of peptidomimetics showing interesting activities against CTSL and Mpro, allowing us to trace the chemical requirements for the binding to both enzymes. The screening in Vero cells infected with 5 different SARS-CoV-2 variants of concerns, highlighted sub-micromolar activities for most of the synthesized compounds (13, 15, 16, 17 and 31) in agreement with the enzymatic inhibition assays results. The compounds showed lack of activity against several different RNA viruses except for the 229E and OC43 human coronavirus strains, also characterized by a cathepsin-L dependent release into the host cells. The most promising derivatives were also evaluated for their chemical and metabolic in-vitro stability, with derivatives 15 and 17 showing a suitable profile for further preclinical characterization.

Diagnostic Potential of Ratio Between Creatine Kinase and Amylase in Acute Pancreatitis

Background

Acute pancreatitis (AP) is an acute inflammatory illness of the pancreas representing a true question in diagnostic process. Laboratory markers of the hepatobiliary tract such as liver transaminases with pancreatic enzymes give a true hint of a hidden diagnosis together with urea, creatinine and creatine kinase (CK).

Objective

This clinical study aims to show whether there is any correlation between alpha-amylase and CK or their ratio examining hospitalized patients with AP diagnosis.

Methods

From total number of 99 patients with a clinical picture of AP, 71 patients in this retrospective analysis (including both genders) were included according to the presence of two biochemical markers in collected laboratory analysis at admission and 72 hours later on a laboratory check-up: CK and alpha-amylase.

Results

The median CK value of AP cases was 92 (41.75 - 207.25) in the acute period and 73 (37 - 159) after 72h staying in the hospital without statistical significant (p=0.521; p<0.05). However, there was a statistically significant correlation between the parameters of CK at admission and creatine kinase after 72h staying in the hospital. The median value of CK/Amylase ratio in the acute period was 0.168 (0.069 - 0.532) and 0.386 (0.12 - 1.12) after 72 hours of staying in the hospital. There was a statistically significant difference between values of CK/amylase ratio in these two groups (p=0.000; p<0.01).

Conclusion

In conclusion, a connection between CK and alpha-amylase needs to be elucidated in further studies and its existence must be researched both in physiological and pathophysiological conditions, and it is two-way and very complex. This study helped us obtain significant information about the perspective of AP in the potential relation to other non-standard laboratory markers for some diseases.